51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC...

16
51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and J. Williams, Exploration and Production Division, BP Research Centre, Sunbury-on-Thames, Middlesex, England INTRODUCTION Composite samples from each of the sites drilled on DSDP Leg 48 were selected for examination by the ship- board geochemist. The samples were placed in carefully cleaned containers, supplied by British Petroleum Corpora- tion. The canned samples were frozen immediately and maintained in this state throughout the leg and thereafter, prior to analysis. A list of the samples collected is given in Table 1 together with relevant characterization data from the summary log. Additional samples from Site 402 were obtained from the IFP Laboratories in order to extend our coverage of the sampled intervals, particularly the more organic-rich Cre- taceous shales. Details of these samples are also included in Table 1. Additional material supplied by the IFP Labora- tories was in the form of dry, ground sediment. EXPERIMENTAL METHODS AND RESULTS The bulk of the water in the frozen samples was removed by freeze-drying, without disruption of the core material; residual water, remaining after this treatment, was removed by drying the samples over phosphorus pentoxide in a des- iccator. Small portions of the dried cores were removed, mounted in resin and polished, and the reflectance of vitrini- tic material present was determined by standard oil immer- sion procedures (Table 2). At this stage, small amounts of sample were also removed and used for kerogen preparation by hydrochloric acid/hydrofluoric acid treatment under nonoxidizing conditions. Visual microscopic examinations of the kerogen concentrates were made, the results of which are summarized in Table 3. Examination of the gross lithol- ogy and a brief X-ray diffraction analysis of each sample were made, the results of which are summarized in Table 4. The remainder of each sample was then ground to <106 μm BSS and stored for further use in clean, dry bottles. The bottles, and all other glassware used throughout the work, were thoroughly cleaned by washing first with methylene chloride, then by immersion in chromic acid and, finally, by washing with doubly distilled water; drying in an oven fol- lowed. If sufficient sample was available, 100 g of core material was solvent extracted. This operation was carried out for 48 hours in a Soxhlet extractor fitted with a glass fiber thimble. The thimble had been extracted extensively with methylene chloride, followed by heating at 450°C for 16 hours. The solvent used in these extractions, and at all other stages of this work, had been previously redistilled from Analar Rea- gent grade material in a 40-plate distillation apparatus. Each solvent was tested prior to use by evaporating 300 ml to dryness, dissolving in 10 μ\ of solvent, and injecting 0.4 μ\ of the solution directly into a gas chromatograph running at maximum usable sensitivity. Only solvents giving no peaks other than that of the solvent were used for this work. The Soxhlet extracts were treated with copper powder to remove any elemental sulfur and filtered through a glass sinter. They were then evaporated to dryness by gentle blowing with filtered, dry nitrogen on a heated block main- tained at 35°C. The residual total soluble extract (TSE) was weighed and then fractionated by liquid chromatography over silica gel. The n + p (saturate alkane) fraction was eluted by n-heptane and the combined aromatics + heterocyclics (A + H) and residual material were eluted by benzene/methanol (3:1 v/v). The per cent weight TSE for each sample is given in Table 5 together with other data obtained on the sediment extracts. Three grams of unextracted material from each core was decarbonated using the following procedure: 30 ml IN HC1 was added to the sample and the bulk of the liquid decanted after effervescence had ceased. A further 30 ml of 2/V HC1 was added until no further effervescence occurred. A final treatment with 10 ml concentrated HC1 (13/V) was given with the container in an ultrasonic bath for 2 hours at 40°C. The mixture was diluted with distilled water and repeatedly washed until neutral. The residue was dried in a vacuum oven and, finally, in a desiccator over phosphorus pent- oxide. The difference in weight between the initial and final material was used to calculate the per cent weight HC1 soluble material given in Table 5. The total organic carbon content (TOC) of the decarbonated sediment was then de- termined by a standard combustion procedure, and the val- ues used to calculate the various indexes are given in Table 5. The n + p fractions obtained from the liquid chromato- graphic separations of the TSE were examined by gas chromatography. The columns used were SGE SCOT type with SE 30 as stationary phase and totally splitless injection was employed. Conditions for all runs were: initial hold for 12 minutes at 100°C, followed by programming at 3°C/ minute up to the final hold at 290°C. Flame ionization detec- tors and injectors were maintained at 35O°C. Examples of the chromatograms obtained are shown in Figures 1 to 8. Carbon preference indexes (CPI) were calculated for n-a\- kanes in the Cis to C32 range, together with the pristane/ phytane ratio (Pr/Ph); these values are also included in Table 5. Distribution profiles of the rc-alkanes were obtained from the quantitative date of the gas chromatograms and are illustrated in Figures 9 to 18. A more detailed examination of a limited number of the n + p fractions was undertaken by capillary column gas chromatography/mass spectrometry, in order to obtain data 977

Transcript of 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC...

Page 1: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL

T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and J. Williams, Exploration and Production Division, BP ResearchCentre, Sunbury-on-Thames, Middlesex, England

INTRODUCTION

Composite samples from each of the sites drilled onDS DP Leg 48 were selected for examination by the ship-board geochemist. The samples were placed in carefullycleaned containers, supplied by British Petroleum Corpora-tion. The canned samples were frozen immediately andmaintained in this state throughout the leg and thereafter,prior to analysis. A list of the samples collected is given inTable 1 together with relevant characterization data from thesummary log.

