CHAPTER 6 GEOLOGY - Utah 007039... · 2014-01-17 · Plate 6-1 presents the surficial geology of...

CHAPTER 6

GEOLOGY

•

Canyon Fuel Company, LLC SCM/Dugout Canyon Mine

Mining and Reclamation Plan May 1998

TABLE OF CONTENTS

Section

610 INTRODUCTION 6-1

611 General Requirements .......... ... .. . 6-1

61 2 Certification .......... ... ......... . 6-1

620 ENVIRONMENTAL DESCRIPTION ................ ... ... . 6-1

624 General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1

622 Cross Sections, Maps and Plans. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-2

623 Geologic Determinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

624 Geologic Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

624.100 Regional Setting ....................... 6-4

Stratigraphy ............................ . Mancos Shale ........................... . Mesaverde Group .................... . Star Point Sandstone ..................... . ..... . Blackhawk Formation . . . . . . . . . . . . . . . . . . . .. . ..... . Castlegate Sandstone ............................. . Price River Formation ............................. . North Horn Formation .... ... ....... ............... . Flagstaff Formation ................... . ..... . Colton Formation ................................ . Quaternary Pediment Gravels and Alluvium .............. . Structure ..................................... . Surface and Groundwater Impact. . . . . . . . . . . . .. . ..... . Coal Geology . . . . . . . . . . . . . . . . . . . . . . . . . .. . ..... . Cross-Sections, Maps, and Plans . . . . . . . . . . . .. . ..... . Drill Logs and Chemical Analyses ............ , ...... .

6-5 6-5 6-5 6-7 6-8 6-9

6-10 6-11 6-12 6-12 6-13 6-13 6-14 6-15 6-16 6-16

624.200 Test Boring and Drill Hole Data (overburden removed) ... 6- 1 6

624.300 Test Boring and Drill Hole Data (overburden not removed) 6-16

Lithologi c Logs ..................... . . . :" .-:- . . . .. 6-16 ,; ,7 '" Acid, Toxic, and Alkaline Chemical Analyses ( bd~ ~nQ ' .J~~; below the coal seam) , , , , , , , , , , , , , , , , , , , , , , ' ,-'fV17 ,cf(0 '

r ..) j ~ ". " \,

6-ii

I'

•

•


Section

TABLE OF CONTENTS (Continued)


Acid, Toxic, and Alkaline Chemical Analyses (coal seam) ..... 6-17 Roof and Floor Rock Clay Content . . . . . . . . . . . . . . . . . . . .. 6-1 7 Ground Water Occurrence . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1 7

625 Additional Geologic Information .... . .

626 Sampling Waivers ............... .

627 Description of the Overburden Thickness and Lithology

630 OPERATION PLAN ................... .

631 Casing and Sealing of Exploration Holes

632 Subsidence Monitoring

640 PERFORMANCE STANDARDS

641 Exploration and Drill Holes

642 Monuments and Surface Markers of Subsidence Monitoring Points .............. .

REFERENCES ........................... .

6-iii l

~. , ..

.----"~ ~ -"'-.. -

6-18

6-18

6-18

6-18

6-18

6-18

6-19

6-19

6-19

6-20

•

•

•


Figure

LIST OF FIGURES

6-1 Dugout Canyon Mine Geologic Cross Section A - A'


6-3

6-2 Stratigraphic Section Dugout Canyon Area .................. . 6-6

LIST OF PLATES

6-1 Geology of the Dugout Canyon Mine Permit Area

6-2 Coal Seams Dugout Canyon Mine Portal Area

6-3 Geologic Cross Sections 8 - 8' and C - C'

6-3A Geologic Cross Sections 0 - 0'

6-38 Geologic Cross Sections E - E' and F - F'

6-4 Rock Canyon Seam - Overburden Thickness

6-5 Rock Canyon/Gilson Seam Interburden Map

6-6 Rock Canyon Seam Isopach Map (Confidential Folder)

6-7 Gilson Seam Isopach Map (Confidential Folder)

LIST OF APPENDICES

Appendix

6-1 Drill Hole Logs (Confidential Folder)

6-2 Rock Canyon Coal Seam Roof and Floor Rock Chemical Analyses (Confidential Folder)

6-iv

Canyon Fuel Company, LLC SCMIDugout Canyon Mine

610 INTRODUCTION

CHAPTER 6

GEOLOGY

Mining and Reclamation Plan March 1998

This chapter presents a description of the geologic resources in the area of the Dugout Canyon

Mine. Most of this chapter has been compiled from the approved Geology section of the Sage

Point-Dugout Canyon Mining and Reclamation Plan , formerly designated by the State as

ACT/007/009 .

611 General Requirements

The geologic resources in the Dugout Canyon Mine area

through 627 of this chapter . The plans for casing and seali

subsidence monitoring are addressed in Section 630 through

612 Certification

All maps, plans, and cross-sections presented in this chapter, required by the regulations, have

been certified by a professional engineer.

620 ENVIRONMENTAL DESCRIPTION

This section presents a description of the geologic resources in the area of the Dugout Canyon

Mine.

621 General Requirements

This section presents the regional and site-specific geologic information for the Dugout Canyon

Mine area.

6-1

Canyon Fuel Company, LLC SCM /Dugout Canyon Mine

622 Cross Sections, Maps and Plans


Plate 6-1 presents the surf icial geology of the permit area, the Rock Canyon coal seam outcrop

line, the strike and dip of the coal seam mined, and the locations of the drill holes in the mine

area. The outcrop lines of the Rock Canyon and Gilson coal seams within the Dugout Canyon

Mine disturbed area are illustrated on Plate 6-2. A north to south cross section, labeled as A

to A' on Plate 6-1, is illustrated on Figure 6-1. This cross section displays the relative

thicknesses of the formations and the stratigraphic position of the Rock Canyon coal seam.

