U-Pb detrital zircon geochronology and provenance of the Tertiary Kootznahoo Formation, southeastern Alaska: A sedimentary record of Coast Mountains

exhumation

Nathan Evenson Senior Integrative Exercise

March 10, 2010

Submitted in partial fulfillment of the requirements for a Bachelor of Arts degree from Carleton College, Northfield, Minnesota.

TABLE OF CONTENTS

IntroductionGeologic SettingThe Kootznahoo FormationField Sampling MethodsSedimentary Petrography Methods ResultsU/Pb Detrital Geochronology Methods Results U/Th Ratios Statistical ComparisonsDiscussion Source Region Classification Source Regions of Detrital Zircons in the Kootznahoo Formation Major Kootznahoo Formation DZ populations Kootznahoo Formation DZ populations older than 200 Ma Implications of Detrital Zircon and Sedimentary Petrography Data Links between Kootznahoo Formation deposition and exhumation of the CMB Timing and continuity of deposition in the Kootznahoo basin Kootznahoo Formation deposition and the northward transport of outboad terranesConclusionsAcknowledgementsReferencesAppendix 1: U/Pb Analytical MethodsAppendix 2: Isotopic Data

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11

1215

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27293033333438434647485658

U-Pb detrital zircon geochronology and provenance of the Tertiary Kootznahoo Formation, southeastern Alaska: A sedimentary record of Coast Mountains

exhumation

Nathan S. Evenson Senior Integrative Exercise

March 10, 2010 Carleton College

Advisors: Cameron Davidson, Carleton College

Karl Wirth, Macalester College Tim White, Pennsylvania State University

ABSTRACT Quartzo-feldspathic arenites of the Kootznahoo Formation in Southeast Alaska contain detrital zircon U-Pb age distributions dominated by plutonic zircon populations at 190- 160, 93-85, and 65-50 Ma. These populations suggest derivation from the adjacent Coast Mountains Batholith complex. Consideration of maximum depositional ages for the Kootznahoo Formation and exhumation rates of the Coast Mountains Batholith suggest that most of the Kootznahoo Formation in the study area was deposited between 60-25 Ma. An abrupt influx of Paleogene-aged zircons suggests that the initial un-roofing of the Coast Plutonic Complex, east of the Coast shear zone, is captured within the Kootznahoo stratigraphy. We use the Kolgomorov-Smirnov statistical test to demonstrate a depositional affinity between the Kootznahoo Formation exposed in lower Little Pybus Bay on Admiralty Island and the lower portion of the Kootznahoo stratigraphy in the Keku Straits region to the south on Kupreanof Island. Our data suggests a depositional history of episodic rapid subsidence and sedimentation alternating with slow subsidence and erosion of previously deposited strata. An episode of slow sedimentation at approximately 54 Ma may be a result of uplift that occurred following the subduction of an oceanic ridge. Observed similarities between the detrital U-Pb zircon ages of the Kootznahoo Formation and the Kulthieth and Poul Creek Formations, deposited on the Yakutat block presently located ~500 km to the north, suggest that these formations were adjacent and shared a sediment source between 45-35 Ma. Keywords: Detrital zircon, Kootznahoo Formation, Coast Mountains Batholith, U/Pb geochronology, provenance, exhumation

INTRODUCTION

Detrital zircon (DZ) studies are a robust method of analyzing the depositional history

and provenance of clastic sedimentary successions and the tectonic and magmatic evolution

of the rocks from which these sediments were derived (Gehrels et al., 2006; Gehrels et al.,

2000). Previous DZ studies have established probable source regions for sedimentary and

metasedimentary strata along the western margin of North America (Gehrels et al., 1995;

Gehrels and Kapp, 1998; Kapp and Gehrels, 1998). Recent advances in analytical techniques

permit greater sampling densities, resulting in the generation of high-resolution age spectra.

Such spectra have been employed to elucidate the details of the tectonic chronology of the

Cordilleran margin (e.g. DeGraaff-Surpless et al., 2003; Haeussler et al., 2004) and other

areas (e.g. Weislogel et al., 2006). DZ data are often complemented by optical point count

analyses. Together, these data provide detailed information on the source terrane lithology

and sediment maturity (Dickinson and Suczek, 1979; Dickinson, 1985). In this study, I

examine high-resolution detrital zircon and sedimentary provenance data from the Tertiary

(Paleocene-Miocene) Kootznahoo Formation of southeast Alaska.

The Mesozoic-Cenozoic geologic history of western North American is defined by

frequent, major changes in the regional tectonic regime, including shifts between convergent

and transform motion (Crawford et al., 2005; Haeussler et al., 2003), accretion and transport

of allocthonous terranes along the margin (Monger et al., 1982; Gehrels and Berg, 1994), and

magmatic events that accompanied these processes (Gehrels et al., 2009; Crawford et al.,

2005). Changes in tectonic setting during the Cretaceous to middle Tertiary are closely tied

to the emplacement, uplift, and exhumation of the plutonic rocks of the Coast Mountains

batholith (CMB), located in present-day British Columbia and southeast Alaska (Crawford et

1

al., 1987; Gehrels et al., 2009). Gehrels et al. (2009) provide a comprehensive review of U-

Pb geochronology of the CMB and the nearby Coast Shear Zone (CSZ). Zircon age data

suggest the occurrence of three periods of relatively high magmatic flux, at 160-140 Ma,

120-78 Ma, and 55-48 Ma. Spatial distribution of U-Pb ages suggests eastward migration of

magmatic activity after 120 Ma. In this study, I compare DZ populations and sedimentary

provenance data from the Kootznahoo Formation to the results of Gehrels et al. (2009) and

geochronological studies of other Cordilleran terranes. The primary objective of these

comparisons is to determine probable sediment source regions for the Kootznahoo

Formation, and to use observed shifts in provenance to make inferences about the timing of

uplift, exhumation, and possible margin-parallel transport history of these source regions.

Within the study area, the Kootznahoo Formation is present in a number of exposures

separated by large covered areas (Fig. 1). Cover material may obstruct the expression of

transform faults or other structures that have modified depositional relationships between

exposures. White et al. (in prep) have created a tentative stratigraphic sequence (Fig. 2) that

links these scattered exposures together. An additional objective of this study is to apply

internal comparisons and tests of similarity to our DZ and sedimentary framework analyses

with respect to the stratigraphy of White et al. (in prep) to determine whether Kootznahoo

DZ data support correlations that these workers have made.

GEOLOGIC SETTING

The Kootznahoo Formation lies unconformably on variably deformed rocks of the

Alexander terrane and the Gravina belt (Loney, 1964; Muffler, 1967; this study). The

Alexander terrane, a sequence of Paleozoic to middle Jurassic sedimentary and igneous

2

PortageBay

Hamil tonBay

Big JohnBay

DavidsonBay

KadakeBay

KuiuIsland

KuiuIsland

KupreanofIsland

Kake Airport

Dak

anee

k Bay

Ro

ck

y P

as s

Po

rt Ca

md

en

Keku Stra i t

Kupreanof Island

133°40

56°55

56°50

56°45

133°45133°50133°55134°00

0 3 km

Tmgb

Tmgb

Tmgb

Tmgb

Tmgb

Tmgb

Tmgb

Tmgb

Tmgb

Tmgb

Tmgb

MDc

MDc

MDc

Pp

Pp

Ksm

Tk

Tk

Ksm

Ksm

Pp

Pp

Qs

Tk

Tk

Tk

TkQTf

QTf

QTf

QTf

QTf

QTf

QTb

QTb

QTb

QTb

QTb

QTb

QTc

QTc

QTc

QTc

vRT

cRT

hRT

hRT

kRT

vRT

vRT

vRT

vRT

vRT

QTc

Qs

QTf

Geologic Map of the Keku Straight Area and Little Pybus Bay (Inset), Southeast Alaska.Modified from Lathram et al. (1965), Muffler (1967), and Brew et al. (1984)

Surficial deposits (Quaternary): Alluvium, glaciofluvial deposits, and tidal mud flats.Felsic volcanics (Quaternary and Tertiary): Grey to buff altered volcanic flows, tuff, or shallow intrusives with myrolitic cavities.Basalt (Quaternary and Tertiary): Dark grey to black aphanitic basalt.

Hound Island volcanics (Triassic): Dark green to black basaltic pillow breccia and pillow lava with some interbedded limestone.

Hamilton limestone (Triassic): Dark grey thinly bedded limestone.

Qs

QTf

QTb

QTc

Tk

Ta

Ksm

Pp

MDc

vRT

Seymour Canal Formation (Late Jurasic and Early Cretaceous): Dark gray to black slate, greywacke, and conglomerate.

ALASKA

MAP LOCATION

hRT

cRT

kRT

Volcaniclastic deposits (Quaternary and Tertiary): Grey to buff conglomerate and lithic sandstone. Gradational contact with Tk.

Admirality Island volcanics (Eocene and Oligocene): Dark grey basalt and andesite flows .

Tmgb Gabbro (Oligocene): Grey to black phaneritic gabbro with olivine and clinopyroxene.

Kootznahoo Formation (Paleocene-Miocene): Grey to buff arkosic sandstone, conglomerate, and black shale. Coal, fossil leaves and wood present.Turbidites (Early Cretaceous?): Rhythmically layered grey to black sandstone, siltstone, and mudstone with carbonate concretions.

Cornwallis limestone (Triassic): Grey medium to thick bedded oolitic limestone.Keku volcanics (Triassic): Altered felsic flows and breccia, basalt, volcanoclastics and limestone.Pybus Formation (Permian): White to light grey limestone, dolostone and chert.

Cannery Formation (Mississipian and Devonian): Dark grey to bluish green thinly bedded volcanic argillite and greywacke with chert.

DZ and FrameworkSample location

Strike and dip of bedding

09TH01

09TH1015

10

15

135

12

16

10

10

10

5

25

15

25 15

15

1510

20

1515

09LA05

09LA08

09TH08

09LA1009NE18

09NE14

09NE12

09NE06

09NE0814

12

20

20

15

15

KJs

57° 19’134° 11’ 134° 05’

57° 15 ’

Ad

mir

al i

ty I

sla

nd

09LA01

09LA14

Lit tle

Pyb

us

Ba

y

Tk

KJs

KJs

MDc

Ta

Ta

Tk

1 km

CamdenPoint Tk

DakaneekPoint

09NE20

09NE1509NE07

09NE29

Framework onlySample location

1 Location of measuredstratigraphic section(see Fig. 4)

1

2

PointHamil ton

3

4

5Porcelaini teBeach

Figure 1. Geologic map of the Keku Strait region and Little Pybus Bay. Sample locations and section numbers correspond to Fig. 2. Note that the Little Pybus Bay outcrops (inset) are separated from the Keku Strait outcrops by Frederick Sound, a distance of approximately 50 km. Map modified from Davidson (pers. comm.)

3

MDc

Ta

09LA1459(55) Ma

BJBS

BJB

Dav. B.Dak. B.

Dak. Pt.

Pt. Ham.

53.5 ± 0.6 Ma

~65 mcoveredinterval

?

?

2

4

s fs cs cglKsm

Cmd. Pt.

Low. PB

Upp. PB

26.5 ± 0.3 Ma

09NE1429(28) Ma

09NE1225(24) Ma

? 09LA1057(31) Ma

5

Ham. B.

Hound Is.Volcanics

3

vRT

?

20 mVertical Scale

LPB

1

MDc Tk

s = shale/mudstonefs = fine sandstonecs = coarse sandstonecgl = conglomerate

EXPLANTION

= sill/intrusion

Stratigraphic Units and Lithologies

= correlation uncertain

= volcanic flow/tuff= covered interval

= unconformity

Horizontal scale

= column number (from Fig. 1)

?

1

Ta

Ksm Tmgb

vRT

26.5 ± 0.3 Ma Ar-Ar cooling age(White et al, in prep.)

=

Units from geologic map (Fig. 1)

Other lithology symbols

09LA0159(52) Ma

09NE0658(54) Ma

09NE0859(53) Ma

09TH0858(53) Ma09LA0858(54) Ma09LA0559(54) Ma

09TH1060(53) Ma

09TH0187(80) Ma

09NE1225(24) Ma

=

s fs cs cgl

s fs cs cgl

Figure 2. Kootznahoo Formation stratigraphic sections (modified from White et al., in prep.). Column numbers correspond to locality from which the column was measured (shown on Fig. 1) Horizontal scale indicates grain size. Marked levels of uncertain correlation indicate areas where stratigraphic relationships have been inferred across large (10+ kilometers) locations. Sample heights are listed with corresponding maximum depositional ages (discussed in the Results section).

DZ sample with maximumdepositional age listed:yngst. pop. (yngst. grain)

4

rocks and their metamorphic equivalents, is joined with the Wrangellia and Peninsular

terranes to form the Insular superterrane, or Wrangellia Composite Terrane (WCT) (Monger

et al., 1982; Gehrels and Berg, 1994). The Gravina belt is a band of upper Jurassic to middle

Cretaceous clastic sediments interbedded with basaltic/andesitic flows and volcaniclastics

(Gehrels and Berg, 1994; Cohen and Lundberg, 1993). Jurassic-age Gravina strata were

deposited unconformably on rocks of the Alexander and Wrangellia terranes to the west,

while the eastern margin of the belt has been obscured by and incorporated into

metamorphism and thrust faulting associated with the accretion and subduction of the WCT

(Kapp and Gehrels, 1998). Sedimentary rocks of the Gravina belt are derived from

subduction arc volcanics and basement strata of the Alexander terrane to the west (Cohen and

Lundberg, 1993; Cohen et al., 1995) as well as northern Cordilleran terranes to the east

(Kapp and Gehrels, 1998). Cessation of sedimentation in the Gravina basin occurred at 95-

85 Ma, when the changes in plate motion caused a return to a compressive regime, resulting

in the collapse of the basin and the deformation and uplift of Gravina strata (Engebretson et

al., 1985; McClelland and Mattinson, 2000; Gehrels et al., 2009).

Convergence during the late Cretaceous (up to ~65 Ma) caused regional deformation,

crustal thickening, and deep emplacement of plutons at the continental margin (McClelland

and Mattinson, 2000; Crawford et al., 1999). The CSZ developed as a structure to

accommodate crustal adjustments and west-side up exhumation that occurred in response to

this thickening (McClelland and Mattinson, 2000). Evidence from metamorphic and plutonic

rocks in and adjacent to the CSZ suggests that during the Paleocene, regional tectonics

shifted from a primarily convergent regime to one that included a substantial transform

5

component (Engebretson et al., 1985; Crawford et al., 1999; Klepeis et al., 1998; McClelland

and Mattinson, 2000; Hollister and Andronicos, 2000; Gehrels et al., 2009).

After 65 Ma, ductile extensional processes facilitated rapid exhumation of the roots the

CMB (Hollister, 1982; Crawford et al., 1987; Rusmore et al., 2005). The presence of melt

along low-angle shear zones facilitated extension (Crawford et al., 2009). Tonalitic-

granodioritic plutons were emplaced syntectonically during east-side up motion along the

CSZ (Ingram and Hutton, 1994) and other transform and normal shear zones at depths of 15-

20 km (Metcalf and Davidson, 1997; Crawford et al., 1999; Andronicos et al., 2003). These

younger plutons were exhumed to shallow crustal levels by ductile extension that persisted

until ~50 Ma (Harrison et al., 1979, Rusmore et al., 2005). Some workers attribute complex

changes in tectonic regime, rapid exhumation and Paleocene magmatism to the subduction of

a spreading ridge and adjacent young, buoyant oceanic crust (Cloos, 1993; Thorkelson, 1996;

Hauessler et al., 2003; Bradley et al., 2003, Madsen et al., 2006). The Kootznahoo basin

system likely developed as an upper crustal response to these lower crustal extensional

processes (as described in Rohr and Currie, 1997).

After 50 Ma, exhumation of the roots of the batholith continued via brittle deformation

of the upper crust. Plate reconstructions suggest that oblique convergence that occurred

during the Paleocene and Eocene shifted to dextral transform motion with a small

transtensional component by ~45-40 Ma (Engebretson et al., 1985; Stock and Molnar, 1988).

Studies of the sediments and structural geology of the Queen Charlotte Basin (located

outboard of the southern reaches of the CMB between Vancouver Island and Alaska’s

southern border) suggest that this margin-normal extensional component initiated rifting in

the middle Eocene, facilitating subsidence along N-S striking normal faults (Rohr and

6

Dietrich, 1992; Hyndman and Hamilton, 1993; Irving et al., 2000). Near Prince Rupert,

similarly oriented normal faults in the CSZ have been dated to 30 Ma (Davidson et al., 2003).

The distribution of brittle extensional structures of middle Tertiary age suggest that the basin

system in which Kootznahoo sediments accumulated was expanded and/or otherwise

modified by brittle extensional processes similar to those described in studies cited above.

The shift to dextral transform motion provided a mechanism for margin-parallel

northward terrane transport. The Chugach terrane is a block of subduction-related deformed

submarine volcanics interbedded with pelagic sediments (Plafker, 1987). Currently located

along the south-central Alaskan coast (~58°N), some paleomagnetic and geologic evidence

suggest that the CPW terrane was located south of 50°N in the early Tertiary, and was

transported to its present position by the middle Miocene along dextral strike-slip faults

(Cowan, 1982; Nilsen and Zuffa, 1982; Cowan, 2003). The Yakutat block consists of

basement of Chugach-Wrangellia affinity, with Eocene-Pleistocene age sedimentary cover

(Plafker, 1987). Detrital zircon evidence suggests that the Yakutat terrane originated off the

coast of British Columbia, and experienced moderate northward transport along the Queen

Charlotte Fault after its detachment from the margin at ~45 Ma (Hyndman and Hamilton,

1993; Perry et al., 2009). It is possible that one or both of these terranes were adjacent to the

Kootznahoo during active deposition, and therefore shared a sediment source, or even

contributed sediment to the Kootznahoo basin.

THE KOOTZNAHOO FORMATION

The Kootznahoo Formation is a composed primarily of feldspathic arenite of Paleocene

to Miocene age, which was deposited in a fluvio-deltaic to marginal marine environment

7

(Brew et al., 1984; White et al., in prep). The Kootznahoo Formation was deposited between

56°50’N and 57°50’N, in a basin oriented parallel to and approximately 50 km west of the

Coast Shear Zone (CSZ) (Dickinson and Pierson, 1988). The Kootznahoo Formation is well-

exposed in the Keku Strait area of Kupreanof Island, in the Kootznahoo Inlet and Little

Pybus Bay on Admiralty Island, and on the southwest side of Zarembo Island (Lathram et al.

1965; Brew et al. 1984; Dickinson and Pierson, 1988). The focus of this study is restricted to

exposures in the Keku Strait and Little Pybus Bay.

The base of the Kootznahoo Formation is in all places an unconformity. In and near

Little Pybus Bay, it lies unconformably on the Late Triassic Hyd Formation of the Alexander

terrane and the deformed Early Jurassic Seymour Canal Formation of the Gravina Belt

(Loney, 1964; Cohen and Lundberg, 1993). In the Keku Strait area, Muffler (1967) observed

the Kootznahoo Formation deposited unconformably on the Triassic Hound Island Volcanics

in the Hamilton Bay locality. I observed an unconformity between the Kootznahoo

Formation sandstones and unnamed Cretaceous Gravina mudstones (unit Ksm on Fig. 1) on

the western side of Point Hamilton (09TH10; Figs. 1 and 3d).

In the Keku Strait area, the Kootznahoo Formation is exposed at several short (20-75 m

of stratigraphic thickness) exposures (see Fig. 1). As shown in Figure 2, the Kootznahoo

Formation in the Keku Strait (right and center columns) consists primarily of coarse-grained

to granular sandstone with poor sorting and highly angular grains. Prominent, mutually

truncating trough cross-stratification is a feature of most of the sandstone beds (Fig. 3e).

Interbedded with the sandstone are beds of shale, some of which bear coal seams or plant

fossils. Preserved stumps, wood fragments, and paleosols are present in sandstone beds

throughout the section. Conglomerate beds are distributed throughout the section as thick

8

A.

E.

D.

C.

Ksm

Ksm

Ksm

Tk

Tk

Arkosic Tk

AIV conglomerate

Ta?

A.B.

Figure 3. Field photos from Keku Strait and Little Pybus Bay outcrops. Photo series progresses clockwise from upper left. A.) Sub-rounded andesitic blocks in matrix-supported congolmerate, from uppermost portions of Kootznahoo stratigraphy in Little Pybus Bay. Clasts likely derived from the Admiralty Island Volcanics (Ta). Gradations on field book are 2 cm. B.) Rounded plutonic and metamorphic clasts in cobble-pebble conglomerate from upper Kootznahoo Formation in Little Pybus Bay. Arrow denotes large garnet crystal in metamorphic clast. C.) Abrupt transition between arkosic sandstone/conglomerate and volcaniclastic AIV conglomerate in upper Kootznahoo Formation, Little Pybus Bay. Black line denotes apparent erosional surface. Sample 09LA01 taken nearby, from 3-4 m below erosional surface. Note honeycomb-type weathering on the outcrop face, indicated by black arrow. Person for scale. D.) Basal contact between Kootznahoo Formation sandstone (Tk) and Cretaceous mudstone (Ksm), near 09TH10 sample location on Point Hamilton. Angular nature of Ksm clasts and apparent rip-up tongue of Ksm that extends above the contact (denoted by white arrow) suggest high-energy deposition of Tk sandstone on partially lithified Ksm mudstone. Hammer is 30 cm long. Photo credit: K. Wirth. E.) Prominent channel forms in at Kadake Bay outcrop, typical of most outcrops of Kootznahoo Formation sandstone. Hammer is 25 cm long.

9

throughout the section. Conglomerate beds are distributed throughout the section as thick

beds and lenses within sandstone, but are concentrated primarily in the Hamilton Bay and

Porcelainite Beach sections. Clast sizes vary, most are 5-25 cm in diameter. In lower

portions of the section, conglomerate clasts are primarily plutonic, gneissic, low- to medium-

grade metamorphic, and vein quartz in composition – volcanic clasts are conspicuously

absent. Clasts of the thick conglomerate beds in the upper portions of the Keku Strait section

(Porcelainite Beach) are entirely volcanic. The section ends in volcaniclastic sandstone and

conglomerate interbedded with Tertiary basalt flows.

The Kootznahoo Formation of the Little Pybus Bay (LPB) locality is lithologically

similar to the lower portions of the Keku Strait section. Notable differences between the two

localities include an increase in the ratio of conglomerate to other lithofacies in the section

and a decrease in measured section thickness (a difference of ~300 meters) (Dickinson and

Pierson, 1988; White et al., in prep). Conglomerate clasts in this locality are similar in

composition to those of the conglomerate beds of the Keku Strait section – consisting

primarily of plutonic and metamorphic (gneissic) rocks, as well as populations of argillite

and chert (Figure 3b; Loney, 1964; Lathram et al., 1965). In the volcaniclastic conglomerate

beds (herein referred to as the AIV conglomerate) that are deposited on the arkosic strata of

the upper Little Pybus Bay section, clasts are almost entirely of volcanic composition, and

are more angular than those found in lower beds (Figure 3a-c). Lying conformably on the

AIV conglomerate are Eocene basaltic-andesitic flows of the Admiralty Island Volcanics

(Loney, 1964).

Correlation between the Little Pybus Bay and Keku Strait sections is based largely on

the work of Lathram et al. (1965). Based on plant fossils taken from shale beds in both

10

localities, Wolfe correlates the Little Pybus Bay section with the Hamilton Bay portion of the

Keku Strait section, assigning these strata a Paleocene age. Other geologic indicators of

depositional age (the positions of which are shown on Fig. 2) in the two sections include a

biotite Ar-Ar date of 53.5 ± 0.6 Ma for a tuff layer in the Big John Bay South section, and a

whole rock Ar-Ar date of 26.5 ± 0.5 Ma for a basaltic flow in the Lower Porcelainite Beach

portion of the Keku Strait section (White et al., in prep.).

The continuity of drainages that fed the Kootznahoo basin, as well as the continuity of

the basin itself, is uncertain (Buddington and Chapin, 1929; Muffler, 1967; Brew et al.,

1984). The Kootznahoo basin formed during deformation that occurred in the late

Cretaceous and early Paleogene (Loney, 1964; Muffler, 1967). Some authors propose that

the basin existed as a continuous drainage (Buddington and Chapin, 1929). Other authors

suggest that the basin may not have been continuous during deposition of some or all

portions of the Kootznahoo stratigraphy, and differences in provenance and lithology

between localities reflect smaller drainages of local source areas (Brew et al., 1984;

Dickinson and Vuletich, 1990).

FIELD SAMPLING METHODS

The goal of the sampling strategy employed in this study was to obtain a set of

samples that were spread evenly across the known Kootznahoo stratigraphy at each of the

two field localities. Where possible, locations of samples relative to a known stratigraphic

datum – geodetic markers, volcanic tuff layers, or other geologically distinct features – were

measured using a Jacob’s staff and compass. Locations of all samples were marked with at

least one portable GPS unit.

11

Each detrital zircon sample consisted of approximately 3-5 kilograms of rock. Most

samples were sandstones with relatively few clasts of larger sizes; a few others were drawn

from the sandstone matrix of a conglomerate. Each sample was taken from a limited

stratigraphic interval; no more than a meter of stratigraphic height separated the rock pieces

that compose a given sample. When possible, samples were taken from a single laterally

contiguous bed. The stratigraphic positions of all samples are shown on Fig. 2.

SEDIMENTARY PETROGRAPHY

Methods

Eighteen thin sections were made from samples from the upper half of the

Kootznahoo sections in the two field localities. All thin sections were stained with sodium

cobaltnitrite for potassium feldspars, and all were examined to determine their detrital

assemblages, alteration states, and other characteristics. Examples of common assemblages

and alteration textures can be seen in Fig. 4.

Ten of these thin sections were subjected to optical point-count analysis. Counting

categories are listed in Table 1. Only thin sections that were free of pervasive diagenetic

alteration and/or apparent secondary matrix development, both of which can obscure the

depositional framework composition of the rock, were subjected to this analysis. For each

modal analysis, at least 350 framework grains were counted. Fewer than 10% of the total

grains counted were classified as unidentifiable or matrix/cement. Point-count analysis was

12

A. B.

C. D.

Figure 4. Common detrital assemblages and textures of arkosic Kootznahoo Formation sandstones. A.) Fine-grained metamorphic mica+quartz lithic fragment (Lm). Partially replaced amphibole (Hbl) fragment is visible above the scale bar. Other components include Plg, Qm (XPL, 40x, 09NE06). B.) Warped biotite grain, partially replaced by chlorite (Chl, purple birefringence) (XPL, 40x, 09NE08). C.) and D.) PPL and XPL views of an identical field, which contains several large Kfs grains, variably altered to calcite (Cal). Note the prominent polysynthetic twinning preserved in the Plg grain in the upper left portion of the field (40x, 09NE24). E.) Foliated, biotite bearing metamor-phic fragments (Lm) in arkosic matrix, note both compaction alteration and warping of biotite grains (PPL, 40x, 09NE20). F.) Volcanic lithic (Lv)-dominated sample from the uppermost portions of the Keku Strait stratigraphy. Note the ubiquity of plagioclase phenocrysts in Lv grains (PPL, 40x, 09NE12).

F.E.

Hbl

Lm

BtPlg

Chl

KfsKfs

KfsCal

Plg

Lm

Bt

Bt

Lv

Lv

Lv

13

Table1.Modalanalysisgrain/graincategoryidentificationparameters.ParameterstakenfromDickinson(1970),Ingersolletal.(1984),andDickinson(1985).

GrainType/Category Type/CategoryParametersQ =Qt=Qm+Qp,totalquartzgrainsQm monocrystallinequartzgrains

Qp polycrystallinequartzgrainswithnoapparentothermineralinclusions

F =P+K,totalfeldspargrains

Pplagioclasegrainsorreplacedgrainswithfeaturesthatsuggestalterationfromplagioclase

Kpotassiumfeldspargrainsorreplacedgrainswithfeaturesthatsuggestalterationfrompotassiumfeldspar

L =Lv+Ls+Lm,totallithicfragmentsLsm =Ls+LmLv volcanicaphaniticlithicfragmentsLs sedimentaryaphaniticlithicfragmentsLm metamorphicaphaniticlithicfragmentsLt =L+QpHv totalamphibolegrainsMica totalmicagrains

Qm/Qt ratioofpolycrystaillinequartzgrainstototalquartzgrains

P/F ratioofplagioclasegrainstototalfeldspargrains

14

performed after the Gazzi-Dickinson (G-D) method1 (Dickinson, 1970; Dickinson and

Suczek, 1979).

Results

Results of Kootznahoo sandstone modal analyses are listed in Table 2. Kootznahoo

Formation sandstones are texturally submature; most samples contain populations of poorly

sorted, angular to sub-rounded grains. The scarcity of silt/clay matrix and the relative

abundance of feldspar over quartz lead to the classification of Kootznahoo sandstones as

feldspathic to quartzo-feldspathic arenites (average composition (excluding 09NE12) =

Q36F57L07). Detrital assemblages are relatively continuous at the locality scale, but vary

widely throughout the whole of the Kootznahoo section. Plagioclase feldspar,

monocrystalline quartz, and potassium feldspar are the primary detrital components. Micas

(Fig. 4b,e) (primarily biotite, some allogenic chlorite) and polycrystalline quartz are an

accessory component of most samples, while amphibole (Fig. 4a) and chert are found in

accessory amounts in only a few samples. Lithic fragments, particularly volcanic lithic

fragments, display the greatest variability of abundance among analyzed samples (Fig. 4f).

Alteration of detrital grains is observed in feldspars, micas, and some lithic

fragments. Plagioclase grains are typically partially to fully replaced by a number of

minerals, most commonly calcite or albite. Relict polysynthetic twinning is present in many

fully replaced plagioclase grains. Potassium feldspar is also often partially altered to calcite

and/or albite (Fig. 4c-d). Complete alteration of potassium feldspar grains is rare. This

1Two important differences between the G-D method and the “traditional” methods exist. First, in the G-D method, any sand-size mineral fragment that can be identified is counted as a mineral, regardless of any apparent affinity with any type of lithic fragment. Second, polycrystalline quartz (Qp in Table X) is counted as such only if the grain appears to be pure, plutonic/metamorphic quartz. The traditional method allows 10% (total grain area) of imperfections – such grains are counted as lithic fragments in the G-D method (Ingersoll et al., 1984).1

15

Table 2. K

ootznahoo Formation sandstone m

odal analysis results. Porc. B. = Porcellainite B

each, Pt. Cam

den = Point Cam

den, BJB

S= Big John B

ay South, B

JB = B

ig John Bay, LPB

= Little Pybus Bay.

  Table 3. L

ocality group average ternary compositions. K

eku Straits locality group includes BJB

, BJB

S, and Pt. Cam

den samples from

Table 1.  Locality G

roup Q

F

L Q

m

F Lt

Qp

Lv Lsm

Q

m

P K

Q

m/Q

t P/F

Porc. B

each 0.01

0.05 0.94

0.01 0.05

0.94 0.00

0.92 0.08

0.13 0.78

0.09 1.00

0.90 Little P

ybus Bay

0.36 0.44

0.20 0.24

0.44 0.32

0.37 0.13

0.50 0.35

0.41 0.24

0.75 0.63

Keku S

trait 0.33

0.62 0.05

0.31 0.62

0.08 0.33

0.00 0.67

0.33 0.37

0.30 0.93

0.56   Locality

Sample

No.

Qm

Q

p C

hert P

K

Lv Lm

Ls

Hv

Mica

Cem

ent U

nident. Total

Frmw

ork P

orc. B.

09NE

12 3

0 0

18 2

326 7

23 0

4 53

14 450

379 P

orc. B.

09NE

14 84

28 14

96 57

15 26

30 0

19 36

20 425

350 P

t. Cam

den 09N

E18

110 8

1 124

98 0

11 7

1 45

31 16

452 359

BJB

S

09NE

20 100

18 0

133 37

7 76

2 0

31 39

7 450

373 B

JBS

09N

E15

93 8

0 197

100 0

0 0

0 27

17 8

450 398

BJB

S

09NE

07 93

23 0

122 69

6 1

3 1

17 62

9 406

317 B

JBS

09N

E06

86 7

0 167

70 0

17 1

0 25

17 7

397 348

BJB

09N

E08

92 8

0 125

60 0

1 3

17 27

36 26

395 289

LPB

09LA

01 168

26 2

185 0

0 8

2 0

16 26

18 451

391 LP

B

09NE

29 137

29 0

173 3

1 12

2 0

47 25

21 450

357

Locality Sam

ple N

o. Q

F

L Q

m

F Lt

Qp

Lv Lsm

Q

m

P K

Q

m/Q

t P/F

Porc. B

. 09N

E12

0.01 0.05

0.94 0.01

0.05 0.94

0.00 0.92

0.08 0.13

0.78 0.09

1.00 0.90

Porc. B

. 09N

E14

0.36 0.44

0.20 0.24

0.44 0.32

0.37 0.13

0.50 0.35

0.41 0.24

0.75 0.63

Pt. C

amden

09NE

18 0.33

0.62 0.05

0.31 0.62

0.08 0.33

0.00 0.67

0.33 0.37

0.30 0.93

0.56 B

JBS

09N

E20

0.32 0.46

0.23 0.27

0.46 0.28

0.17 0.07

0.76 0.37

0.49 0.14

0.85 0.78

BJB

S

09NE

15 0.25

0.75 0.00

0.23 0.75

0.02 1.00

0.00 0.00

0.24 0.51

0.26 0.92

0.66 B

JBS

09N

E07

0.37 0.60

0.03 0.29

0.60 0.10

0.70 0.18

0.12 0.33

0.43 0.24

0.80 0.64

BJB

S

09NE

06 0.27

0.68 0.05

0.25 0.68

0.07 0.28

0.00 0.72

0.27 0.52

0.22 0.92

0.70 B

JB

09NE

08 0.35

0.64 0.01

0.32 0.64

0.04 0.67

0.00 0.33

0.33 0.45

0.22 0.92

0.68 LP

B

09LA01

0.50 0.47

0.03 0.43

0.47 0.10

0.74 0.00

0.26 0.48

0.52 0.00

0.87 1.00

LPB

09N

E29

0.46 0.49

0.04 0.38

0.49 0.12

0.66 0.02

0.32 0.44

0.55 0.01

0.83 0.98

16

suggests that misidentification of potassium feldspar grains is unlikely. Books of plutonic

mica crystals frequently take a warped appearance from chemical alteration, and also

observed bent around other grains, a result of the compaction process. Examples of most of

these alteration processes can be seen in Figure 4.

Lithic fragments of several lithologies are present in Kootznahoo sandstones.

Metamorphic lithic fragments are the most widespread (Fig. 4a,e) – these include fine-

grained phyllitic/schistose fragments and medium-fine grained gneissic fragments that show

variation in grain size, composition, and foliation expression across the grain. Volcanic rock

fragments are typically very rare, with the exception of sample 09NE12 (Q01F05L94), taken

from the upper portions of the Porcelainite Beach locality (Fig. 4f). Most volcanic fragments

contain euhedral plagioclase phenocrysts, some appear to composed almost entirely of

plagioclase. Sedimentary lithic fragments are rare in most samples; where present, they take

the form of chert and siltstone fragments

Figure 5 shows results of Kootznahoo Formation sandstone modal analyses plotted on

ternary diagrams from Dickinson (1985) (ternary end-members are defined in Table 1). On

the QFL and QmFLt plots (Fig. 5a-b), most Kootznahoo sands plot in the basement uplift and

dissected arc fields. Five samples from the Big John Bay and Big John Bay South localities

form a cluster, and the two sandstones from Little Pybus Bay are also grouped. The QPK

plot (Fig. 5c), which emphasizes variation in feldspar composition, shows that that most

Kootznahoo Formation sands share a similar Qm/P ratio (~2:3), but they vary in K-feldspar

composition along the line corresponding to that ratio. Samples from Little Pybus Bay are

devoid of K-feldspar, all other samples contain appreciable amounts.

17

P55Qm45

P60Qm40

Qm

Lt F

A.

B.

C.

Locality Symbols

Keku Straits

Porcellainite Beach

Little Pybus Bay

BasementUplift

BasementUplift

DissectedArc

DissectedArc

TransitionalArc

TransitionalArc

UndissectedArc

UndissectedArc

Qm

K P

Provenance Categories

Continental Block

Recycled Orogen

Magmatic Arc

Q

L F

Figure 5. Ternary plots of modal analysis results. See Table 1 for definitions of each ternary end member used. A.) and B.) QFL and QmFLt plots, respectively, of modal analysis data. Polygon with triangle at center represents the region enclosed by one standard deviation of average components of analyses from the Keku Straits locality group (Table 3). Note that most samples plot in the basement uplift field. The two analyses that plot in the dissected arc field are from the upper portions of the Keku Strait section. These analyses may represent a lithologic transition to sample 09NE12 (plotted near the lithic end member), which was taken from the primarily volcaniclas-tic upper portions of Porcellainite Beach. C.) QPK diagram of modal analysis data. Note that analyses from Little Pybus Bay plot on the Qm-P axis, between Qm40 and Qm45. Most Keku Straits analyses retain a similar Qm/P ratio (shown by the dotted lines), varying only in the proportion of Kfs present.

18

U/PB DETRITAL ZIRCON GEOCHRONOLOGY

Methods

Detrital zircon samples were processed at Union College and Macalester College.

Both institutions used standard procedures to avoid introduction of sample bias and sample

contamination. Zircon separates were transported to the LaserChron Lab at the University of

Arizona-Tuscon, where they were prepared and mounted for analysis per standard

LaserChron procedures.

U-Th-Pb isotopic data were collected using a multicollector inductively coupled

plasma-mass spectrometer coupled to a laser ablation system. Detailed information about the

specifics of the instrumentation and standard analytical procedures can be found in Appendix

1 and Gehrels et al. (2008). Analyses were conducted using a beam diameter of ~30 um,

generating a pit depth of ~12 um. Fragments of a Sri Lankan zircon standard (564 Ma,

Gehrels et al., 2008) mounted with the unknown zircons were analyzed regularly to monitor

and correct for element fractionation.

Isotopic data were processed using Isoplot 3.0 (Ludwig, 2003). Interpreted ages are

based on 206Pb/238U for <960 Ma grains and on 206Pb/ 207Pb for >960 Ma grains. This division

at 960 Ma results from the increasing uncertainty of 206Pb/ 238U ages and the decreasing

uncertainty of 206Pb/ 207Pb ages as a function of increasing age.

Results

U/Pb Detrital Ages

1169 U-Pb isotopic ages of zircon grains from 12 samples of the Kootznahoo

Formation were collected for this study (isotopic data listed in Appendix 2). All <500 Ma

19

analyses are concordant to slightly discordant. 1158 (99%) of all analyzed grains are

Paleozoic age or younger, and 1108 (95%) are younger than 200 Ma. These data are plotted

on relative probability plots in Figure 6. Pronounced peaks in the cumulative dataset (Fig. 7)

include a very narrow peak at 30-24 Ma, moderately narrow peaks at 65-50 Ma and 90-80

Ma, and a broad peak at 185-160 Ma.

Though populations of zircons older than 200 Ma are present, none of these

populations are comparable in magnitude to those younger than 200 Ma. Grains older than

200 Ma are distributed relatively evenly over the 400-200 Ma interval (Fig. 7). Those grains

that are of Proterozoic age or older (n=12) fall in age between 1.3 and 2.9 Ga, with a cluster

of five grains between 1.65 and 1.95 Ga; however, these grains are slightly to highly

discordant.