Additional samples from Site 402 were obtained from theIFP Laboratories in order to extend our coverage of thesampled intervals, particularly the more organic-rich Cre-taceous shales. Details of these samples are also includedin Table 1. Additional material supplied by the IFP Labora-tories was in the form of dry, ground sediment.

EXPERIMENTAL METHODS AND RESULTSThe bulk of the water in the frozen samples was removed

by freeze-drying, without disruption of the core material;residual water, remaining after this treatment, was removedby drying the samples over phosphorus pentoxide in a des-iccator. Small portions of the dried cores were removed,mounted in resin and polished, and the reflectance of vitrini-tic material present was determined by standard oil immer-sion procedures (Table 2). At this stage, small amounts ofsample were also removed and used for kerogen preparationby hydrochloric acid/hydrofluoric acid treatment undernonoxidizing conditions. Visual microscopic examinationsof the kerogen concentrates were made, the results of whichare summarized in Table 3. Examination of the gross lithol-ogy and a brief X-ray diffraction analysis of each samplewere made, the results of which are summarized in Table 4.

The remainder of each sample was then ground to <106µm BSS and stored for further use in clean, dry bottles. Thebottles, and all other glassware used throughout the work,were thoroughly cleaned by washing first with methylenechloride, then by immersion in chromic acid and, finally, bywashing with doubly distilled water; drying in an oven fol-lowed.

If sufficient sample was available, 100 g of core materialwas solvent extracted. This operation was carried out for 48hours in a Soxhlet extractor fitted with a glass fiber thimble.The thimble had been extracted extensively with methylenechloride, followed by heating at 450°C for 16 hours. Thesolvent used in these extractions, and at all other stages ofthis work, had been previously redistilled from Analar Rea-gent grade material in a 40-plate distillation apparatus. Eachsolvent was tested prior to use by evaporating 300 ml to

dryness, dissolving in 10 µ\ of solvent, and injecting 0.4 µ\of the solution directly into a gas chromatograph running atmaximum usable sensitivity. Only solvents giving no peaksother than that of the solvent were used for this work.

The Soxhlet extracts were treated with copper powder toremove any elemental sulfur and filtered through a glasssinter. They were then evaporated to dryness by gentleblowing with filtered, dry nitrogen on a heated block main-tained at 35°C. The residual total soluble extract (TSE) wasweighed and then fractionated by liquid chromatographyover silica gel. The n + p (saturate alkane) fraction waseluted by n-heptane and the combined aromatics +heterocyclics (A + H) and residual material were eluted bybenzene/methanol (3:1 v/v). The per cent weight TSE foreach sample is given in Table 5 together with other dataobtained on the sediment extracts.

Three grams of unextracted material from each core wasdecarbonated using the following procedure: 30 ml IN HC1was added to the sample and the bulk of the liquid decantedafter effervescence had ceased. A further 30 ml of 2/V HC1was added until no further effervescence occurred. A finaltreatment with 10 ml concentrated HC1 (13/V) was givenwith the container in an ultrasonic bath for 2 hours at 40°C.The mixture was diluted with distilled water and repeatedlywashed until neutral. The residue was dried in a vacuumoven and, finally, in a desiccator over phosphorus pent-oxide. The difference in weight between the initial andfinal material was used to calculate the per cent weight HC1soluble material given in Table 5. The total organic carboncontent (TOC) of the decarbonated sediment was then de-termined by a standard combustion procedure, and the val-ues used to calculate the various indexes are given inTable 5.

The n + p fractions obtained from the liquid chromato-graphic separations of the TSE were examined by gaschromatography. The columns used were SGE SCOT typewith SE 30 as stationary phase and totally splitless injectionwas employed. Conditions for all runs were: initial hold for12 minutes at 100°C, followed by programming at 3°C/minute up to the final hold at 290°C. Flame ionization detec-tors and injectors were maintained at 35O°C. Examples ofthe chromatograms obtained are shown in Figures 1 to 8.Carbon preference indexes (CPI) were calculated for n-a\-kanes in the Cis to C32 range, together with the pristane/phytane ratio (Pr/Ph); these values are also included inTable 5. Distribution profiles of the rc-alkanes were obtainedfrom the quantitative date of the gas chromatograms and areillustrated in Figures 9 to 18.

A more detailed examination of a limited number of the n+ p fractions was undertaken by capillary column gaschromatography/mass spectrometry, in order to obtain data

977

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T. DORAN ET AL.