The location offour additional cross sections, labeled as B to B', C to C', D to D', E to E', and

F to F', are identified on Plate 6-1. Cross sections B to B' and C to C' are illustrated on Plate

6-3, D to D' on Plate 6-3A, and E to E' and F to F' on Plate 6-3B. These cross sections

demonstrate the relative position and thicknesses of the Rock Canyon, Sunnyside, and Gilson

coal seams in the permit area. Cross sect ions also illustrate the stratigraphic locations of rider

seams associated with the Rock Canyon and Gilson coal seams . The geologic map and six

cross sections are based upon drill hole_ data and on the work previously performed by

Anderson (1983) and lntrasearch (1998).

The overburden associated with the Rock Canyon coal seam is il lustrated on Plate 6-4. The

interburden thickness between the Rock Canyon and Gilson coal seams is presented on Plate

6-5. The thicknesses of the Rock Canyon and Gilson seams in the perm it area are illustrated

on Plates 6-6 and 6-7, respectively. Since the Sunnyside seam is not of mineable thickness

in the permit area, coal isopach, interburden thickness, and overburden maps are not presented

for this seam in this permit.

The geologic logs from the following coal exploration drill holes have been included as

Append ix 6-1 as a supplement to the geologic maps and cross sections. Although other drill

holes occur within the permit area, the drill logs provided characterize well the stratigraphy oT

the permit area.

• 3-1 • 9-1 • 9-2 • 10-1 • 11-1

6-2

NORTH

A' I o

Roan Cliffs -I - ~ 9000 - ::c

8000

7000

6000

5000

---- SECllON TURNS

I ('II Book Cliffs IN

~ Dugout Creek "*==< > \ T~ ,.

Qat

Mancos Shale

GEOXSEC.DWa UC485-OI 3-05-11

SOUTH

A

9000

8000

7000

Qg

6000

5000

4000 I }' '; , 4000---

1000'

0' 2000'

SCALE

FIGURE 6-1. DUGOUT CANYON MINE GEOLOGIC CROSS SECTION A-A'