Maximum depositional ages (MDAs) of samples, given for each sample in Figure 2

and Figure 6, are given either by the youngest zircon grain or the youngest population of

zircon ages (populations determined with the Age Pick program; see Vermeesch et al., 2004;

Haeussler et al., 2004 for a discussion of MDA determination). Samples from the Keku

Strait locality have MDAs 87-25 Ma. Sample 09TH01, collected from the lowermost portion

of the section in Hamilton Bay yields the oldest MDA, 87 Ma. Above this stratigraphic

level, MDAs range 59-56 Ma, with the exception of 09NE14 and 09NE12 (Porcelainite

Beach), which have distinct peaks between 30-25 Ma. Note that grains with ages <45 Ma

(n=2) are present in 09LA10, but are not classified as a population.

All samples from localities in the Keku Strait (with the exception of 09TH01) have

age distributions such that 60-80% of their total populations are younger than 75 Ma, with

most ages concentrated between 60-55 Ma (Fig. 8). All of these samples have numerous

20

0

10

20

30

40

50

60

70

80

0 50 100 150 200 250 300 350 400

Num

ber

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250 300 350 400

Relative probability

09LA08Dakaneek Bay

n=96

+ 1879 ± 442 Ma + 1953 ± 664 Ma

+ 1961 ± 1333 Ma+ 2290 ± 263 Ma

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250 300 350 400

Num

ber

Age (Ma)

09TH08Davidson Bay

n=97

MDA53.4 ± 0.6 Ma58 Ma (n=35)

0

10

20

30

40

50

0 50 100 150 200 250 300 350 400

Relative probability

Age (Ma)

09NE08Big John Bay

n=98

Figure 6. Individual sample probability plots for all <400 Ma detrital zircons from the Kootznahoo Formation. Rectangles represent 10-Ma bins of analyses, each set of which is traced by a probability curve. Note that the vertical scale for age bins is not consistent between all plots. Numbers of analyses for each sample and analyses of >400 Ma grains from the sample are listed below locality information. Two indicators of maximum depositional age (MDA) are given for each sample: age/uncertainty of the youngest grain, as well as the youngest population of grains determined by the Age Pick program (Gehrels, 2009) with the number of grains contributing to that population.

MDA52.9 ± 0.9 Ma59 Ma (n=38)

0

5

10

15

20

25

30

0 50 100 150 200 250 300 350 400

Relative probability

09TH10Hamilton Pt.

n=97

09TH01Hamilton Bay

n=98

MDA80.2 ± 0.7 Ma87 Ma (n=58)

MDA53.3 ± 1.3 Ma60 Ma (n=26)

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250 300 350 400

Num

ber

09LA05Dakaneek Pt.

n=98

+ 1980.1 ± 16.6 Ma

MDA53.6 ± 2.2 Ma58 Ma (n=29)

MDA54.0 ± 2.1 Ma58 Ma (n=37)

21

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250 300 350 400

Num

ber

09NE06Big John Bay South

n=98

+ 1282 ± 35.6 Ma

25

30

MDA 54.3 ± 1.5 Ma

58 Ma (n=33)

0

10

20

30

40

50

0 50 100 150 200 250 300 350 400

Relative probability

09LA10Pt. Camden

n=98

MDA 31.2 ± 0.2 Ma

57 Ma (n=35)

0

5

10

15

20

0 50 100 150 200 250 300 350 400

Num

ber

09NE14Porcelainite Beach

n=99

MDA 27.8 ± 0.8 Ma

29 Ma (n=6)

0

10

20

30

40

50

60

70

0 50 100 150 200 250 300 350 400

Relative probability

09NE12Porcelainite Beach

n=94

+ 427.3 ± 2.2 Ma+ 430.0 ± 2.8 Ma+ 2689 ± 37.0 Ma+ 2937 ± 20.5 Ma

MDA 23.5 ± 0.8 Ma

25 Ma (n=58)

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250 300 350 400

Age (Ma)

09LA01Little Pybus Bay

n=99 Relative probability

MDA 52.0 ± 1.9 Ma

59 Ma (n=28)

0

5

10

15

20

25

30

35

0 50 100 150 200 250 300 350 400

Num

ber

Age (Ma)

09LA14Little Pybus Bay

n=100

+ 1673 ± 30.2 Ma+ 1763 ± 17.6 Ma+ 1826 ± 39.2 Ma+ 1882 ± 26.1 Ma

MDA 55.1 ± 3.1 Ma

59 Ma (n=19)

22

0

50

100

150

200

250

300

350

400

0 50 100 150 200 250 300 350 400

Relative probability

Num

ber

Age (Ma)

Figure 7. Relative probability plots for all Kootznahoo detrital zircon ages <400 Ma. A.) shows ages <400 Ma. Note the relative scarcity of zircons older than 200 Ma. B.) shows ages <200 Ma. Note the sharp peaks at 30-25 Ma, 65-55 Ma, 90-80 Ma, and 190-160 Ma. Zircons that compose the 30-25 Ma peak are from two samples only, the rest are spread relatively evenly across most samples.

0

50

100

150

200

250

300

0 25 50 75 100 125 150 175 200

Relative probability

Num

ber

A.

B.

23

peaks in the 75-50 Ma age range, including peaks at 60-57 Ma and 71-65 Ma. All samples

except for those from the Big John Bay (09NE08) and Big John Bay South (09NE06) have

95-85 Ma peak. Most samples have few or no grains present from the age range of 150-100

Ma (sample 09NE14 is an exception). All samples except for the lowermost (09TH01) and

the uppermost samples (09NE12) have one to several moderately pronounced peaks between

190-160 Ma.

The youngest population in both samples from Little Pybus Bay is 59 Ma. Both

samples have large 65-59 Ma peaks. Both samples have more pronounced peaks between

90-75 Ma than do most upper Keku Strait samples, though stratigraphically lower Keku

Strait samples do contain grains of this age range (Fig. 8). Sample 09LA14, taken from the

base of the LPB section, has a pronounced, broad peak at 185-160 Ma, a feature shared by

several Keku Strait samples but not 09LA01, the sample from the top of the LPB section.

U/Th Ratios

Detrital zircons from most Kootznahoo Formation samples display low U/Th ratios

(Appendix 2). Zircon grains that display high U/Th ratios (10<U/Th) likely crystallized in an

environment where metamorphic fluids were present (Williams, 2001; Gehrels et al., 2009).

Only in samples 09TH01 and 09TH10 do large portions of the entire population display U/Th

ratios greater than10. In these samples, approximately half of all zircons aged 90-80 Ma

display U/Th>10. Almost all zircons younger than 80 Ma display U/Th ratios below the

metamorphic cutoff; though trace (n<10) populations of metamorphic zircon that fall within

this age range are present in all samples.

24

Peak ofEastern

MagmaticBelt activity

160-140 Ma WMB

magmaticflare-up

120-78 Ma magmaticflare-up, 100-80 Ma metamorphic event

67-52 MaQuottoon, other

CSZ related magmas

55-48 Ma magmatic flare-up

Admiralty Island Volcanics, other Oligocene-age

volcanics

Rel

ativ

e Pr

obab

ility

0 25 50 75 100 125 150 175 200 Age (Ma)

09NE12

09NE14

09LA10

09NE08

09NE06

09TH08

09LA08

09LA05

09TH10

09TH01

09LA01

09LA14

Littl

e Py

bus

Bay

Kek

u St

rait

Figure 8. Stacked relative probability plots for all zircon ages <200 Ma. With the exception of the Eastern Magmatic Belt, peaks of CMB-sourced detrital zircons to the left of the heavy black vertical line at 80 Ma are originally sourced from plutons emplaced east of the CSZ, those to the right are from west of the CSZ. Colored strips represent likely sources of plutonic and metamorphic zircons. Green belts represent high flux magmatic events, while the yellow belt represents the peak flux of the long-lived Eastern Magmatic Belt (Gehrels et al., 2009). The blue belt, which overlaps with the youngest high-flux magmatic event, represents the emplacement of the Quottoon and related plutons adjacent to the east side of the CSZ (Crawford et al., 1999). Zircons in the red strip are likely sourced from Oligocene extrusive rocks (Haeussler et al., 1992; Ford et al., 1996).

25

Statistical Comparisons

The Overlap-Similarity (O-S) test produces a measure of the amount which a given

relative probability spectrum’s age peaks overlap with those of another (overlap), and an

independent measure of whether the proportions of overlapping age peaks of the two spectra

are similar (similarity) (Gehrels, 2000). The K-S test is a non-parametric test that compares

cumulative age probability curves of similarly-sized samples to determine the likelihood

(expressed as a p-value) that any two age curves can be achieved by random sampling of a

single parent population (Guynn, 2006). If p<0.05, one can be 95% confident that the

differences between a population are not due to random sampling error, but rather, derivation

from different parent populations. Other workers have used the K-S test in the comparison of

detrital zircon age spectra (e.g. Berry et al., 2001; DeGraaff-Surpless et al. 2003; Amidon et

al., 2005). Though the K-S test is regarded as a more rigorous test of similarity (Fedo et al.,

2003), results of both tests are provided in Table 4 (K-S) and Table 5 (O-S) for the purpose

of comparison2.

Samples 09TH01 and 09NE12 were excluded from statistical comparisons on the

basis of their unique, clearly unimodal age spectra (Fig. 6). Both tests suggest that the

populations of most samples are highly statistically similar – 09LA14 (lower LPB) is the

only sample included in the comparisons that produces p-values that suggest derivation from

a different source region than a majority of the other samples. In K-S comparisons, 09NE14

was not significantly different from any other sample (Table 4). In the results of both tests,

mutually similar samples 09TH10 and 09LA05 have notably lower similarity values in

comparison to samples from higher stratigraphic levels in the Keku Strait section, as

2Excel program versions both of these tests, as well as the Age Pick program, are available on the LaserChron website (www.geo.arizona.edu/alc).

26

suggested by the lack of uncolored cells in the rows of Table 4 that correspond to these

samples. It should be noted that these two samples share a pronounced 80-90 Ma peak with

the sample that lies directly below in the Kootznahoo stratigraphy, 09TH01.

A comparison of samples from the basal and top portions of the Little Pybus Bay

section (09LA14 and 09LA01, respectively) suggests that these sediments were drawn from

different source areas. K-S and O-S tests strongly suggest that the Keku Strait sample that

09LA14 is most similar to be 09TH10. Comparisons involving 09LA01 are ambiguous:

results suggest that 09LA01 is nearly equally similar to Keku Strait samples from

Porcelainite Beach (09NE14) and a cluster of samples in the Dakaneek Bay and Dakaneek

point localities (09LA05, 09LA05, and 09TH08). As seen on Fig. 2, these two localities are

separated by hundreds of meters of Kootznahoo sediments.

DISCUSSION

Source Region Classification

Quartz, feldspar, and lithic fragments dominate the framework compositions of

Kootznahoo Formation sandstones. Modal analyses of most Kootznahoo sandstones plot in

the “basement uplift” and lithic-poor “dissected arc” fields of ternary classification diagrams

(Fig. 5) (Dickinson, 1970). This suggests that these rocks are derived from feldspar-rich

continental basement or the plutonic roots of a magmatic arc (Dickinson and Suczek, 1979,

Dickinson, 1985). The immature nature of these sediments, evidenced by angular grain

shapes (Fig. 4) and presence of coarse-grained plutonic and metamorphic fragments in most

samples, suggests that these sands experienced minor mechanical breakdown, and were

therefore subjected to relatively short transport (Pettijohn et al., 1987).

27

09NE

1409LA

1009N

E06

09NE

0809TH

0809LA

0809LA

0509TH

1009LA

0109LA

1409N

E14

0.1530.091

0.3380.449

0.0660.153

0.7000.514

0.05109LA

100.153

0.1990.267

0.5320.408

0.0010.007

0.0900.000

09NE

060.091

0.1990.353

0.4590.167

0.0350.199

0.0170.006

09NE

080.338

0.2670.353

0.5850.303

0.0020.029

0.1790.000

09TH08

0.4490.532

0.4590.585

0.9860.088

0.0510.400

0.00009LA

080.066

0.4080.167

0.3030.986

0.0210.010

0.4840.000

09LA05

0.1530.001

0.0350.002

0.0880.021

0.5360.421

0.03309TH

100.700

0.0070.199

0.0290.051

0.0100.536

0.0420.245

09LA01

0.5140.090

0.0170.179

0.4000.484

0.4210.042

0.00109LA

140.051

0.0000.006

0.0000.000

0.0000.033

0.2450.001

0.00-0.050.05-0.150.15-0.350.35-0.500.55-1.0

09LA01

09LA01

09NE14

0.60109N

E1409LA

100.506

0.56809LA

1009N

E060.590

0.5000.597

09NE06

09NE08

0.6710.586

0.5110.648

09NE08

09TH08

0.6060.520

0.4740.572

0.56509TH

0809LA

080.657

0.5910.515

0.6270.641

0.60609LA

0809LA

050.820

0.6930.520

0.6210.683

0.6070.722

09LA05

09TH10

0.5870.603

0.4640.487

0.4780.641

0.5440.600

09TH10

09LA14

0.3130.355

0.4310.435

0.2950.509

0.2980.334

0.579

Table 4. K-S Test of sim

iliarity results. Results are in the form

of p-values, with bin color coding schem

e displayed to the right of the table. Sam

ples are arranged in stratigraphic order. C

omparisons of populations that produce a p-value of less than 0.05 (uncolored cells) suggest that these sam

ples were

drawn from

different parent populations. Note that m

ost p<0.05 results in the Keku S

trait samples are found in com

parisons involving 09LA05 and 09LA

10.

LPB Keku Strait

LPBK

eku Strait

Table 5. Overlap-Sim

ilarity (O-S) test results. R

esults shown in table represent the product of the overlap and sim

ilarity values (O x S

) from each

comparison.

28

Sample 09NE12 falls in the “undissected arc” region of the QtFL and QmFLt

diagrams (Fig. 6). Composed almost entirely of angular volcanic lithic fragments (Fig. 4f),

this sample is evidence of a major shift toward more volcanic provenance in the upper

portions of the Keku Strait section. This shift in provenance is visible on the outcrop scale in

the volcaniclastic upper Porcelainite Beach portion of the Keku Strait section, and is mirrored

in the AIV conglomerate at the top of the exposed Little Pybus Bay section (Fig. 2).

The Paleocene-early Eocene Arkose Ridge Formation in the Matanuska Valley of

southern Alaska (Trop and Ridgway, 2000) is analogous to the Kootznahoo Formation. Its

framework compositions are very similar to those of Kootznahoo arkoses (Arkose Ridge

average = Q23F67L10, Kootznahoo arkoses average = Q36F57L07). In addition, as observed in

the Kootznahoo stratigraphy, an increase in the proportion of lithic fragments is observed in

upper portions of the Arkose Ridge section. Trop and Ridgway (2000) and Trop et al. (2003)

concluded that the Arkose Ridge Formation was sourced from local Mesozoic/Cenozoic

plutonic rocks undergoing active uplift, as well as volcanic sediments from eruptive activity

that was contemporary with its deposition. Based on field observations and petrographic

data, I arrive at a similar conclusion for Kootznahoo sandstones.

Source Regions of Detrital Zircons in the Kootznahoo Formation

Kootznahoo Formation DZ data, when considered as a whole, display four major

populations (Fig. 7). Nearly 50% of all analyzed grains are assigned ages between 65-50 Ma.

Another large population is present at 93-85 Ma, and a moderate, broad population is

observed at 190-160 Ma. Zircons aged 30-24 Ma dominate one sample (09NE12), but are

absent or present only in trace amounts in all other samples.

29

Gehrels et al. (2009) provide a review of the U-Pb zircon and titanite geochronology

of the CMB, approximately 400 km south of our field area (Gehrels and Berg, 1994). Their

analyses suggest three periods of high magmatic flux in the past 200 years (at 160-140 Ma,

~120-80 Ma, and 55-48 Ma), and regional metamorphic events that facilitated zircon growth

at 88-76 Ma and 62-52 Ma. Gehrels et al. (2009) separate magmatic activity into three

spatiotemporal groups. The eastern magmatic belt was stationary during the emplacement of

its constituent plutons 225-100 Ma, while after 110 Ma, the western magmatic belt (located

west of the CSZ), and the <100 Ma magmatic belt define a trend of eastward magmatic

migration that crossed the CSZ at about 80 Ma (Fig. 9).

Major Kootznahoo Formation detrital zircon populations

The cumulative detrital zircon (DZ) age probability curve from this study shares

peaks with the probability curves of two of Gehrels et al. (2009)’s magmatic belts (Fig. 9).

The 190-160 Ma Kootznahoo Formation DZ peak, present in most samples from this study

(Fig. 8), falls near the probability peak of the eastern magmatic belt. Subduction-generated

plutons of this magmatic belt (225-110 Ma, Gehrels et al., 2009) intruded Paleozoic-

Mesozoic continental margin strata of the Yukon-Tanana terrane and accreted arc rocks of

the Stikine and Taku terranes. These host rocks are located exclusively to the east of the

CSZ (Gehrels and Berg, 1994; Currie and Parrish, 1997; Gehrels and Kapp, 1998; Mahoney

et al., 2009). The pronounced 93-85 Ma and 65-50 Ma peaks correspond closely to peaks in

magmatic flux in the <100 Ma magamatic belt (Fig. 8, Gehrels et al., 2009). The 93-85 Ma

population is likely sourced from plutons concentrated 10-30 km west of the CSZ that were

emplaced during an episode of high flux magmatism (Fig. 8, Gehrels et al., 2009). This

30

episode was initiated by a shift to a margin-normal compressive tectonic regime ~100 Ma

(Engebretson et al., 1985). U/Th ratios greater than 10/1 suggest that a proportion of this

zircon population is also drawn from metamorphic rocks generated during regional

metamorphism that occurred during this time period (Williams, 2001; Gehrels et al., 2009).

This shift to a compressive regime juxtaposed the WCT and the Stikine/Yukon-

Tanana terranes, caused the subduction and imbrication of Gravina strata, and initiated an

episode of crustal thickening that persisted until ~65 Ma. Plutons from melt generated in the

lower portions of this overthickened crustal welt were emplaced at deep to mid-crustal levels

in a regime of dextral transpression to transtension between 67 and 52 Ma (Klepeis et al.,

1998; Crawford et al., 1999). These plutons, which are today exposed in a narrow band just

to the east of the CSZ, almost certainly provided a local, plutonic source for the major 65-50

Ma Kootznahoo DZ population. The low (<5/1) U/Th ratios for most Kootznahoo Formation

DZ analyses for this age range are consistent with this conclusion.

The uppermost sample from the Keku Strait locality (09NE12) contains a 30-24 Ma

population that makes up the bulk of the sample. Trace amounts of zircons in this age range

were also encountered in the sample directly below 09NE12 in the section (09NE14).

Sedimentary provenance results for 09NE12 suggest a proximal, undissected volcanic source.

Likely source formations include the Admiralty Island Volcanics (Haeussler et al., 1992,

Ford et al., 1996), presently exposed ~40 km to the northwest, or a volcanic component of

the Kuiu-Etolin magmatic suite (Crawford et al., 2009; Gehrels and Berg, 1992), exposed

~50 km to the southeast.

31

40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230

Rel

ativ

e Pr

obab

lilty

Age (Ma)

Western magmatic beltEastern magmatic belt<100 Ma magmatic beltKootznahoo DZ

Figure 9. Relative probability plot comparing the Kootznahoo Formation detrital zircon population with U/Pb age curves of the major spatiotemporal magmatic belts defined by Gehrels and others (2009). Note the match between the 190-160 Ma detrital peak and the peak of the Eastern magmatic belt curve, as well as the similarities between the distribution of younger, major detrital peaks and the <100 Ma magmatic belt curve.

32

Kootznahoo Formation detrital zircon populations older than 200 Ma

Accessory zircon populations (1-10 grains) are present in most samples detrital zircon

samples. These populations have ages concentrated at 280-200 Ma, 370-310 Ma and 2.9-1.4

Ga. Zircon grains of these ages were likely derived from metamorphosed plutonic and

sedimentary rocks within and adjacent to the CMB. These host rocks were uplifted, eroded,

and deposited along with younger plutonic rocks that contributed <200 Ma zircons that make

up the majority of the Kootznahoo Formation detrital zircon population.

Zircons of 280-200 Ma age (relatively abundant in 09TH01) are present in

metamorphosed plutons within the Alexander terrane basement, which is present west of the

CSZ (Gehrels and Saleeby, 1987). Grains of 370-300 Ma age (relatively abundant in

09TH01, 09TH10, and 09LA14) are likely derived from plutons that intruded the Yukon-

outboard portion of the Tanana terrane, and are present as a detrital component of the strata

of the Taku terrane and the Gravina assemblage (Gehrels and Kapp, 1998; Kapp and Gehrels,

1998; Gehrels, 2001). Gravina sediments and their metamorphic equivalents are present

from a few kilometers northeast of to 10-20 km southwest of the CSZ, while Yukon-Tanana

and Taku strata are present in and adjacent to the Coast Mountains, northeast of the CSZ

(Gehrels and Berg, 1992). Yukon-Tanana strata are also the probable source of recycled

Proterozoic and Archean grains, the ages of which are concentrated in the 2.0-1.6 Ga range

(relatively abundant in 09LA14 and 09LA08) (Gehrels et al., 1995).

Implications of Detrital Zircon and Sedimentary Petrography Data

In this section, I focus my analysis on the implications provenance data from this

study have for the timing and continuity of Kootznahoo Formation deposition, the links

33

between the evolution of the detrital age distribution and the exhumation of the Coast

Mountains batholith (CMB), and the consideration of similarities between the Kootznahoo

Formation detrital signature and that of other sedimentary rocks along the margin.

Links between Kootznahoo Formation deposition and exhumation of the CMB

Determination of depositional age in clastic sedimentary strata, especially those of

non-marine to marginal marine depositional environments, can be difficult, as this rock type

often lacks fossils, continuous layers of volcanic material, and other typical sedimentary rock

age indicators. In such case, where detrital zircon data are available, MDAs determined from

these data are often used as indicators of age. MDAs typically provide only a crude estimate

of true depositional age (Fedo et al., 2003). This lack of accuracy is a result of the time that

exists between crystallization of zircon and its deposition in sedimentary strata – in other

words, exhumation, erosion, and transport are the key processes in determining the difference

between the MDA and the true depositional age of a given sample.

Several studies of plutonic rocks associated with Jurassic to middle Cretaceous

convergent tectonics and late Cretaceous-early Eocene development of the Coast Shear Zone

(CSZ) suggest that exhumation rates were moderate to relatively rapid, and varied spatially

relative to the CSZ. Late Cretaceous plutons emplaced to the west of the CSZ (the proposed

source of the 90-80 Ma Kootznahoo DZ populations) display moderate to rapid rates of uplift

(0.5-1.0 mm/yr, Stowell and Crawford, 2000; Butler et al., 2002; Himmelberg et al., 2004;

Crawford et al., 2009). In the CMB, most plutons aged 65-50 Ma are part of the Quottoon

Pluton, which was emplaced along the eastern margin of the CSZ in several sill-like pulses

between 72-55 Ma (Ingram and Hutton, 1994; Butler et al., 2001). The Quottoon pluton

34

records rapid exhumation (~1.0 mm/yr) between 59 and 52 Ma (Wood et al., 1991; Crawford

et al., 1999; Butler et al., 2001; Rusmore et al., 2005). These exhumation rates suggest that

the time period between crystallization and deposition of zircon in the Kootznahoo for rocks

of CMB origin was ~10-20 Ma for <100 Ma plutons west of the CSZ, and ~3-15 years for

plutons east of the CSZ, with grains of ages <60 Ma displaying the most rapid cooling

histories. Petrographic evidence for short post-erosion transport of Kootznahoo sediments

and a Late Cretaceous-Eocene paleoclimate ideal for an aggressive, brief weathering process

(e.g. Tarduno et al., 1998) suggest that the time difference between crystallization age and

maximum depositional age in this study area is best approximated by the duration of source

rock exhumation.

Limited geologic and fossil evidence (Lathram et al., 1965; Muffler et al., 1967;

White et al., in prep) suggest a Paleocene age for the lower portions of the Kootznahoo

stratigraphy. A biotite K-Ar date of 53.5 ± 0.6 Ma for a tuff layer in the Big John Bay South

section, and a whole rock Ar-Ar date of 26.5 ± 0.5 Ma for a basaltic flow in the Lower

Porcelainite Beach portion of the Keku Strait section give additional constraints on the

depositional age of portions of the Kootznahoo stratigraphy (Fig. 2, White et al., in prep.).

Below, I present a chronology that uses these geologic age markers and MDAs adjusted to

reflect exhumation to link the depositional chronology of the Kootznahoo to the history of

CMB exhumation, with an emphasis on changes in uplift processes across the CSZ.

Sandstone at the base of the Hamilton Bay locality in the Keku Strait (sample

09TH01) contains zircons that suggest derivation from rocks west of the CSZ (Fig. 6). The

major 90-80 Ma and accessory 280-200 Ma DZ populations in this sample are likely drawn

from the western magmatic belt of Gehrels et al. (2009) and Alexander terrane basement

35

rock, respectively. Potential source rocks for the 370-310 Ma accessory population (Gravina,

Yukon-Tanana) are present both west and east of the CSZ. These source rocks were uplifted

85-65 Ma, when the CSZ formed to accommodate west side-up motion (McClelland and

Mattinson, 2000). This uplift event was driven by the partial subduction of Alexander

terrane crust. The buoyancy of this crustal material may have caused it to delaminate from

the lithosphere and rebound (McClelland and Mattinson, 2000; Mahoney et al., 2009).

Resulting uplift of plutons from mid-crustal levels, carried along with Alexander and Gravina

host strata, occurred at moderate rates. Source plutons for 90-80 Ma populations likely

reached the surface at ~70-60 Ma and were deposited by 65-55 Ma, an age consistent with

other proposed ages of lowermost Kootznahoo strata (White et al., in prep).

At approximately 65 Ma, a shift to east side-up motion on the CSZ drove an increase

in sediment sourced from rocks east of the CSZ. This shift occurred in response to high heat

levels and pluton emplacement in the overthickened crust, and is linked with a switch to a

dextral transpressional/transtensional style of deformation (Klepeis et al., 1999; Crawford et

al., 2000; Gehrels et al., 2009). Most samples in the Kootznahoo Formation have MDAs of

60-55 Ma, and large DZ populations from 75-52 Ma. Plutons that shed zircons of this age

range were emplaced primarily east of the CSZ, and were exhumed at moderate to rapid rates

from 70-52 Ma. During the period when exhumation rates were at their highest (59-52 Ma),

the time between crystallization and exhumation may have been as low as 2-5 Ma (Rusmore

et al., 2005). Northeast-directed movement of upper crust on detachment-scale normal faults

accelerated denudation and cooling of 75-52 Ma plutons (Andronicos et al., 2003).

Exhumation patterns suggest that these plutons began to reach the surface 60-55 Ma, with

36

increasing exhumation rates until 52 Ma causing continuous release of sediment. These

volumes of sediment were deposited in the Kootznahoo from ~60 Ma to 35-30 Ma.

Detrital zircon populations suggest that the majority of the Kootznahoo stratigraphy

was deposited during this stage of CMB exhumation (Fig. 8). Samples 09TH10 and 09LA05

(lower Keku Strait, column 2 on Fig. 2), as well as the 09LA01 (lower Little Pybus Bay)

have large populations of both 90-80 Ma and 65-50 Ma grains. Moderate to rapid

exhumation rates recorded in these plutons suggests that these strata were deposited 60-50

Ma. The portion of the section above this stratigraphic level and below the Porcelainite

Beach locality has a relatively homogenous DZ signature that can be attributed to zircon

sources aged 65-50 Ma, but not to those aged 90-80 Ma. The absence of this second

population implies a complete shift to a sediment source east of the CSZ. The presence of a

53.5 Ma tuff date in Big John Bay South suggests that the approximately 300 meters of

sediment between this layer and the base of the Point Hamilton section (Fig. 2; sample

09TH10, MDA=60-53 Ma) accumulated in the Keku Strait portion of the basin over a period

of 6 Ma or less. This rapid accumulation of sediment likely required high levels of sediment

flux and a period of active basin subsidence to create space for this accumulation.

At 45-40 Ma, shifts in the regional tectonic regime initiated dextral transtension

(Engebretson et al., 1985; Stock and Molnar, 1988). This shift is the inferred driver of

normal faulting and subsidence in the Queen Charlotte Basin (QCB) (Rohr and Dietrich,

1992; Hyndman and Hamilton, 1993; Irving et al., 2000), and it may have had similar effects

in the Kootznahoo basin. Comparison to the QCB is problematic, as basin extension began

there in the late Eocene to Early Oligocene (Hyndman and Hamilton, 1993), whereas the

presence of the 53.5 Ma tuff date in the Big John Bay South locality (White et al., in prep)

37

suggests substantial accumulation of Kootznahoo sediments by early Eocene time. I propose

that the transtensional shift that caused extension in the QCB contributed to subsidence and

sediment accumulation in later portions of Kootznahoo deposition, providing accommodation

space for strata at and above the level of Camden Point (Fig. 2).

After the transition to a transtensional regime, ductile extension and exhumation

processes all but ceased. Shallow plutonism and volcanism accompanied brittle extension

(Davidson et al., 2003). This younger magmatic activity was the source of sharp 34-24 Ma

peaks in the samples in the uppermost Keku Strait stratigraphy (09NE14 and 09NE12). The

most probable source of these zircons is the Admiralty Island Volcanic suite, which is

located 40 km north of the field area (Haeussler et al., 1992, Ford et al., 1996).

Timing and continuity of deposition in the Kootznahoo Basin

Internal comparison of detrital zircon and sedimentary petrography data can be used

to examine continuity of deposition within the Kootznahoo basin. Examination of Figure 8

reveals clear changes in the relative magnitudes of major DZ populations through the Keku

Strait stratigraphy. The primary changes that occur moving up through this inferred section

include the decline of the 90-80 Ma population in lowermost three samples (09TH01,

09TH10, and 09LA05, herein referred to as the “basal group”), and the increase of the 30-24

Ma population in Camden Point portion of the section.

Results of the K-S test (Table 4) suggest that there is a relatively high level of

statistical similarity between most Kootznahoo DZ samples and their inferred stratigraphic

neighbors. Only two comparisons between samples adjacent to one another in the

stratigraphy of White et al. (in prep.) yield a result suggesting derivation from different

38

source populations (p<0.05). This result suggests that the outcrop correlations made by

White et al. (in prep.) are permissive.

K-S test results suggest that a shift in DZ age distribution occurs between the basal

group and the rest of the Keku Strait samples. This suggestion is based on two observations:

first, the age distributions of basal group samples are significantly different from most other

Keku Strait samples, and second, the only neighboring pair in the inferred Keku Strait section

to return a comparison result suggesting different source areas is 09LA05 (the uppermost

sample of the basal group) and the superposed sample, 09LA08.

Both the K-S and O-S tests also suggest that the lowermost sample in the Little Pybus

Bay section (09LA14) is most similar to the samples of the Keku Strait basal group,

particularly 09TH10. The upper sample from Little Pybus Bay, 09LA01, displays similar

affinities to both the basal group and to 09NE14, the sample from Lower Porcelainite Beach.

The statistical similarity between 09LA01 and 09NE14, and the relatively dissimilarity

between these two samples and 09LA14 (Table 4) suggest that the upper portion of Little

Pybus Bay should be correlated to the upper portions of the Keku Strait stratigraphy.

However, petrographic data show that upper Little Pybus Bay samples (09LA01 and

09NE29) are devoid of K-feldspar, a trait that distances them from all other samples

subjected to petrographic analysis (Fig. 6c). This difference in lithology likely reflects a

difference in source rock composition. The incomplete nature of the petrographic dataset

obscures my ability to make further relevant comparisons. Therefore, my results with respect

to the correlation of the upper portion of Little Pybus Bay are ambiguous.

The apparent discontinuity in DZ age distribution, present in both Little Pybus Bay

and the Keku Strait (Fig. 2), likely developed during a hiatus in deposition. The base of the

39

Little Pybus Bay section (09LA14) correlates to one of the basal samples (09TH10) of the

Keku Strait section, suggesting that these lower portions of both sections were fed by similar

sediment sources. During the sedimentation process, I suggest that the basin filled to

capacity, causing a temporary cessation of sediment accumulation. During this hiatus,

erosion and reworking of portions of deposited strata likely occurred, which may explain the

low similarity between 09LA01 and 09LA14 (p=0.001). It is also possible that no erosional

surface developed, and the difference in detrital age populations may instead be a result of

some other change that caused a shift in the source regions that contributed sediment to the

basin during active sedimentation.

The Kootznahoo basin was a fluvial-deltaic to marginal marine basin (Fig. 10,

Muffler, 1967; Brew et al., 1982; White et al., in prep) similar to the forearc basin system of

the Matanuska Valley in southern Alaska (Trop et al., 2003; Trop, 2008). In such basins,

especially those undergoing active subsidence that creates a steep scarp along one or both of

the basin margins, sedimentation is fed by fans of coarse-grained sand and conglomerate that

radiate from drainages along the basin margin. In areas of the basin that are more distant

from these fan depocenters, finer-grained sedimentation occurs in low energy environments.

As the basin fills, coarse-grained deposits migrate towards the basin axis, whereas in periods

of subsidence, zones of conglomeratic deposition retreat (Leeder, 1999). In Figure 10, jumps

in the distribution of deposits of different grain sizes represent changes in the base level of

sedimentation, caused by episodes of active subsidence.

Limited accumulation of sediment in the Kootznahoo basin began as early as 65-60

Ma with the deposition of material at the base of Hamilton Bay, which lacks grains younger

than 80 Ma. MDAs of 60-53 Ma for other basal samples in the Kootznahoo stratigraphy

40

KsmTrTr

Tr

Point Hamiltoncomposite

Little Pybus Baycomposite

~225 m

Hamilton Bay

Major source region discontinuityDisconformity surface?Incipient

normal fault

~75 m

Big John BayBig John Bay South

~65-58 Ma: Basin-wide

subsidence drives continuous, rapid sedimentation in both the Keku Strait and Little

Pybus Bay

58-54 Ma:Uneven

subsidence style develops, more rapid in Keku

Strait. Deposition of fine-grained

BJB/BJBS sediments. Possible

hiatus/erosion in LPB

Port Camdencomposite

Little Pybus Baycomposite

Little Pybus Baycomposite

54-35 Ma:Low net

sedimentation, unconformity

development in KS and LPB. Interpreted as

basin-wide slowing or

cessation of subsidence.

~150 m

54 Ma tuff layer in upper portions

ExplanationShale, mudstoneSandstoneGranular sand to conglomerateVolcaniclastic sedimentsVolcanic flows

Unconformitydevelopmentduring slowsubsidence

Slow sedimentation below this level

35-25 Ma:Deposition of

fine to coarse-grained

sediment in both LPB and KS.

Coarse-grained volcaniclastics and volcanic

flows dominate stratigraphy by

27 Ma Figure 10. Kootznahoo Basin development model. Time series of vertically exaggerated, schematically scaled cross sections oriented approximately parallel to the inferred NW-SE elongation of the basin (Dickinson and Vuletich, 1990). Lithology patterns represent expansion of coarse-grained fan deposits (see text for description). Rapid subsidence occurs in the basin between ~57-54 Ma (B.) and 35-25 Ma (C.). During episode of slow subsidence/deposition, unconformity development likely occurred in both the Little Pybus Bay and Port Camden Composite sections. Dotted vertical lines represent approximate placements of measured sections from Fig. 2. Thin, curved horizontal lines are schematic chronostrati-graphic lines.

A.)

B.)

C.)

Ksm Tr

Tr

Ksm Tr

Tr

41

suggest that sedimentation had begun throughout the basin by 60 Ma (Fig. 10a). Statistical

similarity between DZ populations at the bases of Little Pybus Bay and Keku Strait

(09TH10) point to continuous sedimentation between these localities. During this short

period of relatively rapid deposition, the development of a major unconformity is unlikely.

Therefore, I tentatively attribute the apparent discontinuity in age distributions to a shift in

the source regions.

Shortly after 60 Ma, active subsidence in the Keku Strait portion of the Kootznahoo

basin commenced. This first episode of subsidence, which was limited to the Keku Strait

area, allowed the accumulation of ~250-300 meters of sediment of relatively homogenous

provenance below the stratigraphic level of Big John Bay South by 54 Ma. The rapid

sedimentation that occurred between 60-54 Ma was followed by deposition of volcaniclastic

material and volcanic flows that are present at the upper ends of both sections. The MDAs of

samples that contain the earliest components of volcanic populations in the Keku Strait,

beginning with Point Camden, are 33-25 Ma. This implies that 1) there is section missing at

this stratigraphic level, or, 2) the short portion of the measured section present between the

54 Ma tuff layer and the 33 Ma MDA of Point Camden represent a relatively long period of

slow sedimentation. During this period, I suggest that sediment reworking, mixing and

erosion occurred in both sections, resulting in the deposition of relatively heterogeneous age

distributions observed in 09LA01 and 09NE14 at 40-30 Ma. By 30-25 Ma, deposition of

volcaniclastic conglomerates and their source flows had begun. The deposition of these

volcanic strata was accommodated by by basin-wide subsidence that occurred due to a shift

to transtensional tectonics at approximately 45 Ma (Hyndman and Hamilton, 1993).

42

The middle Eocene shift to transtensional tectonics provides a mechanism for

subsidence in the Kootznahoo basin after 45 Ma, but this change does not account for the

earlier subsidence or discontinuity development. The pattern of discontinuity development

followed by further sediment accumulation that we observe in this episode is similar to a

pattern observed by Trop (2008) and Trop et al. (2003) in sediments of the Matanuska Valley

of southern Alaska. Trop (2008) attributes these events to the subduction of a young,

buoyant oceanic ridge, such as the Resurrection-Kula ridge (Haeussler et al. 2003; Bradley et

al., 2003, Taylor et al., 2005). To account for such changes in the Kootznahoo, ridge

subduction must occur at ~58-54 Ma. Haeussler et al. (2003) do not place a ridge near the

site of Kootznahoo deposition during this time period. A modification of their model,

presented by Madsen et al. (2006) suggests that ridge subduction may have begun in this area

at ~53 Ma.

Kootznahoo Formation deposition and northward transport of outboard terranes

The extent to which margin-parallel transport of terranes is a part of the tectonic history

of the Cordillera is a subject of major debate (e.g. Cowan, 2003). Though it is unlikely that

the Kootznahoo experienced syn- or post-depositional transport, similarities between the

provenance of the Kootznahoo and that of sedimentary formations of the Yakutat terrane

suggests that these sedimentary provinces may have shared a source region in Paleocene-

Eocene time.