TABLE 1Samples Examined

Hole 399

Hole 400A

Hole 401

Hole 402

Hole 402A

Hole 403

Core

222

00

OO

00 O

O

00

00

18

29

393939

494949

5

1414141414

111

5555

4444

11

1616

18A18A

18B18B18B18B

323232

333

14

14

26262626

292929

Section

123

123456

1-7

1

123

234

1-5

12345

123

1234

1234

1

12

12

1234

236

123

1

2

1234

124

Interval(cm)

5-7; 60-6238-40; 114-11620-22; 104-106

27-2927-2927-2926-2831-3331-33

(composite)

0-22

0-100-100-10

0-100-100-3

All 0-5

1-81-81-61-61-7

1-51-51-7

15-2310-170-90-9

6-150-6122-1250-6

53-60126-13137-45

63-67, 125-129,144-150

0-8

0-60-10-60-6

9-1778-836-13

Depth(m)

63.05-63.6264.88-65.6566.20-67.06

141.27-141.29142.77-142.79144.27-144.29145.77-145.79147.31-147.32148.81-148.83

236.0-245.5

340.50-340.77

435.50-435.60437.0-437.1438.50-438.60

532.0-532.1533.5-533.6535.0-535.3

198.51-198.58200.01-200.08201.51-201.56203.01-203.06204.01-204.07

40.01-40.0541.51-41.5543.01-43.05

127.65-137.73129.10-139.17130.50-130.59132.00-132.09

165.06-165.15167.00-167.06169.72-169.75170.00-170.06

14.53-14.6016.76-16.8117.37-17.45

119.13-117.17,119.75-119.77,119.97-120.0120.0-120.08

232.50-232.56234.0-234.01235.50-235.56237.00-237.06

261.09-261.17263.28-263.33265.56-265.63

Stage

Pleistocene

Upper Pliocene

Upper Miocene

Middle Miocene

Lower Miocene

Middle Eocene

Middle Eocene

Upper Palaeocene

Pleistocene

Upper Eocene

Middle Eocene

Lower Cretaceous

Lower Cretaceous

Lower Cretaceous

Lower Cretaceous

Lower Cretaceous

Pleistocene

Upper Miocene

Middle Eocene

Lower Eocene

Lithological DescriptionFrom Summary Report

Marly calcareous ooze

Nannofossil ooze

Nannofossil chalk

Nannofossil chalkMarly nannofossil chalk

Marly nannofossil chalk

Nannofossil chalk

Siliceous marly chalk

Nannofossil chalk

Nannofossil chalk

Nannofossil marly ooze

Siliceous marly nannofossil chalk

Siliceous marly nannofossil chalk

Calcareous mudstone

Marly chalk

Carbonaceous marly limestone

Dolomitic marly limestone

Carbonaceous calcareous mudstone

Calcareous mudstone

Nannofossil ooze

Marly nannofossil chalkSiliceous nannofossil chalk

Mudstone

978

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BASIC ORGANIC GEOCHEMICAL DATA

TABLE 1 - Continued

Hole 404

Hole 405

Hole 406

Core

35353535

40

40

171717

212121

222222

4

I0

131313

17171717

40

42

222

13131313

2424

32

3232

3939393939

474747

Section

1234

2

3

123

234

235

1

1-7

235

2345

1

2

13

234

1234

12

3

45

12345

123

Interval(cm)

72-8289-96128-13639-46

10-13, 50-53105-109

0-5, 88-91

87-9020-330-11

0-100-100-6

16-24110-12035-42

0-22

All 0-5

1-976-850-10

110-120110-12050-6050-60

7-12, 144-150

29-33, 141-150

7-1718-27, 100-112

98-107107-1220-7

138-14054-5932-38104-112

33-4367-75

17-26, 12-15

133-14146-56

0-759-7426-3417-2469-70

100-10440-5193-99

Depth(m)

318.72-318.82320.39-320.46322.28-322.36322.89-322.96

375.10-375.13,375.50-375.53,376.05-376.09378.00-378.05,378.88-378.91

294.87-294.90295.70-295.83297.00-297.11

333.50-333.60335.00-335.10336.00-336.06

343.16-343.24345.60-345.70347.35-347.42

36.50-36.72

84.00-93.5

114.01-114.09116.25-116.35118.50-118.60

162.10-162.20162.60-162.70164.50-164.60165.50-165.60

369.07-369.12370.44-370.55370.79-370.83371.41-371.50

388.07-388.17391.18-391.27392.00-392.12

64.48-64.5766.07-66.2266.50-66.57

452.88-452.90453.54-458.59454.82-454.88467.04-467.12

556.83-556.93558.67-558.75

633.67-633.76633.62-633.65637.83-637.91638.46-638.56

698.50-698.57700.09-700.24701.26-701.34702.67-702.74704.69-704.70

775.00-775.04776.40-776.51778.43-778.49

Stage

Lower Eocene

Lower Eocene

Lower Eocene

Lower Eocene

Lower Eocene

Pleistocene

Middle/LowerEocene

Lower Eocene

Lower Eocene

Lower Eocene

Lower Eocene

Pleistocene

Upper Miocene

Middle Miocene

Upper/MiddleOligocene

Upper Eocene

Lower Eocene

Lithological DescriptionFrom Summary Report

Mudstone

Mudstone

Mudstone

Mudstone

Mudstone

Marly nannofossil ooze

Nannofossil ooze

Siliceous marly nannofossil chalkmudstone

Siliceous calcareous mudstone

Siliceous calcareous mudstone

Siliceous calcareous mudstone

Marly nannofossil ooze

Nannofossil chalk

Siliceous chalk

Calcareous and siliceous chalk

Calcareous and siliceous chalk

Calcareous claystone

979

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T. DORAN ET AL.

