DIVISION OF GEOLOGICAL AND GEOPHYSICAL SURVEYS · 2006. 11. 5. · potential geologic hazards to...

STATE OF ALASKA

DEPARTMENT OF NATURAL RESOURCES

DIVISION OF GEOLOGICAL AND GEOPHYSICAL SURVEYS

John W. Katz - Commissioner

Geoffrey Haynes - Deputy Commissioner

Ross G. Schaff - State Geologist

January 1 9 8 2

This is a preliminary publication of the Alaska Division of Geological and Geophysical Surveys and has not received final editing and review. The author will appreciate candid comments on the accuracy of the data and will welcome suggestions t o improve the report.

A l a s k a O p e n - f i l e R e p o r t 1 4 2 COAL I N V E S T I G A T I O N OF THE

S U S I T N A LOWLAND, ALASKA

BY R o y D . M e r r i t t , G i l b e r t R. E a k i n s , and

J a m e s G. C l o u g h

STATE OF ALASKA Department of Natural Resources

DIVISION OF GEOLOGICAL & GEOPHYSICAL SURVEYS

According t o Alaska S t a t u t e 41 , t h e Alaska D iv i s ion of Geological and Geophysical Surveys i s charged with conduct ing ' geo log ica l and geophysical surveys t o determine t h e p o t e n t i a l of Alaska lands f o r product ion of me ta l s , m i n e r a l s , f u e l s , and geo- thermal r e sou rces ; t h e l o c a t i o n s and supp l i e s of ground waters and c o n s t r u c t ion m a t e r i a l s ; t h e p o t e n t i a l geo logic hazards t o b u i l d i n g s , r oads , b r i d g e s , and o t h e r i n s t a l l a t i o n s and s t r u c t u r e s ; and s h a l l conduct o the r surveys and i n v e s t i g a t i o n s a s w i l l advance knowledge of t h e geology of Alaska. '

I n add i t i o n , the D iv i s ion s h a l l c o l l e c t , eval- u a t e , and publ i sh d a t a on the underground, s u r f a c e , and c o a s t a l waters of the s t a t e . It shall . a l s o process and f i l e , d a t a from wa te r -we l l -d r i l l i ng l o g s .

DGGS per forms numerous f u n c t i o n s , a1 1 under t h e d i r e c t i o n of t h e S t a t e Geologist---resource i n v e s t i g a t i o n s ( i nc lud ing minera l , petroleum, and water r e s o u r c e s ) , geologic-hazard and geochemical i n v e s t i g a t i o n s , and informat ion s e r v i c e s .

Admin i s t r a t i ve func t ions a r e performed under t h e d i r e c t i o n of t he S t a t e Geo log i s t , who main ta ins h i s o f f i c e i n Anchorage (3001 Porcupine D r . , 99501, ph 274-9681).

Th i s r e p o r t is f o r s a l e by DGGS f o r $14. It may be inspec ted a t any of t h e four DGGS informat ion o f f i c e s : Alaska Nat ional Bank of t he North Bldg, Ge i s t Rd and Un ive r s i t y Ave, Fa i rbanks , 99701; 323 E. 4 t h Ave., Anchorage; 230 So. F rank l in S t , Juneau; and the S t a t e Of f i ce Bldg, Ketchikan. Mail o rde r s should be addressed t o DGGS, P.O. Box 80007, Col lege, AK 99701.

Beluga Rive r coa l seams, S u s i t n a Lowland, Alaska .

CONTENTS Page

. . . . . . . . . . . . . Abst rac t I n t r o d u c t i o n . . . . . . . . . . .

Locat ion and s e t t l e m e n t s . . . . . . . . . . . . . . . Access

. . . . . . . . . . . Climate . . . . . . . . . . Topography

. . . . . . . . Previous work

. . . . . . . . S t r u c t u r a l geology . . . . T e r t i a r y l i t h o s t r a t i g r a p h y

Tyonek Format ion ( ~ i o c e n e ) . . S t e r l i n g Formation ( ~ l i o c e n e )

Depos i t i ona l environments of Kenai Coal q u a l i t y . . . . . . . . . . . Overburden c h a r a c t e r . . . . . . . Desc r ip t i on of p l a t e s . . . . . . . Conclusions . . . . . . . . . . . .

. . . . . . . . . . Acknowledgments References c i t e d . . . . . . . . .

. . . . . . . . . . . Bibl iography

. . . . . . . . . . . . . . . . . . . 14 . . . . . . . . . . . . . Group c o a l s 15

. . . . . . . . . . . . . . . . . . . 19

. . . . . . . . . . . . . . . . . . . 23

ILLUSTRATIONS

Figure 1 . General l o c a t i o n map of t h e S u s i t n a Lowland . . . . . . . . . 4 . . . . . . . . . . 2 . S t r a t i g r a p h i c nomenclature f o r Kenai Group 8 3 . Coal-bearing T e r t i a r y ou tc rop on the coas t a t Beshta Bay. . . . . . . . . . . . . . . . . . . . . . . . . . Cook I n l e t 11

. . . . . . . . . . . 4 . Volcanic ash p a r t i n g from the Capps seam 13 . . . . . . . . . 5 . Fairview Mountain coal seams C. D. E. and F 13

6 . Paleochannel f i l l ( i n c r o s s s e c t i o n ) w i th in Saturday Creek . . . . . . . . . . . . . . . . . . . . . . . . . coa l seam 16 7 . I l l u s t r a t i o n of c o n t i n e n t a l f l u v i a l environments i n a . . . . . . . . . . . . . . . genera l ized v e r t i c a l sequence 17 8 . Reconstructed block diagram f o r c o n t i n e n t a l f l u v i a l . . . . . . . . . . . . . . . . . . . . . . . . environments 17

. . . . . . . . . . . 9 . Contorted coa l bed on upper Canyon Creek 20 10 . Gradat iona l zones of burn m a t e r i a l a t upper Canyon Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . l o c a l e 21 11 . Thermally a l t e r e d coa l bed a t upper Canyon Creek l o c a l e . . . 21

. . . . . . . . . . . . . 12 . Burn a s soc i a t ed with t he Capps seam 22 . . . . . . . . 13 . Burn a s soc i a t ed with a Chuitna River coa l bed 22 . . . . . . . . . . . . . . . . 14 . Graphi te bed on Johnson creek 23

TABLE S Page

Tab le 1. T e n t a t i v e c o r r e l a t i o n s of g e o l o g i c u n i t s . . . . . . . . . . . 9 2 . C r i t e r i a f o r r e c o g n i t i o n of f l u v i a l d e p o s i t i o n a l

env i ronments . . . . . . . . . . . . . . . . . . . . . . . . 18 3 . Analyses of 16 c o a l samples from Beluga-Yentna r e g i o n ,

A l a s k a . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

APPENDIXES

A. General d e s c r i p t i o n of c o a l o u t c r o p s shown on p l a t e 1 . . . . A 1 B . Geologic columns of d e s c r i b e d c o a l - b e a r i n g s e c t i o n s w i t h i n

t h e K e n a i G r o u p . . . . . . . . . . . . . . . . . . . . . . B 1

PLATES

P l a t e 1. Geology and s t r u c t u r e map of t h e S u s i t n a Lowland 2 . S imple Bouguer g r a v i t y map of t h e S u s i t n a Lowland 3 . Land-s ta tus map of t h e S u s i t n a Lowland 4 . C o a l - p o t e n t i a l map of t h e S u s i t n a Lowland

COAL INVESTIGATION OF THE SUSITNA LOWLAND, ALASKA

BY Roy D. M e r r i t t , G i l b e r t R. E a k i n s , and James G. Clough

ABSTRACT

The S u s i t n a Lowland of s o u t h - c e n t r a l Alaska c o n t a i n s l a r g e r e s e r v e s of sub- b i tuminous and l i g n i t e c o a l s w i t h i n t h e T e r t i a r y Kenai Group. The s t r a t e g i c l o c a t i o n n e a r t i d e w a t e r ; t h i c k n e s s , e x t e n t , and qua1 i t y of t h e numerous c o a l seams; and overburden , i n t e r b u r d e n , and s e a t r o c k c h a r a c t e r i s t i c s combine t o make t h e s e d e p o s i t s economica l ly a t t r a c t i v e f o r new mine development . E x p l o r a t o r y d r i l l i n g by l e a s e h o l d e r s i n t h e s o u t h w e s t e r n p a r t of t h e lowland has proved major c o a l r e s e r v e s s u i t a b l e f o r s u r f a c e mining. Undoubtedly o t h e r r e s e r v e s e x i s t i n t h e S u s i t n a Lowland, bu t t h e l a c k of s u b s u r f a c e i n f o r m a t i o n h a s in- h i b i t e d t h e i r d e f i n i t i o n and development .

T e r t i a r y exposures a r e conf ined t o t h e f o o t h i l l s of t h e Alaska Range and t o i s o l a t e d , u s u a l l y s t e e p , i n c i s e d , and l a r g e l y i n a c c e s s i b l e stream-canyon w a l l s w i t h i n t h e lowland. T e r t i a r y u n i t s a r e d e p o s i t e d on igneous , v o l c a n i c , and s e d i m e n t a r y Mesozoic rocks and a r e o f t e n covered by P l e i s t o c e n e g l a c i a l , f l u v i a l , o r g l a c i o f l u v i a l u n c o n s o l i d a t e d sed iments . Sedimentary b a s i n s w i t h i n t h e r e g i o n a r e t e c t o n i c a l l y c o n t r o l l e d and t h e c o a l d e p o s i t s a r e l o c a l l y f a u l t e d . North of t h e C a s t l e Mountain f a u l t t h e S u s i t n a b a s i n i s r e l a t i v e l y s h a l l o w and t h e Kenai Group s t r a t a a r e u s u a l l y l e s s t h a n 2 ,000 f t t h i c k . Be- c a u s e t h e b a s i n subs ided more r a p i d l y s o u t h of t h i s major d i s c o n t i n u i t y , t h e Kenai Group may a t t a i n t h i c k n e s s e s o v e r 16 ,000 f t i n t h e s o u t h e r n S u s i t n a Low- l a n d alderwo wood and F a c k l e r , 1972; Hartman, P e s s e l , and McGee, 1 9 7 2 ) . D e t a i l e d s t r a t i g r a p h y of t h e Kenai Group remains p o o r l y unders tood and c o r r e l a t i o n of beds is d i f f i c u l t .

The c o a l s and a s s o c i a t e d s t r a t a of t h e S u s i t n a Lowland have been d e s c r i b e d a t 48 o u t c r o p l o c a l e s and s e v e r a l r e p r e s e n t a t i v e s e c t i o n s measured. The fo l low- i n g p r e l i m i n a r y maps have been c o n s t r u c t e d : 1 ) a composite geology and s t r u c t u r e map which emphasizes t h e c o a l - b e a r i n g f o r m a t i o n s of t h e r e g i o n ; 2 ) a s imple Bouguer g r a v i t y map of t h e s o u t h e r n S u s i t n a Lowland ( f rom H a c k e t t , 1977) ; 3 ) a l a n d s t a t u s map; and 4 ) a c o a l p o t e n t i a l map.

Although r e s e a r c h on t h e c o a l d e p o s i t s of t h e r e g i o n c o n t i n u e s , s e v e r a l c o n c l u s i o n s may be drawn a t t h i s s t a g e . The sed imenta ry rocks of t h e Kenai Group d i s p l a y many c h a r a c t e r i s t i c s of a c o n t i n e n t a l f l u v i a l sys tem. Rapid l a t e r a l and v e r t i c a l l i t h o l o g i c changes a r e common. The c o a l s of t h i s paleoenvironment a r e t y p i c a l l y low i n s u l f u r and h i g h i n ash ; t h e y a r e l o c a l l y t h i c k , b u t l a t e r a l l y d i s c o n t i n u o u s .