From And"~n~~ t~,;~" i!"'""-._ _ .. ""'. : lit,

L' OC T 1 6 199;-1 ~, !

~~~'"'

UP4h j

- :;...,.::.. .... ~ ..... '-"""~~ ....... ~-~

"'c. ~,-,

• ~<., '~", ~~-"'~'~"''''''''''' ............ "'-'-.-~!.-,.:., •. , .... ~..-~;.;;.:J

6-3

~ "L;.. ,: \\. f:

........... r ....... • • L.'-#J ...... ---EarthFax

•


• 13-1

• 13-2

• 13-3C

• 14-1

• 14-4

• 14-5

• 15-1

• 15-2

• 15-3

• 19-2

• 24-1

• 24-2 • 24-3C

• 24-4C

• HCC-4

• KCC-A

• KCC-E

• MDC-1A

• N-13

• N-14

• N-15

• N-18

• N-19

• N-20

Mining and Reclamation Plan September 2006

No oil or gas wells are known to exist within the permit area. However, degassification wells have

been drilled for releasing gas from the underground mine workings. Refer to the Degassification

amendment for additional information.

623 Geologic Determinations

The information required by the Division to make a determination of the acid or toxic forming

characteristics of the site strata is presented in Section 624.300 of this M&RP.

The information required by the Division to make a determination as to whether the reclamation plan,

described in Section 540, can be accomplished is presented in Section 624.

The information required to prepare the subsidence control program is addressed in Section 624.

6-4 co PO T

SEP 1 3 2006

Div. of 0" G



Stratigraphy. All rock units within the Dugout Canyon Mine permit area are sedimentary (Plate

6-1 and Figure 6-2). No igneous or metamorphic units have been found in the area. The

exposed, consolidated sedimentary rocks in the area were deposited during the Cretaceous

Age of the Mesozoic Era and the lower Tertiary Subera . The on -es unit ' ~ We.,--__ , --.. _--Cretaceous Mancos Shale, which is overlain in order of increasingl ., yd~ger.A a'c~s,1 by the Star 'J- , if"'

. l,. J J'

Point Sandstone, the Blackhawk Formation, the Castlegate andstor).a,_t~"e,J \ ;r E¥ River

Formation, the North Horn Formation, the Flagstaff Formation and th

(Figure 6-2). I I

I Mancos Shale. The Mancos Shale has been mapped througho t e Hi'vU~ah an,dJW~ltg~ lMNG I Colorado and is the lowest rock unit exposed in the southern h ea. This

formation is best exposed at the base of the steep Book Cliffs where overlying pediment

gravels have been eroded or in the flat valley bottoms where streams have eroded through the

alluvial cover. The Mancos Shale consists of bluish-gray fissile claystone or mudstone which

weathers light bluish-gray to light tan. The formation contains thin calcareous sandstone and

siltstone interbeds which upwardly increase in frequency. The interbeds of sandstone and

siltstone are usually dark gray to light tan to yellow. The formation forms steep, barren, easily

eroded slopes with occasional ledges of more resistant fine-grained sandstone, siltstone, or

sandy claystone. The formation supports little to no vegetation. The Mancos Shale is

between 4,700 and 5050 feet thick in the Book Cliffs Region (Clark, 1928). However, only

approximately 200 feet of the upper Mancos Shale is exposed within the permit boundary .

Mesaverde Group. The name "Mesaverde Group" (Holmes, 1877) was originally used in

southwestern Colorado to describe a sequence of marine sandstone and shale with non-marine

coal-bearing rocks interbedded between marine rocks. The name has since been used in the

Book Cliffs from Utah to Colorado and includes intertonguing marine and non-marine rocks.

The Mesaverde Group in the permit area lies on and intertongues with the Mancos Shale,

making the uppermost Mancos to the east time equivalent with the thinning Mesaverde marine

sandstone to the west. From base to top, the group contains the following formations:

6-5

SYSTD.4

en ::J o W U < J-W 0::: U

SERIES

w Z W U o w

~.

w Z w U o W -.J « a..

DANIAN

Z « I l-I U a::: I(f) W « ~

z « Z « a.. ~ « u

SlRA'IlCRAPHIC UNIT LITHOLOGY

0::: wZ >0 ~t= « Z~ wa::: wo a:::u.. c..?

Z o ~ « ~ 0:: o LL

Z o I-.J o U

z a::: Z 00 II-

« I~ I-a::: 0:::0 Ou.. Z

--:::-:::-:::~

:::-:::-:::~.

- - - -

------~~ ~ - -----

r_-_-_-_I-- - -f-_-_

~' .. ~<.'.2>~ 7 ;',:;:, ~ :

'::: '::L:~ " :;j.': y .':':;' j ';' ..

<:> 1i:. ,':":\7 .. -;; .. o:"~: -1 Z

8 ~ ;~~/ti~ CD -----------

a.. ::l o a::: o

z o i= « ~ a::: o u..

-i--+~-~.·"'y~{ z ------w

o a::: w > « (f) w ~

~ ~ « I ~ U « -.J m

~ -~-=-~-:-=-

; ~ ~~~I~~~~~~

THICKNESS

o N (0

co V

SlRAT.DWG UC485-06 3-11-96

DESCRIPTION

RED SHALE WITH SOME GRAY-GREEN SHALE. INTERBEDDED LIGHT GRAY TO GREEN COARSE TO FINE GRAINED LENTICULAR SANDSTONE. BASAL GRIT AND PEBBLE CONGLOMERA TE IN SANDSTONES.

FORMS THE ROAN CLIFFS.

INTERBEDDED GRAY-GREEN TO RED VARIEGATED SHALE. LIGHT GRAY TO GREEN MEDIUM GRAINED LEN TICULAR SANDSTONE AND THIN BEDS OF FRESHWATER LIMESTONE. FORMS RESISTANT DIP SLOPE.

-~~~' __ ~~h~.~~_~. ~-L __ . .~) <- ~ "=-

U JI J (: \ lr ) 1 ))~() ]0 "]Fi ~ . ... " INTERBEDDED GRAY. GRA Y- ' ~ RE,£ Kf.\j PtJR E: H:[,' :1I". ) [ , J" \ J F1 J)) I

YELLOW- TAN CALCAREOUS HALE. LIGHT . -'~E e ' ~J:: AM MARL WITH SMALL LlMESTO~ E NODUL ~S;--AND LlGH.~~. COARSE TO FINE GRAINED L :::NTICULA CHANNEL . SANDSTONE UP TO 40 FEE IN THICKN oor 16 199(;

UPPER SANDSTONE-GRAY 0 t':IOO ~Pi A' IMOOU A'f,fI,{;j - 'MN , I SANDSTONE, WITH THIN BE[ S OF SILTSTONE, SHALE AND f CARBONACEOUS SHALE. CLlFF~FOt'ffirE -·----i ........ _ -d,_ . MIDDLE PORTION-LIGHT GRAY TO TAN MEDIUM TO FINE GRAIN SANDSTONE INTERBEDDED WITH SHALE AND SILTY SHALE.

GRAY, MEDIUM GRAINED SANDSTONE, WITH SOME THIN LENSES OF CARBONACEOUS SHALE. CLIFF FORMER.

COAL BEARING-INTERBEDDED LIGHT GRAY. MEDIUM TO FINE GRAINED SANDSTONE. SILTSTONE. GRAY TO CARBONACEOUS SHALE AND COAL. LOWER PORTION-GRAY LITTORAL. MEDIUM TO VERY FINE GRAINED BIOTURBATED SANDSTONE AND SANDY SILTSTONE WITH TONGUES OF MANCOS SHALE IN BETWEEN THE MAJOR LITTORAL TONGUES (THICKNESS OF TONGUES NOT TO SCALE) .

~ ~ ~ ~:~~~~t~ g: ~~~~ESA~~~/~L~~l~NSE 6?~~~E~T~R~EA~~AY =--= (f) a... " -:;'-::-:;:-:''7~~-\' N PANTHER TONGUES. NON-RESISTANT. r~~

MASUK TONGUE ------ GRAY TO DARK GRAY. MARINE SHALE, 'r ",' -MANCOS SHALE:::::: CALCAREOUS AND GYPSIFEROUS SLOPE FORMER. l '-I' J _