TABLE 2Vitrinite Reflectance Measurements

Core

399-2400A-8400A-18400A-29400A-39400A-49401-5401-14402-1402-5402A-4402A-11402A-16402A-18A402A-18B402A-32403-3403-14403-26403-29403-35403-40404-17404-21404-22405-4405-10405-13405-17405-40405-42406-2406-13406-24406-32406-3940647

Mean Vitrinite Reflectance

Autochthonous

N.D.

0.32(5)

N.D.

N.D.0.33(19)0.30(2)0.34(4)0.37(9)0.34(19)

N.D.0.34(20)0.37(21)

N.D.N.D.

0.28(20)0.25(10)0.32(19)0.33(3)0.33(2)0.34(20)

N.D.

0.28(2)0.33(5)0.36(9)0.26(1)

N.D.0.37(19)0.32(2)

N.D.

Allochthonous

0.49(1)

0.57(1)0.59(2)0.58(2)

0.45(7)

0.59(2)0.46(4)

0.58(2)0.45(5)

0.86(6)

0.82(9)

0.89(3)

0.63(1)0.92(1)0.85(2)0.84(9)

0.81(1)0.60(1)0.86(2)0.80(7)

0.71(6)

0.77(1)0.71(1)

0.70(14)

0.82(1)

1.27(10)

1.38(1)

1.08(3)

1.20(5)

1.13(1)

1.02(1)1.06(1)

Note: Figures in parentheses are the number of separate deter-minations. N.D. = no determination possible.

on sterane and pentacyclane distributions. The results ofthese analyses are summarized in Tables 6 and 7.

The amount of soluble extract obtained from the variousfrozen composite shipboard samples was insufficient forstable carbon isotope determinations (Ö13CPDB-I) as well asfor the other analyses normally undertaken. However, in thecase of the larger samples subsequently made available fromthe IFP, sufficient extract was available for a comparison ofthe δ1 3C values of the TSE and sediment kerogen, withoutprecluding the other analyses. Extracts and kerogen concen-trates were therefore quantitatively combusted to carbondioxide and their 13C/12C ratios determined on a VG Micro-mass 602C Isotope Ratio Mass Spectrometer. Results ofthese measurements are given in Table 8.

ORGANIC GEOCHEMICAL SUMMARIES

Bay of Biscay

Site 399: Only shallow Pleistocene calcareous oozeexamined. Low organic carbon content (~ 0.2 % wt.) Verylow maturity, indicated by visual kerogen studies. Evidence

for significant amounts of terrestrial plant debris as well asalgal matter. Highly immature n-alkane distribution.

Site 400: Deepest sample collected by shipboard geo-chemist in middle Eocene at —535 meters. Little au-tochthonous vitrinite evident in samples examined. Samplefrom Core 18 indicated low maturity with some evidence ofreworked vitrinite present. Pliocene Core 8 showed evi-dence of terrestrial debris as well as algal matter, all of verylow maturity. Very low organic carbon contents in highlycalcareous samples. Generally low TSE/TOC ratios and lowhydrocarbon contents, but«-alkanes had fairly low CPI val-ues.

Site 401: No indications of autochthonous vitrinite. Bothsamples highly calcareous with very low organic carboncontents; «-alkanes had quite low CPI values.

Site 402: Shipboard samples only extended to middleEocene, but were supplemented by IFP Lower Cretaceoussamples. Low reflectivity autochthonous vitrinite present innearly all samples indicating low maturity. Some evidenceof reworked organic matter. Middle Eocene sample showedevidence of terrestrial debris and low maturity by visualkerogen studies. Lower Cretaceous shales showed markedevidence of terrestrially derived components and increasedmaturity compared with shallower samples. Organic carboncontents were moderate to good but hydrocarbon contentswere low; n-alkanes still showed marked signs of immatur-ity. Sterane distribution patterns supported immature indica-tions as did the pentacyclane distributions, with 17/3Hhopane as a major component. Extract/kerogen δ1 3C valuessuggested a coaly-type component was present in significantquantities.

Rockall Plateau

Site 403: Low reflectivity autochthonous vitrinite inlower Eocene samples. Visual kerogen studies indicatedsome terrestrially derived components to be present. Colormeasurements suggested maturity fairly high, but stillbelow level for significant hydrocarbon generation. Organiccarbon contents all low to very low with generally lowSAC/TOC values; n-alkanes generally had CPI values>l.O. Sterane and pentacyclane distributions indicatedhigher maturity than Site 402 Cretaceous samples withthe pentacyclanes having 17αH hopane as the majorcomponent.

Site 404: Samples confined to lower Eocene mudstones.Low reflectivity autochthonous vitrinite suggested lowmaturity. Visual kerogen studies indicated significant con-tributions of terrestrial organic debris and maturity levelcomparable to Site 403. Organic carbon contents were verylow with low extracts and very low hydrocarbon contents.CPI values of n-alkanes supported maturity indications.

Site 405: Little evidence of autochthonous vitrinite.Low reflectivity of lower Eocene material indicated im-maturity. Visual kerogen studies again suggested significantcontribution of terrestrially derived detritus, with maturitycomparable to, or possibly slightly lower, than Sites 403and 404. Organic carbon contents all very low, but somehigh TSE/TOC values were present. Hydrocarbon contentswere generally quite low, butn-alkane CPI values supportedimmaturity, with a much more mature value in the deepestsample examined.