No major env i ronmenta l problems a r e expec ted d u r i n g mining and r e c l a m a t i o n . However, t h e e f f e c t s of mining i n a r e a s of d i s c o n t i n u o u s pe rmaf ros t need t o be i n v e s t i g a t e d .

INTRODUCTION

Government ag .encies and i n d u s t r y have made s p o r a d i c i n v e s t i g a t i o n s of t h e c o a l s i n Alaska s i n c e about 1900, bu t uniform r e s e r v e f i g u r e s and i n f o r m a t i o n on t h e geo logy and e x t e n t of most o c c u r r e n c e s a r e s c a r c e .

Never the less , it i s c l e a r t h a t Alaska has ex t ens ive coa l r e sou rces . In January 1979, t h e U.S. Department of Energy repor ted a 'demonstrated ' coal- r e s e r v e base f o r Alaska of 6 b i l l i o n tons . Es t imates of the t o t a l coa l resources---including i n f e r r e d and hypo the t i ca l reserves---have va r i ed from 2 t o 4 t r i l l i o n tons .

Desp i t e the immense r e sou rces , Alaska ' s coa l product ion has been minimal because of t he remote l o c a t i o n s of the d e p o s i t s and lack of markets. Coal was produced on a small s c a l e from numerous s i t e s f o r l o c a l use and t o fue l sh ips dur ing the e a r l y p a r t of the century ; s u b s t a n t i a l q u a n t i t i e s were produced from t h e Matanuska coa l f i e l d f o r the Anchorage market u n t i l Cook I n l e t gas became a v a i l a b l e i n 1967. Coal product ion i n Alaska is now l imi t ed t o t h e U s i b e l l i mine near Healy, which produces about 700,000 tons per year from the Nenana Coal F i e ld f o r i n t e r i o r m i l i t a r y bases and the c i t y of Fairbanks.

The h igh cos t of petroleum f u e l s and u n c e r t a i n t y of supply have c rea t ed a s t rong i n t e r e s t by i n d u s t r y , government, and the publ ic i n Alaska ' s coa l r e sou rces and i n t he f e a s i b i l i t y of producing them f o r l o c a l use , expor t , and the gene ra t ion of s y n t h e t i c f u e l s . Accordingly, the Alaska Div is ion of Geologi- c a l and Geophysical Surveys (DGGs) has i n i t i a t e d a program t o i n v e s t i g a t e v a r i o u s coa l f i e l d s t o a s s e s s the coa l resources of the s t a t e . DGGS w i l l com- p i l e a s epa ra t e "coal a t l a s " f o r each important coa l f i e l d . Each a t l a s w i l l be an assemblage of a l l a v a i l a b l e geo log ica l and resource informat ion pe r t i nen t t o c o a l development. The purposes of t hese i n v e s t i g a t i o n s a r e : a ) t o a id land c l a s s i f i c a t i o n and management a s w e l l a s i n i s su ing coal-prospect ing permits and coa l l e a s e s ; b) t o more accu ra t e ly determine coa l r e se rves and the p o t e n t i a l fo r coa l development; c ) t o address the numerous i n q u i r i e s of i ndus t ry i n t e r e s t e d i n developing the coa l resources and of P a c i f i c r i m coun t r i e s seeking coa l sup- p l i e s ; and d ) t o provide a s i n g l e source of information on the coa l depos i t s of an a rea .

The f i r s t reg ion s e l e c t e d fo r s tudy by the DGGS is the Sus i tna Lowland, which inc ludes a broad a rea drained by the Sus i tna River and i t s t r i b u t a r i e s . Subbituminous and l i g n i t e beds exposed along t h e major dra inages of the lowland and along the southern f o o t h i l l s of the Alaska Range i n d i c a t e abundant, re la - t i v e l y shal low subsurface coal d e p o s i t s . Explora tory d r i l l i n g by leaseholders i n t he southwestern S u s i t n a Lowland has a l ready proven major coa l r e se rves s u i t - ab l e fo r su r f ace mining. Whether s i m i l a r ex t ens ive economic d e p o s i t s e x i s t i n t he no r the rn S u s i t n a Lowland i s not known. Barnes (1966) est imated the coal r e s e r v e s wi th in the Beluga-Yentna region a t 2.4 b i l l i o n tons i n beds over 2.5 f t t h i c k ; most of t h i s (2.1 b i l l i o n tons) i s concent ra ted in t he Beluga and Chuitna River bas i n s .

The s t r a t e g i c l o c a t i o n near t i dewa te r ; t h i c k n e s s , e x t e n t , and q u a l i t y of the numerous coa l seams; and overburden, in te rburden , and sea t rock charac te r - i s t i c s combine t o make the d e p o s i t s of the Sus i tna Lowland ( p a r t i c u l a r l y the southern f i e l d s ) the most economically a t t r a c t i v e f o r near-term new mine development i n Alaska.

Although the S u s i t n a Lowland includes seve ra l coa l f i e l d s , a11 coal-bearing u n i t s a r e of s i m i l a r age and c h a r a c t e r , and the e n t i r e region c o n t i t u t e s a d i s - t i n c t physiographic province. Deta i led s t u d i e s a r e d i f f i c u l t because of the s c a r c i t y of ou tcrops and subsurface d a t a over most of the lowland. Therefore ,

t h i s p r o j e c t h a s t a k e n t h e form of a r e g i o n a l b a s i n s t u d y t o p rov ide a c u r r e n t e s t i m a t e of c o a l p o t e n t i a l and t o a i d i n conduc t ing a d d i t i o n a l r e s e a r c h .

The S u s i t n a Lowland was o r i g i n a l l y s e l e c t e d because : a ) i t i n c l u d e s t h e Capps and Chui tna Coal F i e l d s , which have t h e h i g h e s t p o t e n t i a l f o r l a r g e - s c a l e p r o d u c t i o n i n Alaska and which a r e l o c a t e d r e l a t i v e l y n e a r Anchorage; b ) enough g e o l o g i c d a t a e x i s t t o permit a p r e l i m i n a r y c o m p i l a t i o n wi thou t e x t e n s i v e f i e l d - work, and c ) t h e s t a t e h a s r e c e i v e d numerous a p p l i c a t i o n s f o r c o a l - p r o s p e c t i n g p e r m i t s on t h e a r e a and needs i n f o r m a t i o n on t h e c o a l p o t e n t i a l .

The S u s i t n a Lowland i s r e l a t i v e l y unexplored i n t h e s u b s u r f a c e so t h e s t r u c t u r e and s t r a t i g r a p h y a r e p o o r l y u n d e r s t o o d . S e v e r a l o i l and g a s e x p l o r - a t o r y w e l l s have been d r i l l e d i n t h e southernmost p o r t i o n of t h e S u s i t n a Lowland n e a r Cook I n l e t and p rov ide some i n f o r m a t i o n i n t h i s a r e a , but on ly two deep w e l l s have been d r i l l e d f a r t h e r n o r t h and t h e d a t a on one of t h e s e w i l l not be r e l e a s e d f o r 2 y e a r s .

The p r e s e n t r e p o r t i s p r e l i m i n a r y and r e p r e s e n t s t h e c o m p i l a t i o n done dur- i n g 1981. Fie ldwork by t h e pr imary a u t h o r d u r i n g t h e summer o f 1981 was aimed a t d e t e r m i n i n g t h e t y p e s of r e s e a r c h t h a t would be u s e f u l f o r c o n s t r u c t i n g a model f o r t h e b a s i n , u n d e r s t a n d i n g t h e environments of d e p o s i t ion , and a r r i v i n g a t methods f o r c o r r e l a t i n g u n i t s w i t h i n t h e coa l -bea r ing sequences . A g e o l o g i c r e p o r t summarizing t h e s e f i n d i n g s w i l l be completed i n 1982.

LOCATION AND SETTLEMENTS

The approximate a r e a of t h e S u s i t n a Lowland i n c l u d e s Tps. 11-30 N . , Rs. 2 5-16 W . , and encompasses about 8 , 0 0 0 m i . The r e g i o n i s covered by t h e

f o l l o w i n g U.S. G e o l o g i c a l Survey 1 :250 ,000-sca le topograph ic maps: Anchorage, T a l k e e t n a , T a l k e e t n a Mountains , and Tyonek. The g e n e r a l l o c a t i o n and bounds f o r t h e S u s i t n a Lowland ( ~ a h r h a f t i g , 1 9 6 5 ) , a s c o n s i d e r e d i n t h i s r e p o r t , i s shown i n f i g u r e 1. The lowland i s bounded by t h e a r c u a t e Alaska Range on t h e n o r t h and w e s t , t h e T a l k e e t n a Mountains on t h e e a s t , and t h e Cook I n l e t on t h e s o u t h . S u r f a c e e l e v a t i o n s of t h e lowlands i n c r e a s e from s e a l e v e l a t Cook I n l e t nor th - ward t o abou t 1 , 0 0 0 f t a t t h e n o r t h e r n l i m i t . . I s o l a t e d mounta ins of i n t r u s i v e and p r e - T e r t i a r y rocks r i s e above t h e s u r r o u n d i n g a r e a s by as much as 4 ,000 f t .

The S u s i t n a Lowland o v e r l a p s t h e n o r t h e r n p a r t of t h e Cook I n l e t . Some w r i t e r s ( f o r example, M i l l e r and o t h e r s , 1959 , p. 4 7 ) c o n s i d e r t h e S u s i t n a Low- l and t o be t h e n o r t h w e s t e r n e x t e n s i o n of t h e Cook I n l e t T e r t i a r y b a s i n . Barnes (1966) t e rms t h e a r e a t h e Beluga-Yentna r e g i o n . Work completed d u r i n g t h e l a s t s e v e r a l y e a r s by l e a s e h o l d e r s i n t h e s o u t h w e s t e r n p a r t of t h e lowland has r e - s u l t e d i n t h e d i v i s i o n of t h e s o - c a l l e d Beluga Coal F i e l d i n t o t h r e e s e p a r a t e d e p o s i t s : t h e Capps, Chu i tna , and Threemile f i e l d s .

The p resence of t h e C a s t l e Mountain f a u l t , a major n o r t h e a s t - t r e n d i n g d i s - c o n t i n u i t y , c r e a t e s a b reak i n t h e s u b s u r f a c e between t h e Cook I n l e t on t h e s o u t h and t h e S u s i t n a Lowland on t h e n o r t h , and most s t r a t i g r a p h i c s t u d i e s on t h e Cook I n l e t pe t ro leum prov ince t e r m i n a t e a t t h e f a u l t . However, impor tan t c o a l l e a s e s i n t h e Beluga a r e a l i e on bo th s i d e s of t h e f a u l t zone.

The upper Cook I n l e t , s i t e of t h e Anchorage m e t r o p o l i t a n a r e a and of nea rby s e t t l e m e n t s i n t h e Matanuska V a l l e y and on t h e Kenai P e n i n s u l a , i s t h e most d e n s e l y p o p u l a t e d r e g i o n i n Alaska . The s t a t e ' s p r i n c i p a l a g r i c u l t u r a l r e g i o n

Figure 1. General l oca t ion map of the Sus i tna Lowland. Pre-Ter t ia ry rocks a re shaded ( a f t e r Wolfe and o t h e r s , 1966) .

is l o c a t e d i n t h e lower Matanuska V a l l e y , and p l a n s a r e underway by t h e s t a t e t o make a d d i t i o n a l l a n d s a v a i l a b l e f o r a g r i c u l t u r a l development a t MacKenzie P o i n t , a c r o s s Knik A r m from Anchorage. Except f o r smal l s e t t l e m e n t s a long t h e P a r k s Highway and t h e Alaska R a i l r o a d , t h e S u s i t n a Lowland is e s s e n t i a l l y u n i n h a b i t e d . A c t i v i t y i n t h e summer i n c l u d e s p l a c e r miners i n t h e P e t e r s v i l l e - C a c h e Creek a r e a i n t h e n o r t h e r n p a r t of t h e lowland, and d r i l l e r s on a c t i v e c o a l l e a s e s i n t h e s o u t h w e s t e r n p o r t i o n .