FIGURE ........ -~

6-2. STRATIGRAPHIC SECTION DUGOUT CANYON AREA EarthFax AFTER ANDERSON, 1980

6-6


• Star Point Sandstone,

• Blackhawk Formation,

• Castlegate Sandstone, and

• Price River Formation .

M ining and Reclamation Plan March 1998

Star Point Sandstone. Exposures of the Star Point Sandstone , the basal member of the

Blackhawk Formation, form a broad, arcuate band crossing east r~~ - ta r-pad ~tendin-g Into I

'.~(\ (( \1 f- J ]D.l(1J1T' A 17":lJD eastern Wyoming, where it is roughly correlative to the Shannon S n -si o'ne of-A !t~ Coe.' I Shale', .'t.J ~

. >.Jl"f.iE 'T V -:. and into southwestern Colorado and northeastern New Mexico where 11: --e-qUiva en - ~€

Point Lookout Sandstone (McGookey, D.P., 1973) .

The formation reaches thicknesses of more than 1 ,000 feet in th Pleasant Valley area in t e . . UTAH I ':iIO rr Q-,u, d

northern part of the Wasatch Plateau. The formation thins s~uthwar along t ne vva 81t l'-i N J

- -.--

Plateau and eastward in the Book Cliffs, and the lowermost un its of the Star Point -graee ir:lt o,-_

the underlying Mancos Shale (Spieker, 1931). Marley (et . a!. , 1979) state that the Star Point

Sandstone is a coastal complex of distributary channel, delta front, and beach barrier

sediments.

Approximately 230 feet of Star Point Sandstone is exposed in the permit area between Soldier

Creek Canyon and Fish Creek Canyon. However, the formation apparently pinches-out within

the Mancos Shale east of Fish Creek Canyon (Anderson, 1983) . The exposures in Fish Creek

Canyon are generally recognized as the easternmost exposures of the formation (Young,

1955, p. 184; Balsley 1976) . The Star Point Sandstone is a gray to grayish tan, very fine

to fine-grained, calcareous sandstone with gray to dark gray siltstone and mudstone. The

formation is thin to medium bedded. The upper sandy unit contains concretionary, sandy

structures that are better cemented than the enclosing rock . In the permit area, the formation

generally forms slopes with ledges of moderately-resistant sandstones.

The base of the Star Point Sandstone is arbitrarily drawn where the regular, thinly interbedded

siltstone , sandstone, and "Mancos-like" mudstone changes or grades into non-resistant

mudstone (after Folk, 1968, p. 28). This contact is difficult to trace along the cliffs and has

6-7

•



been mapped as inferred. The upper contact with the overlying Blackhawk Formation is

drawn at the first appearance of moderately well cemented, interbedded sandy siltstone that

overlies a thick, 65 to 122 feet thick sequence of "Mancos-like" mudstone (Balsley, 1976).

Blackhawk Formation. The Blackhawk Formation crops out from Thousand Lakes Mountain

in south central Utah, along the Wasatch Plateau northward to the ~o·o 1 ~~~~~~_

along the Book Cliffs to a few miles east of Thompson, Utah ' i~~Pf~r;n)~RL~((lsl irt:i'me ~r~f 10) ,

correlatable with the lower Wahweap Formation of southern Utah ( eterson 1 f'I""" 1B2-

183) and the upper Mancos Shale of western Colorado (Fisher, 1 60).

The formation is well exposed in the cliffs and canyons of the per' it area.

top, the Blackhawk Formation contains the Spring Canyon, Aben e " Kel'il ilw~rt~( ern , lower and upper Sunnyside Members. The Aberdeen and Kenilw ~

cliff-formers of the Blackhawk in the Dugout Canyon area. The Blackhawk has been found

in the subsurface in all the drill holes located north of the outcrop and is present in the

subsurface throughout much of the Uinta Basin to the north (Anderson, 1983).

The thickness of the Blackhawk Formation ranges from over 1440 feet to the west of the

permit area in the Deadman Canyon area (Nethercott, 1985) to about 910 feet to the east

near Pace Creek (Anderson, 1983). The formation thins easterly as the Spring Canyon

Member pinches out. Subsurface information on the entire thickness of the Blackhawk

Formation is lacking since most of the drilling was performed as part of coal exploration and

the coal lies near the middle of the formation.

The aforementioned members of the Blackhawk Formation are a series of upward coarsening

littoral sequences, each related to an episode of marine regression. The Kenilworth Member

is a complete representation of the littoral lithologies and is described herein. The base of the

member is a slightly silty mudstone, gray to dark gray, slightly calcareous and carbonaceous,

and generally massive bedded and non-resistant. Above this is an intensely bioturbated unit

consisting principally of sandy siltstone to very fine-grained thin sandstone beds with interbeds

of mudstone. Overlying this transition unit is fine-grained, yellow-gray sandstone, which is

6-8



hummocky cross-stratified (Harms, 1975, p. 87), thick- to massive-bedded, resistant, and

bioturbated. Overlying this unit is a fine- to medium-grained, yellow-gray sandstone with ~ - - .. ~-.~ .~.--------~

trough cross-stratification, mildly bioturbated, and resistant. The uppermos:\ un,iJ ~Jf ~ 1 ~(~tD fra'

sequence is a fine-grained, horizontally bedded, resistant sandstone that Y u~ '9.;. 5)

referred to as the "white cap". On fresh surfaces, this sandstone is Jsually lig (gray"" to--.::J"!~-gray. This upper unit of the littoral sequence may not always be pr~sent in II esn of the formation.

JTAH n, I,)ION Ou, GA:'> .l\ND MI"1ING

The coal bearing rocks in the permit area are generally found above the Kenilworth Memger "' ............... .,,~

and intertongue with and overlie the Sunnyside Members. These units consist of tan to gray,

fine-grained, occasionally cross-bedded and ripple marked sandstone, tan to gray siltstone,

brown to gray mudstone, and black to dark brown carbonaceous mudstone. All these beds

contain variable amounts of carbonaceous material, rare beds of well preserved plant fossils,

and fresh- to brackish-water mollusks. As a group, the coal-bearing rocks are moderately

resistant. Lenticular coals are present throughout this section of the Blackhawk Formation,