980

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BASIC ORGANIC GEOCHEMICAL DATA

TABLE 3Visual Kerogen Descriptions

Site Core

Site 399

Core 2

Hole 400ACore 8

Site 402

Core 1

Hole 402ACore 4

Core 18B

Core 11

Core 16

Core 18A

Core 32

Site 403

Core 29

Core 40

Site 404

Core 21

Core 22

Site 405

Core 40

Core 42

Site 406

Core 24

Miospores

Tra

ce/R

are

Co

mm

on

Fre

qu

ent

Ab

un

da

nt

1-2 3 4 5

Φ

Φ

Φ

Φ

Φ

Φ

Barren

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

C

o

| j |

1-2 3 4 5

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

tid

sT

asm

an1 2 3

Rew

ork

ing

Φ

Φ

Vascular Plant Debris

Cuticles

1-2 3 4 5

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Bro

wn

"Wo

od

"

(lig

nit

e)

1-2 3 4 5

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

usa

in)

Bla

ck"W

oo

d'

(vit

rain

1-2 3 4 5

late

dF

inel

yD

isse

mir

1 - 2 3 4 5

lize

dS

apro

pe

1-2 34 5

Φ Φ Φ

Φ Φ

Φ Φ

Φ Φ

Φ Φ

Φ Φ

Φ Φ

Φ Φ

Φ Φ

Φ Φ

Φ Φ Φ

Φ Φ Φ

Φ Φ Φ

• Φ ?Φ

Am

orp

h

1-2 3 4 5

tio

nP

rese

rve

a l l

Φ Φ

Φ Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ Φ

Φ?

Color/Maturation

Th

resh

old

?

1 2 3 4 5 6 7

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

Φ

SourcePotential

'/GAS?GAS?GAS

?GAS

GASGAS

GASGAS

-

DepositionalEnvironment

tiat

edri

ne

Un

dif

fere

r

sn M

arin

e

ir-s

ho

re M

arin

e

tric

ted

Mar

ine

nm

arin

e

cno

wn

« O. <u α> o c

S O Z ai 2 D

Φ?

Φ

* '

Φ

Φ

Φ

Φ

Φ

•?

•?

•?

•?

Φ

Φ

Φ

Site 406: Autochthonous vitrinite reflectance valuessuggested some increase in maturity with depth, but allsamples examined were immature. Visual kerogen studieson middle Miocene siliceous chalks indicated some terres-trially derived components as well as significant amounts ofalgal matter. Maturity of middle Miocene samples appearedquite low. Organic carbon contents were very low with lowextracts and hydrocarbon contents. CPI values of n-alkanes

were > 1, but sterane/pentacyclane distributions were simi-lar to Site 403.

Generally, all samples displayed immaturity and kero-gens were dominantly gas prone. Eocene organic matter atSites 403, 404, 405, and 406 appeared mature, or possiblyin some components, more mature than organic matter inthe Lower Cretaceous shales/mudstones from Site 402.

981

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T. DORAN ET AL.

TABLE 4Observed Core Lithology (major components) of Selected Samples

North Margin,Bay ofBiscay

West Margin,RockallPlateau

SouthernMargin,RockallPlateau

Hole

399

400A400A400A

400A

400A

401

401

402

402

402A

403403403403

403

403

404404

404

405

405405405

405

405

406406406406

406

406

Core

2

81829

39

49

5

14

1

5

4

3142629

35

40

1721

22

4

101317

40

42

2132432

39

47

Description of Hand Specimen

Mudstone, calcareous, soft, gray

Mudstone, calcareous, soft, light grayMudstone, calcareous, soft, gray-whiteLime mudstone, argillaceous, soft, chalky,

light gray-whiteLime mudstone, argillaceous, soft, chalky,

light gray-whiteLime mudstone, argillaceous, soft, chalky,

flaky, light gray-green to buff

Lime mudstone, slightly argillaceous, soft,chalky, light greenish white

Lime mudstone, slightly argillaceous, soft,chalky, light buff

Lime mudstone, argillaceous, soft, chalky,light gray

Lime mudstone, slightly argillaceous,soft, greenish white

Lime mudstone, slightly argillaceous, soft,greenish white

Mudstone, calcareous, gray, soft, chalkyLime mudstone, chalky, soft, whiteLime mudstone, chalky, soft, creamMudstone, gray, friable, slightly micaceous

and calcareousMudstone, gray-green friable, silty texture,

calcareousIn thin section, abundant devitrified

volcanic glass debrisMudstone, gray, calcareous

Mudstone, dark gray calcareousMudstone, dark gray, calcareous

Mudstone, mid gray, (calcareous),micaceous

Lime mudstone, buff, soft, chalky,fossiliferous, argillaceous

Lime mudstone, light buff brown, chalkyLime mudstone, buff, chalky, argillaceousMudstone, light gray, calcareous, chalky,

softShale, calcareous, hard, light gray green

with silicified bandsShale, light gray-green, calcareous, hard,

fissile (XRD42S) with burrows füledwith green swelling clay (XRD42G)