A new s i t e f o r t h e s t a t e c a p i t a l h a s been s e l e c t e d nea r Willow about 40 a i r m i l e s n o r t h o f Anchorage. I f t h e move i s c a r r i e d o u t , t h e r e w i l l be a s i g n i f i - c a n t i n c r e a s e i n i n d u s t r i a l growth and p o p u l a t i o n , which w i l l a f f e c t t h e a d j o i n - i n g S u s i t n a Lowland.

ACCESS

The P a r k s Highway and t h e Alaska R a i l r o a d t r a n s e c t t h e S u s i t n a Lowland i n a n o r t h - s o u t h d i r e c t i o n rough ly p a r a l l e l ing t h e S u s i t n a R i v e r . The P a r k s Highway and a 10-mile e x t e n s i o n t o T a l k e e t n a a r e t h e o n l y paved r o a d s . A g r a v e l road from t h e P a r k s Highway connec t s wi th t h e p l a c e r mining d i s t r i c t on P e t e r s and Cache Creeks nor thwes t of T a l k e e t n a . The remain ing p a r t s of t h e lowland a r e a c c e s s i b l e o n l y by a i r c r a f t . ( ~ e l i c o p t e r s a r e g e n e r a l l y used f o r f i e l d i n v e s t i - g a t i o n s . ) S u r f a c e c o n d i t i o n s and env i ronmenta l concerns l i m i t t h e use of of f- road v e h i c l e s . There a r e a few p r i v a t e l a n d i n g s t r i p s of v a r y i n g q u a l i t y n e a r some of t h e mining c l a i m s , bu t pe rmiss ion f o r t h e i r use i s r e q u i r e d . F a c i l i t i e s a r e a v a i l a b l e t o t h e p u b l i c a t t h e T a l k e e t n a a i r f i e l d .

CLIMATE

The c l i m a t e i n t h e S u s i t n a Lowland i s not a s s e v e r e as it i s i n t h e i n t e r i o r of t h e s t a t e and a t h i g h e r e l e v a t i o n s , b u t heavy s n o w f a l l s and h i g h winds a r e not unusual d u r i n g w i n t e r months. The average annual p r e c i p i t a t i o n a t T a l k e e t n a i s 28 i n . , and t h e mean t e m p e r a t u r e i s about 33°F. By compar ison, t h e t o t a l s a t Anchorage I n t e r n a t i o n a l A i r p o r t a r e about 15 i n . and 3 6 " ~ ( u . s . De- par tment o f Commerce, 1 9 6 8 ) .

A 1 though pe rmaf ros t i s not uncommon i n n o r t h e r n r e g i o n s , F e r r i a n s (1965 ) i n d i c a t e s t h a t t h e lower p a r t s of t h e S u s i t n a Lowland nea r t h e Cook I n l e t and a l o n g t h e S u s i t n a River a r e g e n e r a l l y f r e e of p e r m a f r o s t . F lank ing t h e s e a r e a s is a zone u n d e r l a i n by i s o l a t e d masses of p e r m a f r o s t ; n e a r e r t o t h e mounta ins ' d i s c o n t i n u o u s ' permaf ros t i s p r e s e n t .

TOPOGRAPHY

Rugged a l p i n e f e a t u r e s of t h e Alaska Range and t h e T a l k e e t n a Mountains bound t h e S u s i t n a Lowland on t h r e e s i d e s . The lowland c o n s i s t s of b road , r e l a t i v e l y f l a t t o g e n t l y r o l l i n g t e r r a i n over i t s c e n t r a l p a r t s , i n c r e a s i n g s i g n i f i c a n t l y i n r e l i e f toward t h e b a s i n a l - r i m a r e a s i n t h e f o o t h i l l s of t h e Alaska Range. Large g l a c i e r s extend from t h e mounta ins down t o nea r t h e marg ins of t h e lowland. During P l e i s t o c e n e t ime f i v e p e r i o d s of g l a c i a t i o n a r e r ecorded elso son and Reed, 1978) and ev idence i n d i c a t e s t h a t i c e f i l l e d t h e upper Cook I n l e t t o e l e v a t i o n s over 4 ,000 f t ( ~ k w k , 1965, p. 1 1 5 ) . R e t r e a t of g l a c i e r s from t h e S u s i t n a Lowland l e f t a l andscape dominated by g l a c i a l and g l a c i o f l u v i a l l andforms : m o r a i n e s , d r u m l i n s , f l u t e d t i l l , r i d g e s , l a k e s , ponds, marshes , bogs , and scoured bedrock (Dean, 1 9 8 0 ) . V a l l e y f e a t u r e s c r e a t e d by p e r i g l a c i a l

a c t i v i t y and mass movement inc lude t a l u s s l o p e s , l a n d s l i d e s cou r s , avalanche chu te s , and rock g l a c i e r s . F l u v i a l p rocesses cont inue t o modify and i n c i s e t h e g l a c i a l d e p o s i t s .

PREVIOUS WORK

Geological i n v e s t i g a t i o n s and r e p o r t s of the presence of coa l i n t h e S u s i t n a Lowland were made by the U.S. Geological Survey as e a r l y as 1900 ( ~ a r n e s , 1966, p. C4). The 1957 d iscovery of o i l and gas beneath t he Cook I n l e t , i nc reas ing i n t e r e s t i n the coa l and a g r i c u l t u r a l p o t e n t i a l s of t he r eg ion , s t a t e and Nat ive land s e l e c t i o n s under t h e Alaska Statehood Act and t h e Alaska Nat ive Claims Se t t lement Act, and a vo t e t o move the s t a t e c a p i t a l t o t he Willow a r e a have r e s u l t e d i n a growing number of r e p o r t s bear ing on the resources and environment of the reg ion . The p u b l i c a t i o n s which a r e most h e l p f u l f o r a s tudy of t he coa l resources a r e l i s t e d under References Cited and Bibl iography. The s i n g l e most conc lus ive and thorough r epo r t on t he coa l i n t he S u s i t n a Lowland is "Geology and Coal Resources of t h e Beluga-Yentna Region, Alaska" by F.F. Barnes (1966) .

STRUCTURAL GEOLOGY

The major s t r u c t u r a l f e a t u r e s of t he S u s i t n a Lowland a r e depic ted on p l a t e 1. The T e r t i a r y coal-bear ing s t r a t a of t he Sus i tna Lowland occupies the north- e r n p a r t of a roughly e l l i p t i c a l ba s in known as t h e Shel ikov t rough . A major s t r u c t u r a l d i s c o n t i n u i t y c o n s i s t i n g of the Bruin Bay f a u l t , the Moquawkie magnetic c o n t a c t , and t h a t p a r t of t h e C a s t l e Mountain f a u l t l y ing e a s t of t h e Theodore River d iv ides t h i s bas in i n t o a deeper sou theas t e rn segment and a shal- low nor thwes te rn segment. The sou theas t e rn p o r t ion subsided much more r a p i d l y than the nor thwes te rn po r t i on dur ing t h e accumulation of Kenai Group s t r a t a . Broad and g e n t l e no r theas t - t r end ing f o l d s a r e superimposed on the major b a s i n a l s t r u c t u r e ( ~ r a n t z and o t h e r s , 1963; Wolfe and o t h e r s , 1966) .

The C a s t l e Mountain f a u l t is formed by the mergence of t h e Lake Clark and Bruin Bay f a u l t s near the southwestern margin of the Sus i tna Lowland. The Beluga Mountain f a u l t i n t e r s e c t s the C a s t l e Mountain f a u l t a t a near r i g h t angle e a s t of Mount S u s i t n a , forming a t h r u s t wedge which has been moved r e l a t i v e l y upward and eastward. Smaller s c a l e block f a u l t i n g , fo ld ing , t i l t i n g , and slumping a r e c h a r a c t e r i s t i c of o t h e r r e s t r i c t e d a r ea s wi th in t he r eg ion . I n a d d i t i o n , c e r t a i n coa l -bear ing s e c t ions may be r epea t ed , which sugges ts ( e r roneous ly ) e i t h e r a much t h i c k e r coa l o r two beds.

Hackett (1977) pointed out t h a t t h e T e r t i a r y sedimentary bas in s wi th in t he upper Cook I n l e t reg ion were t e c t o n i c a l l y c o n t r o l l e d by l a r g e basement f a u l t s o r f a u l t systems. He proposed t h a t the C a s t l e Mountain, Bruin Bay, and Beluga Mountain f a u l t systems were of a high-angle r eve r se n a t u r e . He was the f i r s t t o recognize t h e Beluga Mountain f a u l t and b e l i e v e s i t t o have a v e r t i c a l d i sp lace- ment over 10,000 f t (3,000 m) .

These basement f a u l t s and smal le r s c a l e high-angle block f a u l t s wi th in the r eg ion have d e f i n i t e l y o f f s e t t he coa l d e p o s i t s . Their u l t i m a t e e f f e c t on f u t u r e coa l e x p l o r a t i o n and development has not yet been f u l l y a s c e r t a i n e d . I n a d d i t i o n t o d i s p l a c i n g the c o a l , downthrown blocks may l o c a l i z e channel ing and r e s u l t i n t h e e ros ion of t he coa l seam(s) .

TERTIARY LITHOSTRATIGRAPHY

The s t r a t i g r a p h i c nomencla ture p r e s e n t l y used f o r t h e T e r t i a r y ( ~ l i g o c e n e - ~ i o c e n e ) coa l -bear ing s t r a t a of t h e S u s i t n a Lowland was f i r s t proposed by Calderwood and F a c k l e r (1972) f o r t h e Cook I n l e t b a s i n ( f i g . 2 ) . Because of t h e t h i c k n e s s and complexi ty of t h e T e r t i a r y coa l -bear ing sequence, t h e y r a i s e d t h e 'Kenai orm mat ion' o r i g i n a l l y adopted by D a l l and H a r r i s (1892) t o group s t a t u s . Within t h i s c l a s s i f i c a t i o n , Calderwood and F a c k l e r r ecognized f i v e s e p a r a t e u n i t s a s d i s t i n c t f o r m a t i o n s . The i r d i v i s i o n s were based t o some degree on t h e f i v e l i t h o l o g i c u n i t s d i s t i n g u i s h e d by K e l l y (1963) from s u b s u r f a c e wel l d a t a i n t h e c e n t r a l p a r t of t h e Cook I n l e t b a s i n . These zones a r e :

Zone 1 - mass ive sand beds (5 ,000 f t t h i c k ) Zone 2 - s a n d s t o n e , s h a l e , and l i g n i t e ( s e v e r a l thousand f e e t t h i c k ) Zone 3 - s i l t s t o n e , s h a l e , and low rank c o a l ( s e v e r a l thousand f e e t t h i c k ) Zone 4 - s a n d s t o n e and conglomerate sil em lock producing zone , ' I 700 f t

t h i c k ) Zone 5 - s i l t s t o n e and s h a l e ( s e v e r a l hundred f e e t ) .