and several beds are of mineable thickness. The characteristics of the coal seams are

discussed further in this chapter under the subheading of Coal Geology.

The contact between the Blackhawk Formation and the overlying Castlegate Sandstone has

been recognized by Spieker (1931), Clark (1928), and Young (1955) as an angular

unconformity in the eastern Book Cliffs and Wasatch Plateau area. Anderson (1983)

described the contact in the permit area as apparently conformable, but thickness variations

within the area may indicate a discontinuity. In the subsurface, the contact is sometimes

identifiable by the first occurrence of the thick carbonaceous mudstone of the Blackhawk

Formation.

Castlegate Sandstone. The Castlegate Sandstone extends across the entire length of the

Wasatch Plateau and the Book Cliffs (Spieker, 1931) but loses its character as a cliff-former

south of the Interstate Highway 70. The formation is believed to have been deposited in a

braided stream environment. It is correlative to the Cliffhouse Sandstone of southwestern

Colorado and northern New Mexico (McGookey, 1973). In the Wasatch Plateau, its thickness

6-9



ranges from 50 to 500 feet (Spieker, 1 931 ). In the permit area, the Castlegate Sandstone

is between 161 and 286 feet thick (Anderson, 1983) .

The Castlegate Sandstone is a fine- to medium- grained Quartz sandstone that is very light

gray on fresh surfaces and weathers light tannish-brown. The unit is cemented with clay and

calcium carbonate and has moderate porosity. Sorting is poor, and rounding ranges from

subangular to subrounded. The sandstone contains trough, planar, and some tabular cross

bedding, current ripples, convolute bedding, and small scale graded beds 0.5 to 2.0 inches

thick. Locally, thin lenticular beds of siltstone and mudstone occur and contain abundant

carbonaceous plant material. These finer grained units are most common in the upper and

lower sections of the formation. The formation typically forms ledges and cliffs in the permit

area.

The upper contact with the overlying Price River Formation is laced ~ a! t'hel[h>n~a(k)) f1l ):lope if~;r) where the sandstone becomes finer grained and interbedded w th mudstonel'a'm'(~L ·Ivst.one. •

The contact is sometimes difficult to map on the surface but is di tinctive in eophysical logl

from area drill holes. 0 T 1 6 1998 I I

Price River Formation. The Price River Formation is the uppermos m9frubep,ot-rt ti'l:e)M. .~s II group and is found in continuous outcrop along the Book Cliffs_-nJ"L~~~Qf-.,.~U~!.!.!..~~~~=--_·

formation are moderately resistant slope formers while the upper units are typically resistant

cliffs formers. The thickness of the formation in the permit area ranges from 327 feet to 489

feet.

The lower slope-forming units of the formation consist of mudstone and siltstone with some

fine-grained sandstone and carbonaceous mudstone. These units are dark gray to tan,

lenticular, and grade into one another. The upper units of the formation are light gray to very

light gray, thick to massively bedded sandstone. The medium- to fine-grained, subrounded to

subangular, moderately well cemented Quartz sandstone is friable and porous at the base and

is upward fining. Some beds contain disseminated carbonaceous material, cast of tree stems

and trunks, and minor bioturbation. The sandstone shows horizontal stratification, ripple

6-10



marks, and trough cross-bedding. The thick and massive sandstone is broken by beds of gray

to dark gray mudstone and siltstone that are less resistant. These uppermost sandstone beds

normally appear on outcrop as three cliff-forming units, each separated by a thin slope forming

unit, but occasionally they join to form a single massive cliff. The contact with the overlying

Cretaceous - Tertiary North Horn Formation in the permit area has been picked as the top of

the uppermost, latera"y consistent, cliff-forming sandstone (Anderson, 1983).

North Horn Formation. The North Horn Formation is Cretaceous-Tertiary in age and

conformably overlies the Price River Formation. It is moderately resistant and forms a steep

slope with occasional sandstone ledges. The contact with the overlying Flagstaff Formation

is difficult to determine. Therefore, thicknesses determined from measured sections, both on

the surface and in the subsurface, vary by several hundred feet. Anderson (1983) determined

that the formation ranges from 620 feet near Fish Creek to 1 330 feet in the subsurface in the

Minnie Maud Creek area .

J

The North Horn Formation was deposited in flood plaint a ~ cf lacust~i.n~ ) l€"'n ~~ rC?{lml~ rylt~J Sandstone beds near the base of the formation are similar to tHe sandston s ~ 0·t~ f1a Fin.ce River

Formation but are finer-grained and thin- to medium-beddled. Th i~wer secti~ 0 the

formation is comprised mainly of interbedded gray to light gra sandst l nQ h d1 a grayish

green calcareous mudstone. The sandstone units are fluvial injl Origin, lenttcu1-a., art reEtuently

conglomeratic at the base with a fining upward trend. (h, • , )~ n r lA:) AND MI~r G

The upper part of the formation consists mainly of yellowish tan to gray marlstone with

numerous sma" limestone nodules and gray, grayish green, yellowish tan and purple

calcareous mudstone. In Soldier Creek Canyon, a local, thin coal bed is present in the upper

North Horn Formation.

The contact with the overlying Flagstaff Formation is typically drawn at the base of the first

relatively pure, fossiliferous, thin limestone beds. The limestone beds are generally consistent

across the permit area, but occasionally the limestone grades into marlstone, thus making

determination of the contact difficult. The limestone beds are underlain and overlain by slope

6- 1 1


M ining and Reclamation Plan March 1998

forming mudstones. Since the limestone beds are typically fractured, they also form slopes,

further complicating the task of determining the upper contact of the North Horn Formation.