Clay, highly calcareous, light grayLime mudstone, white, chalky, compactLime mudstone, gray, soft, chalkyMudstone, calcareous, light gray, hard,

fissileMudstone, light gray, calcareous, micro-

fossiliferous with black clay-filledburrows and patches (SEM)

Shale, (47 Gy) mid gray, soft, goodfissility with thin black clay füledtrace fossil tracks. Patches of greenmudstone (47 Grn)

Abundant

Calcite, quartz

naCalciteCalcite

na

na

Calcite

Calcite

Calcite, quartz

na

Calcite

CalciteCalciteCalcitePlagioclase, quartz

Plagioclase, quartz

Plagioclase, quartz

naQuartz

na

Quartz, calcite

Calcitena

Calcite

Calcite

42S Calcite

42G Montmorillonite(?nontronite)

CalciteCalciteCalciteCalcite

(47 GY) Calcite

(47GRN) Plagioclase

<-Ray Diffraction Results

Present

Mite, kaolinite

na--

na

na

Quartz, illite

Quartz, illite

Illite, kaolinite

na

Quartz, illite

Quartz, illite--

Illite/montmorillonite(M.L.) and heulanditeIllite/montmorillonite(M.L.) and heulandite

Illite/montmorillonite(M.L.) and heulandite

naIllite/montmorillonite(M.L.) Plagioclase

na

Illite, Plagioclase

Plagioclasena

Montmorillonite

Plagioclase, mont-morillonitePlagioclase, mont-morillonite

-

Plagioclase, illite---

Montmorillonite/illite

Montmorillonite/illite

Trace

Dolomite

naQuartz, illite

-

na

na

-

Kaolinite, dolomite

Chlorite, dolomite

na

-

Kaolinite---

Calcite

Calcite

naKaolinite,heulandite

na

Kaolinite

Heulanditena

Plagioclase

-

-

Kaolinite---

_

Note: na: not analyzed.

982

Page 7: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

BASIC ORGANIC GEOCHEMICAL DATA

TABLE 5Organic Carbon and Soluble Extract Data

Core

399-2400A-8400A-18400A-29400A-39400A-49401-5401-14402-1402-5402A-4402A-11402A-16402A-18A402A-18B402A-32403-3403-14403-26403-29403-35403-40404-17404-21404-22405-4405-10405-13405-17405-40405-42406-2406-13406-24406-32406-39406-47

HC1 Solu-bles (% wt.)

59.358.771.386.661.921.458.256.033.762.745.134.824.993.329.922.058.297.485.516.138.424.123.619.217.551.047.542.430.020.635.231.388.567.679.575.430.5

TOC(% wt.)

0.2240.2440.0950.0460.0840.0630.0620.0550.4310.1310.1480.7001.210.0091.351.230.1290.0220.0280.3940.0680.3420.0920.1050.2390.0740.0420.0920.1540.1590.2070.1170.0510.2140.0330.0590.090

TSE(% wt.)

0.01090.00330.00130.00190.00260.00170.00190.00170.00360.00230.00040.00270.00530.00200.00520.00650.00170.00210.00240.00160.00120.00300.00100.00110.00120.00250.00450.00560.00160.00110.00200.00560.00100.00290.00050.00040.0006

TSE/TOC (%o)

4914144231273130

818

344

22245

1394874

179

1010

534

1086010

79

4820141412

7

n +p(% wt.)

16.816.515.714.317.8030.920.213.823.3

8.610.71

5.710.2

6.36.84.4

11.835.116.112.89.65.8

10.45.17.2

26.45.6

14.423.0

3.42.6

35.010.411.314.3

8.39.3

SAC/TOC (%°

82266864220.80.20.4

140.30.21.5

3314

0.51.70.51.00.50.49692.30.20.2

172.11.62.01.00.7

) CPI

2.451.221.241.081.301.131.111.132.341.121.271.261.650.971.791.901.771.181.151.891.431.261.111.461.521.761.151.181.321.131.081.361.271.231.191.201.29

Pr/Ph

0.890.190.430.400.520.600.430.471.190.590.341.051.551.091.701.540.410.770.780.360.370.290.480.380.660.390.480.490.570.540.720.850.630.520.320.470.50

31 29

Figure 1. Gas chromatogram ofn + p fraction, Site 399, Core 2.

983

Page 8: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

29 2827

31

33 32

41 40 39 SSSlliL

30

26

100 80 60 40MINUTES

Figure 2. Gas chromatogram ofn + p fraction, Hole 400A, Core 49.

27 26 2529 28

31

33 32

41 40 39 3837 36

35 34

30

U/J

24

23

22 21 2 0

19

< 18 LU

80 60 40MINUTES

Figure 3. Gas chromatogram ofn + p fraction, Site 401, Core 5.

27

29 28

31

33 32

38 37 3635 34

30

26 25

24

23 22 21 20 19

20

20

17

100 80 60 40MINUTES

20

Figure 4. Gas chromatogram o/n + p fraction, Site 402, Core 5.