Barnes (1966) d i f f e r e n t i a t e d t h r e e u n i t s w i t h i n t h e "Kenai Formation": lower , m i d d l e , and upper . H i s coa l -bear ing middle member c o n t a i n s s a n d s t o n e , s i l t - s t o n e , c lays ' tone, and conglomerate l i t h o l o g i e s , whereas t h e e n c l o s i n g upper and lower s t r a t i g r a p h i c u n i t s c o n s i s t predominant ly of pebbly sands tone and con- g lomera t e . Based p r i n c i p a l l y on t h e p a l e o b o t a n i c a l and pa lyno log i c a l work by Wolfe and o t h e r s (1966) and Calderwood and F a c k l e r ' s T e r t i a r y s t r a t i g r a p h y f o r t h e Cook I n l e t r e g i o n (1972) , t e n t a t i v e c o r r e l a t i o n s of e q u i v a l e n t rock u n i t s on a f o r m a t i o n a l l e v e l have been made and a r e inc luded on g e o l o g i c maps compiled by Magoon and o t h e r s (1976) and Reed and Nelson (1980) . T a b l e 1 compares c o r r e l a - t i o n s from t h e s e maps wi th those of Barnes ' 1966 g e o l o g i c map.

The Kenai Group c o n s i s t s predominant ly of s a n d s t o n e s , s i l t s t o n e s , c l a y - s t o n e s , cong lomera tes , and c o a l s . T e r t i a r y sediments n o r t h of t h e C a s t l e Moun- t a i n f a u l t a r e r e l a t i v e l y t h i n ( t y p i c a l l y 2 ,000 f t o r l e s s ) and l i e on g r a n i t i c r o c k s . The Kenai Group is commonly l e s s t h a n 10,000 f t t h i c k sou th of t h e C a s t l e Mountain f a u l t i n t h e s o u t h e r n S u s i t n a Lowland b u t ranges up t o 16 ,000 f t t h i c k ; i n t h i s r e g i o n i t u s u a l l y o v e r l i e s o l d e r T e r t i a r y o r Mesozoic sed imenta ry r o c k s . I n t h e c e n t r a l p a r t of t h e Cook I n l e t b a s i n t h e group a t t a i n s t h i c k - n e s s e s over 26,000 f t (Calderwood and F a c k l e r , 1972; Hartman, P e s s e l , and McGee, 1972) . These sed imenta ry rocks have many of t h e c h a r a c t e r i s t i c s of a con- t i n e n t a l (nonmarine) f l u v i a l system. Rapid l a t e r a l and v e r t i c a l changes i n l i t h o l o g y a r e common. Exposures a r e conf ined t o t h e b a s i n a l r i m a r e a s ( f o o t - h i l l s ) of t h e Alaska Range and t o i s o l a t e d , u s u a l l y s t e e p , i n c i s e d , and l a r g e l y i n a c c e s s i b l e s t ream canyon w a l l s w i t h i n t h e lowlands . Minor o u t c r o p s of T e r t i a r y rocks a l s o occur a long c o a s t a l a r e a s ( f o r example, a 10-mile exposure on Beshta Bay, f i g . 3 ) . The T e r t i a r y d e p o s i t s a r e u s u a l l y o v e r l a i n by P l e i s t o - cene g l a c i a l d r i f t o r f l u v i a l s u r f i c i a l d e p o s i t s . They a r e d e p o s i t e d on igneous , v o l c a n i c , and sed imenta ry rocks of Mesozoic age.

I n a d d i t i o n t o t h e Kenai Group s t r a t a , f i v e o t h e r fo rmat ions c r o p out i n t h e s o u t h e a s t e r n p a r t of t h e S u s i t n a Lowland. The Chickaloon Formation is a Pa leocene coa l -bear ing sequence which a l s o c o n t a i n s we l l - indura ted c l a y s t o n e s , s i l t s t o n e s , s a n d s t o n e s , and cong lomera tes . The Chickaloon grades upward i n t o t h e Wishbone Format ion, a l s o a w e l l - l i t h i f i e d Paleogene ( ~ a l e o c e n e t o ~ o c e n e ) u n i t ; t h e Wishbone c o n s i s t s of cong lomera tes , s a n d s t o n e s ,

F i g u r e 2 . S t r a t i g r a p h i c nomencla ture f o r Kenai Group ( a f t e r Calderwood and F a c k l e r , 1 9 7 2 ) .

I I- V)

, V)

O

0 Z E W W

w z a

% 8 2 3

o a N a

i=

Rests unconforrnably on older Tertiary, Cretaceous, and Jurassic rocks

0 F O R M A T I O A

Alluvium and glacial deposits

Sterl ing Formation

D E S C R I P T I O N

Massive sandstone and conglomeratebedswith occasional thin lignite bed

I C h

Claystone, siltstone, and thin sandstone beds; thin sub-

. bituminous coal beds

Sandstone, claystone, and siltstone interbeds and massive subbituminous coal beds

Sandstone and conglomerate

Tuffaceous siltstone and claystone; scattered sandstone and conglomerate beds

a

0

C9

2 z u Y

Beluga Formation

a-,

Ty O For a ion

Hemlock Conglomerate

L. - L

West Foreland Formation

Table 1. T e n t a t i v e c o r r e l a t i o n s of g e o l o g i c u n i t s

Barnes (1966) : "Kenai Formation" Member

Magoon and o t h e r s (1976) : Kenai G ~ O U D Format ion Area

Tyonek Quadrangle

1. South o f Capps G l a c i e r a . Lower b . Middle

a . West Fore land b . Tyonek

North of Lone Ridge Lower West F o r e l a n d

Beluga River a . North of Lake C l a r k

f a u l t b . Between Lake C l a r k

and Bruin Bay f a u l t s c . South of Bruin Bay f a u l t

a . Lower a . West Fore land

b . Tyonek

c . Beluga

Tyonek

b . Middle

c . Middle

Middle Chui tna River -- between Lake C l a r k and Bruin Bay f a u l t s

T r i b u t a r i e s of N i k o l a i Creek--south o f Lake C l a r k f a u l t

Lower

Lower

Tyonek

West Fore land Threemi le R i v e r l ~ e w i s River area--south of L i t t l e M t . S u s i t n a and n o r t h o f Lake C l a r k f a u l t

Middle

Middle

D r i l l Creek and Coal Creek Tyone k

Tyonek T a l a c h u l i t n a R i v e r ; F r i d a y and S a t u r d a y Creeks

Canyon Creek Middle

Middle

Tyonek

Tyonek Skwentna R i v e r , n o r t h e a s t o f Porcup ine B u t t e

K a h i l t n a R i v e r , n o r t h of c o n f l u e n c e w i t h Yentna River

Midd 1 e Tyone k

Barnes (1966) : Reed and Nelson (1980) : I! Kenai Format ion" Member Kenai Group Format ion Area

Talkeetna Quadrangle

1 2 . Johnson Creek a . Sands tone Member o f Tyone k

b. S t e r l i n g

a . Middle

b . Upper

Kicha tna River Sandstone Member of Tyonek o r S t e r l i n g

Nakochna River a . Middle

b . Upper

Middle

a . Conglomerate Member Tyone k

b . S t e r l i n g

Yenlo Creek, Lake Creek, and Kahi l t n a River ( n o r t h w e s t of S h u l i n ~ a k e )

Sandstone Member of Tyonek

Bear Creek e a s t of L i t t l e P e t e r s H i l l s

Middle Sandstone Member of T y o n ~ k

Dra inages s o u t h e a s t of P e t e r s H i l l s

Midd 1 e Sandstone Member of Tyonek

Cache Creek Middle Sandstone Member of Tyonek o r S t e r l i n g

D o l l a r Cr6ek Middle

Middle

S t e r l i n g

Long C r e e k / ~ o t t o n w o o d Creek

S t e r l i n g

T r i b u t a r i e s of Long Creek/ Cottonwood Creek nor th- west of P e t e r s Hills--- Willow, Poorman, P a s s , and Div ide Creeks

S t e r l i n g

T r e a s u r e Creek e a s t of C h e l a t n a Lake

S t e r l i n g

F a i r v i e w Mtn and r e g i o n s o u t h o f Mtn Kl i skon

S t e r l i n g

Middle Conglomerate Member of Tyonek

Cottonwood Creek

Middle

Upper

S t e r l i n g Sunflower Creek

Bluf f Creek, southwest margin o f Ruth G l a c i e r

Conglomerate Member of Tyonek o r S t e r l i n g

T e r t i a r y exposures belong t o t h e Tyonek Formation excep t f o r about 5 m i l e s a long i t s lower r e a c h e s , which i s inc luded i n t h e Beluga Formation. A 1 1 T e r t i a r y coa l -bear ing o u t c r o p s i n t h e n o r t h e r n S u s i t n a Lowland have been ass igned t o e i t h e r t h e Tyonek o r t h e S t e r l i n g Format ion.

L i t t l e l i t h o l o g i c informat i o n has been pub1 i s h e d on t h e s t r a t i g r a p h i c u n i t s w i t h i n t h e Kenai Group o t h e r than t h a t f o r t h e Tyonek and S t e r l i n g Formations by Reed and Nelson (1980) on t h e i r g e o l o g i c map of t h e T a l k e e t n a Quadrangle . We w i l l summarize below t h e impor tan t p o i n t s of t h e i r d e s c r i p t i o n s and i n c l u d e g i n a d d i t i o n , o b s e r v a t i o n s made d u r i n g t h e 1981 f i e l d season.

They d i v i d e t h e Tyonek Formation i n t o a s a n d s t o n e member and a conglomerate member. The sands tone member is e i t h e r conformable wi th t h e u n d e r l y i n g con- g lomera te member o r i n t e r f i n g e r s wi th i t . The Tyonek Formation overLies Mesozoic rocks w i t h i n t h e T a l k e e t n a Quadrangle i n an a n g u l a r unconformity . I n a d d i t i o n , t h e S t e r l i n g Format i o n unconf ormably over 1 i e s t h e Tyonek Format ion a s sugges ted by t h e i n c o r p o r a t i o n of c o a l f ragments d e r i v e d from t h e Tyonek w i t h i n t h e S t e r l i n g . Exposures of Tyonek and S t e r l i n g s t r a t a a r e r e s t r i c t e d t o t h e b a s i n a l r i m a r e a s ( f o o t h i l l s ) of t h e Alaska Range and t o o u t c r o p s a long s t reams w i t h i n t h e lowlands . These beds c o n s i s t e n t l y d i p e i t h e r g e n t l y o r modera te ly t o t h e s o u t h e a s t .

TYONEK FORMATION (MIOCENE)

Sands tone Member. Th is u n i t c o n s i s t s predominant ly of s a n d s t o n e s (up t o 80 p e r c e n t ) t h a t a r e t y p i c a l l y medium t o c o a r s e g r a i n e d , pebbly , and p o o r l y in- d u r a t e d . The beds l o c a l l y a r e r e p o r t e d ( ~ e e d and Nelson, 1980) t o be up t o 60 m t h i c k , a l though t h e y occur i n much t h i n n e r l e n s e s as d e s c r i b e d by M e r r i t t a t l o c a l e FM1 (App. A and B). M i n e r a l o g i c a l l y , t h e s e s a n d s t o n e s a r e composed of maf ic g r a i n s ( b i o t i t e , hornb lende , c l i n o z o i s i t e , and c h l o r i t e ) . In te rbedded s i l t s t o n e s and c l a y s t o n e s make up 20 pe rcen t of t h e Sandstone Member. They a r e commonly l i g h t t o medium g r a y , r o o t e d , and l o c a l l y i n c l u d e c o a l s t r i n g e r s , and may a t t a i n t h i c k n e s s e s up t o 50 m. Conglomerate, c o a l , and v o l c a n i c ash compose l e s s t h a n 1 p e r c e n t of t h e Sandstone Member, a s e s t i m a t e d by Reed and Nelson (1980) . The conglomerate o c c u r s i n beds up t o 5 m t h i c k , wi th i n c o r p o r a t e d c l a s t s i z e s rang ing up t o 10, cm b u t averag ing 2-6 cm. The c o a l s occur w i t h i n t h e s e f i n i n g upward ( i . e . , cong lomera te , s a n d s t o n e , s i l t s t o n e , c l a y s t o n e , c o a l ) c y c l i c sequences above t h e c l a y s t o n e s ( u n d e r c l a ~ s ) . The q u a l i t y of t h e c o a l s v a r i e s and they o f t e n have carbonaceous s h a l e o r bone p a r t i n g s ; they a v e r a g e l e s s than 1 m t h i c k but l o c a l l y a t t a i n t h i c k n e s s e s of 3 m w i t h i n t h e Sandstone

. Member. The v o l c a n i c ash p a r t i n g s ( t o n s t e i n s ) w i t h i n t h e c o a l beds may be up t o 30 cm t h i c k and c o n s i s t of " p a r t i a l l y d e v i t r i f i e d g l a s s s h a r d s a l t e r e d t o i l l i t e ( ? ) and l e s s t h a n 0.5 p e r c e n t b i o t i t e t t ( ~ e e d and Nelson, 1980) . The a s h p a r t i n g s a r e o f t e n r o o t e d . An example of a v o l c a n i c ash p a r t i n g from t h e Capps Seam ( ~ y o n e k or mat ion) is shown i n f i g u r e 4 .