43

Num

ber

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250

Age (Ma)

Figure 11. Comparison of detrital zircon age populations between the Kootznahoo Formation and the Kulthieth-Poul Creek formations, which are deposited on the Yakutat terrane. Note that the Kulthieth-Poul Creek age distribution is similar to that of the Kootznahoo, with the exception of the young volcanic peak at 27-29 Ma in the Kootznahoo Formation. Modified from Perry et al. (2009)

Kootznahoo Formation DZ

Kulthieth/Poul Creek DZ

44

The middle Eocene-Oligocene Kulthieth and Poul Creek Formations (Plafker, 1987)

deposited on the Yakutat block, currently located southeast of Prince William Sound, display

a similar DZ provenance as that of the Kootznahoo Formation (Fig. 11). Kulthieth/Poul

Creek strata share a large 65-50 Ma DZ population with the Kootznahoo, and have a similar

petrographic character that suggests a relatively immature plutonic source (Perry et al.,

2009). Sources of the 65-50 Ma DZ population were first exhumed to the east of the CSZ by

60-55 Ma, and that rapid exhumation processes persisted until 52-50 Ma (Crawford et al.,

1999; Rusmore et al., 2005). DZ fission track populations from Kulthieth/Poul Creek strata

with cooling ages of 50-40 Ma imply a somewhat later exhumation history, but not so much

as to negate the similarities in U/Pb ages (Perry et al., 2009). We interpret these similarities

to suggest that Yakutat terrane, which most workers believe was transported northward from

45-0 Ma, was at the paleolatitude of Kootznahoo Formation deposition at 45-35 Ma. At this

point in time, according to our conceptual model of Kootznahoo basin development (Fig. 10),

the Kootznahoo basin was experiencing little or no subsidence, which may have resulted in

the filling of the basin and the bypass of sediments onto the Yakutat terrane.

Pronounced 30-24 Ma age peaks in samples from the Porcellainite Beach outcrops

represent zircon populations that we presume, based on sample lithology and age correlation

of these populations, to be volcanic in origin. Fission-track and U-Pb data indicate that such

a population is not present in the Kulthieth and Poul Creek Formations, suggesting that

northward transport of the Yakutat had begun by this time (Perry et al., 2009).

45

CONCLUSIONS

Detrital zircon and petrographic data suggest that the majority of the Paleocene-

Miocene Kootznahoo Formation of the Keku Strait and Little Pybus Bay was derived

from local, quartzo-feldspathic, primarily plutonic sources that experienced major zircon

crystallization events at 190-160, 95-80, and 65-50 Ma. I identify the Jurassic-early

Tertiary plutons of the Coast Mountains Batholith as the most probable sediment source

for the bulk of the Kootznahoo Formation. Comparison to the plutonic/metamorphic age

distribution of Gehrels et al. (2009) suggests that changes in the relative abundance of

major and accessory detrital zircon populations correspond to changes in the uplift and

exhumation of the CMB across the Coast Shear Zone. Correlations between plutonic

sources and detrital zircon ages suggest depositional ages of 65-54 Ma for lower

Kootznahoo Formation strata. In the upper portions of the Kootznahoo stratigraphy, a

shift to a detrital zircon age distribution dominated by middle-late Tertiary ages and a

volcaniclastic petrographic signature suggests a change to local volcanic sediment

sources.

Statistical comparisons of detrital zircon samples from the Kootznahoo Formation

support the stratigraphy presented by White et al. (in prep). Comparisons of Little Pybus

Bay and Keku Strait samples link lower Little Pybus Bay with the lowermost portions of

the Keku Strait section. Synthesis of detrital zircon ages, statistics, and the Kootznahoo

stratigraphy suggests a depositional history filled with uneven and episodic subsidence

and sedimentation, punctuated by periods of erosion and unconformity development.

Major subsidence events occurred at 60-54 Ma and 45-35 Ma. These periods of

subsidence may have been punctuated by the subduction of an oceanic ridge.

46

Similarities between the detrital zircon age distribution, exhumation chronology,

and sedimentary petrography of the Kootznahoo Formation and the Eocene-Oligocene

Kulthieth and Poul Creek Formations of the Yakutat terrane suggest that these areas may

have shared a sediment source 45-35 Ma. I interpret this similarity to indicate that the

Yakutat block was adjacent to the Kootznahoo Formation during this time period, before

beginning its northward transport prior to 30 Ma.

ACKNOWLEDGEMENTS

I thank the Keck Geology Consortium and Carleton College for providing funding

for this research. I express my profound gratitude to Cameron Davidson for his unlimited

availability, wise advice, and the countless discussions that benefitted this paper a great

deal. I thank Peter Haeussler, and Sue Karl, and especially Tim White for sharing their

experience and previous work on the Kootznahoo Formation, therein making my work

possible. In the field, Captain Karl Wirth embodied the perfect combination of academic

advisor, maritime navigator, and field photographer – I thank him for sharing his

expertise. Lenny Ancuta shared the burden of zircon sample processing, and he, along

with Tiffany Henderson, provided good company in the field and good ideas back at

home. Thanks to Louis Baggetto and Jeff Thole at Macalester College for instruction and

support in zircon sample processing procedures. Finally, thanks to all family and friends,

especially my fellow geology majors, for their support through this often difficult, but

ultimately satisfying process.

47

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55

APPENDIX 1. U/PB ANALYTICAL METHODS (after Gehrels et al., 2009)

U-Pb geochronology of zircons was conducted by laser ablation multicollector

inductively coupled plasma mass spectrometry (LA-MC-ICPMS). The analyses involve

ablation of zircon with a New Wave/Lambda Physik DUV193 Excimer laser (operating

at a wavelength of 193 nm) using a spot diameter of 35 microns. The ablated material is

carried in helium into the plasma source of a GVI Isoprobe, which is equipped with a

flight tube of sufficient width that U, Th, and Pb isotopes are measured simultaneously.

All measurements are made in static mode, using 10e11 ohm Faraday detectors for 238U,

232Th, 208Pb, and 206Pb, a 10e12 ohm faraday collector for 207Pb, and an ion-counting

channel for 204Pb. Ion yields are ~1.0 mv per ppm. Each analysis consists of one 12-

second integration on peaks with the laser off (for backgrounds), 12 one-second

integrations with the laser firing, and a 30 second delay to purge the previous sample and

prepare for the next analysis. The ablation pit is ~12 microns in depth.

For each analysis, the errors in determining 206Pb/ 238U and 206Pb/ 204Pb result in a

measurement error of ~1-2% (at 2-sigma level) in the 206Pb/ 238U age. The errors in

measurement of 206Pb/ 207Pb and 206Pb/ 204Pb also result in ~1-2% (at 2-sigma level)

uncertainty in age for grains that are >1.0 Ga, but are substantially larger for younger

grains due to low intensity of the 207Pb signal. For most analyses, the cross-over in

precision of 206Pb/ 238U and 206Pb/ 207Pb ages occurs at 0.8-1.0 Ga.

Common Pb correction is accomplished by using the measured 204Pb and

assuming an initial Pb composition from Stacey and Kramers (1975) (with uncertainties

of 1.0 for 206Pb/ 204Pb and 0.3 for 207Pb/ 204Pb). Measurement of 204Pb is unaffected by the

56

presence of 204Hg because backgrounds are measured on peaks (thereby subtracting any

background 204Hg and 204Pb), and because very little Hg is present in the argon gas.

Inter-element fractionation of Pb/U is generally ~20%, whereas apparent

fractionation of Pb isotopes is generally ~2%. In-run analysis of fragments of a large

zircon crystal (generally every fifth measurement) with known age of 564 ± 4 Ma (2-

sigma error) is used to correct for this fractionation. The uncertainty resulting from the

calibration correction is generally 1-2% (2-sigma) for both 206Pb/ 207Pb and 206Pb/ 238U

ages.

57

Sample 09LA01, Upper Little Pybus Bay Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N57.22054, W134.15404

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09LA0-1 878 7953 9.0 20.9451 2.6 0.0897 2.7 0.0136 0.7 0.27 87.2 0.6 87.2 2.2 86.6 61.2 87.2 0.6 100.709LA0-2 702 2817 0.7 22.1310 6.7 0.0602 6.7 0.0097 0.6 0.08 62.0 0.3 59.4 3.9 -45.6 163.0 62.0 0.3 -136.009LA0-4 952 6345 4.1 21.6001 3.6 0.0603 3.8 0.0095 1.1 0.29 60.7 0.7 59.5 2.2 13.1 86.7 60.7 0.7 463.809LA01-5 389 1080 4.0 14.7213 17.1 0.0857 17.1 0.0092 0.7 0.04 58.7 0.4 83.5 13.7 866.4 356.9 58.7 0.4 6.809LA01-6 477 4458 7.0 21.5200 3.5 0.0892 3.5 0.0139 0.8 0.22 89.2 0.7 86.8 2.9 22.0 83.0 89.2 0.7 404.909LA01-7 693 8337 1.9 20.1023 2.6 0.1558 2.7 0.0227 0.5 0.19 144.8 0.7 147.1 3.7 183.1 61.1 144.8 0.7 79.109LA01-9 330 2976 3.6 22.1922 6.1 0.0597 6.2 0.0096 0.5 0.08 61.6 0.3 58.9 3.5 -52.3 149.5 61.6 0.3 -117.709LA01-8 660 11130 2.3 20.1953 2.4 0.1724 3.6 0.0253 2.7 0.74 160.8 4.2 161.5 5.4 172.3 56.2 160.8 4.2 93.309LA01-10 408 3783 4.8 22.0301 4.5 0.0570 4.5 0.0091 0.9 0.19 58.4 0.5 56.3 2.5 -34.5 108.2 58.4 0.5 -169.209LA01-11 119 1002 1.8 30.0259 32.2 0.0460 32.2 0.0100 1.0 0.03 64.3 0.6 45.7 14.4 -848.8 941.3 64.3 0.6 -7.609LA01-12 779 6996 11.6 21.6586 3.4 0.0644 3.4 0.0101 0.6 0.16 64.9 0.4 63.4 2.1 6.6 81.8 64.9 0.4 989.809LA01-13 360 2748 3.0 21.9650 4.8 0.0593 5.0 0.0095 1.4 0.28 60.6 0.8 58.5 2.8 -27.3 116.5 60.6 0.8 -221.809LA01-14 1585 14388 3.4 21.5319 3.2 0.0645 3.4 0.0101 1.2 0.34 64.6 0.8 63.4 2.1 20.7 76.5 64.6 0.8 312.509LA01-15 662 6750 1.7 21.5753 3.1 0.0766 3.2 0.0120 0.7 0.23 76.8 0.5 74.9 2.3 15.8 74.8 76.8 0.5 484.909LA01-16 1646 23802 3.1 19.7266 2.7 0.1716 4.3 0.0246 3.3 0.77 156.4 5.1 160.8 6.4 226.9 63.5 156.4 5.1 68.909LA01-17 236 1929 1.8 23.4863 11.4 0.0543 11.5 0.0093 1.9 0.16 59.4 1.1 53.7 6.0 -192.2 285.4 59.4 1.1 -30.909LA01-18 984 6915 9.9 21.1791 2.8 0.0662 3.5 0.0102 2.1 0.59 65.2 1.4 65.1 2.2 60.2 67.7 65.2 1.4 108.409LA01-19 512 5931 4.8 21.3879 2.9 0.0893 3.0 0.0139 0.9 0.29 88.7 0.8 86.8 2.5 36.7 68.9 88.7 0.8 241.409LA01-20 737 11028 9.8 21.1847 2.3 0.0904 2.7 0.0139 1.4 0.54 88.9 1.3 87.8 2.3 59.6 54.0 88.9 1.3 149.209LA01-21 269 6246 2.0 20.8558 4.0 0.1774 4.2 0.0268 1.3 0.32 170.7 2.2 165.9 6.4 96.7 94.0 170.7 2.2 176.509LA01-22 431 3747 3.1 22.0409 5.0 0.0580 5.0 0.0093 0.5 0.10 59.5 0.3 57.3 2.8 -35.7 120.4 59.5 0.3 -166.709LA01-23 572 3573 2.9 22.3744 5.3 0.0549 5.4 0.0089 0.7 0.12 57.2 0.4 54.3 2.8 -72.3 130.3 57.2 0.4 -79.109LA01-24 294 1287 2.6 17.1055 9.4 0.0692 9.7 0.0086 2.5 0.26 55.1 1.4 67.9 6.4 547.0 206.2 55.1 1.4 10.109LA01-25 308 4656 1.9 19.0550 4.4 0.1992 4.5 0.0275 1.0 0.22 175.0 1.7 184.4 7.5 306.4 99.3 175.0 1.7 57.109LA01-26 333 3102 7.9 21.1994 6.9 0.0924 7.0 0.0142 0.5 0.07 90.9 0.5 89.7 6.0 57.9 165.8 90.9 0.5 157.109LA01-27 1571 7305 1.6 20.4786 1.3 0.0582 2.3 0.0086 1.9 0.83 55.5 1.1 57.5 1.3 139.7 30.4 55.5 1.1 39.709LA01-28 308 2499 3.6 23.2991 15.8 0.0566 15.8 0.0096 0.5 0.03 61.3 0.3 55.9 8.6 -172.2 395.6 61.3 0.3 -35.609LA01-29 302 1038 4.0 14.5443 16.9 0.0954 16.9 0.0101 0.5 0.03 64.5 0.3 92.5 14.9 891.4 351.2 64.5 0.3 7.209LA01-30 113 846 3.0 12.6879 28.5 0.1104 28.6 0.0102 2.9 0.10 65.1 1.9 106.3 28.9 1167.5 576.1 65.1 1.9 5.609LA01-31 451 3780 3.2 22.0895 5.4 0.0565 5.4 0.0091 0.6 0.11 58.1 0.3 55.8 3.0 -41.1 131.4 58.1 0.3 -141.509LA01-32 301 2604 3.4 22.0703 13.6 0.0571 13.6 0.0091 0.8 0.06 58.6 0.5 56.4 7.5 -38.9 331.9 58.6 0.5 -150.609LA01-33 509 3522 2.5 20.8260 13.1 0.0681 13.1 0.0103 0.7 0.05 66.0 0.4 66.9 8.5 100.1 311.4 66.0 0.4 65.909LA01-34 489 3348 2.3 22.3247 5.1 0.0521 5.3 0.0084 1.4 0.26 54.1 0.7 51.5 2.7 -66.9 124.9 54.1 0.7 -80.909LA01-35 50 2430 4.8 19.5403 6.5 0.4220 6.5 0.0598 0.9 0.13 374.5 3.2 357.5 19.7 248.8 149.4 374.5 3.2 150.509LA01-36 117 1152 1.5 28.1414 27.4 0.0498 27.4 0.0102 0.8 0.03 65.2 0.5 49.4 13.2 -666.6 767.1 65.2 0.5 -9.809LA01-37 277 2304 3.2 22.4339 7.5 0.0525 7.6 0.0085 1.3 0.17 54.8 0.7 51.9 3.8 -78.8 183.4 54.8 0.7 -69.509LA01-38 1190 10443 13.5 21.5687 3.4 0.0626 3.7 0.0098 1.6 0.42 62.8 1.0 61.6 2.2 16.5 81.0 62.8 1.0 379.809LA01-39 1803 12945 2.1 20.6300 3.8 0.0603 4.1 0.0090 1.4 0.34 57.9 0.8 59.5 2.4 122.4 90.4 57.9 0.8 47.309LA01-40 624 4173 1.4 22.1961 5.3 0.0643 5.3 0.0103 0.7 0.14 66.3 0.5 63.2 3.3 -52.8 128.0 66.3 0.5 -125.709LA01-41 352 3402 4.1 21.5826 3.5 0.0614 3.6 0.0096 0.7 0.20 61.7 0.4 60.5 2.1 15.0 83.7 61.7 0.4 410.909LA01-42 1317 5367 3.7 19.7487 4.3 0.0708 4.3 0.0101 0.5 0.12 65.0 0.3 69.4 2.9 224.3 99.8 65.0 0.3 29.009LA01-43 252 1344 3.6 16.7084 8.2 0.0969 8.2 0.0117 0.5 0.06 75.3 0.4 93.9 7.3 598.2 176.8 75.3 0.4 12.609LA01-44 800 10140 9.6 21.6896 3.7 0.0873 3.7 0.0137 0.5 0.13 88.0 0.4 85.0 3.1 3.1 89.3 88.0 0.4 2824.709LA01-45 157 1692 3.8 24.1822 22.2 0.0561 22.2 0.0098 0.8 0.04 63.2 0.5 55.5 12.0 -265.8 568.3 63.2 0.5 -23.809LA01-46 306 3903 3.7 21.5745 4.9 0.0898 4.9 0.0141 0.6 0.12 90.0 0.5 87.4 4.1 15.9 116.9 90.0 0.5 566.209LA01-47 88 792 2.9 30.9933 33.8 0.0404 33.9 0.0091 1.2 0.04 58.3 0.7 40.3 13.4 -940.7 1013.0 58.3 0.7 -6.209LA01-48 504 7527 8.3 21.3669 3.3 0.0908 3.3 0.0141 0.5 0.15 90.1 0.4 88.3 2.8 39.1 79.2 90.1 0.4 230.309LA01-49 1346 10467 3.0 20.8085 4.3 0.0638 4.4 0.0096 1.2 0.27 61.8 0.7 62.8 2.7 102.1 101.3 61.8 0.7 60.509LA01-50 433 12753 3.9 21.0234 4.3 0.1720 5.6 0.0262 3.5 0.63 166.9 5.8 161.1 8.4 77.7 103.3 166.9 5.8 214.709LA01-51 736 8580 6.8 21.1234 2.6 0.0852 3.1 0.0131 1.8 0.56 83.6 1.5 83.0 2.5 66.4 61.5 83.6 1.5 125.809LA01-52 1335 13914 5.7 21.2481 2.8 0.0978 2.8 0.0151 0.5 0.18 96.4 0.5 94.8 2.6 52.5 66.8 96.4 0.5 183.909LA01-53 1297 9285 1.6 21.2955 2.0 0.0615 2.1 0.0095 0.7 0.34 60.9 0.4 60.6 1.3 47.1 48.3 60.9 0.4 129.309LA01-54 635 5841 15.9 21.6506 2.4 0.0622 3.1 0.0098 2.0 0.64 62.7 1.2 61.3 1.9 7.4 58.3 62.7 1.2 844.209LA01-55 516 3729 2.6 22.3941 5.6 0.0541 5.7 0.0088 1.2 0.22 56.4 0.7 53.5 3.0 -74.4 137.1 56.4 0.7 -75.809LA01-56 490 4677 3.3 22.4855 7.5 0.0562 7.5 0.0092 0.7 0.09 58.8 0.4 55.5 4.0 -84.4 182.9 58.8 0.4 -69.709LA01-57 368 2703 2.6 20.8165 8.4 0.0617 8.4 0.0093 0.5 0.06 59.8 0.3 60.8 5.0 101.2 198.6 59.8 0.3 59.109LA01-58 622 4029 2.4 21.6158 5.3 0.0793 5.3 0.0124 0.5 0.10 79.7 0.4 77.5 4.0 11.3 126.8 79.7 0.4 703.909LA01-59 432 1671 3.0 18.4291 6.1 0.0713 6.1 0.0095 0.5 0.09 61.1 0.3 69.9 4.1 381.9 137.0 61.1 0.3 16.009LA01-60 770 6960 3.3 21.0773 4.0 0.0613 4.0 0.0094 0.7 0.17 60.1 0.4 60.4 2.4 71.7 94.4 60.1 0.4 83.809LA01-61 641 5040 6.4 20.8101 4.0 0.0602 4.7 0.0091 2.6 0.54 58.3 1.5 59.4 2.7 101.9 93.9 58.3 1.5 57.209LA01-62 1172 25800 1.6 20.1288 2.9 0.1829 3.0 0.0267 0.8 0.26 169.9 1.3 170.6 4.7 180.0 67.6 169.9 1.3 94.409LA01-63 715 7008 2.1 21.2846 2.7 0.0752 2.8 0.0116 0.8 0.27 74.4 0.6 73.7 2.0 48.3 64.1 74.4 0.6 154.009LA01-64 164 1779 2.8 23.0016 10.7 0.0742 10.9 0.0124 2.2 0.20 79.3 1.7 72.7 7.6 -140.3 264.4 79.3 1.7 -56.509LA01-65 142 1365 2.6 24.5635 15.5 0.0493 15.7 0.0088 2.5 0.16 56.4 1.4 48.8 7.5 -305.7 399.2 56.4 1.4 -18.409LA01-66 380 3060 2.9 23.3264 9.5 0.0554 9.8 0.0094 2.2 0.23 60.1 1.3 54.7 5.2 -175.1 237.5 60.1 1.3 -34.309LA01-67 358 2568 1.9 22.2646 5.6 0.0551 5.6 0.0089 0.5 0.09 57.1 0.3 54.5 3.0 -60.3 135.4 57.1 0.3 -94.809LA01-68 227 2406 9.3 23.0955 10.0 0.0629 10.0 0.0105 0.5 0.05 67.6 0.3 61.9 6.0 -150.4 247.9 67.6 0.3 -44.909LA01-69 168 1542 1.7 23.1776 11.0 0.0610 11.1 0.0103 1.4 0.12 65.7 0.9 60.1 6.5 -159.2 274.2 65.7 0.9 -41.309LA01-70 2548 54957 6.6 19.6302 4.2 0.1597 6.6 0.0227 5.1 0.78 145.0 7.4 150.5 9.3 238.2 96.2 145.0 7.4 60.909LA01-71 342 2358 4.0 23.4911 11.1 0.0545 11.3 0.0093 2.2 0.19 59.5 1.3 53.8 5.9 -192.7 278.0 59.5 1.3 -30.909LA01-72 307 2538 1.6 21.8148 9.2 0.0639 9.2 0.0101 1.1 0.12 64.8 0.7 62.9 5.6 -10.7 222.1 64.8 0.7 -603.609LA01-73 600 735 8.3 11.4197 42.1 0.0977 42.2 0.0081 3.7 0.09 52.0 1.9 94.7 38.2 1373.0 848.4 52.0 1.9 3.809LA01-74 293 2226 3.6 22.3840 7.1 0.0509 7.4 0.0083 2.2 0.30 53.1 1.2 50.4 3.7 -73.3 174.0 53.1 1.2 -72.409LA01-75 195 2781 2.2 20.9908 4.5 0.1546 7.3 0.0235 5.7 0.79 150.0 8.5 146.0 9.9 81.4 106.2 150.0 8.5 184.309LA01-76 658 7968 0.9 19.5958 2.6 0.1825 2.7 0.0259 0.8 0.31 165.1 1.4 170.2 4.2 242.3 59.0 165.1 1.4 68.209LA01-77 399 3513 2.7 22.8137 8.3 0.0560 8.3 0.0093 0.9 0.11 59.4 0.5 55.3 4.5 -120.0 205.0 59.4 0.5 -49.509LA01-78 783 13905 5.0 19.7694 2.5 0.1397 4.8 0.0200 4.1 0.85 127.9 5.2 132.8 6.0 221.9 57.9 127.9 5.2 57.609LA01-79 1394 15324 2.2 21.3941 3.1 0.0730 3.4 0.0113 1.6 0.45 72.7 1.1 71.6 2.4 36.0 73.7 72.7 1.1 201.609LA01-80 3300 19419 4.2 20.5624 2.7 0.0653 2.8 0.0097 0.7 0.26 62.5 0.5 64.2 1.7 130.2 63.5 62.5 0.5 48.009LA01-81 598 3957 2.5 20.3568 6.0 0.0590 6.2 0.0087 1.7 0.28 55.9 1.0 58.2 3.5 153.7 139.9 55.9 1.0 36.409LA01-82 424 2646 3.4 21.5333 5.7 0.0555 5.9 0.0087 1.7 0.28 55.7 0.9 54.9 3.2 20.5 136.0 55.7 0.9 271.609LA01-83 350 3204 3.4 22.1674 6.4 0.0556 6.4 0.0089 0.8 0.12 57.3 0.4 54.9 3.4 -49.6 155.7 57.3 0.4 -115.509LA01-84 326 1881 2.5 22.0213 14.1 0.0535 14.2 0.0085 1.5 0.11 54.8 0.8 52.9 7.3 -33.6 343.1 54.8 0.8 -163.409LA01-85 247 5496 2.2 19.6328 6.3 0.2030 6.4 0.0289 0.9 0.14 183.7 1.7 187.7 10.9 237.9 145.1 183.7 1.7 77.209LA01-86 203 2634 4.2 21.1132 6.2 0.0933 6.3 0.0143 0.5 0.08 91.5 0.5 90.6 5.4 67.6 148.7 91.5 0.5 135.309LA01-87 1432 8991 18.5 16.1596 13.2 0.1541 13.3 0.0181 1.5 0.11 115.4 1.7 145.5 18.1 670.1 284.5 115.4 1.7 17.209LA01-88 560 3915 2.5 17.5104 4.2 0.2102 4.3 0.0267 0.6 0.14 169.8 1.0 193.7 7.5 495.7 93.4 169.8 1.0 34.309LA01-89 241 900 2.4 16.7423 17.1 0.0891 17.2 0.0108 2.1 0.12 69.4 1.4 86.7 14.3 593.8 373.5 69.4 1.4 11.709LA01-90 310 2136 2.8 19.0366 14.3 0.0746 14.3 0.0103 0.9 0.06 66.1 0.6 73.1 10.1 308.6 326.6 66.1 0.6 21.409LA01-91 481 2844 1.9 18.9902 9.2 0.0636 9.3 0.0088 1.1 0.11 56.2 0.6 62.6 5.6 314.1 210.0 56.2 0.6 17.909LA01-92 359 4056 8.8 20.9127 3.6 0.0933 3.6 0.0142 0.5 0.14 90.6 0.4 90.6 3.1 90.3 85.2 90.6 0.4 100.409LA01-93 240 1896 4.8 23.7622 13.3 0.0522 13.4 0.0090 1.6 0.12 57.7 0.9 51.6 6.7 -221.5 335.4 57.7 0.9 -26.109LA01-94 674 1833 2.8 14.2466 20.7 0.0888 20.7 0.0092 0.9 0.04 58.9 0.5 86.4 17.2 934.0 429.5 58.9 0.5 6.309LA01-95 182 1458 3.2 23.6439 11.2 0.0540 11.2 0.0093 0.7 0.06 59.4 0.4 53.4 5.8 -209.0 282.1 59.4 0.4 -28.409LA01-96 2467 21651 4.3 21.1057 2.7 0.0628 2.8 0.0096 0.7 0.26 61.7 0.4 61.9 1.7 68.4 64.4 61.7 0.4 90.209LA01-97 31 312 126.9 36.7759 48.8 0.0356 48.9 0.0095 2.7 0.06 60.9 1.6 35.5 17.1 -1471.8 1694.2 60.9 1.6 -4.109LA01-98 471 4080 2.8 21.5668 9.3 0.0572 9.5 0.0089 1.5 0.16 57.4 0.9 56.5 5.2 16.8 225.0 57.4 0.9 342.609LA01-99 874 8928 5.8 21.1664 2.2 0.0661 4.1 0.0102 3.5 0.85 65.1 2.2 65.0 2.6 61.6 51.7 65.1 2.2 105.709LA01-100 378 9729 5.6 19.6378 4.9 0.1841 5.1 0.0262 1.5 0.29 166.8 2.5 171.5 8.1 237.3 112.5 166.8 2.5 70.3

APPENDIX 2 - ISOTOPIC DATA

58

Sample 09LA14, Lower Little Pybus Bay Isotope ratios Apparent ages (Ma)Coordinates (WGS-84): N57.24765, W134.1119

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09LA14-1 794 4314 10.1 21.1368 1.8 0.0921 2.0 0.0141 1.0 0.47 90.4 0.9 89.4 1.7 64.9 43.0 90.4 0.9 139.209LA14-2 184 26472 2.3 8.9606 2.2 4.0412 4.8 0.2626 4.3 0.89 1503.3 57.1 1642.5 38.9 1825.6 39.2 1825.6 39.2 82.309LA14-3 413 2691 3.2 21.8576 5.8 0.0846 5.8 0.0134 0.6 0.11 85.9 0.5 82.4 4.6 -15.5 140.0 85.9 0.5 -554.809LA14-4 637 2157 2.3 22.8038 7.9 0.0591 8.0 0.0098 1.5 0.19 62.7 0.9 58.3 4.5 -119.0 194.3 62.7 0.9 -52.709LA14-5 611 1608 12.4 22.6476 8.2 0.0805 8.3 0.0132 1.4 0.16 84.7 1.1 78.6 6.3 -102.0 201.9 84.7 1.1 -83.009LA14-6 437 5949 2.9 19.4994 3.3 0.2201 5.4 0.0311 4.3 0.79 197.6 8.4 202.0 10.0 253.6 76.6 197.6 8.4 77.909LA14-7 328 1827 3.2 23.7527 11.9 0.0535 12.0 0.0092 0.7 0.06 59.1 0.4 52.9 6.2 -220.5 301.4 59.1 0.4 -26.809LA14-8 252 16176 2.3 9.2723 1.0 3.7014 1.9 0.2489 1.6 0.86 1432.9 20.4 1571.7 14.9 1763.4 17.6 1763.4 17.6 81.309LA14-9 323 2355 1.9 22.2759 6.7 0.0598 6.8 0.0097 1.3 0.19 62.0 0.8 59.0 3.9 -61.5 163.2 62.0 0.8 -100.809LA14-10 387 7044 3.8 19.8890 1.0 0.2016 1.4 0.0291 0.9 0.65 184.8 1.6 186.5 2.3 207.9 24.2 184.8 1.6 88.909LA14-11 1360 11730 1.7 20.9840 1.6 0.0791 1.7 0.0120 0.5 0.30 77.1 0.4 77.3 1.3 82.2 38.2 77.1 0.4 93.809LA14-12 251 6012 2.5 20.2399 2.7 0.2018 2.8 0.0296 0.7 0.24 188.2 1.2 186.6 4.8 167.2 64.0 188.2 1.2 112.609LA14-13 535 2775 2.4 21.5156 5.9 0.0691 6.0 0.0108 1.0 0.16 69.1 0.7 67.8 3.9 22.5 142.0 69.1 0.7 307.509LA14-14 515 3294 1.6 22.3532 5.9 0.0565 6.0 0.0092 0.8 0.14 58.8 0.5 55.8 3.3 -70.0 144.9 58.8 0.5 -84.109LA14-15 436 2631 2.4 22.1263 6.0 0.0622 6.0 0.0100 1.0 0.16 64.0 0.6 61.3 3.6 -45.1 144.8 64.0 0.6 -142.009LA14-17 467 2874 2.9 22.2346 7.2 0.0644 7.3 0.0104 1.0 0.13 66.6 0.6 63.4 4.5 -57.0 176.4 66.6 0.6 -116.909LA14-16 992 6810 7.6 21.5086 2.9 0.0852 3.3 0.0133 1.6 0.47 85.1 1.3 83.0 2.6 23.3 69.6 85.1 1.3 365.309LA14-18 187 3054 1.8 21.7198 8.9 0.1590 9.0 0.0250 1.6 0.18 159.5 2.6 149.8 12.6 -0.2 214.6 159.5 2.6 -75936.909LA14-19 251 4224 1.4 20.4575 3.7 0.1944 3.8 0.0288 0.6 0.16 183.3 1.1 180.4 6.2 142.2 87.4 183.3 1.1 129.009LA14-20 400 3384 4.2 21.9348 5.3 0.0835 5.4 0.0133 1.0 0.19 85.1 0.9 81.5 4.2 -24.0 128.2 85.1 0.9 -354.309LA14-21 523 11958 1.8 18.0716 2.4 0.3981 4.6 0.0522 4.0 0.86 327.9 12.7 340.3 13.4 425.8 53.0 327.9 12.7 77.009LA14-22 320 7638 2.5 20.2598 2.0 0.1851 2.3 0.0272 1.2 0.53 173.0 2.1 172.4 3.7 164.9 46.3 173.0 2.1 104.909LA14-23 187 1299 2.5 26.6090 22.4 0.0471 22.5 0.0091 1.9 0.08 58.4 1.1 46.8 10.3 -514.7 605.0 58.4 1.1 -11.309LA14-24 1357 11775 5.7 20.7023 2.5 0.0849 2.7 0.0128 1.1 0.39 81.7 0.9 82.8 2.2 114.2 59.4 81.7 0.9 71.509LA14-25 571 25860 2.0 18.8069 1.4 0.3858 2.3 0.0526 1.9 0.81 330.6 6.0 331.3 6.5 336.2 30.7 330.6 6.0 98.309LA14-26 1012 9048 4.9 21.3047 1.8 0.0699 2.3 0.0108 1.5 0.66 69.2 1.1 68.6 1.5 46.1 41.9 69.2 1.1 150.209LA14-27 914 4566 1.4 21.5836 3.4 0.0581 3.7 0.0091 1.6 0.43 58.4 0.9 57.4 2.1 14.9 80.7 58.4 0.9 392.309LA14-28 267 2289 1.7 22.5038 6.2 0.0602 7.3 0.0098 3.8 0.52 63.0 2.4 59.3 4.2 -86.4 152.5 63.0 2.4 -72.909LA14-29 126 2916 1.1 21.4495 8.3 0.1844 8.3 0.0287 0.8 0.09 182.3 1.4 171.8 13.2 29.8 199.5 182.3 1.4 610.809LA14-30 491 651 2.8 22.5016 8.6 0.0557 8.7 0.0091 1.4 0.16 58.3 0.8 55.0 4.7 -86.2 212.1 58.3 0.8 -67.709LA14-31 648 6279 3.2 21.6661 2.7 0.0663 3.4 0.0104 2.2 0.62 66.8 1.4 65.1 2.2 5.7 64.7 66.8 1.4 1165.809LA14-32 257 35463 1.0 8.6853 1.5 5.1076 1.7 0.3217 0.9 0.52 1798.2 13.8 1837.4 14.4 1882.0 26.1 1882.0 26.1 95.509LA14-33 793 5607 2.4 21.7233 2.9 0.0584 3.0 0.0092 0.7 0.24 59.0 0.4 57.6 1.7 -0.6 70.8 59.0 0.4 -9804.609LA14-34 172 1791 2.7 23.2052 12.7 0.0614 12.8 0.0103 1.2 0.09 66.2 0.8 60.5 7.5 -162.2 316.9 66.2 0.8 -40.809LA14-35 57 13632 2.1 9.7410 1.6 3.8450 2.6 0.2716 2.0 0.78 1549.1 28.1 1602.2 21.1 1672.7 30.2 1672.7 30.2 92.609LA14-36 577 2970 2.1 19.4847 9.8 0.0613 10.1 0.0087 2.2 0.22 55.6 1.2 60.4 5.9 255.3 226.4 55.6 1.2 21.809LA14-37 580 3759 8.0 21.5389 3.9 0.0703 4.2 0.0110 1.5 0.36 70.5 1.0 69.0 2.8 19.9 93.5 70.5 1.0 354.609LA14-38 898 5922 4.0 21.7822 3.1 0.0636 3.3 0.0101 1.1 0.33 64.5 0.7 62.6 2.0 -7.1 74.0 64.5 0.7 -904.509LA14-39 231 3624 2.0 20.7497 3.9 0.1864 3.9 0.0281 0.5 0.13 178.4 0.9 173.6 6.2 108.8 91.3 178.4 0.9 163.909LA14-40 382 4605 1.3 20.3578 2.0 0.1950 2.6 0.0288 1.8 0.67 182.9 3.2 180.9 4.4 153.6 46.3 182.9 3.2 119.109LA14-41 141 1365 5.1 27.3376 24.7 0.0460 24.8 0.0091 2.3 0.09 58.6 1.3 45.7 11.1 -587.4 677.4 58.6 1.3 -10.009LA14-42 246 4548 2.7 20.4737 3.1 0.1877 3.8 0.0279 2.2 0.58 177.2 3.8 174.7 6.1 140.3 72.3 177.2 3.8 126.309LA14-43 360 2988 2.3 22.0488 5.0 0.0682 5.0 0.0109 0.5 0.10 69.9 0.4 67.0 3.3 -36.6 121.9 69.9 0.4 -191.209LA14-44 271 2109 2.8 22.8059 7.7 0.0576 7.7 0.0095 1.1 0.14 61.2 0.7 56.9 4.3 -119.2 189.0 61.2 0.7 -51.309LA14-45 1071 11118 16.2 21.2345 1.8 0.0842 1.9 0.0130 0.7 0.38 83.0 0.6 82.1 1.5 54.0 42.2 83.0 0.6 153.909LA14-46 434 4614 5.2 21.4257 3.5 0.0651 3.6 0.0101 1.0 0.27 64.9 0.6 64.0 2.2 32.5 82.7 64.9 0.6 199.409LA14-47 257 2391 4.2 22.5183 7.3 0.0625 7.4 0.0102 1.0 0.13 65.4 0.6 61.5 4.4 -88.0 180.0 65.4 0.6 -74.409LA14-48 262 6132 2.6 20.8886 3.9 0.1893 4.0 0.0287 0.8 0.19 182.3 1.4 176.1 6.5 93.0 93.4 182.3 1.4 196.009LA14-49 407 3705 3.4 22.7075 9.7 0.0702 9.8 0.0116 1.2 0.13 74.1 0.9 68.9 6.5 -108.5 239.5 74.1 0.9 -68.309LA14-50 378 12813 2.3 18.9720 1.8 0.3675 2.9 0.0506 2.3 0.79 318.0 7.2 317.8 8.0 316.3 41.0 318.0 7.2 100.509LA14-51 809 4239 4.6 21.0842 2.7 0.0697 3.9 0.0107 2.8 0.72 68.4 1.9 68.5 2.6 70.9 64.9 68.4 1.9 96.509LA14-52 358 2985 2.3 22.0354 4.7 0.0732 4.8 0.0117 1.0 0.21 74.9 0.8 71.7 3.3 -35.1 113.7 74.9 0.8 -213.509LA14-53 2333 15321 3.5 17.1181 6.4 0.3479 9.9 0.0432 7.6 0.77 272.6 20.3 303.2 26.1 545.5 139.8 272.6 20.3 50.009LA14-54 602 6555 4.4 21.7362 3.6 0.0827 3.7 0.0130 0.5 0.15 83.5 0.4 80.7 2.8 -2.0 87.1 83.5 0.4 -4102.409LA14-55 586 13455 2.1 20.0434 2.0 0.2046 2.0 0.0297 0.5 0.25 188.9 0.9 189.0 3.5 190.0 45.6 188.9 0.9 99.409LA14-56 176 1362 2.3 25.4882 18.8 0.0515 18.8 0.0095 1.3 0.07 61.1 0.8 51.0 9.4 -401.1 493.1 61.1 0.8 -15.209LA14-57 408 8151 2.5 20.0367 2.3 0.2010 2.6 0.0292 1.2 0.46 185.6 2.2 186.0 4.3 190.8 52.6 185.6 2.2 97.309LA14-58 657 5718 7.9 21.1631 2.0 0.0905 2.5 0.0139 1.5 0.61 88.9 1.3 88.0 2.1 62.0 47.5 88.9 1.3 143.509LA14-59 534 5070 4.7 21.4335 3.9 0.0834 4.1 0.0130 1.2 0.30 83.0 1.0 81.3 3.2 31.7 92.8 83.0 1.0 262.009LA14-60 1106 11256 13.4 21.0592 1.4 0.0915 1.8 0.0140 1.2 0.66 89.5 1.1 88.9 1.6 73.7 32.9 89.5 1.1 121.509LA14-61 666 17643 6.5 18.4496 0.9 0.3508 2.8 0.0469 2.7 0.94 295.7 7.7 305.3 7.4 379.4 20.8 295.7 7.7 77.909LA14-62 317 4167 5.5 22.1157 8.0 0.0819 8.0 0.0131 1.0 0.13 84.1 0.9 79.9 6.2 -43.9 194.2 84.1 0.9 -191.409LA14-63 493 4365 3.8 21.7583 5.0 0.0642 5.1 0.0101 1.2 0.23 65.0 0.8 63.2 3.1 -4.5 120.3 65.0 0.8 -1447.609LA14-64 209 5772 4.1 19.5889 4.6 0.2051 4.7 0.0291 1.0 0.22 185.1 1.9 189.4 8.2 243.1 106.3 185.1 1.9 76.209LA14-65 1142 11322 8.4 21.3481 2.1 0.0729 2.4 0.0113 1.1 0.47 72.3 0.8 71.4 1.6 41.2 49.8 72.3 0.8 175.409LA14-66 896 8343 5.3 21.2494 1.7 0.0714 2.4 0.0110 1.7 0.70 70.5 1.2 70.0 1.6 52.3 41.2 70.5 1.2 134.909LA14-67 313 5595 2.3 20.2469 2.2 0.1999 2.5 0.0294 1.2 0.47 186.5 2.2 185.0 4.3 166.4 52.4 186.5 2.2 112.109LA14-68 404 3309 4.1 21.4391 4.1 0.0827 4.2 0.0129 0.6 0.14 82.4 0.5 80.7 3.3 31.0 99.4 82.4 0.5 265.809LA14-69 918 6654 8.2 21.0952 2.4 0.0838 2.5 0.0128 0.8 0.32 82.1 0.7 81.7 2.0 69.6 57.4 82.1 0.7 118.009LA14-70 516 4593 2.3 22.0855 5.2 0.0646 5.2 0.0103 0.7 0.13 66.4 0.4 63.6 3.2 -40.6 125.6 66.4 0.4 -163.409LA14-71 210 1680 1.7 24.4722 14.2 0.0522 14.4 0.0093 2.2 0.15 59.4 1.3 51.6 7.3 -296.1 365.0 59.4 1.3 -20.109LA14-72 760 6726 4.3 20.9435 2.3 0.0835 2.4 0.0127 0.5 0.21 81.3 0.4 81.5 1.9 86.8 55.4 81.3 0.4 93.609LA14-73 312 2430 3.7 23.9773 12.2 0.0527 12.4 0.0092 2.2 0.18 58.8 1.3 52.1 6.3 -244.2 309.0 58.8 1.3 -24.109LA14-74 398 3327 1.9 21.9068 4.4 0.0709 4.5 0.0113 1.0 0.22 72.2 0.7 69.5 3.0 -20.9 107.0 72.2 0.7 -345.209LA14-75 446 19377 2.9 18.6786 1.7 0.4212 2.8 0.0571 2.2 0.79 357.7 7.6 356.9 8.3 351.6 38.7 357.7 7.6 101.709LA14-76 95 2139 1.3 21.1275 6.3 0.1855 6.4 0.0284 1.0 0.16 180.7 1.9 172.8 10.1 66.0 149.7 180.7 1.9 273.909LA14-77 612 4950 3.6 21.5830 3.9 0.0656 5.2 0.0103 3.5 0.66 65.9 2.3 64.5 3.3 15.0 93.9 65.9 2.3 439.209LA14-78 326 3330 4.7 22.2287 6.6 0.0727 6.6 0.0117 0.6 0.10 75.2 0.5 71.3 4.6 -56.3 160.7 75.2 0.5 -133.409LA14-79 1318 8883 3.7 18.9576 5.8 0.0704 7.8 0.0097 5.2 0.67 62.1 3.2 69.1 5.2 318.0 131.5 62.1 3.2 19.509LA14-80 876 6132 4.0 20.5371 4.2 0.0803 4.9 0.0120 2.5 0.52 76.7 1.9 78.4 3.7 133.1 98.0 76.7 1.9 57.609LA14-81 448 3996 4.0 21.9353 5.0 0.0596 5.2 0.0095 1.5 0.28 60.8 0.9 58.7 3.0 -24.1 120.2 60.8 0.9 -252.609LA14-82 359 2010 4.4 23.1781 10.8 0.0551 10.8 0.0093 1.0 0.09 59.4 0.6 54.5 5.7 -159.3 268.0 59.4 0.6 -37.309LA14-83 220 9831 2.7 19.0405 3.0 0.3862 3.2 0.0533 1.3 0.39 335.0 4.1 331.6 9.1 308.1 67.5 335.0 4.1 108.709LA14-84 270 1779 3.5 23.7435 11.6 0.0515 11.7 0.0089 1.5 0.13 56.9 0.9 51.0 5.8 -219.5 291.6 56.9 0.9 -25.909LA14-85 376 2781 3.0 20.2807 17.6 0.0584 18.5 0.0086 5.6 0.30 55.1 3.1 57.6 10.3 162.5 414.4 55.1 3.1 33.909LA14-86 1119 8838 11.1 21.6546 2.4 0.0603 3.4 0.0095 2.4 0.71 60.7 1.5 59.4 1.9 7.0 56.6 60.7 1.5 866.909LA14-87 333 2736 3.0 22.8283 7.6 0.0587 7.7 0.0097 1.5 0.19 62.4 0.9 58.0 4.4 -121.6 187.9 62.4 0.9 -51.309LA14-88 586 3771 4.0 21.7219 3.5 0.0594 4.3 0.0094 2.5 0.57 60.0 1.5 58.6 2.5 -0.4 85.2 60.0 1.5 -13543.309LA14-89 368 2283 4.2 21.7162 4.0 0.0748 4.1 0.0118 1.1 0.26 75.5 0.8 73.2 2.9 0.2 96.2 75.5 0.8 43678.309LA14-90 297 8544 3.3 20.4286 2.6 0.1998 3.0 0.0296 1.5 0.50 188.1 2.7 185.0 5.0 145.5 60.7 188.1 2.7 129.309LA14-91 1340 11454 5.6 21.2802 2.0 0.0681 2.1 0.0105 0.6 0.29 67.4 0.4 66.8 1.4 48.8 47.8 67.4 0.4 138.009LA14-92 285 6477 2.0 20.9171 3.9 0.1845 4.1 0.0280 1.4 0.34 177.9 2.5 171.9 6.6 89.8 92.3 177.9 2.5 198.109LA14-93 553 4311 2.1 21.6981 3.2 0.0647 3.5 0.0102 1.6 0.44 65.3 1.0 63.7 2.2 2.2 76.6 65.3 1.0 3015.309LA14-94 736 8823 13.9 21.0035 1.9 0.0872 2.0 0.0133 0.8 0.39 85.0 0.7 84.8 1.6 80.0 44.0 85.0 0.7 106.309LA14-95 904 5241 2.4 20.9916 8.8 0.0738 8.9 0.0112 1.0 0.11 72.0 0.7 72.3 6.2 81.3 210.1 72.0 0.7 88.509LA14-96 475 8226 3.3 19.9686 1.6 0.2040 1.7 0.0295 0.5 0.30 187.7 0.9 188.5 2.9 198.7 37.2 187.7 0.9 94.509LA14-97 239 4851 3.5 20.6258 3.0 0.1919 3.0 0.0287 0.5 0.17 182.5 0.9 178.3 4.9 122.9 69.6 182.5 0.9 148.509LA14-98 2159 30900 5.6 18.6561 2.5 0.2585 5.7 0.0350 5.1 0.90 221.6 11.1 233.5 11.8 354.4 56.3 221.6 11.1 62.509LA14-99 472 2229 3.3 23.0339 10.9 0.0635 11.2 0.0106 2.5 0.22 68.1 1.7 62.6 6.8 -143.8 270.8 68.1 1.7 -47.3