Flagstaff Formation. The Tertiary age Flagstaff Formation is found throughout the Wasatch

Plateau and above much of the Book Cliffs. It is contemporaneous with the Claron and

Wasatch Formations of southern and south-central Utah. In the permit area, this formation

forms a gentle dip slope on top of the Book Cliffs . Anderson (1983) determined the thickness

of the formation in th is area to be between 265 and 470 feet. The Flagstaff also thins from

west to east across the permit area.

The Flagstaff Formation is an interbedded sequence of sandstone , mudstone, marlstone , -and

limestone. The sandstone is fluvial in origin , lenticular , calcareous , medium to fine grained,

tan to brown in outcrop and gray to grayish green on a fresh surface . The mudstone is

dominantly grayish green and calcareous w ith some re , '3ri e@B~ ~-Q.ue §. r the top ......... . of the format ion . The lime~tone beds are thin, typi all .~ jless ~haJh ~p't4 r I'~~~~ t ryli9 J[)Th~ limestone is generally fossiliferous, containing fresh ater gastropp ':r ~e~cypods, an

ostracods.

The Flagstaff forms a moderate slope at the top of th Book

limestone and calcareous sandstone protecting and

upper contact of the Flagstaff Formation with the Colt

o illl, t ~ , r,~tJea,t .f t Qe cliffs. T e fi , AS 1""\ Nt MINING

OrllTatfoA is dfaw at tba..,top 0 a

sequence of th in bedded, greenish gray sandstone beds . This contact is well marked in the

permit area by the break in slope at the base of the Roan Cliffs.

Colton Formation. The Tertiary Colton Formation crops out in the northeast corner of the

permit area but a full th ickness of the formation is not present; only about 850 feet of the

Colton Formation is exposed in the permit area . The lower units of this formation forms the

Roan Cliffs which stretch from the Price River Canyon area to beyond the Colorado-Utah

Border. The Colton Formation was formerly called the Wasatch Formation in eastern Utah .

6-12



The formation consists of grayish green, tan to light reddish brown, mostly fine grained,

calcareous sandstone with occasional basal beds of thin clay and marlstone clast

conglomerates and interbeds of mudstone or siltstone. The sandstone is generally lenticular

and resistant and appears to be of fluvial origin. In the lower portion of the formation, the

mudstone and siltstone predominate over the sandstone. The mudstone is mostly dark reddish

brown with some variegated gray, green and yellow colors. The mudstone is usually

calcareous and non-resistant, frequently grading into siltstone.

Quaternary Pediment Gravels and Alluvium. Pediments with gravel veneers are especially well

developed below the Book Cliffs escarpment. They occur east to west across the southern

portion of the permit area. As the more resistant rocks of the cliffs retreat by physical and

chemical weathering, the softer and more erodible Mancos Shale is covered by thin layers of

unconsolidated materials from the retreating cliffs. The deposits gradually thin away from the

cliff face. The pediment deposits are partially cemented with .<:.alcium carbonate, poorly

stratified and sorted, of local origin, and range in size from large ba 19r rs - t o cla-y size--par -IC e-s. ~ 1 , It ~ I ,I J 1L Jl I I 1 .

-' JJ. - • .. l' L l:F 'E( c, I "

The alluvium in the permit area consists of poorly stratified cays, siltls, sands, ang ' me

gravels. Younger than the pediment gravels, it is distributed m inly belo

the drainages between the pediments.

Structure. The permit area lies between the Mancos Lowland a d t~k 'Bo~k~ 'e If s-Roarr 6 lifi'Ts

Plateau (Stokes, 1977). The San Raphael Swell and the Farnum antic me

structure of the area. Both structural features are located south of the mine area.

The regional structure of the Book Cliffs from Price to Green River curves around the plunge

of the San Rafael Swell (Doelling, 1972, page 264, Figure 9). The strike of the beds in the

permit area changes from N 82° W on the west side to N 62° W on the east side,

approximately following the Book Cliffs Escarpment. The dip is north to northeast averaging

about 8 degrees but has a range of 6.2 to 11.5 degrees. The Farnum anticline lies about

seven miles south of the permit area and has a strike of approximately N 30° E and plunges

to the north.

6-13

INn j

•

•



about 8 degrees but has a range of 6.2 to 11.5 degrees. The Farnum anticline lies about

seven miles south of the permit area and has a strike of approximately N 30° E and plunges

to the north.

Faulting in the permit and adjacent areas is minor. Anderson (1983) mapped a small east-west

trending normal fault, with a few feet of displacement down to the north, at the center of the

eastern border of Section 20 and the center of the western border of Section 21, Township

1 3 South, Range 1 2 East (Plate 6-1). The stri ke of the fault, N 83° W, is parallel to the

regional st-rike of the dominant bedrock fracture system. Anderson (1983) supposed that the

fault was probably related to the slumping or breaking away of the rock from the Book Cliffs

escarpment.

A second normal fault in the permit area was mapped by Clark (1928) and confirmed by

Anderson (1983) and is located the northeast quarter of Section 12, Township 13 South,

Range 12 East and through the northeast quarter of Section 18, Township 13 South, Range

13 East. This fault trends northwest-southeast and has a displacement of approximately 25

feet down to the southwest.

Numerous small faults are present along the coal outcrop and appear to be related to the

burning of the coal. Field investigations suggest that this faulting is surficial and does not

extend past the burned coal at depth.

Jointing in the bedrock roughly parallels the local structure and is the result of San Rafael

upwarping. Anderson (1983) mapped several near vertical joints in the perm it area that trend

to the west and northwest . The joint patterns are well displayed in the outcrops in the Book

and Roan Cliffs and Pine Canyon.

Surface and Groundwater Impact. Surface and groundwater impacts are discussed in Chapter