Conglomerate Member. Reed and Nelson, from samples c o l l e c t e d and analyzed from F a i r v i e w Mountain, d e s c r i b e i t s c o n s t i t u e n t s a s 40 p e r c e n t cong lomera te , 20 p e r c e n t s a n d s t o n e , and l e s s than 40 p e r c e n t s i l t s t o n e , c l a y s t o n e , and c o a l . F i g u r e 5 shows an o u t c r o p of t h e upper f o u r c o a l beds exposed a t F a i r v i e w Moun- t a i n ( f rom bottom t o t o p , t h e s e have been l a b e l e d t h e C, D , E , and F seams by M e r r i t t ; A and B a r e p o o r l y exposed below t h i s s e c t i o n ) . The u n i t is m a s s i v e l y bedded and p o o r l y i n d u r a t e d , and is buff t o b l u e g r a y . C l a s t s range up t o 15 cm i n d iamete r bu t average 5-10 cm. P r o p o r t i o n s of t h e d i f f e r e n t c l a s t l i t h o l o g i e s

F i g u r e 4 . Volcanic ash p a r t i n g from t h e Capps seam.

F i g u r e 5 . Fai rv iew Mountain c o a l seams (from bottom t o t o p ) C , D , E , and F.

obvious, and i n a c t u a l i t y , such c o r r e l a t i o n o f t e n is not pos s ib l e . Time-strat i - g raphic marker beds a r e r a r e w i th in t h e S u s i t n a Lowland. Probably our b e s t markers a r e well-defined and r e l a t i v e l y continuous t ime-para l le l key beds such as vo l can i c ash p a r t i n g s o r occas iona l t h i n fresh-water l imes tones . Addi t iona l pa l eobo tan i ca l and pa lynologica l work w i l l g r e a t l y advance our understanding of t h e s t r a t i g r a p h i c complexi t ies i n t h e Kenai Group.

DEPOSITIONAL ENVIRONMENTS OF KENAI GROUP COALS

There has been ve ry l i t t l e publ ished on the d e p o s i t i o n a l environments of c o a l s i n Alaska. Paleoenvironmental i n t e r p r e t a t ion is important t o ga in ing an understanding of coa l seam and overburden c h a r a c t e r i s t i c s wi th in a given b a s i n . Furthermore, i t should be u t i l i z e d as a t o o l fo r t he development and implementa- t i o n of premine p l ans . The s imple a p p l i c a t i o n of r e l a t i o n s h i p s e s t a b l i s h e d i n o t h e r coa l mine reg ions w i th in the "lower-48" w i l l reap huge b e n e f i t s when l a rge - sca l e mining begins i n Alaska. Of course , t h e s e concepts must be app l i ed with cons ide ra t i on given t o c e r t a i n unique Alaskan cond i t i ons .

The c o n s t r u c t i o n of d e p o s i t i o n a l continuum models (paleoenvironmental p r o f i l e s ) a l lows t h e coa l e x p l o r a t i o n i s t t o p r e d i c t coal t r ends from one a r ea t o another w i th in a coa l b a s i n . A key to understanding these t r ends i s recognizing va r ious ~ u b ~ n v i r o n m e n t s w i th in t he f l u v i a l system (backswamp, l e v e e , channel , f lood p l a i n , l a k e , po in t ba r , c r evas se sp l ay d e p o s i t s , e t c . ) . This r e c o g n i t i o n can lead t o exp lana t ions of phys ica l and chemical changes observed i n coa l seams and t h e i r enc los ing s t r a t a .

The c o a l s and a s soc i a t ed s t r a t a of the Sus i tna Lowland a r e c h a r a c t e r i s t i c of c o n t i n e n t a l f l u v i a l ( f resh-water ) paleoenvironments and d i f f e r s i g n i f i c a n t l y from those a s soc i a t ed with marine and brackish-water systems. The fol lowing b r i e f d i s c u s s i o n of f l u v i a l d e p o s i t s can be appl ied t o the coal-bear ing u n i t s w i th in t h e S u s i t n a Lowland. Much of it is based on methods developed by the Caro l ina Coal Group dur ing t h e 1970 ' s i n the Appalachian Coal Province.

Paleogeographic r e c o n s t r u c t i o n s a r e important fo r understanding coal-seam c h a r a c t e r i s t i c s , inc lud ing the e f f e c t s of topography on the developing coa l swamp. Thicker c o a l s may c h a r a c t e r i z e paleo-lows, whereas t h inne r c o a l s may occur over paleo-highs. Terr igenous c l a s t i c wedges t y p i c a l l y t h i n or pinch out over f l e x u r e s , and t h i s may r e s u l t i n the th inn ing or merging of interbedded coa l seams. The longer per iods of exposure and deeper s o i l development over paleo-highs may br ing about increased roo t p e n e t r a t i o n . Thus, t h i n c o a l s o f t e n have t h i c k underc lays , whereas t h i c k coa l s may have t h i n underc lays . The l a t e r a l c o n t i n u i t y of a seam may be a l t e r e d o r d i s rup t ed because of paleo- channels . I n f i g u r e 6 , a small paleochannel ( i n c r o s s s e c t i o n ) c u t s out much of t h e Saturday Creek coa l seam. Channel scouring may completely remove, or 'wash o u t , ' a coa l seam. These channels d i r e c t l y a f f e c t the m i n a b i l i t y of a p a r t i c u l a r seam ( ~ o r n e and o t h e r s , 1978) .

F l u v i a l c o a l s have low s u l f u r and trace-element con ten t s but commonly high a sh ; they a r e d i scont inuous l a t e r a l l y , but can be very t h i c k l o c a l l y . However, t h i s is not a r i g i d a s s o c i a t i o n . There a r e , fo r example, many r e l a t i v e l y low-ash c o a l s w i th in t h e S u s i t n a Lowland. These r e l a t i o n s h i p s , e s t a b l i s h e d a s broad g e n e r a l i z a t i o n s , have been e x t e n s i v e l y s tud ied by the Caro l ina Coal Group. The in f luence of contemporaneous tectonism---more s p e c i f i c a l l y , subsidence rates---on coa l q u a l i t y is a l s o very s i g n i f i c a n t . Horne and o t h e r s (1978) noted

F i g u r e 6 . Paleochannel f i l l ( i n c r o s s s e c t i o n ) w i t h i n Sa tu rday Creek c o a l seam.

t h a t r a p i d subs idence wi th accompanying s e d i m e n t a t i o n r e s u l t s i n lower s u l f u r and t race-e lement abundances and r a p i d changes w i t h i n c o a l s . Because of t h e u s u a l l y abundant c o n t r i b u t i o n s of d e t r i t a l m a t e r i a l s a s s o c i a t e d wi th c o n t i n e n t a l f l u v i a l regimes, c o a l s of t h i s paleoenvironment a r e c h a r a c t e r i z e d by h i g h e r a s h (mos t ly s i l i c a ) c o n t e n t s . Slower subsidence dur ing d e p o s i t i o n r e s u l t s i n more l a t e r a l l y con t inuous c o a l seams wi th h i g h e r c o n t e n t s of chemica l ly p r e c i p i t a t e d m i n e r a l s .

T e c t o n i c i n f l u e n c e s and subsidence r a t e s a1 s o a f f e c t c o a l i f i c a t i o n and c o a l d i a g e n e s i s ( c a t a g e n e s i s ) a s w e l l a s c o a l pe t rography . D e p o s i t i o n a l sed imenta ry f a c i e s tend t o prograde r a p i d l y l a t e r a l l y i n a g r a d u a l l y s u b s i d i n g t o t e c t o n i c a l l y s t a b l e a r e a ; c o n v e r s e l y , they prograde s lowly i n a r a p i d l y s u b s i d i n g a r e a . I n t h e l a t t e r more t e c t o n i c a l l y a c t i v e s e t t i n g , d e p o s i t i o n a l f a c i e s tend t o be s t acked v e r t i c a l l y . Channel sands tones of t h e f l u v i a l paleoenvironment a r e d e s c r i b e d ( ~ o r n e and o t h e r s , 1978) a s " m u l t i s t o r i e d u n i t s " ; t h a t i s , they commonly d i s p l a y many d i r e c t i o n s of l a t e r a l m i g r a t i o n .

F i g u r e s 7 and 8 a r e diagrams i l l u s t r a t i n g t h e subenvironments of con- t i n e n t a l f l u v i a l c o a l d e p o s i t s . Tab le 2 l is ts broad c r i t e r i a f o r r e c o g n i z i n g f l u v i a l d e p o s i t i o n a l environments . Backswamp d e p o s i t s c o n s i s t of t h e b a s a l s e a t r o c k ( o f t e n u n d e r c l a y ) , c o a l , and s u p r a j a c e n t carbonaceous s h a l e . Dis- c o n t i n u i t i e s o r s p l i t s i n c o a l seams o f t e n r e p r e s e n t a n c i e n t l e v e e d e p o s i t s of a c t i v e c h a n n e l s , i n c l u d i n g c r e v a s s e s p l a y s . Loca l i zed , pod-shaped c o a l bod ies

Coal with clay split Seatrock, clayey

San-d$o>+ifpd-fitstone, climbing ripples,,rooted

Sandstone, medium-to coarse- grained, festoon cross-bedded

Coal with seatrock splits, seatrock, silty

Sandstone and siltstone, climbing ripples, rooted

Sandstonelmedium-to coarse- grained..festoon cross-bedded

Ccnglomeraterlag, siderite pebbles. slumss siltstone. thin-bedded

Coal with clay splits

LEVEE

CHANNEL

FLOOD PLAIN BACKSWAMP LEVEE

CHANNEL

LAKE

FLOOD PLAIN BACKSWAMP

F i g u r e 7 . I l l u s t r a t i o n of c o n t i n e n t a l f l u v i a l environments i n a g e n e r a l i z e d v e r t i c a l sequence ( f rom Horne and o t h e r s , 1978, p. 2390) .

Swamp Point bar

A /

SCALES

0 Sandstone ......

Siltstone and shale

. * O H Pebble lag - Coal

11 11 ROothg OrnL 0

300 lo0:L m 0 500 1OOOft

Trough cross-beds

Bedding planes

F i g u r e 8 . Recons t ruc ted b lock diagram f o r c o n t i n e n t a l f l u v i a l environments ( f rom Horne and o t h e e r s , 1978, p. 2390) .