59

Sample 09NE12, Upper Porcellainite Beach Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.7564, W133.86438

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09NE12-1 154 1617 3.7 25.6470 24.4 0.0465 24.5 0.0087 1.7 0.07 55.5 0.9 46.2 11.1 -417.4 647.8 55.5 0.9 -13.309NE12-2 278 2553 2.1 21.8761 5.9 0.0633 6.1 0.0100 1.2 0.19 64.4 0.8 62.3 3.7 -17.5 143.9 64.4 0.8 -367.609NE12-3 1998 53253 8.9 19.4372 2.7 0.1786 3.1 0.0252 1.4 0.47 160.3 2.3 166.9 4.7 260.9 62.0 160.3 2.3 61.409NE12-4 715 3399 2.1 18.8791 5.4 0.0662 5.4 0.0091 0.8 0.14 58.2 0.5 65.1 3.4 327.4 121.8 58.2 0.5 17.809NE12-5 463 870 1.5 21.9810 13.2 0.0245 13.3 0.0039 1.4 0.11 25.1 0.4 24.6 3.2 -29.1 321.5 25.1 0.4 -86.409NE12-6 270 1236 2.4 25.3606 21.9 0.0205 22.1 0.0038 2.6 0.12 24.3 0.6 20.6 4.5 -388.1 575.9 24.3 0.6 -6.209NE12-7 178 474 4.0 24.8202 23.3 0.0209 23.3 0.0038 1.6 0.07 24.2 0.4 21.0 4.9 -332.3 605.9 24.2 0.4 -7.309NE12-8 1177 3420 1.2 22.4254 5.3 0.0241 5.4 0.0039 0.5 0.09 25.2 0.1 24.2 1.3 -77.9 130.6 25.2 0.1 -32.409NE12-9 99 2034 3.5 20.4498 7.9 0.1254 8.0 0.0186 1.0 0.13 118.8 1.2 119.9 9.0 143.0 185.5 118.8 1.2 83.009NE12-10 150 615 3.6 26.5803 62.8 0.0202 62.9 0.0039 3.6 0.06 25.0 0.9 20.3 12.6 -511.8 1845.5 25.0 0.9 -4.909NE12-11 1653 5271 2.1 22.0834 4.0 0.0248 4.1 0.0040 0.7 0.18 25.5 0.2 24.9 1.0 -40.4 97.8 25.5 0.2 -63.209NE12-12 382 1263 1.7 24.3603 14.4 0.0225 14.4 0.0040 1.0 0.07 25.6 0.3 22.6 3.2 -284.5 367.4 25.6 0.3 -9.009NE12-14 232 855 2.8 29.2731 29.2 0.0187 29.2 0.0040 0.7 0.03 25.6 0.2 18.8 5.4 -776.6 837.4 25.6 0.2 -3.309NE12-15 145 627 2.7 27.6785 25.0 0.0201 25.1 0.0040 1.7 0.07 26.0 0.4 20.3 5.0 -621.1 692.0 26.0 0.4 -4.209NE12-16 175 1770 3.1 26.3242 21.3 0.0450 21.5 0.0086 2.6 0.12 55.2 1.4 44.7 9.4 -486.1 571.3 55.2 1.4 -11.309NE12-17 955 2670 3.2 22.7602 13.2 0.0240 13.2 0.0040 1.0 0.08 25.5 0.3 24.1 3.2 -114.2 326.3 25.5 0.3 -22.309NE12-18 150 684 3.6 34.9271 58.9 0.0151 59.0 0.0038 2.5 0.04 24.6 0.6 15.2 8.9 -1304.8 2021.9 24.6 0.6 -1.909NE12-19 454 4671 2.7 21.4889 6.0 0.0565 6.1 0.0088 1.1 0.19 56.6 0.6 55.9 3.3 25.5 143.5 56.6 0.6 222.209NE12-20 332 960 2.3 24.2981 18.7 0.0226 18.7 0.0040 0.9 0.05 25.6 0.2 22.7 4.2 -277.9 478.4 25.6 0.2 -9.209NE12-23 256 2514 2.5 23.0548 8.9 0.0560 9.0 0.0094 0.5 0.06 60.1 0.3 55.3 4.8 -146.0 222.2 60.1 0.3 -41.209NE12-22 213 927 7.1 26.8578 79.9 0.0196 79.9 0.0038 2.1 0.03 24.6 0.5 19.7 15.6 -539.6 2592.8 24.6 0.5 -4.609NE12-24 745 40371 2.1 18.4735 2.9 0.4341 3.1 0.0582 1.2 0.40 364.4 4.4 366.1 9.6 376.5 64.1 364.4 4.4 96.809NE12-25 1060 2529 1.2 21.3137 8.1 0.0261 8.1 0.0040 0.7 0.09 25.9 0.2 26.1 2.1 45.0 194.0 25.9 0.2 57.509NE12-26 1425 3261 1.6 22.2748 4.5 0.0236 4.6 0.0038 1.0 0.21 24.5 0.2 23.7 1.1 -61.4 108.6 24.5 0.2 -39.909NE12-27 1699 4182 4.7 21.2025 3.1 0.0258 3.2 0.0040 0.6 0.18 25.5 0.1 25.8 0.8 57.5 74.2 25.5 0.1 44.309NE12-28 327 1311 3.8 22.9096 14.6 0.0231 14.9 0.0038 3.3 0.22 24.7 0.8 23.2 3.4 -130.4 361.5 24.7 0.8 -18.909NE12-29 267 4734 3.6 22.3586 7.0 0.0854 7.0 0.0138 0.7 0.10 88.7 0.6 83.2 5.6 -70.6 171.1 88.7 0.6 -125.609NE12-30 1512 2637 1.5 21.6900 5.1 0.0246 5.2 0.0039 0.7 0.13 24.9 0.2 24.7 1.3 3.1 124.1 24.9 0.2 807.809NE12-31 31 2388 2.8 19.8452 10.7 0.4762 10.7 0.0685 0.5 0.05 427.3 2.2 395.5 35.2 213.0 249.1 427.3 2.2 200.609NE12-32 712 1944 6.5 18.6074 8.2 0.0293 8.3 0.0040 1.1 0.14 25.4 0.3 29.3 2.4 360.2 185.1 25.4 0.3 7.109NE12-33 638 1887 2.5 21.3425 10.1 0.0255 10.1 0.0040 1.0 0.09 25.4 0.2 25.6 2.6 41.8 241.8 25.4 0.2 60.809NE12-34 300 834 2.5 22.9096 15.0 0.0234 15.0 0.0039 1.4 0.09 25.1 0.4 23.5 3.5 -130.4 371.7 25.1 0.4 -19.209NE12-35 159 582 3.1 24.2794 51.2 0.0220 51.4 0.0039 4.0 0.08 24.9 1.0 22.1 11.2 -276.0 1385.0 24.9 1.0 -9.009NE12-36 368 12687 2.8 20.4071 3.2 0.1983 3.5 0.0294 1.5 0.41 186.5 2.7 183.7 6.0 147.9 75.7 186.5 2.7 126.109NE12-37 453 1707 2.9 24.7105 14.9 0.0214 14.9 0.0038 1.3 0.09 24.7 0.3 21.5 3.2 -320.9 383.3 24.7 0.3 -7.709NE12-38 344 8253 3.3 19.5901 7.1 0.2391 7.3 0.0340 1.8 0.25 215.3 3.9 217.7 14.4 242.9 164.1 215.3 3.9 88.709NE12-39 458 1176 3.7 18.8890 16.8 0.0283 16.9 0.0039 1.9 0.11 24.9 0.5 28.3 4.7 326.2 383.2 24.9 0.5 7.609NE12-40 126 666 3.2 27.4275 24.9 0.0191 25.1 0.0038 2.5 0.10 24.5 0.6 19.2 4.8 -596.3 686.1 24.5 0.6 -4.109NE12-41 166 519 2.7 30.6892 34.1 0.0164 34.3 0.0037 3.4 0.10 23.5 0.8 16.5 5.6 -911.9 1015.1 23.5 0.8 -2.609NE12-42 247 4980 2.3 21.0133 3.7 0.1312 3.8 0.0200 0.6 0.15 127.6 0.7 125.1 4.4 78.9 88.4 127.6 0.7 161.809NE12-43 227 816 1.6 11.9930 20.9 0.1086 20.9 0.0094 0.8 0.04 60.6 0.5 104.7 20.8 1278.2 412.2 60.6 0.5 4.709NE12-44 2078 5874 3.3 21.7943 3.3 0.0249 3.4 0.0039 0.8 0.24 25.3 0.2 25.0 0.8 -8.5 79.4 25.3 0.2 -299.009NE12-45 212 2130 2.2 24.2575 13.9 0.0489 14.0 0.0086 1.5 0.11 55.2 0.8 48.5 6.6 -273.7 354.7 55.2 0.8 -20.209NE12-46 756 1956 8.4 19.0717 9.9 0.0295 9.9 0.0041 1.0 0.10 26.3 0.3 29.5 2.9 304.3 225.5 26.3 0.3 8.609NE12-47 988 2979 1.3 22.4915 5.3 0.0247 5.3 0.0040 0.6 0.12 25.9 0.2 24.8 1.3 -85.1 128.8 25.9 0.2 -30.509NE12-48 352 1386 1.9 24.4141 13.0 0.0227 13.0 0.0040 0.5 0.04 25.9 0.1 22.8 2.9 -290.1 333.3 25.9 0.1 -8.909NE12-49 70 4770 3.9 18.7002 5.3 0.5085 5.3 0.0690 0.7 0.13 430.0 2.8 417.5 18.1 349.0 118.9 430.0 2.8 123.209NE12-50 303 372 3.0 37.5449 44.9 0.0143 45.0 0.0039 2.5 0.06 25.1 0.6 14.4 6.5 -1540.7 1571.9 25.1 0.6 -1.609NE12-51 257 693 1.9 22.2074 20.9 0.0231 21.4 0.0037 4.7 0.22 24.0 1.1 23.2 4.9 -54.0 513.6 24.0 1.1 -44.409NE12-52 381 1308 2.2 24.4175 13.0 0.0226 13.2 0.0040 2.7 0.20 25.8 0.7 22.7 3.0 -290.4 332.1 25.8 0.7 -8.909NE12-53 261 867 2.5 28.3965 26.2 0.0185 26.4 0.0038 3.0 0.11 24.6 0.7 18.7 4.9 -691.6 737.2 24.6 0.7 -3.609NE12-55 444 3078 1.5 22.4771 6.9 0.0530 7.2 0.0086 2.1 0.29 55.4 1.2 52.4 3.7 -83.5 169.1 55.4 1.2 -66.409NE12-56 506 5610 4.6 20.9997 4.8 0.0971 4.8 0.0148 0.5 0.10 94.6 0.5 94.1 4.4 80.4 114.5 94.6 0.5 117.709NE12-58 329 1044 1.0 27.5416 23.2 0.0196 23.4 0.0039 3.0 0.13 25.2 0.8 19.7 4.6 -607.6 639.2 25.2 0.8 -4.109NE12-60 470 1266 1.6 23.8150 11.5 0.0233 11.6 0.0040 0.6 0.05 25.9 0.1 23.4 2.7 -227.1 291.4 25.9 0.1 -11.409NE12-61 349 546 2.0 13.7996 11.9 0.0414 12.4 0.0041 3.5 0.28 26.7 0.9 41.2 5.0 999.0 241.9 26.7 0.9 2.709NE12-62 1339 4098 3.0 22.2494 4.4 0.0260 4.5 0.0042 0.7 0.15 27.0 0.2 26.1 1.1 -58.6 107.6 27.0 0.2 -46.009NE12-64 916 2169 1.1 22.0742 4.7 0.0247 4.8 0.0039 0.9 0.18 25.4 0.2 24.7 1.2 -39.4 115.2 25.4 0.2 -64.509NE12-65 154 654 3.4 35.6489 43.6 0.0145 43.7 0.0038 2.4 0.06 24.1 0.6 14.6 6.3 -1370.2 1461.7 24.1 0.6 -1.809NE12-66 615 9765 5.5 21.1580 1.5 0.0942 2.1 0.0145 1.5 0.70 92.6 1.3 91.4 1.8 62.5 35.4 92.6 1.3 148.009NE12-67 494 1431 2.6 23.7277 10.1 0.0234 10.2 0.0040 1.6 0.16 25.9 0.4 23.5 2.4 -217.8 254.7 25.9 0.4 -11.909NE12-68 761 2385 1.4 22.9462 7.5 0.0228 7.6 0.0038 1.3 0.17 24.4 0.3 22.9 1.7 -134.3 186.8 24.4 0.3 -18.209NE12-69 448 1245 2.3 23.7463 10.7 0.0223 10.8 0.0038 1.6 0.15 24.7 0.4 22.4 2.4 -219.8 270.2 24.7 0.4 -11.209NE12-70 461 6363 6.6 21.5600 4.7 0.0931 4.9 0.0146 1.4 0.29 93.2 1.3 90.4 4.3 17.5 113.3 93.2 1.3 532.309NE12-71 247 825 2.6 26.5640 20.5 0.0190 20.8 0.0037 3.2 0.15 23.5 0.8 19.1 3.9 -510.2 552.0 23.5 0.8 -4.609NE12-72 1774 3582 3.0 22.4439 4.4 0.0245 4.5 0.0040 0.9 0.21 25.6 0.2 24.5 1.1 -79.9 108.8 25.6 0.2 -32.109NE12-73 437 2988 1.5 22.4238 5.6 0.0438 6.2 0.0071 2.7 0.43 45.7 1.2 43.5 2.6 -77.7 137.3 45.7 1.2 -58.909NE12-74 190 624 2.4 27.8317 25.6 0.0199 25.6 0.0040 1.0 0.04 25.9 0.3 20.0 5.1 -636.2 710.1 25.9 0.3 -4.109NE12-75 139 543 3.5 36.9455 49.9 0.0142 50.0 0.0038 2.8 0.06 24.4 0.7 14.3 7.1 -1487.0 1742.9 24.4 0.7 -1.609NE12-76 3429 37605 1.7 19.8919 1.7 0.1748 1.9 0.0252 0.8 0.40 160.5 1.2 163.5 2.9 207.6 40.5 160.5 1.2 77.309NE12-77 215 702 2.3 26.8246 20.9 0.0215 21.1 0.0042 2.6 0.12 26.9 0.7 21.6 4.5 -536.3 565.5 26.9 0.7 -5.009NE12-78 679 1590 1.4 22.3251 6.2 0.0249 6.6 0.0040 2.2 0.34 25.9 0.6 25.0 1.6 -66.9 150.8 25.9 0.6 -38.809NE12-79 520 1623 2.8 23.6149 10.1 0.0234 10.1 0.0040 1.2 0.12 25.8 0.3 23.5 2.4 -205.9 253.0 25.8 0.3 -12.509NE12-80 144 432 2.6 31.4366 33.5 0.0182 33.6 0.0041 1.8 0.05 26.7 0.5 18.3 6.1 -982.4 1012.9 26.7 0.5 -2.709NE12-81 879 40827 1.6 18.3719 1.0 0.4363 1.3 0.0581 0.8 0.62 364.2 2.8 367.6 4.0 388.9 22.9 364.2 2.8 93.709NE12-82 257 909 2.2 24.8207 15.7 0.0229 15.8 0.0041 1.1 0.07 26.6 0.3 23.0 3.6 -332.4 406.5 26.6 0.3 -8.009NE12-83 803 1362 1.2 22.9163 7.0 0.0246 7.1 0.0041 1.4 0.20 26.3 0.4 24.7 1.7 -131.1 172.0 26.3 0.4 -20.109NE12-84 156 1620 1.4 24.3336 15.7 0.0706 15.8 0.0125 1.7 0.11 79.8 1.3 69.2 10.6 -281.7 403.1 79.8 1.3 -28.309NE12-86 1863 12015 12.2 21.0350 3.0 0.0580 3.4 0.0088 1.6 0.48 56.7 0.9 57.2 1.9 76.4 71.1 56.7 0.9 74.309NE12-87 553 1164 3.2 18.1509 19.0 0.0299 19.1 0.0039 2.1 0.11 25.3 0.5 29.9 5.6 416.0 427.3 25.3 0.5 6.109NE12-88 709 12672 1.5 20.8716 1.8 0.1299 3.9 0.0197 3.5 0.89 125.5 4.3 124.0 4.6 94.9 42.1 125.5 4.3 132.309NE12-89 286 837 3.6 26.5872 28.9 0.0207 29.0 0.0040 3.1 0.11 25.7 0.8 20.8 6.0 -512.5 783.9 25.7 0.8 -5.009NE12-90 494 1323 2.1 20.0845 14.8 0.0276 14.8 0.0040 1.3 0.08 25.9 0.3 27.6 4.0 185.2 345.1 25.9 0.3 14.009NE12-91 1092 1869 1.3 22.4896 6.3 0.0246 6.3 0.0040 1.1 0.17 25.8 0.3 24.6 1.5 -84.9 153.4 25.8 0.3 -30.409NE12-92 715 4770 1.9 21.8743 3.9 0.0537 4.0 0.0085 0.6 0.15 54.7 0.3 53.1 2.1 -17.3 95.2 54.7 0.3 -315.609NE12-93 575 8565 5.5 21.1377 3.2 0.0943 3.3 0.0145 0.5 0.15 92.5 0.5 91.5 2.9 64.9 77.1 92.5 0.5 142.709NE12-96 63 26541 1.0 5.4363 2.2 13.3289 2.4 0.5255 0.9 0.37 2722.6 19.8 2703.2 22.8 2688.8 37.0 2688.8 37.0 101.309NE12-97 1114 14004 6.5 21.1418 2.0 0.0915 2.0 0.0140 0.5 0.25 89.8 0.4 88.9 1.7 64.4 47.0 89.8 0.4 139.509NE12-98 382 3486 2.3 22.4356 7.5 0.0546 7.5 0.0089 0.9 0.12 57.0 0.5 54.0 4.0 -79.0 183.4 57.0 0.5 -72.209NE12-99 494 1152 2.1 24.7134 13.8 0.0224 13.8 0.0040 1.0 0.08 25.8 0.3 22.4 3.1 -321.2 355.3 25.8 0.3 -8.009NE12-100 73 37296 1.9 4.6690 1.3 16.9950 1.4 0.5755 0.5 0.37 2930.4 11.8 2934.6 13.1 2937.4 20.5 2937.4 20.5 99.809NE12-101 219 2109 2.4 22.5863 16.6 0.0543 16.6 0.0089 0.9 0.05 57.1 0.5 53.7 8.7 -95.4 409.0 57.1 0.5 -59.909NE12-102 651 5415 3.6 21.8014 3.7 0.0566 3.9 0.0089 1.0 0.27 57.4 0.6 55.9 2.1 -9.3 90.4 57.4 0.6 -619.609NE12-103 333 9126 3.4 18.9168 5.1 0.2131 5.8 0.0292 2.8 0.48 185.8 5.1 196.2 10.4 322.9 116.4 185.8 5.1 57.509LA01-96 2467 21651 4.3 21.1057 2.7 0.0628 2.8 0.0096 0.7 0.26 61.7 0.4 61.9 1.7 68.4 64.4 61.7 0.4 90.209LA01-97 31 312 126.9 36.7759 48.8 0.0356 48.9 0.0095 2.7 0.06 60.9 1.6 35.5 17.1 -1471.8 1694.2 60.9 1.6 -4.109LA01-98 471 4080 2.8 21.5668 9.3 0.0572 9.5 0.0089 1.5 0.16 57.4 0.9 56.5 5.2 16.8 225.0 57.4 0.9 342.609LA01-99 874 8928 5.8 21.1664 2.2 0.0661 4.1 0.0102 3.5 0.85 65.1 2.2 65.0 2.6 61.6 51.7 65.1 2.2 105.709LA01-100 378 9729 5.6 19.6378 4.9 0.1841 5.1 0.0262 1.5 0.29 166.8 2.5 171.5 8.1 237.3 112.5 166.8 2.5 70.3

60

Sample 09NE14, Lower Porcellainite Beach Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.7866, W133.87573

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09NE14-1 269 2124 3.6 17.8771 12.6 0.0714 12.6 0.0093 1.4 0.11 59.4 0.8 70.1 8.6 449.9 280.0 59.4 0.8 13.209NE14-2 455 2319 2.6 18.1724 9.9 0.0729 9.9 0.0096 0.5 0.05 61.6 0.3 71.4 6.8 413.4 221.7 61.6 0.3 14.909NE14-3 160 1230 2.5 21.5194 18.9 0.0664 18.9 0.0104 1.3 0.07 66.5 0.9 65.3 12.0 22.1 456.1 66.5 0.9 301.409NE14-4 739 5658 2.3 19.8546 10.0 0.0694 10.1 0.0100 0.5 0.05 64.1 0.3 68.1 6.6 211.9 233.1 64.1 0.3 30.309NE14-5 2423 5511 1.9 19.3002 3.7 0.0919 3.8 0.0129 0.7 0.18 82.4 0.6 89.2 3.2 277.2 84.5 82.4 0.6 29.709NE14-7 432 4869 2.5 21.8443 5.0 0.0864 5.1 0.0137 0.9 0.18 87.6 0.8 84.1 4.1 -14.0 120.8 87.6 0.8 -625.709NE14-6 231 1743 2.2 21.0703 10.6 0.0660 10.6 0.0101 0.9 0.09 64.7 0.6 64.9 6.7 72.4 252.9 64.7 0.6 89.309NE14-8 255 1386 1.9 24.3245 14.3 0.0361 14.3 0.0064 0.9 0.06 40.9 0.4 36.0 5.1 -280.7 365.5 40.9 0.4 -14.609NE14-9 223 651 3.1 18.5884 13.1 0.0343 13.2 0.0046 1.4 0.11 29.7 0.4 34.2 4.4 362.5 297.3 29.7 0.4 8.209NE14-10 181 1785 2.0 20.2333 8.9 0.0729 8.9 0.0107 1.1 0.12 68.5 0.7 71.4 6.2 167.9 207.5 68.5 0.7 40.809NE14-11 379 1695 1.3 18.0321 12.8 0.0796 12.8 0.0104 0.7 0.05 66.7 0.5 77.7 9.6 430.7 285.5 66.7 0.5 15.509NE14-12 131 1836 2.6 20.7110 8.9 0.1273 9.0 0.0191 1.7 0.19 122.1 2.0 121.7 10.3 113.2 209.2 122.1 2.0 107.909NE14-13 929 6876 2.9 20.7328 3.9 0.0731 4.0 0.0110 1.2 0.29 70.4 0.8 71.6 2.8 110.7 91.2 70.4 0.8 63.609NE14-14 93 636 3.5 18.4439 35.8 0.0649 35.9 0.0087 1.7 0.05 55.7 1.0 63.9 22.2 380.1 830.2 55.7 1.0 14.709NE14-15 384 1641 2.0 17.2936 19.1 0.0721 19.5 0.0090 4.1 0.21 58.0 2.3 70.7 13.3 523.1 422.0 58.0 2.3 11.109NE14-16 47 1365 2.2 23.2743 15.2 0.1660 15.3 0.0280 1.8 0.12 178.1 3.2 155.9 22.1 -169.6 379.6 178.1 3.2 -105.009NE14-17 819 6246 0.8 21.6406 3.3 0.0674 4.0 0.0106 2.2 0.55 67.8 1.5 66.2 2.5 8.6 79.5 67.8 1.5 790.309NE14-18 499 3483 3.7 21.5337 4.4 0.0761 5.1 0.0119 2.5 0.50 76.1 1.9 74.4 3.6 20.5 105.3 76.1 1.9 371.809NE14-19 969 16116 4.0 19.7541 2.0 0.1883 2.1 0.0270 0.5 0.24 171.6 0.8 175.2 3.3 223.7 46.1 171.6 0.8 76.709NE14-20 106 2283 5.4 22.0464 9.8 0.1470 9.8 0.0235 0.7 0.07 149.8 1.0 139.3 12.8 -36.3 238.0 149.8 1.0 -412.509NE14-21 116 576 1.3 18.2718 20.0 0.0819 20.0 0.0109 0.9 0.04 69.6 0.6 80.0 15.4 401.2 451.7 69.6 0.6 17.409NE14-22 157 978 2.7 18.4494 11.8 0.0839 11.8 0.0112 0.8 0.06 72.0 0.5 81.8 9.3 379.4 266.6 72.0 0.5 19.009NE14-23 375 4245 2.2 17.6019 6.7 0.2338 6.7 0.0298 0.7 0.10 189.6 1.3 213.3 12.9 484.3 147.6 189.6 1.3 39.109NE14-24 288 786 2.5 16.1957 9.7 0.0759 9.8 0.0089 1.8 0.18 57.2 1.0 74.3 7.0 665.3 207.4 57.2 1.0 8.609NE14-25 751 7281 1.8 20.4456 1.9 0.1261 2.0 0.0187 0.7 0.32 119.4 0.8 120.6 2.3 143.6 44.4 119.4 0.8 83.209NE14-26 142 1038 2.3 18.0185 10.2 0.0768 10.5 0.0100 2.5 0.24 64.3 1.6 75.1 7.6 432.3 227.5 64.3 1.6 14.909NE14-27 196 1527 2.4 24.4853 18.7 0.0579 18.7 0.0103 1.0 0.05 65.9 0.7 57.1 10.4 -297.5 481.4 65.9 0.7 -22.109NE14-28 371 7614 2.8 21.5483 4.4 0.1130 5.1 0.0177 2.6 0.52 112.8 3.0 108.7 5.3 18.9 105.5 112.8 3.0 598.209NE14-29 541 6051 4.6 20.4940 2.5 0.0981 2.6 0.0146 0.7 0.25 93.3 0.6 95.0 2.4 138.0 59.7 93.3 0.6 67.609NE14-30 316 1611 2.6 17.1317 11.3 0.0793 11.6 0.0099 2.9 0.25 63.2 1.8 77.5 8.7 543.7 246.7 63.2 1.8 11.609NE14-31 70 612 3.8 25.3411 124.0 0.0463 124.1 0.0085 4.8 0.04 54.6 2.6 46.0 55.9 -386.1 1618.5 54.6 2.6 -14.209NE14-32 185 1653 2.8 23.9042 13.7 0.0487 13.9 0.0084 2.2 0.16 54.2 1.2 48.3 6.6 -236.5 348.3 54.2 1.2 -22.909NE14-33 4031 24138 1.7 20.9513 1.8 0.0799 2.0 0.0121 1.0 0.47 77.8 0.7 78.0 1.5 85.9 42.7 77.8 0.7 90.509NE14-34 202 3624 1.0 19.2656 4.9 0.2047 5.0 0.0286 0.7 0.14 181.8 1.3 189.1 8.6 281.3 112.6 181.8 1.3 64.609NE14-35 426 2928 1.3 22.3361 7.1 0.0551 7.2 0.0089 0.8 0.11 57.3 0.4 54.5 3.8 -68.1 174.1 57.3 0.4 -84.109NE14-36 133 1659 1.7 26.0756 21.3 0.0552 21.4 0.0104 2.2 0.10 66.9 1.4 54.5 11.4 -460.9 567.3 66.9 1.4 -14.509NE14-37 869 2370 1.2 19.2518 19.9 0.0318 20.0 0.0044 1.0 0.05 28.6 0.3 31.8 6.3 282.9 460.0 28.6 0.3 10.109NE14-38 800 19476 3.7 20.1652 2.2 0.1948 2.3 0.0285 0.6 0.28 181.1 1.1 180.7 3.7 175.8 50.7 181.1 1.1 103.009NE14-39 601 4233 2.2 20.6482 4.9 0.0592 5.0 0.0089 1.2 0.23 56.9 0.7 58.4 2.8 120.3 114.6 56.9 0.7 47.209NE14-40 1436 9792 3.5 19.4428 10.5 0.1151 10.5 0.0162 1.2 0.11 103.8 1.2 110.6 11.0 260.3 241.1 103.8 1.2 39.909NE14-41 228 2286 2.7 22.3942 8.3 0.0781 8.3 0.0127 0.5 0.06 81.3 0.4 76.4 6.1 -74.4 202.4 81.3 0.4 -109.209NE14-42 296 1992 2.3 22.0847 7.9 0.0597 8.0 0.0096 1.3 0.16 61.3 0.8 58.8 4.6 -40.5 192.0 61.3 0.8 -151.309NE14-43 234 1977 3.3 22.8197 9.4 0.0661 9.5 0.0109 1.4 0.14 70.1 1.0 65.0 6.0 -120.7 232.8 70.1 1.0 -58.109NE14-44 259 1983 2.5 22.8148 11.6 0.0540 11.6 0.0089 0.9 0.08 57.3 0.5 53.4 6.1 -120.1 287.1 57.3 0.5 -47.709NE14-45 255 984 2.8 27.3190 23.8 0.0225 23.9 0.0045 2.3 0.10 28.7 0.7 22.6 5.3 -585.5 651.3 28.7 0.7 -4.909NE14-46 474 3660 3.0 22.1130 4.6 0.0583 4.7 0.0094 1.1 0.22 60.0 0.6 57.6 2.7 -43.6 112.6 60.0 0.6 -137.509NE14-47 87 432 1.4 11.9938 49.4 0.1207 49.8 0.0105 5.8 0.12 67.3 3.9 115.7 54.4 1278.0 1030.7 67.3 3.9 5.309NE14-48 126 1002 2.7 26.2829 20.4 0.0458 20.7 0.0087 3.7 0.18 56.1 2.1 45.5 9.2 -481.9 545.1 56.1 2.1 -11.609NE14-49 464 3447 3.1 19.2715 6.9 0.1086 7.4 0.0152 2.8 0.37 97.1 2.7 104.7 7.4 280.6 157.5 97.1 2.7 34.609NE14-50 456 21135 1.5 18.9543 2.0 0.4074 2.2 0.0560 0.8 0.37 351.2 2.8 347.0 6.4 318.4 46.2 351.2 2.8 110.309NE14-51 223 1809 1.6 22.8216 9.0 0.0502 9.1 0.0083 1.3 0.14 53.4 0.7 49.8 4.4 -120.9 221.6 53.4 0.7 -44.209NE14-52 238 1797 2.4 22.5652 9.7 0.0546 9.8 0.0089 0.7 0.07 57.4 0.4 54.0 5.1 -93.1 239.2 57.4 0.4 -61.609NE14-53 178 705 2.1 17.5637 12.0 0.0694 12.1 0.0088 1.6 0.13 56.7 0.9 68.1 8.0 489.0 265.6 56.7 0.9 11.609NE14-54 523 4830 2.2 21.0530 4.6 0.0668 4.8 0.0102 1.2 0.24 65.5 0.8 65.7 3.0 74.4 110.3 65.5 0.8 88.009NE14-56 407 3591 2.7 19.3642 6.1 0.1121 6.8 0.0158 2.8 0.42 100.7 2.8 107.9 6.9 269.6 140.7 100.7 2.8 37.409NE14-57 407 429 1.5 8.8192 12.2 0.0745 12.6 0.0048 3.2 0.25 30.6 1.0 73.0 8.9 1854.4 220.8 30.6 1.0 1.709NE14-58 108 1380 3.1 22.2055 16.4 0.1110 16.5 0.0179 1.3 0.08 114.2 1.5 106.9 16.7 -53.8 402.3 114.2 1.5 -212.309NE14-59 100 2520 3.5 22.0671 10.8 0.1708 10.8 0.0273 0.7 0.07 173.9 1.3 160.1 16.0 -38.6 261.9 173.9 1.3 -450.609NE14-60 897 2169 1.7 17.7027 7.8 0.0745 7.8 0.0096 1.0 0.12 61.4 0.6 73.0 5.5 471.6 172.2 61.4 0.6 13.009NE14-61 394 2748 1.9 21.0856 10.8 0.0580 11.6 0.0089 4.2 0.36 56.9 2.4 57.2 6.4 70.7 256.9 56.9 2.4 80.509NE14-62 483 10014 1.6 19.7309 3.1 0.2146 3.1 0.0307 0.5 0.16 195.0 1.0 197.4 5.6 226.4 70.8 195.0 1.0 86.109NE14-63 186 1320 2.2 19.1810 18.2 0.0669 18.2 0.0093 1.5 0.08 59.7 0.9 65.7 11.6 291.4 417.8 59.7 0.9 20.509NE14-64 1002 4752 14.1 20.2065 4.0 0.0693 4.2 0.0102 1.5 0.35 65.2 0.9 68.1 2.8 171.0 92.6 65.2 0.9 38.109NE14-65 698 4515 2.1 21.8206 3.8 0.0622 4.0 0.0099 1.1 0.28 63.2 0.7 61.3 2.4 -11.4 92.4 63.2 0.7 -554.809NE14-66 595 2952 2.1 19.9705 9.1 0.0803 9.2 0.0116 0.9 0.10 74.6 0.7 78.4 6.9 198.4 212.0 74.6 0.7 37.609NE14-67 387 1578 2.2 25.3564 16.0 0.0245 16.1 0.0045 1.2 0.07 29.0 0.3 24.6 3.9 -387.6 419.0 29.0 0.3 -7.509NE14-68 141 1545 1.2 25.0435 18.1 0.0616 18.1 0.0112 1.0 0.05 71.8 0.7 60.7 10.7 -355.4 471.1 71.8 0.7 -20.209NE14-69 1602 10632 4.1 21.2270 2.4 0.0644 2.5 0.0099 0.8 0.33 63.6 0.5 63.4 1.6 54.8 57.5 63.6 0.5 116.109NE14-70 699 1623 1.0 22.4642 7.0 0.0265 7.6 0.0043 2.9 0.38 27.8 0.8 26.6 2.0 -82.1 172.6 27.8 0.8 -33.909NE14-71 1644 2247 2.2 13.6247 26.2 0.1916 26.2 0.0189 1.0 0.04 120.9 1.2 178.0 42.8 1024.9 538.5 120.9 1.2 11.809NE14-72 139 1284 1.1 12.9684 39.4 0.2666 39.7 0.0251 4.7 0.12 159.7 7.5 240.0 85.0 1124.0 817.5 159.7 7.5 14.209NE14-73 878 2028 17.6 15.8822 6.9 0.1252 6.9 0.0144 0.6 0.08 92.3 0.5 119.8 7.8 707.0 147.1 92.3 0.5 13.109NE14-74 252 2130 1.6 20.2766 6.6 0.1277 6.7 0.0188 0.7 0.11 119.9 0.9 122.0 7.7 162.9 155.2 119.9 0.9 73.609NE14-75 359 2046 2.8 21.9851 7.3 0.0584 7.4 0.0093 1.3 0.17 59.7 0.8 57.6 4.1 -29.6 176.6 59.7 0.8 -202.009NE14-76 344 5925 2.1 19.0950 3.4 0.2114 3.5 0.0293 0.8 0.23 186.0 1.5 194.7 6.3 301.6 78.4 186.0 1.5 61.709NE14-77 367 6438 2.4 20.5327 2.2 0.1863 2.3 0.0277 0.5 0.22 176.4 0.9 173.5 3.6 133.6 52.0 176.4 0.9 132.109NE14-78 399 3618 1.9 21.8657 5.4 0.0673 5.4 0.0107 0.7 0.13 68.4 0.5 66.1 3.5 -16.4 130.2 68.4 0.5 -417.509NE14-79 480 3708 1.3 21.4034 6.4 0.0584 6.5 0.0091 1.3 0.20 58.2 0.8 57.6 3.7 35.0 153.6 58.2 0.8 166.009NE14-80 368 2958 2.6 22.8290 10.8 0.0547 10.9 0.0091 1.1 0.10 58.2 0.6 54.1 5.7 -121.7 267.3 58.2 0.6 -47.809NE14-81 1351 12318 1.7 21.4849 2.8 0.0758 2.8 0.0118 0.5 0.18 75.7 0.4 74.2 2.0 25.9 67.2 75.7 0.4 292.309NE14-82 216 1578 2.5 21.7975 21.8 0.0561 21.9 0.0089 2.1 0.10 56.9 1.2 55.4 11.8 -8.8 532.0 56.9 1.2 -644.809NE14-84 864 5496 1.7 21.0104 1.6 0.0717 2.6 0.0109 2.0 0.78 70.0 1.4 70.3 1.7 79.2 37.7 70.0 1.4 88.409NE14-85 335 2580 2.5 22.0397 5.5 0.0596 5.7 0.0095 1.7 0.30 61.1 1.0 58.7 3.3 -35.6 132.7 61.1 1.0 -171.709NE14-86 214 1581 1.7 23.7959 11.7 0.0504 12.2 0.0087 3.5 0.29 55.8 1.9 49.9 5.9 -225.1 294.8 55.8 1.9 -24.809NE14-87 249 4014 2.2 21.2609 4.0 0.1221 4.1 0.0188 1.0 0.24 120.2 1.2 116.9 4.6 51.0 95.9 120.2 1.2 235.809NE14-88 537 9606 1.5 21.0542 3.2 0.1204 3.6 0.0184 1.7 0.47 117.5 2.0 115.5 3.9 74.2 75.9 117.5 2.0 158.209NE14-89 131 2649 2.4 21.7345 7.8 0.1477 8.3 0.0233 3.0 0.36 148.4 4.4 139.9 10.9 -1.8 187.3 148.4 4.4 -8053.009NE14-90 402 3270 3.1 21.3668 8.4 0.0620 8.6 0.0096 1.4 0.17 61.7 0.9 61.1 5.1 39.1 202.3 61.7 0.9 157.609NE14-91 567 1872 1.4 18.1913 9.3 0.0682 9.3 0.0090 0.5 0.05 57.8 0.3 67.0 6.0 411.0 208.5 57.8 0.3 14.109NE14-92 327 2553 1.7 17.6913 12.5 0.1205 12.5 0.0155 1.0 0.08 98.9 1.0 115.5 13.7 473.1 277.0 98.9 1.0 20.909NE14-93 167 1665 2.3 25.0892 16.8 0.0471 17.0 0.0086 2.1 0.12 55.0 1.2 46.8 7.8 -360.1 438.3 55.0 1.2 -15.309NE14-94 207 2988 2.0 21.3574 10.4 0.1165 10.4 0.0180 1.1 0.11 115.3 1.3 111.9 11.0 40.2 248.7 115.3 1.3 286.709NE14-95 272 2019 2.0 21.8171 10.4 0.0608 10.4 0.0096 1.2 0.12 61.7 0.8 59.9 6.1 -11.0 250.9 61.7 0.8 -560.809NE14-96 349 11385 1.6 19.6075 1.2 0.2585 1.3 0.0368 0.6 0.42 232.7 1.3 233.4 2.7 240.9 27.2 232.7 1.3 96.609NE14-97 156 999 2.8 19.9401 29.9 0.0579 29.9 0.0084 2.2 0.07 53.8 1.2 57.2 16.6 202.0 707.0 53.8 1.2 26.609NE14-98 1670 11439 4.0 20.4575 3.7 0.0722 3.8 0.0107 0.6 0.16 68.7 0.4 70.8 2.6 142.1 87.9 68.7 0.4 48.309NE14-99 202 1740 2.0 22.2693 21.6 0.0572 21.7 0.0092 1.5 0.07 59.3 0.9 56.5 11.9 -60.8 532.8 59.3 0.9 -97.509NE14-100 449 3504 2.9 22.0061 8.0 0.0601 8.0 0.0096 0.5 0.06 61.6 0.3 59.3 4.6 -31.9 195.0 61.6 0.3 -193.109NE14-101 221 1899 2.3 19.1650 11.2 0.0663 11.3 0.0092 1.1 0.10 59.1 0.6 65.2 7.1 293.2 257.5 59.1 0.6 20.2