28

30

32

40 39 38 37 "» 35

3436 oR I 33

31

29

26

2725 2,4 23 22 21 20 19 < <

17

100 80 60 40MINUTES

Figure 5. Gas chromatogram ofn + p fraction, Site 403, Core 29.

20

984

T. DORAN ET AL.

Page 9: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

BASIC ORGANIC GEOCHEMICAL DATA

80 60 40 20

MINUTES

Figure 6. Gas chromatogram o /n + p fraction, Site 404, Core 21.

29

MINUTES

Figure 7. Gas chromatogram ofn + p fraction, Site 405, Core 42.

36

MINUTES

Figure 8. Gas chromatogram ofn + p fraction, Site 406, Core 47.

985

Page 10: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

T. DORAN ET AL.

π-ALKANE DISTRIBUTIONS

50-

Core 399-2

C P I 2.45

100π

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 400A-8C P I 1.22

- M - -U100η

50-

12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core400A-18CP I 1.24

100-1

50-

12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core 400A-29

CP I 1.08

"i 1 r12 14 16 18 20 22 24 26 28 30 32 34 36

CARBON NUMBER

Figure 9. Distribution profiles of n-alkanes derived fromgas chromatograms for Cores 399-2, 400A-8, 400A-18,and 400A-29.

rt-ALKANE DISTRIBUTIONS100-,

Core 400A-39C P I 1.30

+-L+12 14 16 18 20 22 24 26 28 30 32 34 36

Core 400A-49C P I 1.13

—i 1 1 —12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core 401-5C P I 1.11

—•—I—•—1—•—(

12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core 401-14CP I 1.13

12 14 16 18 20 22 24 26 28 30 32 34 36CARBON NUMBER

Figure 10. Distribution profiles of n-alkanes derived fromgas chromatograms for Cores 400A-39, 400A-49, 401-5,and 401-14.

986

Page 11: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

BASIC ORGANIC GEOCHEMICAL DATA

n-ALKANE DISTRIBUTIONS100-,

50i

Core 402-1C P I 2.34

100-,

50-

12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core 402-5CP I 1.12

-U100-,

50

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 402A-4

CP I 1.27

100-,

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 402A-11

CP I 1.26

4-J-r-12 14 16 18 20 22 24 26 28 30 32 34 36

CARBON NUMBER

Figure 11. Distribution profiles of n-alkanes derived fromgas chromatograms for Cores 402-1, 402-5, 402A-4,402A-11.

π-ALKANE DISTRIBUTIONS

a- 50 πLU>

Core402A-16

CP I 1.65

100-,

5 0 -

12 14 16 18 20 22 24 26 28 30 32 34 36

Core402A-18A

C P I 0.97

I I I

100-,

50-

Core402A-18BCP I 1.79

100-,

50-

12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core 402A-32

CP I 1.90

12 14 16 18 20 22 24 26 28 30 32 34 36CARBON NUMBER

Figure 12. Distribution profiles of n-alkanes derived fromgas chromatograms for Cores 402A-16, 402A-18A,402A-18B, and 402A-32.

987

Page 12: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

T. DORAN ET AL.

π-ALKANE DISTRIBUTIONS

100-,π-ALKANE DISTRIBUTIONS

Core 403-3

CP I 1.77

100-,

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 403-14

CP I 1.18

-M-12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core 403-26

CPI 1.15

12 14 16 18 20 22 24 26 28 30 32 34 36 38

Core 403-29

C P I 1.89

12 14 16 18 20 22 24 26 28 30 32 34 36CARBON NUMBER

Figure 13. Distribution profiles for n-alkanes derived fromgas chromatograms for Cores 403-13, 403-14, 403-26,and 403-29.

1 0 0 π

50-

Core 403-35

CP I 1.43

5 0 -

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 403-40

C P I 1.26

100-,

50-

—•—I—"―r—12 14 16 18 20 22 24 26 28 30 32 34 36

Core 404-17

CP I 1.11

100-,

5 0 -

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 404-21

C P I 1.46

12 14 16 18 20 22 24 26 28 30 32 34 36

CARBON NUMBER

Figure 14. Distribution profiles for n-alkanes derived fromgas chromatograms for Cores 403-35, 403-40, 404-17,404-21.

988

Page 13: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

BASIC ORGANIC GEOCHEMICAL DATA

100 π

π-ALKANE DISTRIBUTIONS

5 0 -

Core 404-22

CP I 1.52

α+±100-,

50-

"i2 14 16 18 20 22 24 26 28 30 32 34 36

Core 405-4

CP I 1.76

100-1

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 405-10

CPI 1.15

1 0 0 η

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 405-13

CP I 1.18

12 14 16 18 20 22 24 26 28 30 32 34 36

CARBON NUMBER

Figure 15. Distribution profiles for n-alkanes derived fromgas chromatograms for Cores 404-32, 405-4, 405-10,405-13.

π-ALKANE DISTRIBUTIONS100-π

50-

Core 405-17

C P I 1.32

100-,

50-

14 I^ 18 20 22 24 26 28 30 32 34 36

Core 405-40

CP I 1.13

100-,

50-

~\2 14 16 18 20 22 24 26 28 30 32 34 36

Core 405-42

C P I 1.08

100-,

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 406-2

C P I 1.36

12 14 16 18 20 22 24 26 28 30 32 34 36

CARBON NUMBER

Figure 16. Distribution profiles for n-alkanes derived fromgas chromatograms for Cores 405-17, 405-40, 405-42,and 406-2.