Table 2 . C r i t e r i a f o r r e c o g n i t i o n of f l u v i a l d e p o s i t i o n a l environments ( f rom Horne and o t h e r s , 1978)

I. Coarsening upward

A. Sha le and s i l t s t o n e sequences . . . . . . . . . . . . common t o r a r e 1. G r e a t e r t h a n 50 f t . . . . . . . . . . . . . . . not p r e s e n t 2 . 5 t o 25 f t . . . . . . . . . . . . . . . . . . . common t o r a r e

B. Sandstone sequences . . . . . . . . . . . . . . . . . r a r e t o n o t p r e s e n t

1. G r e a t e r t h a n 50 f t . . . . . . . . . . . . . . . not p r e s e n t 2 . 5 t o 25 f t . . . . . . . . . . . . . . . . . . . r a r e

11. Channel d e p o s i t s

. . . . . . . . . . . . . A. ~ i n e - g r a i n e d abandoned f i l l . . . . . . . . . . . . . . . . . 1. Clay and s i l t .

2 . Organic d e b r i s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. Ac t ive s a n d s t o n e f i l l

. . . . . . . . . . . . . . . . . . 1. F ine g r a i n e d 2. Medium and c o a r s e g r a i n e d . . . . . . . . . . . .

3 . P e b b l e l a g s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 . C o a l s p a r

r a r e r a r e r a r e abundant common abundant abundant abundant

111. C o n t a c t s

A. Abrupt ( s c o u r ) . . . . . . . . . . . . . . . . . . . . abundant B. G r a d a t i o n a l . . . . . . . . . . . . . . . . . . . . . common t o r a r e

I V . Bedding

A. Cross-beds. . . . . . . . . . . . . . . . . . . . . . abundant 1. R i p p l e s . . . . . . . . . . . . . . . . . . . . . common 2 . R ipp le d r i f t . . . . . . . . . . . . . . . . . . . common-abundant 3. Herringbone f e s t o o n . . . . . . . . . . . . . . . abundant 4 . Graded beds . . . . . . . . . . . . . . . . . . . r a r e 5 . P o i n t b a r a c c r e t i o n s . . . . . . . . . . . . . . abundant 6 . I r r e g u l a r bedding. . . . . . . . . . . . . . . . abundant

V . Levee d e p o s i t s . . . . . . . . . . . . . . . . . . . . . . abundant

V I . Mineralogy of s a n d s t o n e s

A . L i t h i c graywacke. . . . . . . . . . . . . . . . . . . abundant B . O r t h o q u a r t z i t e s . . . . . . . . . . . . . . . . . . . not p r e s e n t

V I I . F o s s i l s

A . Marine. . . . . . . . . . . . . . . . . . . . . . . . not p r e s e n t B . Brack i sh . . . . . . . . . . . . . . . . . . . . . . . r a r e C . F r e s h . . . . . . . . . . . . . . . . . . . . . . . . c o r n o n t o r a r e D . Burrow s t r u c t u r e s . . . . . . . . . . . . . . . . . . r a r e

may r e p r e s e n t accumulat ions of o r g a n i c m a t e r i a l s a d j a c e n t t o meander c h a n n e l s of a n c i e n t f l o o d p l a i n s . These broad f lood p l a i n p l a t f o r m s ( a l l u v i a l p l a i n s ) were c h a r a c t e r i z e d by abundant p l a n t growth. Rapid s e d i m e n t a t i o n by f l o o d s b u r i e d t h e s e p l a n t m a t e r i a l s . Upright stumps ( ' k e t t l e s ' ) a r e abundant i n c o n t i n e n t a l f l u v i a l paleoenvironments ( ~ o r n e and o t h e r s , 1 9 7 8 ) .

A s f u r t h e r i n t e r p r e t a t i o n s a r e made from s u r f a c e exposures of t h e Kenai Group s t r a t a w i t h i n t h e S u s i t n a Lowland and more s u b s u r f a c e and d e t a i l e d physi- c a l and geochemical d a t a a r e c o l l e c t e d , d e p o s i t i o n a l models f o r t h e c o a l b a s i n s o f t h e r e g i o n can be developed and r e f i n e d . These models can t h e n be r e l a t e d t o g e n e r a l c o a l - q u a l i t y assessments and overburden c h a r a c t e r i z a t i o n d u r i n g premine p l a n n i n g , t o c o a l e x p l o r a t i o n d r i l l i n g programs on l e a s e t r a c t a r e a s , t o t h e p r e d i c t i o n of g e o l o g i c and geochemical ( e n v i r o n m e n t a l ) problems d u r i n g min ing , and t o postmining rec lamat i o n .

COAL QUALITY

The major c o a l d e p o s i t s w i t h i n t h e S u s i t n a Lowland can g e n e r a l l y be ranked a s e i t h e r subbi tuminous B , subbi tuminous C , o r l i g n i t e . A l a r g e number of c o a l beds w i t h i n t h e Kenai Group (mos t ly w i t h i n t h e Tyonek orm mat ion) a r e more t h a n 50 f t t h i c k . One bed of t h e r m a l l y a l t e r e d c o a l of smal l a r e a l e x t e n t was d i s c o v e r e d i n t h e upper r e a c h e s of Canyon Creek ( s e e l o c a l e s CnC2, CnC3, and CnC4 on p l . 1 and i n app. A and B) . A t CnC2 t h e bed was l o c a l l y s e v e r e l y c o n t o r t e d as a r e s u l t of t h e su r rounding i n t r u s i v e s ( f i g . 9 ) . G r a d a t i o n a l zones of burn m a t e r i a l a s s o c i a t e d wi th t h e metamorphic a u r e o l e s e p a r a t i n g Mesozoic i n t r u s i v e b o d i e s and i n t e r v e n i n g T e r t i a r y metasediments from t h e remain ing Kenai Group s t r a t a a r e shown i n f i g u r e 10 ( s i t e ~ n C 3 ) . The bed shown h e r e t h i c k e n s t o over 20 f t a t CnC3. F i g u r e 11 is a c lose-up view of one of t h e t h e r m a l l y a l t e r e d c o a l beds w i t h i n t h e seam.

There h a s been v e r y l i t t l e c o a l - q u a l i t y d a t a pub l i shed on t h e S u s i t n a Lowland. Coal companies h o l d i n g l e a s e s w i t h i n t h e s o u t h e r n p o r t i o n have g a t h e r e d e x t e n s i v e d a t a but a r e keeping t h e informat i o n conf i d e n t i a l . Barnes (1966) r e p o r t e d a n a l y s e s on s e v e r a l c o a l s ; t h e s e a n a l y s e s were performed by t h e U.S. Bureau of Mines i n P i t t s b u r g h , Pennsy lvan ia ( t a b l e 3 ) .

Tab le 3 . Analyses o f 16 c o a l samples from Beluga-Yentna r e g i o n , Alaska . ( l i s t e d as a range f o r d i f f e r e n t pa ramete rs ana lyzed ;

adapted from Barnes , 1966, p. C26-C27.)

Rank: Subb i tuminous B , subb i tuminous C , and l i g n i t e C a l c u l a t e d mois t m i n e r a l - f r e e h e a t i n g v a l u e ( ~ t u ) : 7,650-9,800

Sample V o l a t i l e Fixed Heat i n g c o n d i t i o n Mois tu re m a t t e r ca rbon Ash S u l f u r v a l u e ( ~ t u )

As re- 19.7-33.1 30.1-39.9 26.4-40.6 2.0-16.8 0.1-0.4 7,030-9,520 c e i v e d

,vlois t u r e - - - - 39.8-56.1 38.0-50.5 2.7-22.2 0.1-0.6 9,470-12,070

f r e e ~ o i s t u r e - - - - 47.2-57.9 42.1-52.8 - - - 0.1-0.6 11,860-12,600

and ash- f r e e

F i g u r e 9 . Contor ted c o a l bed a t upper Canyon Creek l o c a l e .

The c h i e f a t t r a c t i o n of Alaskan c o a l s i s t h e i r ext remely low s u l f u r con- t e n t . L o c a l l y , t h e ash c o n t e n t i s low t o moderate . Heat ing v a l u e s a r e compar- a b l e t o o t h e r wes te rn U.S. c o a l s . Seams range from d u l l and blocky wi th o c c a s i o n a l v i t r a i n bands t o d u l l and p l a t y , t o woody and papery, and t o bone. Beds of b r i g h t c o a l a r e r a r e . Volcanic ash and carbonaceous s h a l e o r c l a y s t o n e p a r t i n g s occur l o c a l l y w i t h i n seams observed throughout t h e lowland. I n addi- t i o n , c o a l seams have burned i n s e v e r a l a r e a s , baking t h e a d j a c e n t rock m a t e r i a l s . The burn o f t e n weathers t o v a r i c o l o r e d g l e y s . The baked s h a l e s and c l a y s t o n e s o f t e n c o n t a i n abundant p l a n t f o s s i l s ( s e e l o c a l e CR7, f o r example, p l . 1 and app. A). Two a r e a s where c o a l beds have been burned---the Capps Seam and a Chui tna River seam---are shown i n f i g s . 12 ( l o c a l e C G ~ ) and 13 ( l o c a l e C ~ 1 0 ) . L o c a l l y , c o a l beds have been conver ted l a r g e l y t o g r a p h i t e ; f o r example, g r a p h i t e and g r a p h i t i c c l a y s t o n e s a r e common a t Johnson Creek ( f i g . 14) and Nakochna R i v e r . These beds o f t e n c o n t a i n q u a r t z v e i n s and nodules w i t h a l t e r e d c a l c i t e r ims.

' a 1 ~ 3 0 1 yaaa3 aaddn 2~ paq 1 ~ 0 3 paaa3-t" A l l e t u ~ a y ; ~ '11 a a n % ? ~

' a l e301 yaaa3 uodue3 laddn 3e 1e;aaJsm u lnq go sauoz leuo;3epel3 '01 axn%;d

F i g u r e 1 2 . Burn a s s o c i a t e d wi th t h e Capps seam.

F i g u r e 13. Burn a s s o c i a t e d wi th a Chui tna River c o a l bed.

-22-

Figure 14. Graph i t e bed on Johnson Creek.

OVERBURDEN CHARACTER

The c o a l seams of the Kenai Group w i t h i n the S u s i t n a Lowland a r e i n t e r - bedded wi th c l a y s t o n e s , s i l t s t o n e s , s a n d s t o n e s , and conglomerates . L o c a l l y , t h e c o a l beds a r e covered by P l e i s t o c e n e f l u v i a l , g l a c i a l , o r g l a c i o f l u v i a l unconso l ida ted sed iments . These range from g l a c i a l t i l l (sometimes a d iamic ton) and outwash g r a v e l ( i n c l u d i n g cobb les and b o u l d e r s ) t o col luvium and a l luv ium, widely s c a t t e r e d a r e a s of slump and l a n d s l i d e m a t e r i a l , and beach d e p o s i t s . Roof rocks a r e u s u a l l y sands tones , carbonaceous s h a l e s , o r uncon- s o l i d a t e d sed iments . Sea t rocks a r e commonly c l a y s t o n e s o r carbonaceous s h a l e s .

Again, v e r y l i t t l e geochemical and p h y s i c a l d a t a have been pub l i shed i n r e l a t i o n t o overburden c h a r a c t e r i z a t i o n i n Alaska. General f i e l d o b s e r v a t i o n s sugges t t h a t few environmental problems can be expected i n r egard t o t h e qua1 i t y of overburden, i n t e r b u r d e n , and s e a t r o c k m a t e r i a l s w i t h i n t h e S u s i t n a Lowland. S o i l s , a l though o f t e n t h i n , appear t o be r i c h , brown sandy loams wi th abundant o r g a n i c m a t t e r and n u t r i e n t s . Most of t h e rock m a t e r i a l s a r e h igh chroma, t h a t i s , u s u a l l y buff t o l i g h t brown o r a r e ox id ized t o ye l low and o range . Although v e r y l i t t l e p y r i t e was observed i n any of the coa l -bea r ing s t r a t a , c e r t a i n dark-gray and b l a c k ( low chroma) carbonaceous s h a l e s , c l ay - s t o n e s , and bony c o a l should not be l e f t on t h e rec la imed s u r f a c e .