61

Sample 09LA10, Point Camden Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.80942, W133.86588

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09LA10-1 279 2169 2.3 21.5238 13.7 0.0666 13.8 0.0104 2.1 0.15 66.7 1.4 65.5 8.8 21.6 329.9 66.7 1.4 309.209LA10-2 399 2409 2.4 21.6165 8.1 0.0554 8.2 0.0087 1.2 0.15 55.8 0.7 54.8 4.4 11.3 195.4 55.8 0.7 495.709LA10-3 110 333 2.9 9.9911 33.2 0.1262 33.3 0.0091 1.9 0.06 58.7 1.1 120.6 37.9 1625.7 636.0 58.7 1.1 3.609LA10-4 501 2028 1.8 22.5410 7.8 0.0518 7.9 0.0085 1.2 0.15 54.4 0.6 51.3 3.9 -90.4 191.4 54.4 0.6 -60.109LA10-5 332 1794 2.9 22.4272 6.2 0.0548 6.3 0.0089 0.8 0.12 57.2 0.4 54.1 3.3 -78.0 153.0 57.2 0.4 -73.209LA10-6 327 2466 2.0 23.6213 10.6 0.0507 10.9 0.0087 2.6 0.24 55.8 1.4 50.2 5.3 -206.6 266.2 55.8 1.4 -27.009LA10-7 149 519 2.1 17.3679 12.0 0.0709 12.1 0.0089 1.2 0.10 57.3 0.7 69.5 8.1 513.7 264.5 57.3 0.7 11.209LA10-8 256 1581 3.4 23.1014 8.7 0.0536 8.7 0.0090 0.5 0.06 57.6 0.3 53.0 4.5 -151.0 215.6 57.6 0.3 -38.109LA10-9 626 4056 2.3 22.0010 5.0 0.0563 5.0 0.0090 0.5 0.10 57.7 0.3 55.6 2.7 -31.3 121.7 57.7 0.3 -184.109LA10-10 191 960 2.3 24.8345 16.0 0.0465 16.1 0.0084 2.3 0.14 53.7 1.2 46.1 7.3 -333.8 413.1 53.7 1.2 -16.109LA10-11 1320 10743 2.1 20.2979 8.2 0.0540 10.2 0.0079 6.1 0.60 51.0 3.1 53.4 5.3 160.5 192.1 51.0 3.1 31.809LA10-12 106 876 3.3 28.2432 28.0 0.0413 28.1 0.0085 1.4 0.05 54.4 0.8 41.1 11.3 -676.6 786.7 54.4 0.8 -8.009LA10-13 134 981 4.2 24.8810 16.7 0.0569 16.7 0.0103 1.1 0.07 65.9 0.7 56.2 9.2 -338.6 432.9 65.9 0.7 -19.509LA10-14 269 2220 2.7 23.1024 8.5 0.0521 8.5 0.0087 1.0 0.12 56.0 0.6 51.5 4.3 -151.1 210.9 56.0 0.6 -37.009LA10-15 303 2178 2.5 22.4566 7.6 0.0616 7.7 0.0100 1.2 0.16 64.3 0.8 60.7 4.5 -81.3 185.3 64.3 0.8 -79.209LA10-16 386 4143 2.6 21.8076 5.3 0.0938 5.5 0.0148 1.3 0.23 94.9 1.2 91.0 4.8 -9.9 128.8 94.9 1.2 -954.409LA10-17 1255 6492 3.2 21.3676 2.6 0.0633 2.7 0.0098 0.6 0.22 62.9 0.4 62.3 1.6 39.0 62.4 62.9 0.4 161.309LA10-18 466 2736 2.7 21.8284 5.0 0.0564 5.1 0.0089 0.9 0.18 57.3 0.5 55.7 2.7 -12.3 120.1 57.3 0.5 -467.909LA10-19 278 2136 2.5 23.7097 12.2 0.0529 12.4 0.0091 1.8 0.14 58.3 1.0 52.3 6.3 -215.9 308.4 58.3 1.0 -27.009LA10-20 174 1428 1.6 24.9683 17.4 0.0596 17.4 0.0108 1.0 0.06 69.2 0.7 58.8 9.9 -347.7 451.3 69.2 0.7 -19.909LA10-21 285 2838 3.1 23.0535 12.4 0.0620 12.5 0.0104 1.4 0.11 66.4 0.9 61.0 7.4 -145.9 308.6 66.4 0.9 -45.509LA10-22 225 1392 2.1 24.2619 13.4 0.0485 13.5 0.0085 1.7 0.13 54.8 0.9 48.1 6.3 -274.1 341.7 54.8 0.9 -20.009LA10-23 1805 16974 4.8 21.3907 1.4 0.0671 1.8 0.0104 1.2 0.64 66.8 0.8 66.0 1.2 36.4 33.5 66.8 0.8 183.509LA10-24 592 10260 2.0 20.1420 2.0 0.1947 2.0 0.0284 0.6 0.28 180.8 1.0 180.7 3.4 178.5 45.6 180.8 1.0 101.309LA10-25 682 13539 5.7 20.1252 4.1 0.1936 9.0 0.0283 8.0 0.89 179.7 14.1 179.7 14.8 180.4 95.4 179.7 14.1 99.609LA10-26 3709 14907 12.0 21.5488 2.5 0.0601 2.6 0.0094 0.6 0.23 60.3 0.4 59.3 1.5 18.8 60.8 60.3 0.4 320.709LA10-27 415 1638 1.5 22.3629 5.7 0.0558 5.8 0.0091 0.9 0.15 58.1 0.5 55.2 3.1 -71.0 140.2 58.1 0.5 -81.809LA10-28 218 2418 2.2 20.9448 3.9 0.1807 4.3 0.0275 1.8 0.41 174.6 3.0 168.7 6.6 86.7 92.4 174.6 3.0 201.509LA10-29 455 1428 2.6 22.3032 5.7 0.0590 5.7 0.0095 0.5 0.09 61.2 0.3 58.2 3.2 -64.5 139.4 61.2 0.3 -94.909LA10-30 332 3960 2.1 19.5847 3.6 0.2041 3.7 0.0290 0.6 0.17 184.2 1.1 188.6 6.3 243.6 83.6 184.2 1.1 75.609LA10-31 113 2616 2.7 20.7944 11.2 0.1684 11.2 0.0254 0.8 0.07 161.7 1.2 158.0 16.4 103.7 264.9 161.7 1.2 155.909LA10-32 565 2007 2.2 22.2583 5.3 0.0532 5.4 0.0086 1.0 0.19 55.1 0.6 52.6 2.8 -59.6 130.3 55.1 0.6 -92.509LA10-33 415 2211 3.2 22.3455 10.6 0.0568 10.6 0.0092 0.5 0.05 59.0 0.3 56.1 5.8 -69.1 258.5 59.0 0.3 -85.409LA10-34 453 1764 1.9 19.4390 10.0 0.0627 10.1 0.0088 1.5 0.15 56.8 0.9 61.8 6.1 260.8 230.0 56.8 0.9 21.809LA10-35 386 1443 3.0 17.1674 29.6 0.0803 29.6 0.0100 1.5 0.05 64.1 1.0 78.4 22.3 539.1 660.0 64.1 1.0 11.909LA10-36 327 2592 3.0 21.4978 15.6 0.0576 15.6 0.0090 1.4 0.09 57.6 0.8 56.9 8.6 24.5 375.3 57.6 0.8 235.709LA10-37 364 4428 4.1 22.3731 6.9 0.0627 7.1 0.0102 1.3 0.18 65.3 0.8 61.8 4.2 -72.1 170.0 65.3 0.8 -90.509LA10-38 759 7830 2.4 21.2376 4.9 0.0604 4.9 0.0093 0.5 0.10 59.6 0.3 59.5 2.8 53.6 115.8 59.6 0.3 111.209LA10-39 337 2388 2.9 18.2287 34.0 0.0705 34.4 0.0093 5.0 0.15 59.8 3.0 69.2 23.0 406.4 781.2 59.8 3.0 14.709LA10-40 739 8892 4.3 21.9870 8.0 0.0812 8.0 0.0130 0.5 0.06 83.0 0.4 79.3 6.1 -29.8 193.0 83.0 0.4 -278.709LA10-41 458 10935 2.2 20.2600 1.7 0.1936 2.0 0.0285 1.0 0.49 180.9 1.7 179.7 3.3 164.9 40.6 180.9 1.7 109.709LA10-42 2908 20184 2.8 21.6058 1.8 0.0545 2.4 0.0085 1.6 0.65 54.8 0.8 53.9 1.3 12.4 43.6 54.8 0.8 440.709LA10-43 292 2523 2.2 21.4546 3.3 0.0589 3.3 0.0092 0.7 0.22 58.8 0.4 58.1 1.9 29.3 78.3 58.8 0.4 201.009LA10-44 433 3090 1.3 22.2107 5.7 0.0522 5.7 0.0084 0.7 0.13 54.0 0.4 51.7 2.9 -54.4 137.8 54.0 0.4 -99.309LA10-45 937 24351 4.7 18.5023 2.3 0.2885 3.5 0.0387 2.6 0.74 244.9 6.2 257.4 7.9 373.0 52.5 244.9 6.2 65.709LA10-46 628 1134 1.0 15.9679 13.5 0.0731 14.2 0.0085 4.4 0.31 54.3 2.4 71.6 9.8 695.6 289.4 54.3 2.4 7.809LA10-47 259 1011 2.2 19.8490 13.4 0.0619 13.4 0.0089 0.6 0.05 57.2 0.4 61.0 7.9 212.6 311.6 57.2 0.4 26.909LA10-48 603 1431 1.7 15.1170 8.1 0.1405 8.2 0.0154 1.0 0.12 98.6 1.0 133.5 10.2 811.2 169.9 98.6 1.0 12.109LA10-49 744 3816 2.2 22.3080 5.2 0.0560 5.2 0.0091 0.5 0.10 58.2 0.3 55.4 2.8 -65.0 126.1 58.2 0.3 -89.509LA10-50 336 1788 2.1 21.9870 8.8 0.0723 9.0 0.0115 2.1 0.24 73.9 1.6 70.9 6.2 -29.8 212.6 73.9 1.6 -248.109LA10-51 237 1734 2.3 23.7205 12.3 0.0721 12.3 0.0124 0.5 0.04 79.4 0.4 70.6 8.4 -217.1 310.7 79.4 0.4 -36.609LA10-52 342 4635 2.3 21.6694 3.9 0.0969 3.9 0.0152 0.5 0.13 97.4 0.5 93.9 3.5 5.4 93.2 97.4 0.5 1819.309LA10-53 253 1365 3.5 18.4100 20.6 0.0636 20.6 0.0085 1.4 0.07 54.5 0.7 62.6 12.5 384.2 466.6 54.5 0.7 14.209LA10-54 828 2742 3.0 23.1093 8.2 0.0292 8.3 0.0049 0.6 0.07 31.5 0.2 29.2 2.4 -151.9 204.8 31.5 0.2 -20.709LA10-55 920 10674 2.6 21.0831 2.5 0.0771 2.5 0.0118 0.6 0.25 75.6 0.5 75.5 1.8 71.0 58.3 75.6 0.5 106.509LA10-56 241 2211 1.3 23.4375 11.3 0.0602 11.4 0.0102 1.1 0.10 65.6 0.7 59.4 6.5 -187.0 283.1 65.6 0.7 -35.109LA10-57 187 1557 5.1 24.0879 13.4 0.0495 13.8 0.0087 3.3 0.24 55.6 1.8 49.1 6.6 -255.9 339.9 55.6 1.8 -21.709LA10-58 279 1278 1.2 22.2392 5.3 0.0663 5.5 0.0107 1.3 0.24 68.5 0.9 65.2 3.4 -57.5 129.1 68.5 0.9 -119.209LA10-59 783 14262 1.4 20.1890 1.5 0.1762 1.7 0.0258 0.8 0.49 164.2 1.3 164.8 2.5 173.1 33.9 164.2 1.3 94.909LA10-60 116 513 3.7 26.5467 23.2 0.0398 23.4 0.0077 3.2 0.13 49.2 1.5 39.6 9.1 -508.4 625.7 49.2 1.5 -9.709LA10-61 320 7056 2.5 20.0919 3.2 0.1992 3.6 0.0290 1.6 0.43 184.5 2.8 184.4 6.1 184.3 75.3 184.5 2.8 100.109LA10-62 133 1218 3.0 26.8125 28.4 0.0458 28.5 0.0089 2.5 0.09 57.1 1.4 45.5 12.7 -535.1 773.2 57.1 1.4 -10.709LA10-63 499 4266 2.7 21.9013 5.1 0.0553 5.3 0.0088 1.5 0.28 56.4 0.8 54.7 2.8 -20.3 123.2 56.4 0.8 -277.709LA10-64 116 657 3.3 26.0375 20.8 0.0467 20.8 0.0088 1.3 0.06 56.7 0.7 46.4 9.4 -457.1 552.7 56.7 0.7 -12.409LA10-65 211 2043 2.3 23.5186 12.5 0.0590 12.7 0.0101 1.8 0.14 64.5 1.1 58.2 7.2 -195.6 314.9 64.5 1.1 -33.009LA10-66 1048 8283 3.7 22.0052 4.4 0.0641 4.4 0.0102 0.5 0.12 65.6 0.3 63.0 2.7 -31.8 105.8 65.6 0.3 -206.309LA10-67 220 2223 2.6 22.3810 6.8 0.0617 6.9 0.0100 1.0 0.14 64.3 0.6 60.8 4.0 -73.0 166.1 64.3 0.6 -88.009LA10-68 598 4386 3.1 21.5057 3.2 0.0593 3.3 0.0093 0.8 0.25 59.4 0.5 58.5 1.9 23.6 77.2 59.4 0.5 252.109LA10-69 1117 6825 7.3 21.4667 3.4 0.0584 3.6 0.0091 1.3 0.35 58.4 0.7 57.7 2.0 27.9 80.5 58.4 0.7 209.109LA10-70 345 2856 2.4 22.1032 6.1 0.0540 6.5 0.0086 2.4 0.36 55.5 1.3 53.4 3.4 -42.6 147.2 55.5 1.3 -130.409LA10-71 408 3240 1.8 22.2913 7.4 0.0670 7.4 0.0108 0.5 0.07 69.4 0.3 65.8 4.7 -63.2 180.9 69.4 0.3 -109.909LA10-72 338 1389 4.1 22.1266 5.9 0.0581 6.0 0.0093 1.2 0.20 59.8 0.7 57.3 3.4 -45.1 143.6 59.8 0.7 -132.509LA10-73 876 5040 1.3 21.7691 3.8 0.0678 3.8 0.0107 0.7 0.18 68.6 0.5 66.6 2.5 -5.7 90.7 68.6 0.5 -1209.109LA10-74 143 966 2.9 24.3999 16.9 0.0722 16.9 0.0128 0.8 0.05 81.8 0.7 70.8 11.6 -288.6 433.2 81.8 0.7 -28.409LA10-75 189 2340 2.3 20.4296 4.2 0.2145 4.2 0.0318 0.5 0.13 201.7 1.1 197.3 7.6 145.3 98.6 201.7 1.1 138.809LA10-76 281 2910 2.7 21.0351 4.4 0.1834 4.5 0.0280 0.9 0.21 177.8 1.6 170.9 7.0 76.4 104.0 177.8 1.6 232.809LA10-77 675 4851 7.7 21.8544 5.1 0.0662 5.2 0.0105 0.5 0.10 67.3 0.4 65.1 3.3 -15.1 124.5 67.3 0.4 -445.009LA10-78 117 387 3.2 37.1248 51.9 0.0217 51.9 0.0058 2.9 0.06 37.5 1.1 21.8 11.2 -1503.1 1826.0 37.5 1.1 -2.509LA10-79 291 2853 3.5 22.2299 7.0 0.0662 7.2 0.0107 1.8 0.24 68.4 1.2 65.1 4.6 -56.5 171.2 68.4 1.2 -121.209LA10-80 350 2379 2.0 21.8326 4.4 0.0669 4.4 0.0106 0.5 0.11 67.9 0.3 65.7 2.8 -12.7 106.5 67.9 0.3 -534.209LA10-81 326 2853 2.8 23.3194 9.9 0.0489 10.2 0.0083 2.3 0.22 53.1 1.2 48.5 4.8 -174.4 247.4 53.1 1.2 -30.509LA10-82 227 2010 2.9 20.6208 22.0 0.0713 22.0 0.0107 2.0 0.09 68.4 1.4 69.9 14.9 123.5 522.5 68.4 1.4 55.409LA10-83 264 2268 2.0 22.1317 5.8 0.0595 5.9 0.0096 0.7 0.11 61.3 0.4 58.7 3.4 -45.7 142.1 61.3 0.4 -134.109LA10-84 272 2310 2.2 23.2668 9.8 0.0505 9.9 0.0085 1.2 0.12 54.7 0.7 50.0 4.8 -168.8 244.3 54.7 0.7 -32.409LA10-85 926 25020 1.9 18.6833 2.6 0.3332 2.6 0.0451 0.5 0.19 284.7 1.4 292.0 6.7 351.1 58.6 284.7 1.4 81.109LA10-86 321 57645 4.3 8.1591 1.7 4.1440 2.1 0.2452 1.1 0.53 1413.8 13.8 1663.0 16.8 1993.8 30.9 1993.8 30.9 70.909LA10-87 147 2262 2.5 21.6292 7.7 0.1765 7.8 0.0277 1.2 0.16 176.0 2.1 165.0 11.8 9.8 184.9 176.0 2.1 1788.909LA10-88 232 1110 1.6 24.7782 15.1 0.0454 15.2 0.0082 1.3 0.09 52.4 0.7 45.1 6.7 -328.0 390.3 52.4 0.7 -16.009LA10-90 303 2295 2.1 23.8799 13.2 0.0510 13.2 0.0088 0.8 0.06 56.7 0.4 50.5 6.5 -234.0 333.9 56.7 0.4 -24.209LA10-89 385 4362 1.6 20.6344 2.5 0.1821 2.6 0.0273 0.9 0.35 173.4 1.6 169.9 4.1 121.9 58.1 173.4 1.6 142.209LA10-91 628 3540 2.4 21.6890 3.2 0.0566 3.4 0.0089 1.0 0.30 57.1 0.6 55.9 1.8 3.2 77.9 57.1 0.6 1811.809LA10-92 1768 33051 0.6 19.9554 4.2 0.1752 7.0 0.0254 5.6 0.80 161.5 8.9 164.0 10.5 200.2 96.7 161.5 8.9 80.709LA10-93 617 5796 2.5 22.3101 6.3 0.0591 6.4 0.0096 1.3 0.20 61.4 0.8 58.3 3.6 -65.3 152.9 61.4 0.8 -94.009LA10-94 272 2343 2.2 24.4508 14.2 0.0479 14.2 0.0085 0.5 0.04 54.6 0.3 47.5 6.6 -293.9 363.1 54.6 0.3 -18.609LA10-95 245 1815 2.2 24.5431 14.5 0.0475 14.5 0.0085 0.6 0.04 54.3 0.3 47.1 6.7 -303.5 372.5 54.3 0.3 -17.909LA10-96 1473 7488 1.5 21.3639 1.4 0.0605 1.8 0.0094 1.2 0.64 60.2 0.7 59.7 1.1 39.5 33.3 60.2 0.7 152.509LA10-97 697 5139 2.0 22.2079 5.6 0.0577 5.7 0.0093 1.2 0.21 59.6 0.7 56.9 3.1 -54.1 135.5 59.6 0.7 -110.309LA10-98 49 1167 3.5 22.7940 25.9 0.1521 25.9 0.0251 1.8 0.07 160.1 2.8 143.7 34.7 -117.9 646.6 160.1 2.8 -135.809LA10-99 236 5163 1.7 20.7472 3.1 0.1866 3.2 0.0281 0.6 0.20 178.5 1.1 173.7 5.1 109.1 73.7 178.5 1.1 163.709LA10-100 236 5163 1.7 20.7472 3.1 0.1866 3.2 0.0281 0.6 0.20 178.5 1.1 173.7 5.1 109.1 73.7 178.5 1.1 163.7

62

Sample 09NE06, Big John Bay South Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.8059, W133.68925

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09NE06-1 349 7905 4.5 19.8406 4.3 0.1958 4.3 0.0282 0.5 0.12 179.2 0.9 181.6 7.2 213.6 99.5 179.2 0.9 83.909NE06-2 131 1203 2.5 25.0760 16.0 0.0468 16.2 0.0085 2.3 0.14 54.6 1.2 46.5 7.3 -358.8 416.3 54.6 1.2 -15.209NE06-3 464 11868 2.6 19.9168 5.5 0.1986 5.5 0.0287 1.0 0.18 182.3 1.8 183.9 9.3 204.7 126.7 182.3 1.8 89.109NE06-4 597 5427 3.8 21.6910 6.2 0.0624 6.2 0.0098 0.5 0.09 63.0 0.3 61.4 3.7 3.0 149.8 63.0 0.3 2133.309NE06-5 711 19968 3.1 20.0298 1.4 0.1933 1.6 0.0281 0.7 0.43 178.5 1.2 179.4 2.6 191.6 33.5 178.5 1.2 93.209NE06-6 395 3273 1.3 23.2547 10.1 0.0572 10.1 0.0096 1.0 0.10 61.8 0.6 56.4 5.6 -167.5 251.1 61.8 0.6 -36.909NE06-7 236 38133 2.9 11.9711 1.8 2.2879 2.0 0.1986 0.7 0.36 1168.0 7.5 1208.6 13.8 1281.7 35.6 1281.7 35.6 91.109NE06-8 923 8247 3.1 21.4979 4.3 0.0591 4.5 0.0092 1.4 0.30 59.2 0.8 58.3 2.5 24.5 102.5 59.2 0.8 242.009NE06-9 702 4515 2.5 20.5456 4.3 0.0598 4.7 0.0089 1.8 0.39 57.2 1.0 59.0 2.7 132.1 101.4 57.2 1.0 43.309NE06-10 147 735 2.8 14.5882 23.8 0.0799 24.0 0.0085 2.8 0.12 54.3 1.5 78.1 18.0 885.2 499.5 54.3 1.5 6.109NE06-11 442 3843 2.7 22.4595 7.6 0.0532 7.7 0.0087 1.3 0.17 55.6 0.7 52.6 3.9 -81.6 185.7 55.6 0.7 -68.209NE06-12 628 20205 2.5 20.3384 2.0 0.1960 2.1 0.0289 0.6 0.27 183.7 1.0 181.7 3.4 155.9 46.4 183.7 1.0 117.909NE06-13 471 11463 1.8 20.0754 4.5 0.1800 4.7 0.0262 1.5 0.31 166.8 2.4 168.1 7.3 186.2 104.9 166.8 2.4 89.609NE06-14 295 3345 3.4 21.1722 7.6 0.0655 7.8 0.0101 2.0 0.25 64.5 1.3 64.4 4.9 61.0 180.8 64.5 1.3 105.809NE06-15 578 6789 4.6 22.4080 6.5 0.0590 7.3 0.0096 3.4 0.46 61.5 2.1 58.2 4.2 -76.0 159.6 61.5 2.1 -81.009NE06-16 346 3168 2.8 22.4043 8.9 0.0562 8.9 0.0091 0.8 0.09 58.6 0.5 55.5 4.8 -75.6 217.1 58.6 0.5 -77.509NE06-17 432 10236 2.5 20.1259 6.3 0.1972 6.3 0.0288 0.7 0.11 183.0 1.3 182.8 10.6 180.4 146.6 183.0 1.3 101.509NE06-18 392 3198 2.5 22.2626 6.1 0.0583 6.1 0.0094 0.7 0.12 60.4 0.4 57.6 3.4 -60.1 148.8 60.4 0.4 -100.609NE06-19 338 4236 4.4 22.5660 14.4 0.0600 14.5 0.0098 1.4 0.10 63.0 0.9 59.2 8.3 -93.2 356.1 63.0 0.9 -67.709NE06-20 663 6117 2.7 21.0427 5.1 0.0597 5.2 0.0091 0.8 0.16 58.5 0.5 58.9 3.0 75.5 121.2 58.5 0.5 77.409NE06-21 1073 26655 1.4 19.7976 1.5 0.1979 1.6 0.0284 0.5 0.31 180.6 0.9 183.3 2.7 218.6 35.7 180.6 0.9 82.609NE06-22 244 2622 2.5 23.6194 11.7 0.0527 11.7 0.0090 0.8 0.07 57.9 0.5 52.1 6.0 -206.4 294.4 57.9 0.5 -28.109NE06-23 712 23421 11.4 19.8803 2.3 0.2235 2.5 0.0322 1.1 0.43 204.4 2.2 204.8 4.7 208.9 53.1 204.4 2.2 97.809NE06-24 754 3273 2.8 15.5756 23.9 0.0910 24.0 0.0103 1.7 0.07 65.9 1.1 88.4 20.3 748.3 512.3 65.9 1.1 8.809NE06-25 310 3024 0.7 22.5706 6.9 0.0643 7.0 0.0105 0.5 0.07 67.5 0.3 63.3 4.3 -93.7 170.5 67.5 0.3 -72.109NE06-26 477 5808 2.9 21.4192 4.1 0.0839 4.2 0.0130 0.5 0.12 83.5 0.4 81.8 3.3 33.2 98.9 83.5 0.4 251.109NE06-27 139 1137 1.6 23.1900 11.4 0.0562 11.4 0.0094 0.7 0.06 60.6 0.4 55.5 6.2 -160.5 284.1 60.6 0.4 -37.809NE06-28 560 15132 1.9 20.0431 2.9 0.1924 3.0 0.0280 1.1 0.35 177.8 1.8 178.7 5.0 190.0 66.4 177.8 1.8 93.609NE06-29 180 1545 2.4 24.4086 15.3 0.0486 15.3 0.0086 1.3 0.08 55.2 0.7 48.2 7.2 -289.5 390.9 55.2 0.7 -19.109NE06-30 341 5877 1.5 19.9865 1.4 0.1984 1.5 0.0288 0.7 0.46 182.8 1.3 183.8 2.6 196.6 31.4 182.8 1.3 93.009NE06-31 168 1506 1.4 23.8634 12.9 0.0562 12.9 0.0097 0.8 0.06 62.4 0.5 55.5 7.0 -232.2 326.2 62.4 0.5 -26.909NE06-32 1839 15567 4.3 21.1459 2.6 0.0564 2.6 0.0087 0.5 0.19 55.6 0.3 55.7 1.4 63.9 60.9 55.6 0.3 86.909NE06-33 327 11163 6.0 19.0793 2.4 0.2559 2.6 0.0354 0.8 0.32 224.3 1.8 231.3 5.3 303.5 55.0 224.3 1.8 73.909NE06-34 539 13005 1.9 20.5014 2.3 0.1969 2.4 0.0293 0.5 0.22 186.1 1.0 182.5 3.9 137.2 54.1 186.1 1.0 135.709NE06-35 205 2661 2.4 23.3407 10.7 0.0756 10.8 0.0128 1.1 0.10 82.0 0.9 74.0 7.7 -176.7 268.1 82.0 0.9 -46.409NE06-36 822 7680 2.4 21.2346 5.4 0.0657 5.6 0.0101 1.4 0.24 64.9 0.9 64.6 3.5 53.9 129.6 64.9 0.9 120.309NE06-37 875 5931 2.7 21.7325 3.0 0.0560 3.1 0.0088 0.7 0.21 56.7 0.4 55.3 1.7 -1.6 72.9 56.7 0.4 -3484.809NE06-38 692 6744 4.4 20.9424 4.3 0.0607 4.4 0.0092 0.7 0.15 59.2 0.4 59.8 2.5 86.9 102.8 59.2 0.4 68.109NE06-39 608 5442 2.5 21.8874 4.8 0.0551 4.9 0.0088 1.0 0.20 56.2 0.6 54.5 2.6 -18.8 116.8 56.2 0.6 -299.109NE06-40 397 10455 2.3 20.3656 2.2 0.1984 2.3 0.0293 0.7 0.30 186.2 1.3 183.8 3.9 152.7 52.3 186.2 1.3 121.909NE06-41 272 2517 2.2 23.1047 10.6 0.0540 10.6 0.0090 0.5 0.05 58.1 0.3 53.4 5.5 -151.4 263.5 58.1 0.3 -38.409NE06-42 352 9123 2.4 20.3886 3.3 0.2034 3.3 0.0301 0.5 0.15 191.0 0.9 188.0 5.6 150.1 76.3 191.0 0.9 127.309NE06-43 223 1683 2.4 18.2712 20.9 0.0908 21.5 0.0120 4.8 0.22 77.1 3.7 88.3 18.2 401.2 473.8 77.1 3.7 19.209NE06-44 1545 21891 0.7 19.8946 2.3 0.1994 2.9 0.0288 1.7 0.59 182.9 3.0 184.6 4.8 207.2 53.9 182.9 3.0 88.209NE06-45 1393 11130 8.5 21.5929 2.7 0.0567 3.2 0.0089 1.6 0.51 57.0 0.9 56.0 1.7 13.9 65.8 57.0 0.9 410.609NE06-46 524 12393 1.7 20.6051 2.3 0.1884 3.0 0.0282 1.9 0.63 179.0 3.3 175.2 4.8 125.2 54.3 179.0 3.3 142.909NE06-47 508 4458 3.3 23.1863 9.4 0.0525 9.5 0.0088 1.2 0.12 56.6 0.7 51.9 4.8 -160.1 234.5 56.6 0.7 -35.409NE06-48 805 6723 2.5 21.7995 3.9 0.0564 4.8 0.0089 2.8 0.58 57.2 1.6 55.7 2.6 -9.0 94.6 57.2 1.6 -632.609NE06-49 341 4287 5.6 20.7935 4.6 0.0814 4.7 0.0123 0.9 0.18 78.6 0.7 79.4 3.6 103.8 109.1 78.6 0.7 75.809NE06-50 3755 30297 11.7 20.8982 1.4 0.0678 1.6 0.0103 0.7 0.41 65.9 0.4 66.6 1.0 91.9 34.2 65.9 0.4 71.709NE06-51 1477 13752 1.7 21.0081 3.0 0.0726 3.2 0.0111 1.2 0.37 70.9 0.8 71.2 2.2 79.4 70.7 70.9 0.8 89.309NE06-52 888 12027 93.7 21.2761 3.5 0.0747 3.5 0.0115 0.7 0.19 73.9 0.5 73.1 2.5 49.3 82.5 73.9 0.5 149.909NE06-53 2177 21291 5.0 21.0480 1.5 0.0681 1.8 0.0104 1.0 0.54 66.7 0.6 66.9 1.2 75.0 36.0 66.7 0.6 89.009NE06-54 787 15195 1.6 19.7720 2.0 0.1957 2.1 0.0281 0.7 0.33 178.4 1.2 181.5 3.5 221.6 46.4 178.4 1.2 80.509NE06-55 1065 22269 22.7 20.3129 2.2 0.1825 2.6 0.0269 1.3 0.51 171.0 2.2 170.2 4.1 158.8 52.3 171.0 2.2 107.709NE06-56 599 6141 2.0 19.9856 2.3 0.1577 8.6 0.0229 8.3 0.96 145.7 12.0 148.7 11.9 196.7 52.9 145.7 12.0 74.109NE06-57 223 2343 2.1 21.6610 7.6 0.0682 7.6 0.0107 0.7 0.09 68.7 0.5 67.0 5.0 6.3 183.7 68.7 0.5 1088.609NE06-58 1048 3459 1.8 18.5173 9.6 0.0681 9.8 0.0091 2.2 0.22 58.7 1.3 66.9 6.4 371.2 216.8 58.7 1.3 15.809NE06-59 175 1938 10.0 23.2685 10.2 0.0590 10.2 0.0100 1.0 0.09 63.9 0.6 58.2 5.8 -168.9 253.9 63.9 0.6 -37.809NE06-60 470 12972 2.1 20.2162 2.6 0.1945 2.8 0.0285 1.2 0.43 181.2 2.2 180.4 4.7 169.9 59.7 181.2 2.2 106.709NE06-61 797 22164 2.2 20.0757 2.1 0.1958 2.3 0.0285 0.9 0.38 181.2 1.6 181.6 3.8 186.2 48.7 181.2 1.6 97.309NE06-62 576 4626 2.8 21.5016 6.7 0.0618 6.7 0.0096 0.6 0.08 61.9 0.3 60.9 4.0 24.0 160.7 61.9 0.3 257.409NE06-63 278 2169 2.7 23.4165 10.2 0.0522 10.2 0.0089 0.7 0.06 56.9 0.4 51.7 5.1 -184.8 254.1 56.9 0.4 -30.809NE06-65 2155 23754 5.2 21.1112 1.3 0.0601 1.4 0.0092 0.5 0.36 59.1 0.3 59.3 0.8 67.8 30.7 59.1 0.3 87.009NE06-66 394 12423 2.4 20.1758 2.0 0.1986 2.1 0.0291 0.7 0.34 184.6 1.3 183.9 3.6 174.6 46.4 184.6 1.3 105.809NE06-67 559 14064 2.1 20.0031 1.9 0.1966 2.1 0.0285 0.9 0.44 181.3 1.6 182.2 3.4 194.7 43.1 181.3 1.6 93.109NE06-68 438 3861 2.5 22.4284 7.7 0.0557 7.7 0.0091 0.7 0.08 58.2 0.4 55.1 4.1 -78.2 188.5 58.2 0.4 -74.409NE06-69 156 1971 1.0 27.4440 25.9 0.0483 25.9 0.0096 0.7 0.03 61.6 0.4 47.9 12.1 -597.9 714.1 61.6 0.4 -10.309NE06-70 464 12000 2.9 20.5140 3.0 0.1773 3.2 0.0264 1.3 0.39 167.8 2.1 165.7 4.9 135.7 69.5 167.8 2.1 123.609NE06-71 206 1797 2.1 25.0390 19.9 0.0529 19.9 0.0096 1.3 0.07 61.6 0.8 52.4 10.2 -355.0 518.1 61.6 0.8 -17.409NE06-72 232 2229 3.8 22.5276 6.0 0.0535 6.2 0.0087 1.2 0.20 56.1 0.7 52.9 3.2 -89.0 148.2 56.1 0.7 -63.009NE06-73 302 2271 2.6 24.1095 13.9 0.0513 13.9 0.0090 0.6 0.05 57.6 0.4 50.8 6.9 -258.1 354.3 57.6 0.4 -22.309NE06-74 371 3774 2.6 22.6422 7.6 0.0679 7.7 0.0111 1.2 0.15 71.5 0.8 66.7 5.0 -101.4 187.2 71.5 0.8 -70.409NE06-75 515 3714 1.7 22.8746 7.8 0.0540 7.8 0.0090 0.8 0.10 57.5 0.4 53.4 4.1 -126.6 191.7 57.5 0.4 -45.509NE06-76 505 11229 2.6 20.5794 2.8 0.1460 3.4 0.0218 1.9 0.55 138.9 2.6 138.3 4.4 128.2 66.7 138.9 2.6 108.309NE06-77 982 8988 2.2 21.0281 9.9 0.0602 9.9 0.0092 0.7 0.07 58.9 0.4 59.3 5.7 77.2 234.9 58.9 0.4 76.309NE06-78 423 10248 8.4 19.9152 10.7 0.1689 11.8 0.0244 5.2 0.43 155.4 7.9 158.4 17.4 204.9 248.0 155.4 7.9 75.809NE06-79 804 25434 3.3 18.9328 10.3 0.2635 10.7 0.0362 2.8 0.26 229.2 6.3 237.5 22.6 321.0 234.3 229.2 6.3 71.409NE06-80 396 4194 3.3 20.8909 19.9 0.0762 20.1 0.0115 2.7 0.13 74.0 2.0 74.5 14.4 92.8 475.7 74.0 2.0 79.809NE06-81 526 4242 3.0 21.5087 3.2 0.0596 3.2 0.0093 0.5 0.16 59.6 0.3 58.7 1.8 23.3 76.1 59.6 0.3 256.109NE06-82 218 2805 2.0 18.7384 16.0 0.2089 16.0 0.0284 0.5 0.03 180.5 0.9 192.7 28.1 344.4 363.4 180.5 0.9 52.409NE06-83 710 5322 2.9 21.2135 10.0 0.0580 10.0 0.0089 0.9 0.09 57.2 0.5 57.2 5.6 56.3 238.0 57.2 0.5 101.609NE06-84 376 3288 3.3 22.7696 8.1 0.0550 8.1 0.0091 0.5 0.06 58.3 0.3 54.4 4.3 -115.3 200.2 58.3 0.3 -50.609NE06-85 720 18912 2.0 20.3836 3.9 0.1995 3.9 0.0295 0.5 0.13 187.4 0.9 184.7 6.6 150.6 90.6 187.4 0.9 124.409NE06-86 1194 12219 5.1 21.8053 7.5 0.0568 7.5 0.0090 0.6 0.08 57.7 0.4 56.1 4.1 -9.7 180.4 57.7 0.4 -594.709NE06-87 404 3642 2.4 22.7942 7.6 0.0547 7.6 0.0090 0.6 0.07 58.1 0.3 54.1 4.0 -117.9 187.4 58.1 0.3 -49.209NE06-88 384 4158 2.2 21.8571 7.1 0.0750 7.2 0.0119 0.6 0.08 76.1 0.4 73.4 5.1 -15.4 172.7 76.1 0.4 -493.509NE06-89 3563 24966 9.3 20.8232 10.6 0.0638 10.7 0.0096 1.5 0.14 61.8 0.9 62.8 6.5 100.4 250.4 61.8 0.9 61.609NE06-90 813 24321 2.3 20.3569 9.0 0.1927 9.0 0.0284 0.5 0.06 180.8 0.9 178.9 14.8 153.7 211.2 180.8 0.9 117.709NE06-91 2510 22188 6.3 20.8294 6.5 0.0662 6.8 0.0100 2.0 0.30 64.2 1.3 65.1 4.3 99.7 153.0 64.2 1.3 64.409NE06-92 347 7641 1.9 20.5069 1.9 0.1786 2.9 0.0266 2.2 0.75 169.0 3.6 166.8 4.4 136.5 44.5 169.0 3.6 123.809NE06-93 509 4305 1.8 22.3209 9.9 0.0551 10.0 0.0089 1.9 0.19 57.2 1.1 54.4 5.3 -66.4 241.1 57.2 1.1 -86.109NE06-94 584 5235 2.4 21.8070 10.6 0.0612 10.6 0.0097 0.7 0.07 62.1 0.4 60.4 6.2 -9.9 255.5 62.1 0.4 -628.909NE06-95 495 3252 2.4 20.0765 24.7 0.0597 24.8 0.0087 2.9 0.12 55.8 1.6 58.8 14.2 186.1 582.1 55.8 1.6 30.009NE06-96 123 1050 3.0 30.1010 39.6 0.0391 39.8 0.0085 4.3 0.11 54.8 2.3 39.0 15.2 -856.0 1173.5 54.8 2.3 -6.409NE06-97 259 2106 2.4 20.4600 15.2 0.0616 15.3 0.0091 1.3 0.08 58.7 0.8 60.7 9.0 141.9 358.8 58.7 0.8 41.409NE06-99 2765 21840 25.7 21.0448 1.4 0.0678 1.6 0.0104 0.8 0.47 66.4 0.5 66.6 1.0 75.3 33.5 66.4 0.5 88.209NE06-100 282 2514 1.4 22.7982 8.2 0.0626 8.3 0.0103 1.0 0.12 66.4 0.7 61.6 5.0 -118.4 203.4 66.4 0.7 -56.1