989

Page 14: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

T. DORAN ET AL.

100-,n-ALKANE DISTRIBUTIONS

50-

Core 406-13

CP I 1.27

-M-f-

100-1

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 406-24

CP I 1.23

100-,

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 406-32

CP I 1.19

100-,

50-

12 14 16 18 20 22 24 26 28 30 32 34 36

Core 406-39

CP I 1.20

12 14 16 18 20 22 24 26 28 30 32 34 36

CARBON NUMBER

Figure 17. Distribution profiles for n-alkanes derived fromgas chromatograms for Cores 406-13, 406-24, 406-32,and 406-39.

π-ALKANE DISTRIBUTIONS100

5 0 -

Core 406-47

C P I 1.29

12 14 16 18 20 22 24 26 28 30 32 34 36

CARBON NUMBER

Figure 18. Distribution profile for n-alkanes derived fromgas chromatogram for Core 406-47.

990

Page 15: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

BASIC ORGANIC GEOCHEMICAL DATA

TABLE 6Relative Distributions of 5α Type Steranes in Selected Samples From Leg 48

RelativeCarbon Sterane

No.a Designation

Core

402A-16 402A-32 402A-18B 402-1 403-35 403-14 406-32

20.8

21.1

21.6

21.7

22.6

23.6

24.0

24.4

24.75

24.9

26.0

26.3

26.6

26.75

26.8

27.4

27.5

27.6

27.65

27.8

28

28.25

28.4

28.5

28.6

28.7

28.9

29.2

29.4

29.6

29.8

30.65

30.8

31.1

31.6

Sssss

sssss

ss

sssssssssssssssssssssss

10

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

43

19

61

26

56

27.5

24

33

17

10

100

18

16

36

21

18

30

39

36

55

24

56

32

54

42.5

31

17

49

40

100

32

20

17

21

32

29

46

43

21

60

37

52

32

22

16

51

62

74

36

21

26

13

65

38

6

13

21

29

35

48

29

28

42

19

32

18

51

35

100

30

22

40

18

90

15

14

40

33

36

35

76

34

62

62

65

29

32

41

18

82

76

100

20

58

52

23

23

49

100

48

58

72

64

45

40

35

68

88

74

99

20

20

37

21

15

12

14

40

13

24

98

81

40

61

57

46

100

45

45

58

83

79

47

40

46

52

59

63

74

63

50

19

36

31

30

70

61

51

77

41

68

43

37

50

50

59

62

100

Values in relation to normal alkane eluting on 20-meter OV1 Jaeggi column; temperature programmed80 to 260 at 4°C/min, 12 psi He.

991

Page 16: 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL · 2007. 5. 14. · 51. BASIC ORGANIC GEOCHEMICAL DATA OF LEG 48 MATERIAL T. Doran, P.G. Johnson, P.J.D. Park, G.C. Speers, and

T. DORAN ET AL.

TABLE 7Relative Distributions of Pentacyclic Triterpanes From Selected Samples From Leg 48

RelativeCarbon

No. a

27.0027.2127.3927.4327.7628.1129.1129.2029.6930.0530.2130.3430.4331.0531.1931.4031.5331.9031.2032.4632.6332.8733.1733.58

Tentative Identification

C~η Mono unsaturated triterpeneUnknownUnknownUnknown17-α H-Trisnorhopane17-/3 H-TrisnorhopaneC~Q Mono unsaturated triterpene17-α H-Norhopane30-Normoretine17-α H-HopaneMono unsaturated triterpene17-/3 H-NorhopaneC2Q Saturated triterpaneC_22 Diastereoisomer of 17-α H-homohopaneC22 Diastereoisomer of 17-α H-homohopane17-/3 H-HopaneHomomoretaneC22 Diastereoisomer of 17-α homohopane17-α H-BishomohopaneUnknown17-/3 HomohopaneC22 Diastereoisomer of 17-α H-trishomohopaneC22 Diastereoisomer of 17-α H-trishomohopane17-jß H-Bishomohopane

402A-16

26

113855262435275422

672

10012

68

15

402A-32

23

93456

1521273816

45100

53

10

402A-18B

21

144541112635196415

807815

100

15

Core

402-1

1227

824174110311118

10047

9

83

403-35

20202625

7332

100

19223374372826

30402835

403-14

24

279

7216

100

153123

1112

77

406-32

919

193320

7826

100

1624336237122321

521412

aValues in relation to normal alkane eluting on 20-meter OVl Jaeggi column temperature programmed 80 to 260 at 4°C/min, 12 psi He.

TABLE 8Stable Carbon Isotope Values of Kerogens and Extracts

From Hole 402A, Leg 48

IFP Sample No.

2416824169241712417224176

Core

1811161832

Section

1-41

1-21-2

2,3,6

δ 1 3 %o of TotalSoluble Extract

-28.1-27.1-27.6-26.1-26.4

δ 1 3 C % o ofKerogen

-22.9-23.4-23.7-24.0-22.7

992