Most m a t e r i a l hand l ing problems dur ing mining w i l l undoubtedly be r e l a t e d t o t e x t u r e , e s p e c i a l l y i n r egard t o t h e l a r g e g l a c i a l - t i l l b o u l d e r s . It is h i g h l y u n l i k e l y t h a t e i t h e r an a c i d or a l k a l i n e s p o i l w i l l deve lop dur ing min-

ing , and abundances of p o t e n t i a l l y t ox i c t r a c e elements should be extremely low. This can be pred ic ted from the c o n t i n e n t a l f l u v i a l paleoenvironment of t h e Kenai Group s t r a t a . However, f u r t h e r research is needed on the e f f e c t s of mining on those a r e a s of t h e lowland unde r l a in by d iscont inuous or i s o l a t e d permafrost .

For mining t o be economic i n most a r ea s of t he Sus i tna Lowland and to maximize r e sou rce recovery, a multiple-seam mining plan w i l l have t o be implemented. I n a d d i t i o n , the s t r i p p i n g r a t i o (overburden: c o a l ) must be low. Large d r a g l i n e s would be unsu i ted fo r mining on most l e a s e t r a c t s w i th in the S u s i t n a Lowland. A small drag1 i n e , o r shove ls and tandem equipment, w i l l produce t he g r e a t e s t f l e x i b i l i t y i n handl ing in t e rbu rden m a t e r i a l s and winning t h e m u l t i p l e coa l seams.

DESCRIPTION OF PLATES

Geology and s t r u c t u r e map of t he S u s i t n a Lowland ( p l . 1 ) . The T e r t i a r y coa l -bear ing u n i t s a r e s t i p p l e d . The darkened c i r c l e s and appended blocked-in code numbers r e f e r t o l o c a l e s descr ibed i n app. A and B . Most of the coa l geology was taken from Barnes (1966); fol lowing t h i s , no attempt has been made t o d i v i d e t h e Kenai Group i n t o i t s fo rmat ions . The major s t r u c t u r a l f e a t u r e s of t he reg ion a r e a l s o shown.

Simple Bouguer g r a v i t y map of t he S u s i t n a Lowland ( p l . 2 ) . (From S.W. Hacket t , 1977, Gravi ty survey of Beluga Basin and ad jacent a r e a , Cook I n l e t r eg ion , sou th-cent ra l Alaska; DGGS Geologic Report 49. )

The g r a v i t y map presented on t h i s p l a t e covers only the southern par t of t h e S u s i t n a Lowland; t h e no r the rn reg ion is s t i l l unsurveyed. The fol lowing b r i e f d i s c u s s i o n has been summarized from ~ a c k e t t ' s 1977 r e p o r t .

The g r a v i t y highs c o r r e l a t e with exposures of pre-Tert i a r y basement rocks , whereas t h e g r a v i t y lows i n d i c a t e a r ea s under la in by T e r t i a r y sediments . The Beluga, S u s i t n a , and Yentna bas in s a r e cha rac t e r i zed by s t e e p g r a v i t y g r a d i e n t s and low Bouguer anomaly v a l u e s . This i n d i c a t e s the presence of l a r g e basement d i s c o n t i n u i t i e s and implies t h a t t he se bas ins a r e t e c t o n i c a l l y deep. The r eg iona l g r a v i t y g rad i en t over t he upper Cook I n l e t reg ion sugges ts a g radua l westward th ickening of t he e a r t h ' s c r u s t . Re l ie f on the pre-Ter t ia ry basement su r f ace gene ra t e s t he l a r g e r anomalies over the lowlands.

Land-status map of t h e S u s i t n a Lowland ( p l . 3 ) . The fol lowing genera l c a t e g o r i e s of land s t a t u s information a r e i n d i c a t e d :

a . Alaska D iv i s ion of Lands (ADL) coa l l e a s e s , inc lud ing a d e s c r i p t i o n of each l e a s e and the name of the l e s s e e

b . S t a t e parks c . S t a t e game re fuges ( ~ o o s e Bay, Palmer Hay F l a t s , P o t t e r P o i n t , Sus i tna

F l a t s , and Trading ~ a y ) d . Nat ive lands 4

e . Boroughs f . Nat ional parks g . Petroleum and gas we l l s with the wel l name and owner, and Bureau of

Mines c o a l - t e s t d r i l l h o l e s .

The c u r r e n t s t a t e of f l u x between U.S. and Alaska l ands precludes an a t tempt t o d i s t i n g u i s h the s t a t u s of a l l a r e a s w i t h i n the S u s i t n a Lowland a t t h i s t ime.

An i n d i v i d u a l wishing t o e n t e r any a rea of the S u s i t n a Lowland should check t h e land s t a t u s f i r s t , because many a r e a s r e q u i r e s p e c i a l pe rmi t s . These inc lude Nat ive l a n d s , l e a s e t r a c t a r e a s , mining c la ims , and s t a t e game re fuges . P a r t i c u l a r l y , t h e s t a t e game re fuges have been c l a s s i f i e d as e s s e n t i a l t o w i l d l i f e and f i s h e r i e s r e sources and a r e managed by the Alaska Department of Fish and Game (ADF&G). For any e x p l o r a t i o n , c o n s t r u c t i o n , or development work i n a des igna ted re fuge , a S t a t e Game Refuge Permit from the ADF&G i s r e q u i r e d .

Coa l -po ten t i a l map of t h e S u s i t n a Lowland ( p l . 4 ) . This map was based s o l e l y on previous geology and coa l r e source maps of the S u s i t n a Lowland with ve ry l i t t l e subsur face in fo rmat ion . Hence, t h i s map i s h i g h l y i n t e r p r e t i v e and open t o q u e s t i o n ; major r e v i s i o n s w i l l be r equ i red as informat ion becomes a v a i l a b l e .

We have subdivided the a r e a according to r e l a t i v e p o t e n t i a l fo r f u t u r e c o a l development, recogniz ing t h a t t h i s i s only a p re l iminary c l a s s i f i c a t i o n .

Four c a t e g o r i e s have been e s t a b l i s h e d , and the numbers i n d i c a t e a reas of dec reas ing c o a l p o t e n t i a l as £01 lows:

1 - h i g h e s t p o t e n t i a l ; 2 - moderate p o t e n t i a l ; 3 - l i t t l e p o t e n t i a l or a r e a s of s c a r c e informat ion; and 4 - no p o t e n t i a l f o r coa l development ( c h i e f l y r e s t r i c t e d t o exposures of

p re -Ter t i a ry basement).

Many areas judged to have a h igh p o t e n t i a l f o r coal development have a l r e a d y been l eased ( p l . 3 ) . However, t h e r e a r e undoubtedly o t h e r l a r g e a r e a s i n t h e S u s i t n a Lowland with l a r g e coa l r e s e r v e s which a r e poor ly def ined or unknown because of the l ack of a v a i l a b l e subsur face informat ion.

CONCLUSIONS

The Kenai Group of t h e S u s i t n a Lowland of sou th -cen t ra l Alaska c o n t a i n s s u b s t a n t i a l r e s e r v e s of subbituminous and l i g n i t e c o a l s s u i t a b l e f o r s u r f a c e mining. The c h i e f a t t r a c t i o n s of t h e s e c o a l s a r e t h e i r extremely low s u l f u r con ten t and favorab le l o c a t i o n with r e s p e c t to p o t e n t i a l markets . The c o a l s a r e a l l products of c o n t i n e n t a l f luv i a l d e p o s i t i o n a l environments. Although t h e s e c o a l s a r e l a t e r a l l y d i scon t inuous and o f t e n high i n a s h , the l a r g e number of seams, p a r t i c u l a r l y w i t h i n t h e Tyonek orn nation, and the geochemical and phys ica l c h a r a c t e r of the enc los ing s t r a t a r e s u l t i n economically a t t r a c t i v e d e p o s i t s w i t h i n s e v e r a l f i e l d s . However, due t o the l ack of subsur face informat ion over much of t h e S u s i t n a Lowland, the t r u e e x t e n t of t h e s e d e p o s i t s i s p r e s e n t l y unknown.

Research r e l a t e d t o the c o a l d e p o s i t s of the region c o n t i n u e s , and a summary geo log ic r e p o r t i s scheduled f o r completion i n 1982. Current r e sea rch t o p i c s inc lude c o a l and overburden geochemical c h a r a c t e r i z a t i o n (of n e a r l y 400 samples c o l l e c t e d dur ing t h e 1981 f i e l d season) , coa l and rock pet rography, and

compi la t ion of subsur face d a t a from the reg ion . When combined with work a l r e a d y completed, these s t u d i e s w i l l enable the development of b a s i n a l paleoenvironmental models. These models i n t u r n w i l l be important f o r p r e d i c t i n g c o a l t r e n d s w i t h i n the reg ion , f o r developing and implementing premine p l a n s , and f o r a s s u r i n g s u c c e s s f u l r ec lamat ion .

Alaska has about h a l f of the t o t a l c o a l r e sources of the United S t a t e s and t h e i r development should begin i n e a r n e s t w i t h i n the next 5 t o 10 y e a r s . The a v a i l a b i l i t y of d e t a i l e d geo log ic informat ion on t h e n a t u r e of t h e s e c o a l s and t h e i r enc los ing s t r a t a w i l l enable i n d u s t r y to e x t r a c t t h i s c o a l economically i n an environmental ly sound manner. The advantages to the reasonab le and o r d e r l y development of t h e huge c o a l r e s e r v e s w i t h i n t h e S u s i t n a Lowland a r e obv ious ly s i g n i f i c a n t f o r the s t a t e of Alaska and i t s people , and a l s o f o r P a c i f i c r i m c o u n t r i e s d e s p e r a t e f o r new s u p p l i e s of energy. Coal mines have proved t h a t they can e x i s t i n harmony with the unique Alaskan environment. Indeed, mined land can be improved with c o n s c i e n t i o u s rec lamat ion (conwel l , 1976) . The time to begin the j u d i c i o u s development of these c o a l r e sources i s a t hand.

ACKNOWLEDGMENTS

This r e p o r t has been produced through the e f f o r t s of many i n d i v i d u a l s . The au thors would l i k e to t ake t h i s oppor tun i ty to r ecogn ize and extend our g r a t i t u d e t o them. Don M. T r ip lehorn reviewed the o r i g i n a l manuscript and made many h e l p f u l comments, as d id Frank Larson and Cher i Dan ie l s of the DGGS editorial s t a f f . Roberta Mann typed the manuscr ip t . Jonathan Sperber served a s a f i e l d a s s i s t a n t f o r the primary author dur ing the 1981 f i e l d season; he a l s o took t h e photographs, assembled the b ib l iography , and aided i n d r a f t i n g . Karen Pearson and Ann S c h e l l d i r e c t e d t h e ca r tography and helped to produce the p l a t e s a s we l l a s the geo log ic columns of appendix B . K r i s t i e MacDonald d r a f t e d the t e x t f i g u r e s .

The cooperat i o n of the fo l lowing i n d i v i d u a l s and c o r p o r a t i o n s i s g r e a t l y a p p r e c i a t e d : Benno J . G . Pa tsch of P l a c e r Amex (Beluga Coal Company); John W . Blumer of Mobil O i l Corporat ion; Robert Sanders of Diamond Shamrock; Cook I n l e t Region Nat ive Corporat ion and Tyonek Native Corpora t ion ; and p i l o t s of Trans-Alaska H e l i c o p t e r s , Inc .

REFERENCES CITED

Barnes, F .F . , 1966, Geology and c o a l r e sources of the Beluga-Yentna reg ion Alaska: U.S. Geological Survey B u l l e t i n 1202-C, 54 p .