63

Sample 09NE08, Big John Bay Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.81799, W133.72681

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09NE08-1 462 12519 3.0 19.9672 18.6 0.1990 18.6 0.0288 1.0 0.05 183.1 1.8 184.3 31.4 198.8 435.1 183.1 1.8 92.109NE08-2 209 2511 4.2 21.3478 13.9 0.0543 14.3 0.0084 3.5 0.24 53.9 1.9 53.7 7.5 41.3 332.8 53.9 1.9 130.709NE08-3 364 3714 5.1 18.8390 15.8 0.0781 16.1 0.0107 2.9 0.18 68.4 2.0 76.4 11.8 332.3 360.9 68.4 2.0 20.609NE08-4 160 771 1.8 15.3329 24.5 0.0789 24.6 0.0088 1.9 0.08 56.3 1.1 77.1 18.2 781.4 521.7 56.3 1.1 7.209NE08-5 634 7602 7.1 20.0958 6.6 0.0693 10.6 0.0101 8.3 0.78 64.8 5.3 68.0 7.0 183.9 153.8 64.8 5.3 35.209NE08-6 329 6024 2.4 19.8806 7.3 0.1830 8.3 0.0264 3.8 0.46 167.9 6.3 170.6 13.0 208.9 170.0 167.9 6.3 80.409NE08-8 3752 15471 7.3 20.3841 11.4 0.0686 11.6 0.0101 2.1 0.18 65.0 1.4 67.3 7.6 150.6 268.8 65.0 1.4 43.209NE08-7 1266 36048 3.1 19.8988 14.3 0.1896 14.3 0.0274 1.2 0.09 174.0 2.1 176.3 23.2 206.8 332.0 174.0 2.1 84.209NE08-9 526 1743 4.3 16.3347 19.1 0.0757 19.1 0.0090 1.1 0.06 57.6 0.6 74.1 13.7 647.0 413.5 57.6 0.6 8.909NE08-10 366 4470 3.4 23.0814 12.2 0.0535 12.2 0.0090 1.4 0.11 57.5 0.8 53.0 6.3 -148.9 302.4 57.5 0.8 -38.609NE08-11 362 3519 3.0 20.7452 8.6 0.0555 8.6 0.0083 0.8 0.09 53.6 0.4 54.8 4.6 109.3 202.9 53.6 0.4 49.009NE08-12 1485 6591 7.0 20.0899 4.0 0.0566 4.4 0.0082 1.6 0.37 52.9 0.9 55.9 2.4 184.5 94.3 52.9 0.9 28.709NE08-13 388 2223 4.3 19.1512 11.3 0.0635 11.3 0.0088 1.2 0.11 56.6 0.7 62.5 6.9 294.9 257.8 56.6 0.7 19.209NE08-14 440 9066 2.4 19.5994 6.4 0.1965 6.6 0.0279 1.7 0.25 177.6 3.0 182.1 11.1 241.8 148.3 177.6 3.0 73.409NE08-15 253 7839 3.9 19.7412 5.7 0.1855 6.3 0.0266 2.7 0.43 169.0 4.5 172.8 10.0 225.2 131.5 169.0 4.5 75.109NE08-16 404 3366 3.3 19.8088 16.5 0.0614 16.6 0.0088 2.2 0.13 56.6 1.3 60.5 9.8 217.3 383.8 56.6 1.3 26.109NE08-17 256 1032 3.5 17.7486 16.8 0.0660 17.2 0.0085 3.7 0.21 54.6 2.0 64.9 10.8 465.9 374.7 54.6 2.0 11.709NE08-18 187 4338 7.4 19.5698 9.8 0.1199 10.0 0.0170 2.2 0.22 108.8 2.3 115.0 10.9 245.3 225.9 108.8 2.3 44.409NE08-19 293 2142 2.6 18.6727 17.3 0.0617 17.5 0.0084 2.3 0.13 53.6 1.2 60.8 10.3 352.4 394.5 53.6 1.2 15.209NE08-20 536 3096 4.1 18.6188 12.0 0.0657 12.0 0.0089 0.5 0.04 56.9 0.3 64.6 7.5 358.8 272.2 56.9 0.3 15.909NE08-21 473 3024 5.1 18.7614 13.2 0.0722 13.2 0.0098 1.2 0.09 63.0 0.7 70.8 9.0 341.6 299.7 63.0 0.7 18.409NE08-22 396 6849 4.1 19.3236 4.9 0.1729 6.9 0.0242 4.9 0.70 154.3 7.4 161.9 10.3 274.4 112.6 154.3 7.4 56.209NE08-23 243 1773 3.0 16.7852 20.3 0.0723 20.5 0.0088 2.6 0.13 56.5 1.4 70.9 14.0 588.2 444.8 56.5 1.4 9.609NE08-24 1277 8247 6.2 19.1604 12.7 0.0628 14.1 0.0087 6.2 0.44 56.0 3.4 61.8 8.5 293.8 290.4 56.0 3.4 19.109NE08-25 276 3669 4.8 22.7414 10.7 0.0515 10.8 0.0085 1.6 0.15 54.5 0.9 51.0 5.4 -112.2 263.6 54.5 0.9 -48.609NE08-27 338 10548 2.9 19.6415 12.5 0.1994 12.7 0.0284 1.9 0.15 180.6 3.5 184.6 21.4 236.9 289.6 180.6 3.5 76.209NE08-28 351 918 7.6 14.4887 4.9 0.0855 5.4 0.0090 2.3 0.42 57.6 1.3 83.3 4.3 899.3 101.3 57.6 1.3 6.409NE08-29 544 1962 12.2 17.3561 12.4 0.0785 12.8 0.0099 3.1 0.25 63.4 2.0 76.8 9.4 515.2 272.4 63.4 2.0 12.309NE08-30 748 3429 2.1 19.7309 8.8 0.0630 9.1 0.0090 2.0 0.22 57.9 1.2 62.1 5.4 226.4 204.3 57.9 1.2 25.609NE08-31 215 1587 2.8 17.9874 16.0 0.0670 16.2 0.0087 2.6 0.16 56.1 1.4 65.9 10.3 436.2 357.7 56.1 1.4 12.909NE08-33 551 2859 2.7 19.1314 7.7 0.0659 8.0 0.0091 2.2 0.27 58.7 1.3 64.8 5.0 297.2 175.4 58.7 1.3 19.709NE08-34 438 7719 1.8 18.7865 14.0 0.1957 14.2 0.0267 1.9 0.13 169.6 3.2 181.5 23.5 338.6 319.4 169.6 3.2 50.109NE08-35 235 714 3.4 16.0690 10.0 0.0746 10.2 0.0087 1.9 0.19 55.8 1.0 73.1 7.2 682.1 213.7 55.8 1.0 8.209NE08-36 339 10854 3.1 20.8558 4.6 0.1891 4.8 0.0286 1.6 0.32 181.8 2.8 175.9 7.8 96.7 108.1 181.8 2.8 188.009NE08-37 841 5298 12.8 19.4117 4.7 0.0898 4.8 0.0126 0.9 0.19 81.0 0.7 87.3 4.0 263.9 107.7 81.0 0.7 30.709NE08-38 275 2121 3.7 18.7838 19.1 0.0697 19.3 0.0095 2.8 0.15 60.9 1.7 68.4 12.7 338.9 435.4 60.9 1.7 18.009NE08-39 506 807 5.1 16.3281 19.6 0.0904 19.8 0.0107 3.2 0.16 68.7 2.2 87.9 16.7 647.8 423.8 68.7 2.2 10.609NE08-40 893 5625 2.3 19.5416 4.5 0.1355 7.3 0.0192 5.8 0.79 122.7 7.0 129.1 8.9 248.6 104.1 122.7 7.0 49.309NE08-41 52 777 2.5 28.9782 29.6 0.0543 29.8 0.0114 3.5 0.12 73.2 2.6 53.7 15.6 -748.1 844.1 73.2 2.6 -9.809NE08-43 316 6021 3.8 20.7410 6.0 0.1145 6.6 0.0172 2.8 0.42 110.1 3.1 110.1 6.9 109.8 141.8 110.1 3.1 100.309NE08-42 286 6702 3.7 19.4933 12.4 0.1889 12.4 0.0267 0.9 0.07 169.9 1.4 175.7 20.1 254.3 286.2 169.9 1.4 66.809NE08-44 994 2754 4.6 17.1740 22.9 0.0810 22.9 0.0101 1.0 0.04 64.7 0.7 79.1 17.4 538.3 507.1 64.7 0.7 12.009NE08-45 291 1248 4.5 17.5500 8.3 0.0720 8.4 0.0092 1.0 0.12 58.8 0.6 70.6 5.7 490.8 183.7 58.8 0.6 12.009NE08-46 274 2766 3.3 19.2317 13.4 0.0622 13.7 0.0087 2.6 0.19 55.7 1.4 61.3 8.1 285.3 308.2 55.7 1.4 19.509NE08-48 2873 34341 43.5 21.1918 2.9 0.0661 3.0 0.0102 0.8 0.26 65.2 0.5 65.0 1.9 58.8 69.4 65.2 0.5 110.909NE08-47 1632 15156 2.6 18.7522 3.9 0.2090 4.7 0.0284 2.6 0.56 180.7 4.7 192.8 8.2 342.8 87.3 180.7 4.7 52.709NE08-49 2301 21156 28.7 21.5901 2.4 0.0594 2.7 0.0093 1.1 0.43 59.7 0.7 58.6 1.5 14.2 57.6 59.7 0.7 420.709NE08-50 381 6345 8.8 21.0800 4.3 0.0678 4.9 0.0104 2.4 0.49 66.5 1.6 66.6 3.2 71.3 102.5 66.5 1.6 93.209NE08-51 1441 13041 17.1 21.9073 3.7 0.0560 3.8 0.0089 1.1 0.28 57.1 0.6 55.3 2.1 -21.0 89.0 57.1 0.6 -272.109NE08-52 391 5787 9.5 19.2009 5.3 0.1708 9.9 0.0238 8.4 0.85 151.6 12.5 160.2 14.7 288.9 120.9 151.6 12.5 52.509NE08-53 405 11466 3.1 20.6117 9.4 0.1489 9.6 0.0223 1.9 0.19 141.9 2.6 140.9 12.6 124.5 221.9 141.9 2.6 114.009NE08-54 315 6180 2.7 19.3783 7.2 0.1984 7.2 0.0279 0.5 0.07 177.3 0.9 183.7 12.2 267.9 165.9 177.3 0.9 66.209NE08-55 933 8931 8.0 21.1334 1.7 0.0636 2.0 0.0097 1.1 0.54 62.5 0.7 62.6 1.2 65.3 39.8 62.5 0.7 95.709NE08-56 562 4668 2.7 20.3643 9.7 0.0574 9.9 0.0085 1.8 0.18 54.4 1.0 56.7 5.5 152.9 228.6 54.4 1.0 35.609NE08-58 264 3090 2.8 23.4512 10.6 0.0602 10.7 0.0102 1.2 0.11 65.7 0.8 59.4 6.2 -188.5 266.7 65.7 0.8 -34.909NE08-57 597 16212 2.3 20.2119 28.4 0.1907 28.4 0.0280 1.0 0.03 177.8 1.7 177.2 46.3 170.4 675.8 177.8 1.7 104.309NE08-59 245 750 3.7 15.5310 9.8 0.0834 9.8 0.0094 0.6 0.06 60.3 0.3 81.4 7.7 754.4 207.3 60.3 0.3 8.009NE08-60 114 801 2.7 10.9681 55.2 0.1196 55.3 0.0095 2.3 0.04 61.1 1.4 114.7 60.0 1450.2 1149.2 61.1 1.4 4.209NE08-61 565 16113 2.8 20.2686 5.8 0.1922 5.9 0.0283 0.7 0.12 179.6 1.3 178.5 9.6 163.9 136.5 179.6 1.3 109.609NE08-62 1400 11811 23.2 20.8187 4.4 0.0598 5.7 0.0090 3.6 0.64 57.9 2.1 59.0 3.2 100.9 103.4 57.9 2.1 57.409NE08-63 745 3171 3.5 18.8913 4.6 0.0634 5.4 0.0087 2.7 0.51 55.7 1.5 62.4 3.2 326.0 104.7 55.7 1.5 17.109NE08-65 344 3879 2.6 23.0647 8.8 0.0541 8.9 0.0090 1.1 0.13 58.1 0.7 53.5 4.6 -147.1 218.6 58.1 0.7 -39.509NE08-67 556 3051 8.1 19.4357 7.8 0.0652 7.9 0.0092 1.0 0.13 59.0 0.6 64.1 4.9 261.1 180.0 59.0 0.6 22.609NE08-66 376 4119 2.2 22.3593 6.3 0.0534 6.7 0.0087 2.2 0.33 55.6 1.2 52.8 3.4 -70.6 153.7 55.6 1.2 -78.709NE08-68 394 3210 3.3 22.7400 11.3 0.0533 11.3 0.0088 0.9 0.08 56.4 0.5 52.7 5.8 -112.0 279.0 56.4 0.5 -50.309NE08-69 1615 684 1.0 9.0841 24.7 0.1254 26.3 0.0083 8.9 0.34 53.1 4.7 120.0 29.8 1800.8 457.5 53.1 4.7 2.909NE08-70 372 1692 3.5 18.2390 18.2 0.0669 18.3 0.0088 1.2 0.07 56.8 0.7 65.7 11.6 405.2 410.8 56.8 0.7 14.009NE08-71 2388 24219 23.2 21.0779 8.5 0.0647 8.6 0.0099 1.4 0.16 63.4 0.9 63.6 5.3 71.6 201.3 63.4 0.9 88.609NE08-72 313 3144 2.8 21.7856 10.4 0.0562 10.4 0.0089 1.0 0.10 57.0 0.6 55.5 5.6 -7.5 251.0 57.0 0.6 -758.209NE08-73 414 9786 1.5 20.6526 8.7 0.1916 8.8 0.0287 1.0 0.11 182.4 1.8 178.0 14.4 119.8 206.3 182.4 1.8 152.209NE08-74 245 1455 3.4 20.3856 11.6 0.0606 11.6 0.0090 0.5 0.04 57.5 0.3 59.7 6.7 150.4 272.0 57.5 0.3 38.209NE08-75 327 3138 2.0 22.2895 5.3 0.0559 5.7 0.0090 2.0 0.35 58.0 1.2 55.2 3.1 -63.0 130.5 58.0 1.2 -92.009NE08-76 1751 9738 1.2 18.7624 15.8 0.0924 15.8 0.0126 1.2 0.08 80.6 1.0 89.8 13.6 341.5 359.7 80.6 1.0 23.609NE08-77 535 5076 2.7 21.5706 17.6 0.0577 17.8 0.0090 2.3 0.13 57.9 1.3 57.0 9.9 16.3 426.7 57.9 1.3 354.309NE08-78 595 14652 2.1 20.4271 10.2 0.1919 10.2 0.0284 0.9 0.09 180.7 1.6 178.3 16.7 145.7 238.9 180.7 1.6 124.109NE08-79 972 6708 1.8 21.0928 11.7 0.0630 11.7 0.0096 0.7 0.06 61.8 0.4 62.0 7.0 69.9 278.4 61.8 0.4 88.409NE08-80 280 2115 2.3 21.2488 7.5 0.0636 7.6 0.0098 1.4 0.19 62.9 0.9 62.6 4.6 52.4 178.2 62.9 0.9 120.109NE08-82 413 11403 2.4 20.5629 4.8 0.1821 4.9 0.0272 1.1 0.23 172.7 1.9 169.9 7.6 130.1 112.0 172.7 1.9 132.809NE08-84 251 6747 1.7 20.6082 8.5 0.1858 8.5 0.0278 0.5 0.06 176.6 0.9 173.0 13.5 124.9 200.4 176.6 0.9 141.409NE08-85 205 1152 7.0 18.3373 9.3 0.0673 9.5 0.0090 1.7 0.18 57.5 1.0 66.2 6.1 393.1 210.0 57.5 1.0 14.609NE08-86 510 4515 7.5 20.4734 6.3 0.0590 6.3 0.0088 0.9 0.14 56.3 0.5 58.2 3.6 140.3 147.2 56.3 0.5 40.109NE08-87 494 9162 2.6 19.6079 3.1 0.1898 3.4 0.0270 1.5 0.45 171.7 2.6 176.5 5.6 240.8 70.9 171.7 2.6 71.309NE08-88 448 2535 2.9 20.8307 11.1 0.0590 11.2 0.0089 1.2 0.11 57.2 0.7 58.2 6.3 99.6 264.3 57.2 0.7 57.409NE08-89 819 8547 2.1 21.4984 4.0 0.0660 4.2 0.0103 1.4 0.32 66.0 0.9 64.9 2.7 24.4 96.3 66.0 0.9 270.409NE08-90 496 18975 3.2 19.4122 2.3 0.1977 2.7 0.0278 1.4 0.51 176.9 2.4 183.1 4.5 263.9 53.1 176.9 2.4 67.109NE08-91 475 7164 8.2 20.4283 19.0 0.0824 19.1 0.0122 0.7 0.04 78.2 0.6 80.4 14.7 145.5 450.3 78.2 0.6 53.809NE08-92 1004 8229 3.3 21.1543 3.2 0.0584 4.2 0.0090 2.7 0.63 57.5 1.5 57.7 2.3 63.0 76.8 57.5 1.5 91.309NE08-93 1194 27750 4.0 19.7395 6.2 0.1931 6.8 0.0277 2.9 0.42 175.8 4.9 179.3 11.2 225.4 142.7 175.8 4.9 78.009NE08-94 160 1500 2.5 21.3859 17.0 0.0537 17.1 0.0083 1.7 0.10 53.4 0.9 53.1 8.8 37.0 408.7 53.4 0.9 144.609NE08-95 251 2244 2.8 21.1328 19.9 0.0556 20.5 0.0085 4.9 0.24 54.7 2.7 55.0 11.0 65.4 478.4 54.7 2.7 83.709NE08-96 737 4194 3.6 19.6409 26.2 0.0761 26.2 0.0108 0.7 0.03 69.5 0.5 74.5 18.8 236.9 614.0 69.5 0.5 29.309NE08-97 920 20097 8.0 19.8049 7.5 0.1711 8.1 0.0246 3.2 0.39 156.5 4.9 160.3 12.1 217.7 174.1 156.5 4.9 71.909NE08-98 202 2916 2.3 20.9915 7.5 0.1208 7.9 0.0184 2.5 0.32 117.5 2.9 115.8 8.6 81.3 177.7 117.5 2.9 144.509NE08-99 895 18612 1.5 18.2359 8.1 0.3772 8.2 0.0499 1.1 0.14 313.8 3.4 325.0 22.8 405.6 181.8 313.8 3.4 77.409NE08-100 1058 12039 2.8 19.7920 2.7 0.1920 3.3 0.0276 1.9 0.59 175.3 3.3 178.3 5.4 219.2 61.5 175.3 3.3 80.0

64

Sample 09TH08, Davidson Bay Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.85573, W133.83607

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09TH08-1 533 4476 3.1 22.1092 5.0 0.0626 5.4 0.0100 1.8 0.34 64.4 1.2 61.6 3.2 -43.2 122.2 64.4 1.2 -148.909TH08-2 261 1728 2.0 22.9617 9.2 0.0626 9.2 0.0104 0.8 0.09 66.9 0.6 61.7 5.5 -136.0 227.0 66.9 0.6 -49.209TH08-3 306 2313 3.3 22.8839 7.8 0.0564 7.9 0.0094 1.5 0.19 60.1 0.9 55.7 4.3 -127.6 191.9 60.1 0.9 -47.109TH08-4 2399 8628 1.2 21.0710 1.6 0.0632 1.9 0.0097 1.1 0.56 62.0 0.7 62.2 1.1 72.4 36.9 62.0 0.7 85.609TH08-5 462 2676 1.0 23.5203 12.2 0.0624 12.5 0.0106 2.4 0.20 68.3 1.6 61.5 7.4 -195.8 306.8 68.3 1.6 -34.909TH08-6 841 6285 1.9 21.6923 2.7 0.0571 4.1 0.0090 3.0 0.74 57.7 1.7 56.4 2.2 2.8 65.2 57.7 1.7 2054.709TH08-7 461 2553 1.9 21.9488 8.5 0.0543 8.5 0.0086 0.7 0.09 55.5 0.4 53.7 4.4 -25.6 205.0 55.5 0.4 -217.109TH08-8 1053 3132 0.5 21.3393 3.0 0.0625 3.4 0.0097 1.6 0.46 62.0 1.0 61.5 2.0 42.2 71.8 62.0 1.0 147.009TH08-9 354 1752 2.2 22.1098 5.7 0.0567 5.7 0.0091 0.8 0.14 58.3 0.5 56.0 3.1 -43.3 138.0 58.3 0.5 -134.709TH08-10 511 3141 2.0 21.3101 4.5 0.0569 4.7 0.0088 1.3 0.28 56.4 0.7 56.2 2.6 45.5 108.4 56.4 0.7 124.009TH08-11 1704 11496 2.7 21.4763 2.0 0.0578 2.2 0.0090 0.9 0.41 57.8 0.5 57.1 1.2 26.8 47.3 57.8 0.5 215.309TH08-12 283 1773 1.4 22.4877 6.8 0.0520 6.9 0.0085 1.1 0.15 54.4 0.6 51.5 3.5 -84.6 167.2 54.4 0.6 -64.309TH08-13 403 1854 1.7 21.9284 9.0 0.0553 9.0 0.0088 0.7 0.07 56.5 0.4 54.7 4.8 -23.3 218.4 56.5 0.4 -242.309TH08-14 584 2598 1.8 21.8961 4.4 0.0669 4.5 0.0106 0.8 0.18 68.1 0.5 65.7 2.8 -19.7 106.4 68.1 0.5 -345.009TH08-15 307 1749 2.0 22.1813 8.2 0.0555 8.3 0.0089 0.9 0.10 57.3 0.5 54.9 4.4 -51.1 200.5 57.3 0.5 -112.109TH08-16 621 18912 8.4 14.3253 6.9 0.3292 7.6 0.0342 3.2 0.42 216.8 6.8 289.0 19.1 922.7 141.6 216.8 6.8 23.509TH08-17 399 2298 3.9 21.7158 12.2 0.0606 12.3 0.0095 1.6 0.13 61.2 1.0 59.7 7.2 0.2 295.6 61.2 1.0 30068.409TH08-18 662 5304 2.7 21.4286 3.0 0.0621 3.4 0.0096 1.7 0.50 61.9 1.0 61.1 2.0 32.2 71.2 61.9 1.0 192.009TH08-19 433 2256 1.1 21.4312 7.5 0.0554 7.5 0.0086 0.8 0.11 55.2 0.5 54.7 4.0 31.9 179.0 55.2 0.5 173.209TH08-20 351 3156 1.2 22.3845 9.7 0.0719 9.8 0.0117 1.6 0.16 74.8 1.2 70.5 6.7 -73.4 236.5 74.8 1.2 -101.909TH08-21 272 1647 1.4 18.1954 30.2 0.0748 30.7 0.0099 5.9 0.19 63.4 3.7 73.3 21.7 410.5 688.7 63.4 3.7 15.409TH08-22 273 2334 2.3 23.5472 10.8 0.0562 10.9 0.0096 1.6 0.15 61.5 1.0 55.5 5.9 -198.7 270.5 61.5 1.0 -31.009TH08-23 843 4812 1.2 21.7915 3.4 0.0583 3.6 0.0092 1.3 0.36 59.1 0.8 57.5 2.0 -8.2 81.4 59.1 0.8 -724.309TH08-24 552 4167 3.2 22.3961 5.5 0.0539 5.7 0.0088 1.5 0.26 56.2 0.8 53.3 2.9 -74.6 133.8 56.2 0.8 -75.309TH08-25 2389 11109 1.7 20.4450 2.4 0.0671 2.6 0.0099 1.0 0.37 63.8 0.6 65.9 1.7 143.6 57.2 63.8 0.6 44.409TH08-26 229 1800 1.7 22.6025 8.5 0.0636 8.6 0.0104 0.7 0.09 66.9 0.5 62.6 5.2 -97.1 210.2 66.9 0.5 -68.909TH08-28 707 2235 1.1 19.2066 3.6 0.0762 3.7 0.0106 0.6 0.16 68.1 0.4 74.6 2.7 288.3 83.2 68.1 0.4 23.609TH08-29 408 3549 2.5 22.8897 9.7 0.0561 9.7 0.0093 1.3 0.14 59.8 0.8 55.4 5.3 -128.2 239.1 59.8 0.8 -46.609TH08-30 607 7107 1.4 19.2161 8.6 0.2007 8.6 0.0280 0.7 0.08 177.9 1.3 185.8 14.6 287.1 196.6 177.9 1.3 62.009TH08-31 244 8598 1.7 19.2325 2.5 0.3505 2.9 0.0489 1.5 0.50 307.7 4.4 305.1 7.6 285.2 56.9 307.7 4.4 107.909TH08-32 331 1818 1.6 20.9999 4.7 0.0603 5.0 0.0092 1.7 0.33 58.9 1.0 59.4 2.9 80.4 111.3 58.9 1.0 73.309TH08-33 323 6933 1.5 20.0069 3.4 0.2018 3.5 0.0293 0.8 0.24 186.1 1.5 186.7 6.0 194.2 79.7 186.1 1.5 95.809TH08-34 185 1485 3.5 22.7898 8.9 0.0583 9.0 0.0096 1.4 0.15 61.8 0.8 57.5 5.1 -117.4 220.7 61.8 0.8 -52.609TH08-35 60 3369 4.7 19.5870 6.3 0.4209 6.5 0.0598 1.4 0.21 374.4 5.0 356.7 19.5 243.3 145.8 374.4 5.0 153.909TH08-36 1069 6444 1.3 21.5622 3.3 0.0583 3.6 0.0091 1.4 0.38 58.5 0.8 57.5 2.0 17.3 79.9 58.5 0.8 338.809TH08-37 468 4899 1.6 21.1858 2.5 0.0792 2.7 0.0122 0.9 0.33 78.0 0.7 77.4 2.0 59.5 60.3 78.0 0.7 131.109TH08-38 523 9816 1.4 19.6575 2.4 0.2029 2.8 0.0289 1.3 0.47 183.8 2.4 187.5 4.7 235.0 56.0 183.8 2.4 78.209TH08-39 252 1836 1.7 21.8365 16.4 0.0553 16.5 0.0088 1.4 0.09 56.2 0.8 54.6 8.8 -13.1 398.8 56.2 0.8 -427.309TH08-40 716 7131 2.0 21.4738 3.4 0.0753 3.7 0.0117 1.2 0.34 75.2 0.9 73.7 2.6 27.1 82.6 75.2 0.9 277.209TH08-41 1056 19809 0.8 20.1931 1.8 0.1930 2.0 0.0283 0.7 0.35 179.7 1.2 179.2 3.2 172.6 43.0 179.7 1.2 104.109TH08-42 3274 26214 2.8 21.4555 3.8 0.0836 3.8 0.0130 0.7 0.17 83.3 0.5 81.5 3.0 29.2 90.8 83.3 0.5 285.209TH08-43 195 1032 2.1 25.3192 17.3 0.0468 17.3 0.0086 0.5 0.03 55.2 0.3 46.4 7.9 -383.8 452.9 55.2 0.3 -14.409TH08-44 572 4725 2.4 22.0706 5.5 0.0581 5.5 0.0093 0.5 0.09 59.7 0.3 57.3 3.1 -39.0 133.6 59.7 0.3 -153.109TH08-45 583 2646 1.2 22.3546 5.6 0.0545 5.6 0.0088 0.5 0.09 56.7 0.3 53.9 3.0 -70.1 137.4 56.7 0.3 -80.909TH08-46 665 6528 3.7 22.0140 4.5 0.0609 4.7 0.0097 1.5 0.32 62.4 0.9 60.1 2.8 -32.7 109.1 62.4 0.9 -190.609TH08-47 1424 8130 1.7 21.6972 4.7 0.0553 4.8 0.0087 0.6 0.13 55.9 0.3 54.7 2.5 2.3 113.7 55.9 0.3 2467.609TH08-48 1039 4398 1.5 21.5214 3.3 0.0557 3.5 0.0087 1.3 0.38 55.8 0.7 55.1 1.9 21.8 78.5 55.8 0.7 255.909TH08-49 509 14856 2.4 19.9819 1.0 0.1896 1.6 0.0275 1.2 0.77 174.7 2.1 176.3 2.5 197.1 23.3 174.7 2.1 88.609TH08-50 1062 6375 4.0 21.4675 2.2 0.0605 2.7 0.0094 1.6 0.59 60.5 1.0 59.7 1.6 27.9 52.4 60.5 1.0 216.809TH08-51 334 7641 2.6 20.5139 2.7 0.1644 2.9 0.0245 1.1 0.38 155.8 1.7 154.5 4.2 135.7 63.1 155.8 1.7 114.809TH08-52 739 9861 0.9 20.3240 2.6 0.1835 2.6 0.0271 0.6 0.21 172.1 0.9 171.1 4.2 157.5 60.7 172.1 0.9 109.209TH08-53 132 825 2.1 23.6637 10.8 0.0493 11.0 0.0085 1.8 0.16 54.3 1.0 48.9 5.2 -211.1 272.6 54.3 1.0 -25.709TH08-54 384 3879 2.1 22.3416 7.6 0.0720 7.7 0.0117 0.7 0.09 74.8 0.5 70.6 5.2 -68.7 186.5 74.8 0.5 -108.909TH08-55 1424 28068 1.4 20.2771 1.9 0.1843 2.4 0.0271 1.6 0.64 172.4 2.7 171.8 3.9 162.9 43.8 172.4 2.7 105.909TH08-56 1233 10194 2.6 21.2700 2.2 0.0635 2.7 0.0098 1.6 0.60 62.8 1.0 62.5 1.6 50.0 51.7 62.8 1.0 125.609TH08-57 604 6678 3.0 21.4163 2.9 0.0775 3.3 0.0120 1.6 0.49 77.1 1.3 75.8 2.4 33.6 69.1 77.1 1.3 229.809TH08-58 212 1920 1.8 25.1378 16.8 0.0456 16.8 0.0083 1.0 0.06 53.4 0.6 45.3 7.4 -365.2 436.9 53.4 0.6 -14.609TH08-59 485 4089 2.5 22.2372 5.9 0.0578 6.0 0.0093 1.0 0.17 59.8 0.6 57.0 3.3 -57.3 144.8 59.8 0.6 -104.409TH08-60 2010 21936 6.9 21.0024 1.3 0.0660 1.6 0.0101 0.8 0.54 64.5 0.5 64.9 1.0 80.1 31.4 64.5 0.5 80.509TH08-61 543 11016 2.3 21.0548 5.8 0.1127 10.7 0.0172 9.0 0.84 110.0 9.8 108.4 11.0 74.2 137.6 110.0 9.8 148.309TH08-62 1649 13803 9.2 21.8885 3.6 0.0593 3.9 0.0094 1.5 0.39 60.4 0.9 58.5 2.2 -18.9 86.7 60.4 0.9 -319.609TH08-63 413 10383 2.7 20.3274 1.5 0.1987 1.7 0.0293 0.6 0.38 186.1 1.2 184.0 2.8 157.1 36.2 186.1 1.2 118.409TH08-64 312 1377 2.3 20.5420 11.4 0.0581 11.5 0.0087 1.1 0.10 55.6 0.6 57.4 6.4 132.5 269.1 55.6 0.6 42.009TH08-65 98 1356 1.8 36.1363 45.1 0.0456 45.1 0.0120 1.2 0.03 76.6 0.9 45.3 20.0 -1414.3 1533.0 76.6 0.9 -5.409TH08-66 216 1593 2.2 23.4059 11.9 0.0518 11.9 0.0088 0.7 0.06 56.4 0.4 51.3 6.0 -183.6 297.8 56.4 0.4 -30.709TH08-67 1504 10929 2.6 20.9067 3.6 0.0688 3.9 0.0104 1.6 0.40 66.9 1.1 67.5 2.6 90.9 85.0 66.9 1.1 73.509TH08-68 363 2325 1.9 21.2716 10.1 0.0591 10.1 0.0091 0.5 0.05 58.5 0.3 58.3 5.7 49.8 240.8 58.5 0.3 117.409TH08-69 980 9180 2.6 21.0837 2.0 0.0753 2.4 0.0115 1.3 0.55 73.8 1.0 73.7 1.7 70.9 47.3 73.8 1.0 104.009TH08-70 560 4266 2.0 22.0119 4.5 0.0591 4.7 0.0094 1.3 0.28 60.5 0.8 58.3 2.7 -32.5 109.4 60.5 0.8 -186.109TH08-71 619 5124 2.4 22.2534 6.3 0.0570 6.4 0.0092 1.0 0.15 59.0 0.6 56.3 3.5 -59.0 154.5 59.0 0.6 -99.909TH08-72 570 4299 2.6 21.7861 3.6 0.0593 4.0 0.0094 1.6 0.41 60.1 1.0 58.5 2.3 -7.6 87.4 60.1 1.0 -794.609TH08-73 266 2949 2.1 22.5740 8.3 0.0772 8.4 0.0126 0.6 0.07 81.0 0.5 75.5 6.1 -94.0 204.8 81.0 0.5 -86.109TH08-74 646 4335 2.1 21.8197 4.7 0.0591 4.7 0.0094 0.7 0.14 60.0 0.4 58.3 2.7 -11.3 113.3 60.0 0.4 -531.509TH08-75 889 5094 1.5 21.5601 3.1 0.0609 3.3 0.0095 1.1 0.33 61.0 0.7 60.0 1.9 17.5 74.9 61.0 0.7 348.809TH08-76 507 10236 3.2 20.1347 2.0 0.1958 2.1 0.0286 0.7 0.34 181.7 1.3 181.5 3.5 179.3 45.8 181.7 1.3 101.309TH08-77 270 5106 1.6 20.0890 2.8 0.1878 3.1 0.0274 1.3 0.43 174.0 2.3 174.7 5.0 184.6 65.4 174.0 2.3 94.209TH08-78 491 3369 1.7 22.4733 7.0 0.0562 7.0 0.0092 0.5 0.07 58.7 0.3 55.5 3.8 -83.1 171.9 58.7 0.3 -70.709TH08-79 421 3054 1.5 22.1842 6.4 0.0594 6.5 0.0096 1.3 0.19 61.3 0.8 58.6 3.7 -51.5 156.4 61.3 0.8 -119.109TH08-80 1948 16410 2.6 21.0065 1.8 0.0787 2.3 0.0120 1.5 0.63 76.8 1.1 76.9 1.7 79.6 43.1 76.8 1.1 96.509TH08-81 317 1995 1.3 23.2681 10.6 0.0524 10.7 0.0088 1.8 0.16 56.8 1.0 51.9 5.4 -168.9 264.3 56.8 1.0 -33.609TH08-82 613 4203 2.0 21.6914 3.8 0.0687 4.0 0.0108 1.1 0.28 69.3 0.8 67.5 2.6 2.9 91.9 69.3 0.8 2369.009TH08-83 1357 8748 1.9 21.2257 2.1 0.0759 3.1 0.0117 2.3 0.73 74.8 1.7 74.2 2.2 55.0 49.5 74.8 1.7 136.209TH08-84 215 4425 6.0 20.8503 4.1 0.1738 4.5 0.0263 1.8 0.41 167.2 3.0 162.7 6.8 97.3 97.1 167.2 3.0 171.909TH08-85 1108 4197 1.4 19.6511 5.7 0.0689 5.9 0.0098 1.4 0.23 63.0 0.8 67.6 3.8 235.8 131.7 63.0 0.8 26.709TH08-86 399 2202 1.8 22.3105 6.0 0.0538 6.0 0.0087 0.7 0.11 55.9 0.4 53.2 3.1 -65.3 146.2 55.9 0.4 -85.509TH08-87 258 8484 1.8 20.5226 3.3 0.1877 4.1 0.0279 2.5 0.60 177.7 4.3 174.7 6.6 134.7 77.6 177.7 4.3 131.909TH08-88 151 1407 1.7 23.7512 12.5 0.0518 12.5 0.0089 0.9 0.07 57.3 0.5 51.3 6.3 -220.3 314.8 57.3 0.5 -26.009TH08-89 123 1389 2.7 24.9001 17.7 0.0579 17.9 0.0105 2.7 0.15 67.0 1.8 57.1 9.9 -340.6 458.6 67.0 1.8 -19.709TH08-90 160 4197 3.3 20.9524 6.3 0.2076 6.3 0.0316 0.5 0.08 200.3 1.0 191.6 11.1 85.8 150.0 200.3 1.0 233.409TH08-91 496 5709 2.5 20.2507 3.9 0.0926 4.0 0.0136 1.0 0.26 87.1 0.9 89.9 3.4 165.9 90.1 87.1 0.9 52.509TH08-92 666 5640 2.5 21.8145 3.7 0.0585 3.9 0.0093 1.3 0.32 59.4 0.7 57.7 2.2 -10.7 89.8 59.4 0.7 -554.409TH08-93 328 8532 1.7 20.4123 3.1 0.1954 3.6 0.0289 1.7 0.48 183.8 3.1 181.2 5.9 147.4 73.0 183.8 3.1 124.709TH08-94 359 2979 2.2 23.5440 10.6 0.0507 10.8 0.0087 1.9 0.18 55.6 1.1 50.2 5.3 -198.3 265.9 55.6 1.1 -28.009TH08-95 373 3492 2.9 21.4487 7.4 0.0602 7.5 0.0094 0.6 0.09 60.1 0.4 59.4 4.3 30.0 178.2 60.1 0.4 200.609TH08-96 300 1191 1.9 21.2117 14.9 0.0559 15.0 0.0086 1.5 0.10 55.2 0.8 55.2 8.1 56.5 357.5 55.2 0.8 97.609TH08-98 267 2382 1.9 22.4144 7.1 0.0545 7.1 0.0089 0.5 0.07 56.8 0.3 53.9 3.7 -76.6 172.8 56.8 0.3 -74.109TH08-99 259 13266 2.5 18.8571 3.9 0.4264 4.0 0.0583 0.5 0.13 365.4 1.8 360.6 12.0 330.1 89.2 365.4 1.8 110.7