7 of this M&RP.

.--

6-14

•

•



Coal Geology. Anderson (1983) identified the following five coal seams within the permit

area:

(Bottom to Top)

• Kenilworth,

• Gilson,

• Fish Creek,

• Rock Canyon, and

• Sunnyside.

According to Anderson (1983)' the coal beds are lenticular and sometimes difficult to correlate

between drill holes. However, the five seams listed above do show some lateral continuity in

the permit area and can be identified as individual coal beds. Only the Gilson and Rock Canyon

coal seams appear to be sufficiently developed in the permit area to allow for economic mining

under current conditions .

The Rock Canyon and Gilson coal seams will be mined at the Dugout Canyon Mine under this

permit. A northwest-southeast trending want area in the Rock Canyon coal seam is present

in the north-central portion of the permit area (Plate 6-3). In the want area, the coal thins to

less than 3 feet and contains several splits. Outside the want area, the coal ranges between

5 and 8 feet thick. In the areas where the Rock Canyon seam is of mineable thickness, the

interburden between the Gilson and Rock Canyon seams ranges from less than 30 to more

than 80 (Plate 6-5).

The as-mined quality of the Rock Canyon coal seam west of Dugout Canyon is projected to

average 12,000 + BTU, 10.3 % ash, and 0.65 % sulfur. The coal is ranked as a bituminous

high volatile B.

East of Dugout Canyon, sulfur content in the Rock Canyon coal seam increases to greater than

1.00/0 thus rendering coal from this seam unsaieable and unprofitable to mine at this ti~ e.

Additionally, the interburden thickness between the Rock Canyo and Gilson seams generally '\) . c{"y r .

\ . 6-15 \

_-.l . -----------

•

•



diminishes to the east of Dugout Canyon and near the center of the federal lease coal making

multiple seam mining difficult, dangerous, and uneconomical (Plate 6-5).

The as-mined quality from the Gilson coal seam in the area of Dugout Canyon Mine and to the

east of the canyon is expected to average 12,250 BTU, 10.4% ash, and 0.55 % sulfur. This

coal is also ranked as a bituminous high volatile B.

The Gilson seam is of mineable thickness in limited areas west of Dugout Canyon, therefore,

the majority of the mining in this seam will occur east of the canyon in the federal lease area.

Multiple seam mining will occur in a relatively limited portion of the permit area, generally in

the vicinity of Dugout Canyon.

Cross-Sections, Maps and Plans. The cross-sections and maps are discussed in Section 624

and are located at the end of this chapter.

Drill Logs and Chemical Analyses. See Section 624.300 and Appendices 6-1 and 6-2. The

applicant requests that this information remain confidential.

624.200 Test Boring and Drill Hole Data {overburden removed}

Currently, there are no plans to remove overburden from above the coal seam to be mined.

Regulations related to overburden removal do not apply to this M&RP.

624.300 Test Boring and Drill Hole Data (overburden not removed)

The drill logs and chemical analyses required by regulations 614-301-624.310 through 614-

301-624.330 are presented in Appendices 6-1 and 6-2.

lithologic Logs. Lithologic logs of drill holes are presented in Appendix 6-1. The applicant

requests that this information be kept confidential .

6-16



Acid, Toxic, and Alkaline Chemical Analyses (above and below the coal seam). The chemical

analyses for acid- and toxic-forming and alkalinity-producing materials from the roof and floor

rock material above and below the Rock Canyon and Gilson coal seams are provided in

Appendix 6-2. Samples for these analyses were obtained from a fresh coal outcrop a few

hundred feet into the abandoned Rock Canyon coal seam mine and approximately 800 feet into

the Gilson coal seam mine in Dugout Canyon. The location of the Gilson seam sample site is

illustrated on Figure A-1 in Appendix 6-2. Using the parameters listed in Table 2 in the r=

"Guidelines fu nagement of To .~ verburden for Undergroun9 and Surfac

Mining", no values outside of the acceptable range were reported.

Acid, Toxic, and Alkaline Chemical Analyses (coal seam). The chemical analyses discussed

above are also representative of the coal bed to be mined. Samples for these analyses were

also obtained from a fresh coal outcrop a few hundred feet into the abandoned Rock Canyon

coal seam mine in Dugout Canyon. The results of these analyses are reported in Appendix 6-

2.

Roof and Floor Rock Clay Content. The clay content of two roof and floor rock samples taken

from within an abandoned portal in the Rock Canyon coal seam in Dugout Canyon was

determined analytically. The roof rock clay content was measured at 7.6 % while the floor

rock clay content was measured at 9.6%. Two samples for roof and floor analysis were also

obtained from the Gilson seam. The roof rock clay content was measured at 19.6% while the

floor rock clay content was measured at 8.6%. Copies of the laboratory data sheets for this

analysis is included in Appendix 6-2. The logs of drill holes within the permit area (Appendix

6-1) indicate that the lithology of the stratum immediately above and below the mineable coal

varies within the permit area.

Ground Water Occurrence. The depth to ground water was not noted on the logs prepared

by the geologist onsite during the drilling of the exploration holes (Appendix 6-2). Since the

holes have been plugged and abandoned, with the exception of those retained for ground

water monitoring (Chapter 7), revisiting the locations for the purpose of obtaining ground water

information is not feasible.

6-17

•

•

•


625 Additional Geologic Information

Mining and Reclamation Plan ' October 2010

It is not anticipated that any additional geologic data will need to be collected forthis site. During the

drilling of degassification wells geologic data may be collected, refer to Chapter 6 of the Degassification .

amendment for details.

626 Sampling Waivers