65

Sample 09LA08, Dakaneek Bay Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.86602, W133.85295

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09LA08-1 1885 19152 7.7 21.3368 2.8 0.0797 2.9 0.0123 0.9 0.30 79.0 0.7 77.8 2.2 42.5 66.5 79.0 0.7 185.909LA08-2 679 6144 8.7 22.2281 10.2 0.0632 10.2 0.0102 0.8 0.08 65.4 0.5 62.3 6.2 -56.3 249.2 65.4 0.5 -116.209LA08-3 325 2289 2.7 20.7827 6.5 0.0651 6.7 0.0098 1.6 0.24 62.9 1.0 64.0 4.1 105.0 153.5 62.9 1.0 59.909LA08-4 299 1443 2.4 19.6103 4.1 0.0614 4.4 0.0087 1.5 0.34 56.1 0.8 60.5 2.6 240.5 95.1 56.1 0.8 23.309LA08-5 149 1389 2.4 20.3847 9.1 0.0857 9.2 0.0127 0.9 0.10 81.1 0.7 83.5 7.4 150.5 214.3 81.1 0.7 53.909LA08-6 240 1350 2.4 20.6861 13.9 0.0587 13.9 0.0088 1.1 0.08 56.5 0.6 57.9 7.8 116.0 328.7 56.5 0.6 48.709LA08-7 184 2364 4.6 21.8211 12.3 0.0864 12.4 0.0137 1.3 0.11 87.6 1.1 84.2 10.0 -11.4 299.1 87.6 1.1 -765.009LA08-8 280 2289 3.0 21.0192 7.9 0.0574 8.0 0.0087 0.9 0.12 56.1 0.5 56.6 4.4 78.2 188.8 56.1 0.5 71.809LA08-9 377 1230 1.9 15.6561 12.9 0.0787 13.0 0.0089 1.8 0.14 57.3 1.0 76.9 9.6 737.4 273.6 57.3 1.0 7.809LA08-10 810 1707 1.8 16.6044 7.3 0.0768 7.6 0.0092 2.1 0.28 59.4 1.3 75.1 5.5 611.6 157.6 59.4 1.3 9.709LA08-11 114 369 2.1 6.8898 15.2 0.6580 15.4 0.0329 2.4 0.15 208.5 4.8 513.4 62.0 2289.5 262.9 2289.5 262.9 9.109LA08-12 1003 5034 3.2 19.6230 2.7 0.0982 2.8 0.0140 0.9 0.33 89.5 0.8 95.1 2.6 239.0 61.4 89.5 0.8 37.409LA08-13 201 5754 1.7 20.0567 2.5 0.2019 2.7 0.0294 0.9 0.34 186.6 1.7 186.7 4.6 188.4 58.7 186.6 1.7 99.009LA08-14 549 807 2.1 12.6177 8.3 0.0991 8.4 0.0091 0.9 0.11 58.2 0.5 95.9 7.7 1178.5 164.8 58.2 0.5 4.909LA08-15 321 1506 2.3 18.7556 5.0 0.0646 5.1 0.0088 1.1 0.21 56.4 0.6 63.6 3.2 342.3 113.3 56.4 0.6 16.509LA08-16 302 9093 2.9 20.2536 3.2 0.2007 3.3 0.0295 0.9 0.26 187.3 1.6 185.7 5.6 165.6 74.3 187.3 1.6 113.109LA08-17 100 786 2.0 22.4156 27.4 0.0548 27.4 0.0089 1.7 0.06 57.1 1.0 54.1 14.5 -76.8 680.7 57.1 1.0 -74.409LA08-18 738 2409 2.5 18.6582 6.3 0.0673 6.3 0.0091 0.6 0.10 58.4 0.4 66.1 4.0 354.1 141.7 58.4 0.4 16.509LA08-19 447 1689 3.2 17.8459 8.7 0.0692 8.8 0.0090 1.5 0.17 57.5 0.8 67.9 5.8 453.8 192.4 57.5 0.8 12.709LA08-20 787 6546 2.3 20.9733 5.6 0.0601 5.8 0.0091 1.4 0.24 58.7 0.8 59.3 3.3 83.4 133.0 58.7 0.8 70.409LA08-21 429 2508 1.9 16.8022 4.9 0.2321 5.6 0.0283 2.8 0.49 179.8 4.9 212.0 10.8 586.0 106.6 179.8 4.9 30.709LA08-22 1374 1137 1.2 13.3061 14.5 0.0989 14.5 0.0095 1.1 0.07 61.2 0.7 95.8 13.3 1072.6 292.7 61.2 0.7 5.709LA08-24 398 3429 2.4 20.8855 3.9 0.0597 4.0 0.0090 0.9 0.22 58.0 0.5 58.9 2.3 93.3 93.4 58.0 0.5 62.209LA08-25 241 1797 2.3 20.7352 6.9 0.0565 7.0 0.0085 1.3 0.19 54.6 0.7 55.8 3.8 110.4 162.5 54.6 0.7 49.409LA08-26 274 828 4.2 13.4772 18.5 0.1480 18.5 0.0145 1.0 0.05 92.6 0.9 140.2 24.3 1046.9 376.5 92.6 0.9 8.809LA08-27 1085 9528 2.1 21.4711 3.7 0.0607 3.8 0.0094 0.6 0.17 60.6 0.4 59.8 2.2 27.5 88.9 60.6 0.4 220.609LA08-28 583 18075 1.6 19.7386 2.6 0.2320 2.8 0.0332 1.1 0.39 210.6 2.2 211.8 5.4 225.5 59.8 210.6 2.2 93.409LA08-29 1046 13101 8.9 21.3805 2.8 0.0785 2.8 0.0122 0.5 0.18 78.0 0.4 76.7 2.1 37.6 66.3 78.0 0.4 207.709LA08-30 296 2208 3.4 20.8770 6.0 0.0629 6.1 0.0095 1.3 0.21 61.1 0.8 61.9 3.7 94.3 141.3 61.1 0.8 64.709LA08-31 525 4050 2.1 21.7089 7.4 0.0582 7.4 0.0092 1.1 0.15 58.8 0.7 57.5 4.2 1.0 177.4 58.8 0.7 5936.309LA08-32 864 7443 2.7 21.4885 3.3 0.0594 3.4 0.0093 0.7 0.20 59.4 0.4 58.6 1.9 25.5 79.5 59.4 0.4 232.809LA08-34 301 2283 2.2 22.9013 19.6 0.0530 19.6 0.0088 0.8 0.04 56.5 0.4 52.4 10.0 -129.5 487.7 56.5 0.4 -43.609LA08-35 650 17163 1.7 20.0907 2.1 0.1969 2.2 0.0287 0.5 0.23 182.3 0.9 182.5 3.6 184.4 48.8 182.3 0.9 98.909LA08-36 271 2700 2.6 21.1587 6.9 0.0693 7.0 0.0106 1.0 0.15 68.2 0.7 68.1 4.6 62.5 165.4 68.2 0.7 109.209LA08-37 306 717 2.8 11.9454 7.9 0.1117 8.0 0.0097 1.1 0.14 62.1 0.7 107.5 8.2 1285.9 154.2 62.1 0.7 4.809LA08-38 1364 7941 3.5 21.0236 1.9 0.0645 2.0 0.0098 0.5 0.25 63.1 0.3 63.5 1.2 77.7 45.5 63.1 0.3 81.209LA08-39 703 4536 3.1 20.1673 6.9 0.0630 7.0 0.0092 1.5 0.22 59.2 0.9 62.1 4.2 175.6 160.0 59.2 0.9 33.709LA08-40 488 1548 2.5 17.6580 8.8 0.0657 9.6 0.0084 3.9 0.41 54.0 2.1 64.6 6.0 477.2 194.3 54.0 2.1 11.309LA08-41 1411 12099 4.3 21.0787 2.9 0.0705 3.0 0.0108 0.6 0.20 69.1 0.4 69.2 2.0 71.5 69.3 69.1 0.4 96.709LA08-42 1113 5997 1.4 21.2599 3.1 0.0695 3.2 0.0107 0.7 0.20 68.8 0.4 68.3 2.1 51.1 74.4 68.8 0.4 134.509LA08-43 452 8889 1.5 20.4064 5.4 0.1311 9.9 0.0194 8.4 0.84 123.9 10.3 125.1 11.7 148.0 126.2 123.9 10.3 83.709LA08-44 360 3243 3.6 20.6954 4.4 0.0637 4.6 0.0096 1.5 0.33 61.4 0.9 62.7 2.8 114.9 102.7 61.4 0.9 53.409LA08-45 299 1443 4.8 15.7317 9.9 0.1267 9.9 0.0145 0.5 0.05 92.5 0.5 121.1 11.3 727.2 209.8 92.5 0.5 12.709LA08-46 278 2277 2.6 21.0011 7.5 0.0648 7.7 0.0099 1.6 0.21 63.3 1.0 63.8 4.7 80.2 178.3 63.3 1.0 79.009LA08-47 417 5784 2.3 18.4383 6.7 0.2160 6.7 0.0289 0.5 0.07 183.5 0.9 198.5 12.1 380.8 150.9 183.5 0.9 48.209LA08-48 521 1152 7.3 11.2594 6.4 0.3741 7.2 0.0305 3.3 0.46 194.0 6.2 322.7 19.8 1400.1 122.4 194.0 6.2 13.909LA08-49 1853 8577 0.9 19.0589 6.6 0.1715 7.6 0.0237 3.6 0.48 151.0 5.4 160.7 11.2 305.9 151.3 151.0 5.4 49.409LA08-50 414 1500 3.5 16.5495 7.0 0.0757 7.1 0.0091 1.1 0.15 58.3 0.6 74.1 5.1 618.8 152.1 58.3 0.6 9.409LA08-51 169 1260 2.5 21.0125 13.8 0.0571 13.9 0.0087 0.9 0.06 55.9 0.5 56.4 7.6 78.9 329.9 55.9 0.5 70.809LA08-52 571 21282 4.3 19.5597 2.3 0.3029 2.3 0.0430 0.6 0.26 271.2 1.6 268.7 5.5 246.5 51.9 271.2 1.6 110.009LA08-53 408 2148 4.3 19.9485 7.4 0.0656 7.6 0.0095 1.7 0.22 60.9 1.0 64.5 4.8 201.0 172.5 60.9 1.0 30.309LA08-54 873 4164 2.7 18.6701 2.3 0.1007 2.4 0.0136 0.6 0.24 87.3 0.5 97.4 2.2 352.6 52.0 87.3 0.5 24.809LA08-55 442 1131 2.8 14.2561 9.5 0.0856 9.6 0.0088 1.2 0.13 56.8 0.7 83.4 7.7 932.6 195.1 56.8 0.7 6.109LA08-56 124 801 2.4 19.2354 10.6 0.0624 10.7 0.0087 1.5 0.14 55.8 0.8 61.4 6.4 284.9 242.4 55.8 0.8 19.609LA08-58 286 7302 2.5 19.7107 3.1 0.1926 3.3 0.0275 1.2 0.36 175.1 2.0 178.8 5.4 228.7 70.8 175.1 2.0 76.509LA08-59 285 2739 4.3 20.7900 5.9 0.0631 6.0 0.0095 1.2 0.20 61.1 0.7 62.2 3.6 104.2 139.5 61.1 0.7 58.609LA08-60 653 17943 2.1 19.8003 5.3 0.1946 5.3 0.0279 0.5 0.09 177.6 0.9 180.5 8.7 218.2 121.7 177.6 0.9 81.409LA08-61 1132 7233 3.5 20.2385 3.0 0.0865 3.5 0.0127 1.8 0.50 81.3 1.4 84.2 2.8 167.4 70.4 81.3 1.4 48.609LA08-62 713 4062 2.9 20.3275 5.9 0.0664 5.9 0.0098 0.9 0.15 62.8 0.6 65.3 3.8 157.1 137.5 62.8 0.6 40.009LA08-63 719 2184 2.7 17.9017 4.6 0.0755 4.7 0.0098 0.5 0.11 62.9 0.3 73.9 3.3 446.8 102.8 62.9 0.3 14.109LA08-64 257 609 2.7 12.2233 7.4 0.1034 7.5 0.0092 1.3 0.18 58.8 0.8 99.9 7.1 1241.0 144.2 58.8 0.8 4.709LA08-65 302 807 2.8 13.1851 12.7 0.1016 12.8 0.0097 0.9 0.07 62.3 0.6 98.3 12.0 1090.9 256.2 62.3 0.6 5.709LA08-66 338 3327 3.3 21.4696 6.1 0.0586 6.2 0.0091 1.1 0.17 58.6 0.6 57.8 3.5 27.6 147.4 58.6 0.6 211.909LA08-67 235 1896 2.4 21.2507 9.4 0.0585 9.4 0.0090 1.0 0.11 57.8 0.6 57.7 5.3 52.1 223.7 57.8 0.6 111.009LA08-68 881 7164 2.3 21.5932 4.0 0.0579 4.0 0.0091 0.7 0.18 58.2 0.4 57.2 2.2 13.8 95.1 58.2 0.4 421.509LA08-69 649 5991 3.1 20.9776 2.8 0.0620 2.9 0.0094 0.8 0.27 60.5 0.5 61.1 1.7 82.9 65.4 60.5 0.5 73.009LA08-70 734 18081 1.6 20.3797 2.7 0.1936 2.8 0.0286 0.8 0.29 181.9 1.5 179.7 4.6 151.1 62.4 181.9 1.5 120.409LA08-71 2704 10044 4.4 20.5892 2.6 0.0585 2.8 0.0087 1.1 0.38 56.0 0.6 57.7 1.6 127.1 60.7 56.0 0.6 44.109LA08-72 92 705 2.6 20.3347 19.9 0.0769 20.1 0.0113 2.5 0.13 72.7 1.8 75.2 14.6 156.3 470.7 72.7 1.8 46.509LA08-73 674 2235 2.6 16.8663 3.5 0.1029 3.6 0.0126 0.6 0.18 80.6 0.5 99.4 3.4 577.7 76.6 80.6 0.5 14.009LA08-74 284 1839 2.0 20.6962 7.3 0.0602 7.4 0.0090 0.9 0.12 58.0 0.5 59.3 4.3 114.9 173.5 58.0 0.5 50.509LA08-75 363 2637 3.1 21.4874 9.6 0.0574 9.6 0.0089 0.6 0.07 57.4 0.4 56.7 5.3 25.6 231.2 57.4 0.4 224.109LA08-76 432 1413 2.4 17.5966 6.3 0.0705 6.4 0.0090 1.0 0.15 57.7 0.5 69.1 4.3 484.9 139.0 57.7 0.5 11.909LA08-77 644 3312 2.0 20.9208 8.2 0.0595 8.3 0.0090 0.8 0.09 57.9 0.4 58.6 4.7 89.4 195.7 57.9 0.4 64.809LA08-78 425 3126 4.4 21.3918 7.3 0.0636 7.3 0.0099 0.5 0.07 63.3 0.3 62.6 4.4 36.3 174.0 63.3 0.3 174.509LA08-79 724 3954 2.1 20.5599 3.3 0.0648 3.4 0.0097 0.7 0.21 62.0 0.4 63.7 2.1 130.4 77.4 62.0 0.4 47.509LA08-80 422 2067 1.9 20.7047 15.1 0.0616 15.1 0.0093 0.7 0.05 59.4 0.4 60.7 8.9 113.9 357.7 59.4 0.4 52.109LA08-81 1081 9753 7.4 21.2066 2.2 0.0649 2.3 0.0100 0.7 0.30 64.1 0.4 63.9 1.4 57.1 51.9 64.1 0.4 112.309LA08-82 790 672 1.9 8.3483 35.9 0.1466 36.6 0.0089 7.5 0.20 57.0 4.2 138.9 47.6 1953.0 664.1 1953.0 664.1 2.909LA08-83 185 1494 3.1 21.8345 13.9 0.0557 15.0 0.0088 5.5 0.36 56.6 3.1 55.0 8.0 -12.9 337.8 56.6 3.1 -437.909LA08-84 251 498 2.2 8.6979 24.1 0.1531 24.5 0.0097 4.0 0.16 61.9 2.4 144.6 33.0 1879.4 441.7 1879.4 441.7 3.309LA08-85 1517 4911 4.8 17.6706 4.6 0.1562 6.6 0.0200 4.7 0.71 127.7 6.0 147.3 9.1 475.6 102.7 127.7 6.0 26.909LA08-86 402 11826 2.4 20.1892 2.9 0.1936 3.0 0.0283 0.6 0.21 180.2 1.1 179.7 4.9 173.0 68.0 180.2 1.1 104.109LA08-87 293 588 2.9 9.8740 15.9 0.1319 15.9 0.0094 0.8 0.05 60.6 0.5 125.8 18.8 1647.6 296.6 60.6 0.5 3.709LA08-88 317 1437 1.9 18.1079 10.3 0.0749 10.4 0.0098 1.7 0.16 63.1 1.1 73.3 7.4 421.3 229.5 63.1 1.1 15.009LA08-89 674 7356 1.2 20.9773 3.6 0.0838 3.9 0.0128 1.4 0.35 81.7 1.1 81.7 3.0 82.9 86.2 81.7 1.1 98.509LA08-90 390 849 2.9 8.3111 65.0 0.1495 65.3 0.0090 6.4 0.10 57.8 3.7 141.5 86.4 1961.0 1332.6 1961.0 1332.6 2.909LA08-91 255 1212 3.8 16.0275 34.2 0.0751 34.2 0.0087 1.8 0.05 56.1 1.0 73.6 24.3 687.6 750.1 56.1 1.0 8.209LA08-92 1127 9564 1.6 21.3786 3.2 0.0589 3.3 0.0091 0.5 0.17 58.6 0.3 58.1 1.8 37.8 77.0 58.6 0.3 155.009LA08-93 345 3900 2.5 21.3784 6.2 0.0621 6.2 0.0096 0.5 0.08 61.7 0.3 61.1 3.7 37.8 149.0 61.7 0.3 163.309LA08-94 124 504 3.2 9.6058 13.8 0.1840 14.0 0.0128 2.1 0.15 82.1 1.7 171.5 22.0 1698.5 255.8 82.1 1.7 4.809LA08-95 304 1653 3.2 20.3390 6.6 0.0588 7.0 0.0087 2.4 0.34 55.7 1.3 58.0 4.0 155.8 154.9 55.7 1.3 35.709LA08-97 450 13962 3.3 19.9398 3.0 0.2058 3.0 0.0298 0.5 0.17 189.0 0.9 190.0 5.2 202.0 68.7 189.0 0.9 93.609LA08-98 733 2610 1.7 18.2571 7.3 0.0658 7.8 0.0087 2.7 0.35 55.9 1.5 64.7 4.9 403.0 163.2 55.9 1.5 13.909LA08-99 478 621 2.1 9.5310 13.1 0.1385 13.1 0.0096 0.6 0.04 61.4 0.3 131.7 16.2 1712.9 242.0 61.4 0.3 3.609LA08-100 243 1296 2.6 17.4575 13.8 0.0708 13.8 0.0090 0.6 0.05 57.5 0.4 69.4 9.3 502.4 305.5 57.5 0.4 11.4

66

Sample 09LA05, Dakaneek Point Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.86115, W133.87505

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09LA05-1 180 1506 1.9 22.8584 9.0 0.0597 9.2 0.0099 1.8 0.19 63.5 1.1 58.9 5.3 -124.9 222.9 63.5 1.1 -50.909LA05-2 537 6045 6.2 21.3737 4.1 0.0918 4.2 0.0142 0.8 0.20 91.1 0.8 89.2 3.6 38.3 98.0 91.1 0.8 237.809LA05-3 358 2271 3.8 23.1545 10.8 0.0573 10.8 0.0096 0.5 0.05 61.7 0.3 56.6 5.9 -156.7 268.0 61.7 0.3 -39.409LA05-4 249 4038 0.8 19.8109 8.3 0.1994 8.4 0.0287 0.9 0.11 182.1 1.6 184.6 14.1 217.0 192.8 182.1 1.6 83.909LA05-5 597 4587 1.3 21.5392 3.8 0.0606 3.8 0.0095 0.5 0.13 60.7 0.3 59.7 2.2 19.9 90.6 60.7 0.3 306.009LA05-6 992 8334 10.7 21.4637 2.5 0.0629 2.6 0.0098 0.5 0.20 62.8 0.3 61.9 1.5 28.3 60.0 62.8 0.3 222.009LA05-7 409 2847 10.4 21.7925 4.9 0.0645 5.0 0.0102 0.7 0.14 65.4 0.4 63.5 3.0 -8.3 118.5 65.4 0.4 -791.109LA05-8 884 6606 2.9 21.3742 2.8 0.0625 3.7 0.0097 2.4 0.65 62.1 1.5 61.5 2.2 38.3 67.5 62.1 1.5 162.409LA05-9 628 4134 1.2 21.4241 4.1 0.0831 4.4 0.0129 1.6 0.37 82.7 1.3 81.1 3.4 32.7 98.1 82.7 1.3 253.009LA05-10 540 4659 21.6 21.1261 2.1 0.0736 2.4 0.0113 1.1 0.46 72.3 0.8 72.2 1.7 66.2 51.1 72.3 0.8 109.309LA05-11 224 1998 1.6 23.9879 14.2 0.0582 14.3 0.0101 1.5 0.10 65.0 1.0 57.5 8.0 -245.3 360.3 65.0 1.0 -26.509LA05-12 748 8967 8.0 21.2879 2.6 0.0924 3.1 0.0143 1.7 0.54 91.3 1.5 89.8 2.7 48.0 63.1 91.3 1.5 190.409LA05-13 952 11409 3.2 21.3954 2.7 0.0883 2.7 0.0137 0.5 0.19 87.7 0.4 85.9 2.2 35.9 63.5 87.7 0.4 244.309LA05-14 139 1431 4.4 23.0331 9.8 0.0611 9.8 0.0102 0.9 0.09 65.5 0.6 60.2 5.7 -143.7 242.6 65.5 0.6 -45.609LA05-15 247 5436 2.0 20.7975 4.0 0.1917 4.0 0.0289 0.5 0.13 183.7 0.9 178.1 6.5 103.4 93.5 183.7 0.9 177.809LA05-16 232 2460 1.7 22.2358 17.4 0.0569 17.4 0.0092 0.5 0.03 58.9 0.3 56.2 9.5 -57.1 425.6 58.9 0.3 -103.009LA05-17 386 5556 5.5 21.1939 3.4 0.0918 3.6 0.0141 1.0 0.29 90.3 0.9 89.2 3.0 58.5 81.5 90.3 0.9 154.309LA05-18 505 4731 1.6 21.9048 3.9 0.0570 3.9 0.0091 0.5 0.13 58.1 0.3 56.3 2.1 -20.7 94.1 58.1 0.3 -280.809LA05-19 643 9072 8.1 21.6696 3.7 0.0906 3.7 0.0142 0.5 0.13 91.1 0.5 88.0 3.2 5.3 89.5 91.1 0.5 1704.909LA05-20 311 5784 1.3 20.3217 3.4 0.1782 3.7 0.0263 1.5 0.40 167.1 2.4 166.5 5.6 157.8 78.8 167.1 2.4 105.909LA05-21 474 5082 5.0 22.0006 7.1 0.0628 7.7 0.0100 3.0 0.39 64.3 1.9 61.8 4.6 -31.3 172.7 64.3 1.9 -205.509LA05-22 994 9294 5.1 21.6503 2.7 0.0586 2.8 0.0092 0.9 0.33 59.0 0.5 57.8 1.6 7.5 64.4 59.0 0.5 789.709LA05-23 275 2856 2.0 22.4186 6.4 0.0676 6.4 0.0110 0.6 0.10 70.5 0.4 66.4 4.1 -77.1 155.9 70.5 0.4 -91.409LA05-24 428 3996 2.6 22.0405 5.9 0.0582 5.9 0.0093 0.8 0.13 59.7 0.5 57.4 3.3 -35.7 142.2 59.7 0.5 -167.309LA05-25 688 6120 2.6 21.5450 2.9 0.0636 3.5 0.0099 2.0 0.57 63.8 1.2 62.6 2.1 19.2 68.7 63.8 1.2 331.709LA05-26 186 777 2.0 17.4529 15.9 0.0709 16.1 0.0090 2.6 0.16 57.6 1.5 69.5 10.8 503.0 352.1 57.6 1.5 11.409LA05-27 1017 8070 3.9 21.4190 4.5 0.0640 4.6 0.0099 0.8 0.16 63.7 0.5 63.0 2.8 33.2 107.8 63.7 0.5 191.709LA05-28 919 8442 3.4 21.7101 2.9 0.0655 3.0 0.0103 0.6 0.19 66.1 0.4 64.4 1.9 0.9 70.4 66.1 0.4 7667.909LA05-29 378 3087 3.4 22.5876 7.2 0.0608 7.6 0.0100 2.3 0.31 63.9 1.5 60.0 4.4 -95.5 177.0 63.9 1.5 -66.909LA05-30 396 6840 1.6 20.5943 1.8 0.1695 2.5 0.0253 1.8 0.70 161.2 2.8 159.0 3.7 126.5 42.4 161.2 2.8 127.409LA05-31 770 5712 1.3 21.7009 5.9 0.0597 5.9 0.0094 1.0 0.17 60.3 0.6 58.9 3.4 1.8 141.3 60.3 0.6 3288.109LA05-32 355 4125 3.2 21.3884 3.6 0.0936 3.7 0.0145 0.5 0.14 92.9 0.5 90.9 3.2 36.7 87.1 92.9 0.5 253.409LA05-33 2867 25017 2.4 20.6493 2.2 0.0834 2.4 0.0125 0.9 0.39 80.0 0.7 81.3 1.8 120.2 51.1 80.0 0.7 66.509LA05-35 247 6291 1.7 20.7623 3.4 0.1835 3.4 0.0276 0.5 0.15 175.8 0.9 171.1 5.4 107.4 80.2 175.8 0.9 163.709LA05-36 276 2349 1.8 22.1980 14.4 0.0689 14.4 0.0111 0.9 0.06 71.1 0.7 67.7 9.4 -53.0 352.2 71.1 0.7 -134.309LA05-37 536 1110 5.9 22.4737 10.3 0.0512 11.0 0.0083 4.0 0.37 53.6 2.2 50.7 5.5 -83.1 252.4 53.6 2.2 -64.509LA05-38 261 4071 3.4 22.3025 7.6 0.0874 7.7 0.0141 1.2 0.15 90.5 1.1 85.1 6.3 -64.4 186.4 90.5 1.1 -140.609LA05-39 468 5019 6.4 21.1726 2.5 0.0925 2.8 0.0142 1.1 0.39 90.9 1.0 89.8 2.4 60.9 60.7 90.9 1.0 149.109LA05-40 463 3183 2.8 21.3990 3.8 0.0761 4.8 0.0118 2.8 0.59 75.6 2.1 74.4 3.4 35.5 91.8 75.6 2.1 213.209LA05-41 135 1140 1.3 25.5661 19.1 0.0561 19.2 0.0104 1.7 0.09 66.7 1.2 55.4 10.4 -409.1 503.4 66.7 1.2 -16.309LA05-42 797 5529 2.2 21.1295 5.2 0.0605 5.4 0.0093 1.3 0.23 59.5 0.7 59.6 3.1 65.8 124.4 59.5 0.7 90.409LA05-43 334 2712 3.3 22.6846 7.3 0.0592 7.3 0.0097 0.5 0.07 62.4 0.3 58.4 4.1 -106.0 179.0 62.4 0.3 -58.909LA05-44 304 2883 3.5 21.7491 4.9 0.0911 4.9 0.0144 0.5 0.10 92.0 0.5 88.6 4.2 -3.5 117.6 92.0 0.5 -2652.509LA05-45 1335 8994 0.9 21.0771 1.9 0.0777 2.2 0.0119 1.0 0.46 76.1 0.8 76.0 1.6 71.7 45.6 76.1 0.8 106.109LA05-46 304 2547 1.7 22.7921 8.7 0.0592 8.8 0.0098 0.5 0.06 62.7 0.3 58.4 5.0 -117.7 215.8 62.7 0.3 -53.309LA05-47 454 6696 1.0 21.7370 4.9 0.1068 10.6 0.0168 9.3 0.89 107.6 10.0 103.0 10.3 -2.1 118.4 107.6 10.0 -5063.309LA05-48 290 2142 4.9 21.0342 7.1 0.0918 7.3 0.0140 1.4 0.19 89.7 1.2 89.2 6.2 76.5 169.7 89.7 1.2 117.209LA05-50 1018 3633 2.5 20.5952 3.2 0.0627 3.5 0.0094 1.4 0.39 60.1 0.8 61.7 2.1 126.4 75.2 60.1 0.8 47.509LA05-51 240 5682 1.4 19.7910 4.7 0.1890 4.9 0.0271 1.3 0.26 172.5 2.2 175.7 7.9 219.4 109.5 172.5 2.2 78.709LA05-52 544 5451 3.1 21.5317 4.8 0.0588 4.8 0.0092 0.5 0.10 58.9 0.3 58.0 2.7 20.7 114.5 58.9 0.3 284.809LA05-53 855 10911 6.4 21.1895 1.9 0.0855 2.0 0.0131 0.9 0.42 84.2 0.7 83.3 1.6 59.0 44.2 84.2 0.7 142.509LA05-54 293 2409 1.9 23.6002 12.5 0.0536 12.6 0.0092 1.4 0.11 58.9 0.8 53.0 6.5 -204.3 314.6 58.9 0.8 -28.809LA05-55 577 3510 1.6 21.0300 10.6 0.0605 10.6 0.0092 0.9 0.09 59.2 0.5 59.6 6.2 77.0 252.0 59.2 0.5 76.909LA05-56 495 3942 2.5 22.0053 6.6 0.0553 6.7 0.0088 0.5 0.08 56.7 0.3 54.7 3.5 -31.8 161.2 56.7 0.3 -178.309LA05-57 386 2844 2.4 21.9999 5.7 0.0584 5.7 0.0093 0.5 0.09 59.8 0.3 57.6 3.2 -31.2 138.6 59.8 0.3 -191.709LA05-58 300 5622 1.8 21.0100 3.7 0.1485 7.2 0.0226 6.1 0.86 144.3 8.7 140.6 9.4 79.2 87.9 144.3 8.7 182.109LA05-59 332 2463 1.3 22.3880 9.0 0.0624 9.0 0.0101 0.5 0.06 65.0 0.3 61.5 5.4 -73.8 219.4 65.0 0.3 -88.109LA05-60 984 5856 0.9 20.9669 3.2 0.0802 3.3 0.0122 0.8 0.24 78.1 0.6 78.3 2.5 84.1 75.6 78.1 0.6 92.909LA05-61 693 4398 7.6 20.5067 5.8 0.0715 6.2 0.0106 1.9 0.32 68.2 1.3 70.1 4.2 136.5 137.3 68.2 1.3 50.009LA05-62 327 1521 1.8 19.1228 20.9 0.0652 21.0 0.0090 1.5 0.07 58.1 0.8 64.2 13.0 298.3 482.0 58.1 0.8 19.509LA05-63 193 1860 2.2 23.3499 10.9 0.0509 10.9 0.0086 0.8 0.07 55.3 0.4 50.4 5.4 -177.6 272.3 55.3 0.4 -31.109LA05-64 390 3603 1.3 22.0555 5.6 0.0656 5.6 0.0105 0.5 0.09 67.3 0.3 64.5 3.5 -37.3 136.6 67.3 0.3 -180.309LA05-65 466 5643 16.5 21.4835 2.9 0.0774 3.2 0.0121 1.4 0.45 77.3 1.1 75.7 2.3 26.1 68.7 77.3 1.1 296.809LA05-66 351 3207 1.4 22.1356 6.2 0.0677 6.3 0.0109 0.9 0.14 69.7 0.6 66.5 4.0 -46.1 151.5 69.7 0.6 -151.109LA05-67 599 2754 1.5 21.5507 5.0 0.0583 5.1 0.0091 0.7 0.13 58.5 0.4 57.6 2.8 18.6 121.3 58.5 0.4 314.509LA05-68 228 2379 3.0 21.1154 7.3 0.0942 7.5 0.0144 1.7 0.23 92.3 1.6 91.4 6.5 67.3 173.3 92.3 1.6 137.009LA05-69 327 3444 1.9 22.2109 5.9 0.0599 6.0 0.0097 1.4 0.24 61.9 0.9 59.1 3.5 -54.4 143.0 61.9 0.9 -113.909LA05-70 305 5229 0.9 20.3966 2.3 0.1910 2.5 0.0283 0.9 0.35 179.6 1.5 177.5 4.0 149.2 54.2 179.6 1.5 120.409LA05-71 143 1470 1.8 23.1300 10.9 0.0685 10.9 0.0115 0.5 0.05 73.7 0.4 67.3 7.1 -154.1 271.6 73.7 0.4 -47.809LA05-72 415 3693 2.1 21.8932 5.3 0.0601 5.4 0.0095 1.2 0.22 61.2 0.7 59.2 3.1 -19.4 127.9 61.2 0.7 -315.109LA05-73 97 618 2.1 23.4996 11.1 0.0551 11.1 0.0094 1.3 0.11 60.2 0.7 54.4 5.9 -193.6 277.9 60.2 0.7 -31.109LA05-74 356 2226 2.3 22.2107 6.1 0.0581 6.1 0.0094 0.8 0.12 60.1 0.4 57.4 3.4 -54.4 147.9 60.1 0.4 -110.509LA05-75 512 3117 1.6 19.7918 10.3 0.0924 10.3 0.0133 1.1 0.10 84.9 0.9 89.7 8.9 219.2 238.7 84.9 0.9 38.709LA05-76 446 2925 5.7 22.1457 4.9 0.0621 4.9 0.0100 0.6 0.12 64.0 0.4 61.2 2.9 -47.2 119.5 64.0 0.4 -135.409LA05-77 951 747 7.3 14.3036 8.9 0.1291 8.9 0.0134 1.0 0.11 85.8 0.9 123.3 10.3 925.8 182.3 85.8 0.9 9.309LA05-79 339 5937 0.6 19.9771 3.1 0.1902 3.3 0.0276 1.1 0.34 175.3 2.0 176.8 5.3 197.6 71.7 175.3 2.0 88.709LA05-80 327 8478 2.5 20.6623 3.9 0.1943 4.2 0.0291 1.7 0.40 185.0 3.0 180.3 7.0 118.7 91.1 185.0 3.0 155.809LA05-81 426 3384 1.5 22.3122 5.8 0.0607 5.9 0.0098 0.8 0.14 63.0 0.5 59.8 3.4 -65.5 142.0 63.0 0.5 -96.209LA05-82 138 1341 3.3 24.7736 16.6 0.0525 16.7 0.0094 1.6 0.10 60.5 1.0 51.9 8.4 -327.5 428.5 60.5 1.0 -18.509LA05-83 349 2016 1.8 20.4997 13.9 0.0624 14.0 0.0093 1.0 0.07 59.5 0.6 61.5 8.3 137.4 329.0 59.5 0.6 43.309LA05-84 293 2784 1.3 22.9038 8.2 0.0633 8.3 0.0105 1.2 0.14 67.5 0.8 62.4 5.0 -129.8 202.7 67.5 0.8 -52.009LA05-85 2114 15540 4.2 21.5832 4.5 0.0668 5.2 0.0105 2.7 0.51 67.1 1.8 65.7 3.3 14.9 107.3 67.1 1.8 448.909LA05-86 188 1656 1.7 22.1345 10.5 0.0639 10.6 0.0103 1.6 0.15 65.8 1.0 62.9 6.4 -46.0 255.1 65.8 1.0 -142.909LA05-87 729 6162 1.1 21.7498 4.4 0.0662 4.6 0.0104 1.5 0.32 67.0 1.0 65.1 2.9 -3.5 105.3 67.0 1.0 -1891.109LA05-88 676 6759 2.7 21.6026 3.5 0.0706 7.9 0.0111 7.1 0.89 70.9 5.0 69.3 5.3 12.8 84.7 70.9 5.0 553.509LA05-89 846 3882 2.4 21.3105 6.3 0.0564 6.3 0.0087 0.5 0.08 55.9 0.3 55.7 3.4 45.4 150.5 55.9 0.3 123.109LA05-90 480 3861 2.0 20.8679 14.7 0.0564 15.0 0.0085 2.7 0.18 54.7 1.5 55.7 8.1 95.4 350.5 54.7 1.5 57.409LA05-91 1118 9294 2.1 21.7525 3.0 0.0605 3.0 0.0095 0.6 0.21 61.2 0.4 59.7 1.8 -3.8 71.3 61.2 0.4 -1594.709LA05-92 550 3387 2.3 21.5662 4.0 0.0634 4.6 0.0099 2.2 0.48 63.6 1.4 62.4 2.8 16.8 96.6 63.6 1.4 378.409LA05-93 151 1677 2.5 22.2180 7.1 0.0684 7.2 0.0110 1.2 0.16 70.7 0.8 67.2 4.7 -55.2 173.8 70.7 0.8 -128.209LA05-94 291 2604 3.3 20.8090 17.6 0.0761 17.6 0.0115 1.1 0.06 73.7 0.8 74.5 12.6 102.0 418.1 73.7 0.8 72.209LA05-95 493 2739 2.0 21.5334 2.4 0.0580 2.7 0.0091 1.1 0.42 58.1 0.6 57.2 1.5 20.5 58.8 58.1 0.6 283.609LA05-96 622 3237 2.4 18.2492 21.6 0.0733 21.7 0.0097 2.0 0.09 62.3 1.3 71.8 15.0 403.9 487.8 62.3 1.3 15.409LA05-97 117 27048 1.5 8.2226 0.9 5.2943 2.0 0.3157 1.8 0.89 1768.8 27.4 1867.9 17.1 1980.1 16.6 1980.1 16.6 89.309LA05-98 398 3177 2.9 22.1865 5.8 0.0599 5.8 0.0096 0.5 0.09 61.8 0.3 59.1 3.4 -51.7 141.9 61.8 0.3 -119.609LA05-99 274 2442 1.8 18.7425 20.7 0.0957 21.0 0.0130 3.4 0.16 83.3 2.8 92.8 18.6 343.9 472.6 83.3 2.8 24.209LA05-100 243 7374 1.9 20.4266 2.9 0.1955 3.1 0.0290 1.0 0.33 184.1 1.8 181.3 5.1 145.7 67.9 184.1 1.8 126.3

67

Sample 09TH10, Point Hamilton Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.88178, W133.89398

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09TH10-1 503 4605 1.5 21.4296 9.4 0.0808 9.5 0.0126 0.8 0.08 80.5 0.6 78.9 7.2 32.1 226.4 80.5 0.6 -50.909TH10-2 1516 9273 40.1 20.4323 2.3 0.0905 2.4 0.0134 0.8 0.32 85.9 0.7 88.0 2.0 145.0 53.6 85.9 0.7 237.809TH10-3 590 2025 1.1 17.1592 17.0 0.0699 17.8 0.0087 5.3 0.30 55.8 2.9 68.6 11.8 540.2 373.8 55.8 2.9 -39.409TH10-4 281 2025 1.7 21.9211 4.6 0.0562 4.7 0.0089 1.0 0.21 57.4 0.6 55.6 2.5 -22.5 111.6 57.4 0.6 83.909TH10-5 1020 6312 1.1 20.7143 2.6 0.0809 2.8 0.0122 1.0 0.34 77.9 0.8 79.0 2.1 112.8 62.4 77.9 0.8 306.009TH10-6 418 1758 3.4 19.5248 9.3 0.0658 9.4 0.0093 1.2 0.13 59.7 0.7 64.7 5.9 250.6 214.3 59.7 0.7 222.009TH10-8 353 1293 1.6 16.6260 21.4 0.0725 21.5 0.0087 1.8 0.09 56.1 1.0 71.1 14.8 608.8 468.2 56.1 1.0 -791.109TH10-9 116 2499 4.0 17.9361 6.2 0.2503 7.2 0.0326 3.7 0.51 206.5 7.4 226.8 14.6 442.5 138.0 206.5 7.4 162.409TH10-10 144 1131 1.3 20.8348 19.9 0.0666 19.9 0.0101 1.7 0.08 64.5 1.1 65.4 12.6 99.1 474.3 64.5 1.1 253.009TH10-11 695 5556 2.1 22.0765 10.8 0.0674 10.9 0.0108 0.5 0.05 69.2 0.3 66.3 7.0 -39.6 263.9 69.2 0.3 109.309TH10-12 934 25956 1.5 18.3914 2.5 0.4468 2.5 0.0596 0.7 0.27 373.2 2.5 375.1 8.0 386.5 55.0 373.2 2.5 -26.509TH10-13 578 3444 1.0 21.8061 5.2 0.0680 5.2 0.0108 0.5 0.10 69.0 0.3 66.8 3.4 -9.8 124.7 69.0 0.3 190.409TH10-15 184 708 1.9 10.1063 13.7 0.1340 13.9 0.0098 2.8 0.20 63.0 1.8 127.7 16.7 1604.4 255.8 63.0 1.8 244.309TH10-16 700 1488 1.9 14.3996 14.9 0.0910 14.9 0.0095 0.5 0.03 61.0 0.3 88.5 12.6 912.0 308.7 61.0 0.3 -45.609TH10-17 184 1530 1.8 22.5786 15.7 0.0599 15.7 0.0098 0.9 0.05 62.9 0.5 59.0 9.0 -94.5 387.8 62.9 0.5 177.809TH10-18 150 480 1.8 10.5947 34.7 0.1396 34.9 0.0107 3.2 0.09 68.8 2.2 132.7 43.4 1515.8 676.9 68.8 2.2 -103.009TH10-19 672 13059 2.0 19.0285 3.4 0.2209 5.0 0.0305 3.6 0.73 193.6 6.9 202.6 9.1 309.5 77.1 193.6 6.9 154.309TH10-20 277 2151 2.1 21.3219 9.4 0.0640 9.7 0.0099 2.3 0.24 63.5 1.4 63.0 5.9 44.1 225.7 63.5 1.4 -280.809TH10-21 345 3411 1.9 19.9279 14.0 0.0818 14.1 0.0118 1.7 0.12 75.8 1.3 79.8 10.9 203.4 326.9 75.8 1.3 1704.909TH10-22 158 3303 1.2 20.2470 4.7 0.1982 4.8 0.0291 0.9 0.18 184.9 1.6 183.6 8.1 166.4 110.9 184.9 1.6 105.909TH10-23 226 2616 2.4 22.4117 8.3 0.0805 8.4 0.0131 0.7 0.08 83.8 0.6 78.6 6.3 -76.4 204.4 83.8 0.6 -205.509TH10-24 1006 8127 2.4 21.3040 7.4 0.0665 7.4 0.0103 0.8 0.11 65.9 0.5 65.4 4.7 46.2 176.7 65.9 0.5 789.709TH10-25 375 2964 1.9 22.4674 6.7 0.0662 6.8 0.0108 0.7 0.11 69.1 0.5 65.1 4.3 -82.4 164.8 69.1 0.5 -91.409TH10-26 472 9297 1.9 20.3378 3.1 0.2012 3.3 0.0297 1.3 0.39 188.6 2.4 186.2 5.7 155.9 72.0 188.6 2.4 -167.309TH10-27 322 8055 2.0 19.8981 2.6 0.2051 2.9 0.0296 1.2 0.40 188.0 2.1 189.4 5.0 206.9 61.2 188.0 2.1 331.709TH10-28 574 1938 2.4 15.9383 11.7 0.1179 11.7 0.0136 1.2 0.10 87.3 1.0 113.2 12.6 699.5 249.1 87.3 1.0 11.409TH10-29 333 2322 2.1 21.5623 5.9 0.0595 6.0 0.0093 0.5 0.09 59.7 0.3 58.7 3.4 17.3 142.7 59.7 0.3 191.709TH10-30 412 3504 10.1 18.5396 16.4 0.0865 16.6 0.0116 2.7 0.16 74.6 2.0 84.3 13.4 368.5 371.6 74.6 2.0 7667.909TH10-31 823 5385 1.6 21.1899 4.0 0.0598 4.1 0.0092 0.6 0.15 58.9 0.4 58.9 2.3 59.0 96.3 58.9 0.4 -66.909TH10-32 237 810 1.7 12.8522 21.7 0.0983 22.0 0.0092 4.0 0.18 58.8 2.3 95.2 20.0 1142.0 436.2 58.8 2.3 127.409TH10-33 1034 8181 3.0 20.5861 3.8 0.0828 4.0 0.0124 1.0 0.25 79.2 0.8 80.7 3.1 127.5 90.2 79.2 0.8 3288.109TH10-34 1577 18588 98.7 20.9947 1.2 0.0907 1.6 0.0138 1.1 0.68 88.4 0.9 88.2 1.3 81.0 28.0 88.4 0.9 253.409TH10-35 1300 4908 2.3 19.7279 3.5 0.0740 4.6 0.0106 3.0 0.65 67.9 2.0 72.4 3.2 226.7 81.0 67.9 2.0 66.509TH10-36 692 7341 0.9 21.0929 2.2 0.1198 3.2 0.0183 2.3 0.72 117.1 2.7 114.9 3.4 69.9 52.2 117.1 2.7 163.709TH10-37 413 3402 2.2 21.8833 6.7 0.0564 7.3 0.0090 2.7 0.37 57.4 1.5 55.7 3.9 -18.3 163.2 57.4 1.5 -134.309TH10-38 971 6159 2.5 18.9361 18.8 0.0882 19.0 0.0121 2.6 0.14 77.6 2.0 85.8 15.6 320.6 430.7 77.6 2.0 -64.509TH10-39 480 23061 2.1 18.5653 1.8 0.4097 2.2 0.0552 1.2 0.56 346.1 4.1 348.6 6.5 365.3 41.6 346.1 4.1 -140.609TH10-40 528 6969 6.4 21.7566 5.2 0.0867 5.3 0.0137 1.1 0.20 87.6 0.9 84.4 4.3 -4.3 124.6 87.6 0.9 149.109TH10-41 1033 8370 44.9 20.3100 4.4 0.0946 4.5 0.0139 0.6 0.14 89.2 0.5 91.7 3.9 159.1 103.2 89.2 0.5 213.209TH10-42 502 3027 2.2 19.7715 13.3 0.0649 13.4 0.0093 1.0 0.07 59.8 0.6 63.9 8.3 221.6 309.3 59.8 0.6 -16.309TH10-43 672 10671 1.3 20.0357 9.1 0.1657 9.3 0.0241 1.9 0.21 153.4 2.9 155.7 13.4 190.9 210.9 153.4 2.9 90.409TH10-44 517 7668 7.7 21.4737 3.7 0.0908 3.8 0.0141 1.0 0.26 90.5 0.9 88.2 3.2 27.1 88.6 90.5 0.9 -58.909TH10-45 325 1707 3.3 16.8905 9.0 0.1134 9.2 0.0139 1.9 0.21 88.9 1.7 109.1 9.5 574.7 195.5 88.9 1.7 -2652.509TH10-46 443 3702 2.7 22.6604 8.6 0.0586 8.7 0.0096 0.8 0.09 61.8 0.5 57.8 4.9 -103.4 212.8 61.8 0.5 106.109TH10-47 844 5409 3.5 19.6924 4.3 0.0919 5.0 0.0131 2.6 0.52 84.1 2.2 89.3 4.3 230.9 98.5 84.1 2.2 -53.309TH10-48 336 1860 1.9 18.5845 13.0 0.0685 13.1 0.0092 1.7 0.13 59.3 1.0 67.3 8.5 363.0 293.5 59.3 1.0 -5063.309TH10-49 351 3675 6.2 21.1414 6.9 0.0874 7.1 0.0134 1.5 0.21 85.8 1.3 85.1 5.8 64.4 165.5 85.8 1.3 117.209TH10-50 420 4974 11.2 20.9331 8.5 0.0935 8.7 0.0142 1.6 0.18 90.9 1.4 90.8 7.5 88.0 202.8 90.9 1.4 47.509TH10-51 799 6546 3.4 21.4979 13.8 0.0616 13.8 0.0096 0.5 0.04 61.6 0.3 60.7 8.2 24.5 333.3 61.6 0.3 78.709TH10-52 259 10722 2.7 20.9372 13.0 0.1858 13.1 0.0282 1.2 0.09 179.4 2.1 173.0 20.8 87.5 309.2 179.4 2.1 284.809TH10-53 1062 15393 46.4 20.7779 6.1 0.0864 6.3 0.0130 1.6 0.25 83.4 1.3 84.1 5.1 105.5 143.4 83.4 1.3 142.509TH10-54 282 2568 2.5 22.2673 6.0 0.0590 6.3 0.0095 2.0 0.31 61.1 1.2 58.2 3.6 -60.6 145.8 61.1 1.2 -28.809TH10-55 584 1278 4.1 12.8648 21.4 0.0974 21.5 0.0091 2.1 0.10 58.3 1.2 94.4 19.4 1140.0 430.5 58.3 1.2 76.909TH10-56 325 3921 2.1 21.2677 4.7 0.0558 5.6 0.0086 3.0 0.54 55.2 1.7 55.1 3.0 50.2 112.1 55.2 1.7 -178.309TH10-57 656 7026 0.8 22.0182 11.9 0.0695 11.9 0.0111 1.0 0.09 71.2 0.7 68.2 7.9 -33.2 289.3 71.2 0.7 -191.709TH10-58 443 17241 2.4 20.0800 10.9 0.2008 10.9 0.0292 0.6 0.06 185.8 1.1 185.8 18.5 185.7 254.5 185.8 1.1 182.109TH10-59 412 4440 3.4 20.6632 7.0 0.0634 7.2 0.0095 1.6 0.22 61.0 1.0 62.4 4.3 118.7 164.7 61.0 1.0 -88.109TH10-60 315 4692 2.4 21.8464 8.7 0.0567 9.0 0.0090 2.5 0.27 57.7 1.4 56.0 4.9 -14.2 210.5 57.7 1.4 92.909TH10-61 989 16905 1.7 19.6262 2.3 0.1916 2.9 0.0273 1.7 0.59 173.5 2.9 178.0 4.7 238.7 54.0 173.5 2.9 50.009TH10-62 1397 8607 4.3 20.9425 2.4 0.0718 3.2 0.0109 2.0 0.64 69.9 1.4 70.4 2.2 86.9 57.9 69.9 1.4 19.509TH10-63 514 6579 3.2 21.4053 6.5 0.0595 6.6 0.0092 1.5 0.22 59.3 0.9 58.7 3.8 34.8 154.8 59.3 0.9 -31.109TH10-64 697 5676 2.2 21.4061 3.7 0.0578 3.9 0.0090 1.2 0.30 57.5 0.7 57.0 2.2 34.7 89.7 57.5 0.7 -180.309TH10-65 576 7290 4.4 21.4163 11.0 0.0611 11.0 0.0095 1.2 0.10 60.9 0.7 60.2 6.5 33.6 263.8 60.9 0.7 296.809TH10-66 560 6459 12.7 20.1039 5.9 0.0919 5.9 0.0134 0.8 0.14 85.8 0.7 89.3 5.1 182.9 136.7 85.8 0.7 -151.109TH10-68 1502 17313 3.1 20.8953 3.0 0.0589 3.9 0.0089 2.6 0.66 57.3 1.5 58.1 2.2 92.2 70.4 57.3 1.5 314.509TH10-67 4096 14442 2.6 20.1685 2.3 0.0742 2.4 0.0109 0.6 0.24 69.6 0.4 72.7 1.7 175.4 54.5 69.6 0.4 137.009TH10-69 396 3744 2.9 22.8809 8.0 0.0507 8.0 0.0084 0.6 0.08 54.0 0.3 50.2 3.9 -127.3 197.0 54.0 0.3 -113.909TH10-70 2619 24480 2.8 20.6693 2.4 0.0676 2.5 0.0101 0.5 0.20 65.0 0.3 66.5 1.6 117.9 56.6 65.0 0.3 120.409TH10-71 275 3918 2.0 23.7341 13.3 0.0539 13.4 0.0093 1.1 0.08 59.5 0.7 53.3 6.9 -218.5 336.5 59.5 0.7 -47.809TH10-72 774 11415 5.1 20.6312 14.5 0.0795 14.7 0.0119 2.0 0.14 76.2 1.5 77.7 11.0 122.3 343.7 76.2 1.5 -315.109TH10-74 659 6030 2.2 20.4974 5.8 0.0560 5.9 0.0083 1.1 0.19 53.4 0.6 55.3 3.2 137.6 136.6 53.4 0.6 -31.109TH10-73 299 11793 2.7 20.6108 4.0 0.1834 4.1 0.0274 0.8 0.19 174.3 1.3 171.0 6.4 124.6 93.7 174.3 1.3 -110.509TH10-75 272 1107 3.2 15.0837 9.7 0.0882 9.8 0.0097 1.2 0.12 61.9 0.8 85.8 8.1 815.8 203.6 61.9 0.8 38.709TH10-76 421 4008 2.2 21.6468 10.8 0.0736 10.8 0.0116 1.1 0.10 74.1 0.8 72.1 7.5 7.9 260.1 74.1 0.8 -135.409TH10-77 232 2418 2.7 21.3462 8.8 0.0610 8.8 0.0094 0.7 0.08 60.6 0.4 60.1 5.2 41.4 210.7 60.6 0.4 9.309TH10-78 745 4317 3.4 20.3595 12.3 0.0576 12.3 0.0085 0.6 0.05 54.6 0.3 56.9 6.8 153.4 289.6 54.6 0.3 88.709TH10-79 499 5595 3.4 19.8849 9.4 0.0775 9.5 0.0112 1.8 0.19 71.6 1.3 75.8 7.0 208.4 217.7 71.6 1.3 155.809TH10-80 602 6426 3.1 22.0913 4.8 0.0535 5.8 0.0086 3.2 0.55 55.0 1.8 52.9 3.0 -41.3 117.8 55.0 1.8 -96.209TH10-82 743 6498 2.5 21.6473 4.0 0.0529 4.7 0.0083 2.5 0.53 53.3 1.3 52.3 2.4 7.8 95.3 53.3 1.3 -18.509TH10-81 1423 6318 4.4 15.2762 36.0 0.0982 36.0 0.0109 1.4 0.04 69.8 1.0 95.1 32.7 789.2 779.8 69.8 1.0 43.309TH10-83 277 3318 2.9 21.7373 11.1 0.0712 11.1 0.0112 0.6 0.06 72.0 0.5 69.8 7.5 -2.2 267.6 72.0 0.5 -52.009TH10-84 1286 52638 1.7 18.6213 31.4 0.3818 31.4 0.0516 0.5 0.02 324.1 1.6 328.4 88.4 358.5 725.9 324.1 1.6 448.909TH10-85 500 9486 19.6 21.1239 9.7 0.0894 9.7 0.0137 0.8 0.09 87.7 0.7 87.0 8.1 66.4 231.0 87.7 0.7 -142.909TH10-86 546 5328 9.2 19.8102 2.5 0.0940 2.8 0.0135 1.3 0.46 86.4 1.1 91.2 2.5 217.1 58.0 86.4 1.1 -1891.109TH10-88 443 6828 11.1 21.0222 2.4 0.1106 2.9 0.0169 1.7 0.58 107.8 1.8 106.5 2.9 77.8 56.5 107.8 1.8 553.509TH10-87 3678 48423 3.9 19.6567 9.9 0.1781 10.4 0.0254 3.0 0.29 161.6 4.8 166.4 15.9 235.1 229.6 161.6 4.8 123.109TH10-90 418 3960 2.0 22.5716 7.9 0.0538 8.4 0.0088 2.9 0.34 56.5 1.6 53.2 4.3 -93.8 193.5 56.5 1.6 57.409TH10-91 223 2736 1.9 23.5465 12.3 0.0631 12.5 0.0108 2.0 0.16 69.1 1.4 62.2 7.5 -198.6 310.3 69.1 1.4 -1594.709TH10-92 658 3240 3.4 18.0314 14.6 0.0714 14.6 0.0093 0.8 0.06 59.9 0.5 70.0 9.9 430.7 325.8 59.9 0.5 378.409TH10-94 1586 15630 2.9 20.9765 12.8 0.0632 13.1 0.0096 2.9 0.22 61.7 1.8 62.3 7.9 83.0 303.9 61.7 1.8 -128.209TH10-93 594 7035 1.8 17.0417 33.4 0.2280 33.4 0.0282 0.5 0.01 179.1 0.9 208.5 63.1 555.2 748.1 179.1 0.9 72.209TH10-95 242 3147 2.0 23.2431 22.5 0.0678 22.5 0.0114 1.3 0.06 73.2 0.9 66.6 14.5 -166.2 565.6 73.2 0.9 283.609TH10-96 326 1143 2.9 14.2613 24.1 0.0858 24.3 0.0089 2.7 0.11 57.0 1.5 83.6 19.5 931.9 502.4 57.0 1.5 15.409TH10-97 2795 7683 5.8 19.4181 3.0 0.0831 3.1 0.0117 0.8 0.25 75.0 0.6 81.0 2.5 263.2 69.9 75.0 0.6 89.309TH10-98 453 29436 2.6 18.4665 8.0 0.4204 8.0 0.0563 0.9 0.11 353.1 3.0 356.3 24.2 377.4 180.0 353.1 3.0 -119.609TH10-99 1023 10503 2.6 21.3491 7.6 0.0658 7.7 0.0102 0.9 0.11 65.3 0.6 64.7 4.8 41.1 182.5 65.3 0.6 24.209TH10-100 414 3009 2.3 21.8714 24.5 0.0546 24.5 0.0087 1.1 0.04 55.5 0.6 53.9 12.9 -17.0 599.8 55.5 0.6 126.3

68

Sample 09TH01, Lower Hamilton Bay Isotope ratios Apparent ages (Ma)Coordinates (WGS 84): N56.88599, W133.79785

Analysis U 206Pb U/Th 206Pb* ± 207Pb* ± 206Pb* ± error 206Pb* ± 207Pb* ± 206Pb* ± Best age ± Conc(ppm) 204Pb 207Pb* (%) 235U* (%) 238U (%) corr. 238U* (Ma) 235U (Ma) 207Pb* (Ma) (Ma) (Ma) (%)

09TH01-1 585 2583 5.1 21.2401 2.6 0.0882 2.7 0.0136 0.7 0.25 87.0 0.6 85.9 2.2 53.3 61.8 87.0 0.6 163.309TH01-2 682 3402 13.2 20.8116 4.8 0.0940 5.1 0.0142 1.6 0.31 90.9 1.4 91.3 4.4 101.8 114.7 90.9 1.4 89.309TH01-3 550 4641 5.1 21.3329 2.7 0.0911 2.9 0.0141 1.1 0.38 90.2 1.0 88.5 2.5 42.9 64.9 90.2 1.0 210.209TH01-4 2131 5538 5.4 16.8720 8.6 0.2159 8.7 0.0264 1.4 0.16 168.1 2.3 198.5 15.7 577.0 187.7 168.1 2.3 29.109TH01-5 1407 5652 7.9 20.8505 1.6 0.0892 1.8 0.0135 0.9 0.49 86.4 0.8 86.8 1.5 97.3 36.9 86.4 0.8 88.809TH01-6 1133 33315 2.2 18.6323 0.9 0.4166 1.1 0.0563 0.6 0.56 353.1 2.0 353.6 3.2 357.2 19.9 353.1 2.0 98.809TH01-7 3721 5238 41.0 17.6517 5.3 0.2085 6.5 0.0267 3.7 0.56 169.8 6.1 192.3 11.3 478.0 118.1 169.8 6.1 35.509TH01-8 715 6117 8.2 20.7649 4.2 0.0922 4.3 0.0139 0.8 0.19 88.9 0.7 89.5 3.7 107.1 100.4 88.9 0.7 83.009TH01-9 680 3150 14.7 21.1083 2.1 0.0907 2.2 0.0139 0.6 0.29 88.9 0.6 88.1 1.8 68.1 49.2 88.9 0.6 130.409TH01-10 573 2268 7.5 21.4485 2.5 0.0891 2.7 0.0139 0.8 0.31 88.7 0.7 86.7 2.2 30.0 61.0 88.7 0.7 296.109TH01-11 461 2340 14.2 21.8532 4.6 0.0902 4.7 0.0143 0.5 0.11 91.5 0.5 87.7 3.9 -15.0 111.8 91.5 0.5 -610.209TH01-12 450 2784 4.6 21.8913 4.6 0.0857 4.8 0.0136 1.2 0.26 87.2 1.1 83.5 3.8 -19.2 111.7 87.2 1.1 -453.909TH01-13 2276 6759 8.8 20.3761 2.1 0.0924 2.4 0.0137 1.2 0.51 87.4 1.1 89.7 2.1 151.5 48.9 87.4 1.1 57.709TH01-15 769 15552 4.5 18.1050 5.7 0.3407 5.8 0.0447 0.6 0.10 282.1 1.6 297.7 14.9 421.7 127.9 282.1 1.6 66.909TH01-16 393 2361 4.9 21.5489 3.7 0.0887 3.8 0.0139 0.8 0.20 88.8 0.7 86.3 3.2 18.8 89.9 88.8 0.7 472.609TH01-17 972 5544 23.3 20.6767 2.8 0.0940 3.3 0.0141 1.7 0.53 90.3 1.6 91.2 2.9 117.1 65.4 90.3 1.6 77.109TH01-18 347 2091 8.9 21.5382 4.8 0.0902 4.8 0.0141 0.5 0.10 90.2 0.4 87.7 4.0 20.0 114.7 90.2 0.4 451.509TH01-19 939 6849 7.3 21.3726 3.3 0.0886 3.3 0.0137 0.5 0.15 87.9 0.4 86.2 2.7 38.4 77.8 87.9 0.4 228.709TH01-20 2370 7887 109.2 20.2680 1.9 0.0895 3.4 0.0132 2.8 0.82 84.2 2.4 87.0 2.9 163.9 45.4 84.2 2.4 51.409TH01-21 596 2244 6.6 21.1831 2.9 0.0902 3.0 0.0139 0.5 0.17 88.7 0.4 87.7 2.5 59.8 69.7 88.7 0.4 148.509TH01-22 717 3045 10.3 21.3984 3.4 0.0839 3.4 0.0130 0.7 0.20 83.4 0.6 81.8 2.7 35.6 80.3 83.4 0.6 234.609TH01-23 459 1728 7.6 21.5082 3.2 0.0849 3.2 0.0133 0.6 0.18 84.9 0.5 82.8 2.6 23.3 76.2 84.9 0.5 363.709TH01-24 1006 21813 4.1 18.3277 1.1 0.3857 1.6 0.0513 1.1 0.71 322.3 3.5 331.2 4.4 394.3 24.8 322.3 3.5 81.709TH01-25 2483 8811 7.1 17.4321 4.3 0.2423 4.3 0.0306 0.6 0.13 194.5 1.1 220.3 8.6 505.6 94.4 194.5 1.1 38.509TH01-26 1303 6276 10.9 21.2762 1.8 0.0864 1.9 0.0133 0.5 0.26 85.4 0.4 84.2 1.5 49.2 43.6 85.4 0.4 173.409TH01-27 556 3609 5.0 21.4168 3.8 0.0888 3.9 0.0138 0.5 0.13 88.3 0.4 86.4 3.2 33.5 92.2 88.3 0.4 263.409TH01-28 1925 29886 2.5 18.5395 1.5 0.3127 2.1 0.0420 1.5 0.71 265.5 3.9 276.3 5.2 368.5 33.8 265.5 3.9 72.109TH01-29 565 4083 12.1 21.4976 4.5 0.0862 4.6 0.0134 0.5 0.11 86.1 0.4 84.0 3.7 24.5 108.9 86.1 0.4 351.409TH01-30 684 4146 11.6 21.0541 1.8 0.0879 2.0 0.0134 0.7 0.37 86.0 0.6 85.6 1.6 74.3 43.9 86.0 0.6 115.809TH01-31 4602 102312 3.1 18.5016 2.3 0.3874 2.8 0.0520 1.6 0.58 326.7 5.2 332.5 7.9 373.1 50.9 326.7 5.2 87.609TH01-32 1372 4986 4.0 21.1646 2.2 0.0843 2.2 0.0129 0.5 0.22 82.9 0.4 82.2 1.8 61.8 51.8 82.9 0.4 134.109TH01-33 634 2967 7.7 21.8429 5.0 0.0820 5.0 0.0130 0.6 0.13 83.2 0.5 80.0 3.8 -13.9 119.7 83.2 0.5 -600.309TH01-34 518 1842 12.1 20.9536 2.3 0.0866 2.5 0.0132 1.1 0.43 84.3 0.9 84.3 2.0 85.7 53.6 84.3 0.9 98.409TH01-35 1015 4296 10.1 21.1819 4.8 0.0880 4.8 0.0135 0.7 0.15 86.6 0.6 85.6 4.0 59.9 113.8 86.6 0.6 144.609TH01-37 2884 24723 10.5 18.3227 4.0 0.2833 4.1 0.0376 0.9 0.21 238.2 2.0 253.2 9.2 394.9 89.8 238.2 2.0 60.309TH01-38 895 4929 9.8 21.4264 3.0 0.0837 3.1 0.0130 0.5 0.16 83.3 0.4 81.6 2.4 32.4 72.1 83.3 0.4 257.009TH01-39 776 4395 20.3 21.1543 2.2 0.0875 2.2 0.0134 0.5 0.22 86.0 0.4 85.2 1.8 63.0 52.1 86.0 0.4 136.509TH01-40 927 5457 17.0 21.5209 3.0 0.0850 3.0 0.0133 0.5 0.17 85.0 0.4 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719 2166 8.5 19.8906 6.5 0.0908 6.6 0.0131 1.0 0.15 83.9 0.8 88.2 5.6 207.7 151.9 83.9 0.8 40.409TH01-51 866 3099 14.5 19.6452 3.3 0.0964 3.3 0.0137 0.6 0.18 88.0 0.5 93.5 3.0 236.4 75.9 88.0 0.5 37.209TH01-52 297 2502 5.5 21.4438 4.5 0.0907 5.0 0.0141 2.0 0.41 90.3 1.8 88.2 4.2 30.5 108.2 90.3 1.8 296.309TH01-53 914 1410 7.8 17.7973 4.4 0.1037 4.6 0.0134 1.5 0.33 85.7 1.3 100.2 4.4 459.8 97.0 85.7 1.3 18.609TH01-54 578 1821 15.3 19.1542 4.7 0.0991 4.7 0.0138 0.5 0.11 88.1 0.4 95.9 4.3 294.5 106.6 88.1 0.4 29.909TH01-55 1501 19830 13.8 19.4901 3.1 0.1846 6.9 0.0261 6.1 0.89 166.1 10.1 172.0 10.9 254.7 70.6 166.1 10.1 65.209TH01-56 921 4884 7.3 20.6820 2.5 0.0887 4.4 0.0133 3.6 0.81 85.2 3.0 86.3 3.6 116.5 59.7 85.2 3.0 73.109TH01-57 382 1677 8.7 21.5851 4.7 0.0891 4.9 0.0139 1.4 0.28 89.3 1.2 86.6 4.1 14.8 113.1 89.3 1.2 604.909TH01-58 798 1173 9.9 12.9870 16.3 0.1433 16.4 0.0135 0.7 0.04 86.5 0.6 136.0 20.8 1121.2 328.1 86.5 0.6 7.709TH01-59 294 6009 4.1 18.8779 2.9 0.2843 4.2 0.0389 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82.5 0.8 43.409TH01-69 748 4017 17.8 19.8346 9.5 0.0939 9.6 0.0135 1.4 0.14 86.5 1.2 91.1 8.4 214.3 220.2 86.5 1.2 40.409TH01-70 395 2571 9.0 21.2145 6.7 0.0874 6.7 0.0134 0.5 0.08 86.1 0.4 85.1 5.5 56.2 159.1 86.1 0.4 153.209TH01-71 569 4542 9.6 21.0933 2.2 0.0880 2.3 0.0135 0.6 0.24 86.2 0.5 85.7 1.9 69.8 53.2 86.2 0.5 123.509TH01-72 2789 22626 30.6 21.3707 2.6 0.0808 2.8 0.0125 0.9 0.33 80.2 0.7 78.9 2.1 38.7 62.6 80.2 0.7 207.509TH01-73 1158 12060 8.5 21.1461 1.4 0.0914 1.5 0.0140 0.5 0.33 89.8 0.4 88.8 1.3 63.9 33.7 89.8 0.4 140.509TH01-74 446 3801 5.1 21.6375 3.9 0.0873 3.9 0.0137 0.5 0.13 87.8 0.4 85.0 3.2 8.9 92.9 87.8 0.4 983.409TH01-75 435 6834 8.2 20.2626 3.1 0.0947 3.4 0.0139 1.3 0.38 89.1 1.2 91.9 3.0 164.6 72.9 89.1 1.2 54.109TH01-76 577 4638 9.6 21.3705 3.0 0.0876 3.1 0.0136 0.7 0.24 86.9 0.6 85.3 2.5 38.7 71.5 86.9 0.6 224.809TH01-77 451 2937 23.4 21.2883 3.7 0.0986 3.7 0.0152 0.6 0.17 97.4 0.6 95.5 3.4 47.9 87.5 97.4 0.6 203.409TH01-78 517 5253 6.2 21.5288 3.0 0.0881 3.6 0.0138 2.1 0.56 88.1 1.8 85.7 3.0 21.0 72.1 88.1 1.8 419.409TH01-79 415 3951 10.8 21.5877 3.8 0.0872 4.0 0.0137 1.3 0.32 87.4 1.1 84.9 3.3 14.4 92.1 87.4 1.1 605.109TH01-80 794 8673 9.5 21.5150 4.3 0.0908 4.4 0.0142 0.5 0.11 90.7 0.5 88.3 3.7 22.6 104.1 90.7 0.5 402.309TH01-81 492 2376 7.9 21.3457 3.3 0.0853 3.4 0.0132 0.8 0.23 84.6 0.7 83.1 2.7 41.5 79.5 84.6 0.7 203.909TH01-82 521 4143 10.0 21.4161 3.6 0.0840 3.9 0.0130 1.7 0.42 83.6 1.4 81.9 3.1 33.6 85.1 83.6 1.4 248.809TH01-83 655 6612 9.4 21.6853 3.8 0.0853 3.8 0.0134 0.5 0.13 85.9 0.4 83.1 3.0 3.6 90.8 85.9 0.4 2391.909TH01-84 792 6630 9.2 21.5030 3.0 0.0865 3.0 0.0135 0.6 0.20 86.4 0.5 84.3 2.4 23.9 71.0 86.4 0.5 361.809TH01-85 145 4452 2.7 18.8282 2.9 0.4223 3.0 0.0577 0.5 0.17 361.4 1.8 357.7 8.9 333.6 66.1 361.4 1.8 108.309TH01-86 344 3462 6.4 21.4378 3.6 0.0901 3.7 0.0140 0.5 0.14 89.6 0.4 87.6 3.1 31.1 87.2 89.6 0.4 287.809TH01-87 608 2376 29.7 20.0325 2.6 0.0936 2.8 0.0136 1.2 0.43 87.0 1.1 90.8 2.5 191.2 59.3 87.0 1.1 45.509TH01-88 752 1485 9.7 14.0886 20.1 0.1346 20.1 0.0137 1.2 0.06 88.0 1.0 128.2 24.2 956.8 414.1 88.0 1.0 9.209TH01-89 550 3603 13.3 21.4168 4.3 0.0876 4.3 0.0136 0.5 0.12 87.1 0.4 85.2 3.5 33.5 102.3 87.1 0.4 259.909TH01-90 656 3459 18.6 19.8920 4.9 0.0927 4.9 0.0134 0.8 0.17 85.6 0.7 90.0 4.3 207.6 113.2 85.6 0.7 41.209TH01-91 553 3816 7.4 21.4510 4.3 0.0852 4.4 0.0133 0.8 0.17 84.9 0.6 83.0 3.5 29.7 103.1 84.9 0.6 286.009TH01-92 2298 36075 17.6 18.6400 2.4 0.2419 4.5 0.0327 3.8 0.84 207.4 7.7 220.0 8.8 356.3 54.2 207.4 7.7 58.209TH01-93 519 4833 7.3 21.0440 4.9 0.0948 4.9 0.0145 0.8 0.16 92.6 0.7 92.0 4.3 75.4 115.7 92.6 0.7 122.909TH01-94 751 6642 9.4 21.3286 2.3 0.0896 2.4 0.0139 0.5 0.21 88.7 0.4 87.1 2.0 43.4 55.2 88.7 0.4 204.409TH01-95 3399 14019 2.3 17.1179 12.9 0.2904 13.3 0.0360 3.2 0.24 228.3 7.2 258.8 30.3 545.5 282.3 228.3 7.2 41.809TH01-96 303 9930 4.0 19.2127 1.6 0.3423 2.7 0.0477 2.1 0.80 300.4 6.3 298.9 6.9 287.6 36.1 300.4 6.3 104.509TH01-97 1579 41970 2.6 18.7814 1.7 0.3667 2.2 0.0500 1.4 0.63 314.3 4.2 317.2 6.0 339.2 38.9 314.3 4.2 92.609TH01-98 410 3846 21.1 21.2599 3.6 0.0884 3.7 0.0136 0.8 0.21 87.3 0.7 86.0 3.0 51.1 85.6 87.3 0.7 170.909TH01-99 373 2748 6.3 21.7968 4.3 0.0849 4.4 0.0134 0.8 0.19 86.0 0.7 82.8 3.5 -8.8 104.5 86.0 0.7 -982.609TH01-100 593 3168 10.5 21.3417 2.7 0.0874 2.8 0.0135 0.7 0.24 86.6 0.6 85.1 2.2 41.9 63.9 86.6 0.6 206.7

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