A sampling waiver is not requested at this time for this site.

627 Description of the Overburden Thickness and Lithology

Overburden thickness above the coal seam ranges from approximately 600 feet in the southern portions

of the permit area to over 2400 in the northern and northeastern portions (Plate 6-4). Stratigraphically,

the overburden consists of the Upper Blackhawk Formation, which contains the coal seams, the Castlegate

Sandstone, the Price River Formation, the North Horn Formation, and the Flagstaff Formation as described '

in Section 624.100 of this M&RP.

630 OPERATION PLAN

631 Casing and Sealing of Exploration Holes

The information addressing regulations for casing and sealing of exploration holes isfound in Section 765

ofthis M&RP. This includes both the temporary and permanent casing and sealing of drilled holes and

exploration holes and boreholes.

632 Subsidence Monitoring

Subsidence and subsidence monitoring points are discussed in detail in Section 525 ofthis M&RP and a

map showing the subsidence monitoring locations is provided in the annual report.

6-18

INCORPORATED

-Eo a 8 2011

Div. of Oil, Gas & Mining


640 PERFORMANCE STANDARDS

641 Exploration and Drill Holes

Mining and Rec lamation Plan May 1998

The performance standards used in the casing and sealing of all exploration holes and drill

holes are outlined in Section 765 of this M&RP.

642 Monuments and Surface Markers of Subsidence Monitoring Points

The performance standards used in the reclamation of all monuments and surface markers

used as subsidence monitoring points are outl ined in Section 525.

6-19


REFERENCES:


Anderson, P.B. 1983. Geologic Map of the Pine Canyon Quadrangle, Carbon County, Utah. Utah Geological and Mineral Survey, Map 72.

Balsley, John K. 1980. Cretaceous Wave-dominated Delta Systems: Book Cl iffs, East Central Utah. AAPG Field Guide, p. 163 .

Clark, F.R. 1928. Economic Geology of the Castlegate, Wellington, and Sunnyside Quadrangles, Carbon County, Utah. U.S. Geological Survey Bulletin 793, p 165.

Doelling, H .H. 1972. Central Utah Coal Fields: Sevier-Sanpete, Wasatch Plateau, Bookcliffs and Emery. UGMS Mon. Ser. 3.

Fisher, D.J., Erdmann, C.E., and Reeside, J .B., Jr. 1960. Cretaceous and Tertiary Formations of the Book Cliffs, Carbon, Emery, and Grand Counties, Utah County and Garfield and Mesa Counties, Colorado. U.S. Geological Survey Professional Paper, p.80.

Harms, J.C., et. al. 1975. Depositional Environments as Interpreted from Sedimentary Structures and Stratification Sequences. SEPM Short Course No.2, p. 161.

Intrasearch, Inc., 1998. Geologic Map of the Dugout Canyon and Kaiser North Lease Areas. -Unpublished Canyon Fuel Company, LLC internal report.

Marley, W.E., et al. 1979. Coal Accumulation in Upper Cretaceous Marginal Deltaic Environments of the Blackhawk Formation and Star Point Sandstone, Emery, Utah. Utah Geo!. V. 6, No.2.

McGookey, D.P. 1973. Cretaceous System, in Geologic Atlas of the Rocky Mountain Region. Rocky Mtn. Assoc. Geol., pp 190-228.

Nethercott, M. 1985. Geology of the Deadman Canyon Quadrangle, Carbon County, Utah. Utah Geological and Mineral Survey.

Peterson, F. and Ryder, R.T. 1975. Cretaceous Rocks in the Henry Mountains Region and Their Relation to Neighboring Regions. Four Corners Geological Society Guidebook, 8th Field Conference, Canyonlands. p.182-183.

Spieker, E.M. 1931. The Wasatch Plateau Coal Field, Utah. USGS Bull. 819, p 46.

Stokes, W.L. 1977. Subdivisions of the major physiographic provinces in Utah. Utah Geology, v. 4, no. 1, p. 1-17.

Young, R.G. 1955. Sedimentary Facies and Intertonguing on the Upper Cretaceous of the Book Cliffs, Utah. Geological Society of America Bulletin, v. 66, p. 177-202. •

6-20

• Place in Confidential Folder

Appendix 6-1

•

• ARCH WESTERN BITUMINOUS GROUP,lLC.

A Sub8idary of Arch Western Resources, LLC .

August 31, 2006

Mr. John T. Blake School and Institutional Trust Lands Administration State of Utah 675 East 500 South, Suite 500 Salt Lake City, Utah 84102-2818

Dugout Canyon Mine P.O. Box 1029 Wellington, UT 84542 (435) 637-6360 Fax (435) 636·2897

Subject: Permission to Core Seams at Degas Well Site G-14A, Dugout Canyon Mine

Dear Mr. Blake:

Per discussions at the Dugout Canyon Mine on August 31, 2006, we request SITLA's approval to core the coal seams at degas well site G-14A located in the northern part of SITLA Lease ML-48435. Information obtained from the hole would be valuable in characterizing the seam where data is sparse. Furthermore, it would provide information

. necessary to meet data adequacy requirements for a soon to be submitted Lease Modification. Dugout Canyon Mine is considering acquisition of coal for eastward and

• northward expansion of longwall panels.

•

Both the Rock Canyon and Gilson coal seams are planned to be cored at the site. The coal core would be used for the analysis of gas content and coal quality. Rock core may be tested for mechanical strength properties. The hole would be geophysically logged and the core would be described in detail. The hole would be cased for use as a degasification site and left open for venting during mining. However, the coal sequence would be cemented upon completion of drilling.

Exploration data generated from site G-14A would be provided to SITLA. This data would include but not be limited to copies of the geophysical log, geologists core descriptions, analytical data, and completion records.

Dugout Canyon Mine thanks you for your consideration and awaits approval of this addition to the drilling program.

Respectively Submitted,

INCORPORATED Erwin Sass General Mine Manager SEP 1 3 2006

Cc: D. Spillman Sitla File

Oi\!, of Oil, GelS 8t N'llnlng

Dugout Canyon rvline


APPENDIX 6-1

Drill Hole Logs (CONFIDENTIAL FOLDER)



APPENDIX 6-2


Rock Canyon Coal Seam Roof and Floor Rock Chemic:a~1 ~A~n::a~ly:se:s~----J (CONFIDEN1-'AL FOLDER)

CHAPTER 6 GEOLOGY - Utah 007039... · 2014-01-17 · Plate 6-1 presents the surficial geology of...

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