Calderwood, K.W., and F a c k l e r , W . C . , 1972, Proposed s t r a t i g r a p h i c nomenclature Kenai Group, Cook I n l e t b a s i n , Alaska: B u l l e t i n of the American Associa- t i o n of Petroleum G e o l o g i s t s , v . 56, no. 4 , p. 739-754.

Chleborad, A.F., Yehle, L.A., Schmoll, H . R . , and Gardner, C .A . , 1980, Pre- l iminary f i e l d geo techn ica l and geophysical logs from a d r i l l hole i n t h e Capps Coal F i e l d , Cook I n l e t r eg ion , Alaska: U.S. Geological Survey Open- f i l e Report 80-393, 17 p .

Conwell, C . N . , 1976, Reclaiming mined l ands i n Alaska: AIME T r a n s a c t i o n s , v . 260, p . 81-84.

D a l l , W.H., and H a r r i s , G . D . , 1892, C o r r e l a t i o n papers ; Neocene: U.S. Geological Survey B u l l e t i n 84, p. 232-268.

Dean, K . G . , 1980, S u r f i c i a l geology of t h e S u s i t n a - C h u l i t n a R ive r a r e a , A la ska : Nor the rn Remote Sens ing L a b o r a t o r y , Geophys i ca l I n s t i t u t e , U n i v e r s i t y of A la ska , F a i r b a n k s , p r epa red f o r Alaska Department of N a t u r a l Resources , 35 p . , 14 s h e e t s , s c a l e 1 :125 ,000.

F e r r i a n s , O . J . , J r . , 1965, Pe rmaf ros t map of Alaska : U.S. G e o l o g i c a l Survey M i s c e l l a n e o u s Geo log ic I n v e s t i g a t i o n s Map 1-445, s c a l e 1 :2 ,500 ,000 .

G r a n t z , A . , Z i e t z , I . , and Andreasen , G . E . , 1963, An aeromagnet ic r econna i s - s ance of t h e Cook I n l e t a r e a , Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Paper 3166, p. 117-134.

H a c k e t t , S.W., 1977 , G r a v i t y s u r v e y of Beluga b a s i n and a d j a c e n t a r e a , Cook I n l e t r e g i o n , s o u t h - c e n t r a l Alaska : Alaska D i v i s i o n of Geo log ica l and

Geophys i ca l Surveys Geologic Repor t 4 9 , 26 p . Hartman, D . C . , P e s s e l , G . H . , and McGee, D.L., 1972, P r e l i m i n a r y r e p o r t on t h e

s t r a t i g r a p h y of Kenai Group, upper Cook I n l e t , Alaska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys S p e c i a l Repor t 5 , 1 1 p l .

Horne , J . C . , Ferm, J . C . , C a r u c c i o , F . T . , Baganz, B.P. , 1978, D e p o s i t i o n a l models i n c o a l e x p l o r a t i o n amd mine p l a n n i n g , Appalachian r e g i o n : American A s s o c i a t i o n of P e t r o l e u m G e o l o g i s t s B u l l e t i n , v . 62 , no. 1 2 , p . 2379-2419.

K a r l s t r o m , T.N.V., 1965 , Resume of t h e Q u a t e r n a r y geology of t h e upper Cook I n l e t a r e a and Matanuska R ive r v a l l e y : i n PAW&. T.L., ed., Guidebook t o t h e Qua te rna ry geo logy , c e n t r a l and s o u x - c e n t r a l Alaska ( ~ 1 1 t h INQUA C o n g r e s s ) ; Department of N a t u r a l Resources , D i v i s i o n of G e o l o g i c a l and Geophys ica l Su rveys , p . 114-141.

K e l l y , T.E. , 1963, Geology and hydrocarbons i n Cook I n l e t b a s i n , Alaska i n C h i l d s , O.E., and Beebe, B.W. , e d s . , Backbone of t h e k n e r i c a s a s y m ~ s i u m ; Memoir of t h e American A s s o c i a t i o n of Pe t ro l eum G e o l o g i s t s 2 , p . 278-296: Houston G e o l o g i c a l S o c i e t y B u l l e t i n , v . 5, no. 10, p . 15-18.

Magoon, L.B. , Adkison, W.L., and E g b e r t , R . M . , 1976, Map showing geo logy , wild- c a t w e l l s , T e r t i a r y p l a n t f o s s i l l o c a l i t i e s , K-Ar age d a t e s , and pe t ro l eum o p e r a t i o n s , Cook I n l e t a r e a , Alaska : U.S. Geo log ica l Survey Map 1-1019, s c a l e 1 :250 ,000.

M i l l e r , D . J . , Payne, T.G., and Gryc , G . , 1959, Geology of p o s s i b l e pe t ro l eum p r o v i n c e s i n Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 1094, 127 p.

Ne l son , S.W., and Reed, B.L., 1978, S u r f i c i a l d e p o s i t s , T a l k e e t n a Quadrangle Alaska : U.S. G e o l o g i c a l Survey Misce l l aneous F i e l d S t u d i e s Map MF-870-J.

Reed, B.L., and Nelson , S.W., 1980, Geologic map of t h e T a l k e e t n a Quadrang le , Alaska : U.S. G e o l o g i c a l Survey Map 1-1174, s c a l e 1 :250 ,000 .

U .S . Department of Commerce, 1968, C l ima te s of t h e s t a t e s ; Alaska : Environment S c i e n c e S e r v i c e s A d m i n i s t r a t i o n , Cl imatography of t h e U.S. Report No. 60-49, 23 p .

Wahrha f t i g , Clyde , 1965, P h y s i o g r a p h i c d i v i s i o n s of Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 482 , 52 p.

Wolfe , J . A . , Hopkins, D . M . , and Leopold , E . B . , 1966, T e r t i a r y s t r a t i g r a p h y and pa l eobo tany of t h e Cook I n l e t r e g i o n , Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 398-A, 29 p .

BIBLIOGRAPHY

Aamodt, P .L . , J acobsen , S . I . , and H i l l , D.E., 1979, Uranium hydrogeochemica l and s t r e a m sediment r e c o n n a i s s a n c e of t h e McGrath and T a l k e e t n a Mountains Quadrang le s , A la ska , i n c l u d i n g c o n c e n t r a t i o n s of f o r t y - t h r e e e l e m e n t s : U.S. Department of Energy , ~ ~ ~ ~ - 1 2 3 ( 7 9 ) , 214 p .

Adkison, W.L., K e l l e y , J . S . , and Newman, K . R . , 1975, L i t h o l o g y and pa lyno logy o f T e r t i a r y r o c k s exposed nea r Capps G l a c i e r and a long Chu i tna R i v e r , Tyonek Quadrangle , s o u t h e r n Alaska : U.S. G e o l o g i c a l Survey Open- f i l e Repor t 75-21, 58 p .

A l a s k a Department of Commerce and Economic Development , 1979, Alaska r e g i o n a l ene rgy r e s o u r c e s p l a n n i n g p r o j e c t , phase 2: Coa l , h y d r o e l e c t r i c , and ene rgy a l t e r n a t i v e s , v . 1, 452 p .

A la ska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l S u r v e y s , 1973a, Aeromagnetic map, Anchorage Quadrang le , Alaska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys Open- f i l e Map 21 , 1 s h . , s c a l e 1 :250 ,000 .

, 1973b, Aeromagnetic map, T a l k e e t n a Quadrang le , Alaska : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Surveys Open-f i l e Map 1 9 , 1 s h O , s c a l e 1 : 250,000.

, 1973c , Aeromagnetic map, T a l k e e t n a Mountains Quadrang le , Alaska : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Surveys Open- f i l e Map 20, 1 s h . , s c a l e 1 :250 ,000 .

A l a s k a D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys S t a f f , 1976, Resource a p p r a i s a l of l and exchanges o u t s i d e of t h e Beluga-Capps G l a c i e r a r e a ; - i n Dobey, P .L . , McGee, D.L., and Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys S t a f f 1976, ~ c o n o m i c and g e o l o g i c s t u d i e s of t h e Beluga-Capps a r e a and g e o l o g i c r e s o u r c e o c c u r r e n c e s i n o t h e r a r e a s of the proposed Cook I n l e t Land Trade : A la ska D i v i s i o n of G e o l o g i c a l and Geophys ica l Su rveys Open- f i l e Report 9 4 , p . 29-64.

A la ska G e o l o g i c a l S o c i e t y , 1969, West t o e a s t s t r a t i g r a p h i c c o r r e l a t i o n s e c t i o n , West Fo re l and t o Swan Lake, upper Cook I n l e t b a s i n , A la ska : Anchorage, s c a l e 1 i n . = 500 f t .

A la ska G e o l o g i c a l S o c i e t y , 1976, Alaska G e o l o g i c a l S o c i e t y Symposium P r o c e e d i n g s , A p r i l 1975, Recent and a n c i e n t s ed imen ta ry envi ronments i n A 1 a s k a .

A l a s k a Power A d m i n i s t r a t i o n , 1970, Development of new l a n d s i n Matanuska- S u s i t n a Borough: U.S. Department of I n t e r i o r , A la ska Power Admin i s t r a - t i o n , 90 p .

Alaskan Geology Branch, U.S. G e o l o g i c a l Su rvey , 1972, The s t a t u s of m i n e r a l r e s o u r c e i n f o r m a t i o n on t h e major land wi thd rawa l s of t h e Alaska Na t ive Claims S e t t l e m e n t Act of 1971: U.S. G e o l o g i c a l Survey Open- f i l e Report 546-G, 164 p.

Anderson, Donald, 1978, F e a s i b i l i t y s t u d y of mining Alaska c o a l and t r a n s p o r t a t i o n by s l u r r y t o t h e West Coas t : U.S. Bureau of Mines Open- f i l e Report 17 (1 ) -78 , 30 p .

Anderson , G.S., 1969 , Geology and geochemis t ry of t h e Wel ls Mountain a r e a , T a l k e e t n a Mountains Q u a d r a n g l e , A la ska [ a b s . ] ; i n Alaska D i v i s i o n of Mines and Geology Report f o r t h e yea r 1969: ~ l a x a D i v i s i o n of G e o l o g i c a l and Geophys i ca l Su rveys , p . 7.

Anderson , R.E. , 1969a , Geology and geochemis t ry , Diana Lakes a r e a , wes t e rn T a l k e e t n a Mounta ins , Alaska : A la ska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Surveys Geologic Repor t 34 , 27 p .

, 1969b, P r e l i m i n a r y geochemis t ry and geo logy , L i t t l e F a l l s Creek a r e a , T a l k e e t n a Mountains Quadrang le , Alaska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys Geochemical Repor t 1 9 , 16 p .

-28-

Andreasen , G . E . , Z i e t z , I s i d o r e , and G r a n t z , A r t h u r , 1958, An aeromagnet ic r e c o n n a i s s a n c e of Cook I n l e t a r e a , Alaska [ a b s . ] : American A s s o c i a t i o n o f Pe t ro l eum G e o l o g i s t s B u l l e t i n , v . 4 2 , no. 1 , p . 219-220.

Armstrong, A . K . , M i c r o f a c i e s and environment of d e p o s i t ion and s t r a t i g r a p h y of t h e S i l u r i a n rocks of t h e Alaska Range, D i l l i n g e r River a r e a : U.S. G e o l o g i c a l Survey p r o j e c t i n p r o g r e s s , A r c t i c Environment a 1 In fo rma t i on and Data C e n t e r , U n i v e r s i t y of A la ska , Anchorage.

Atwood, W . W . , 1909 , Mine ra l r e s o u r c e s of sou thwes t e rn Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 379 , p. 108-152.

A v e r i t t , P a u l , 1961, Coal r e s e r v e s of t h e Uni ted S t a t e s - A p r o g r e s s r e p o r t , J a n u a r y 1, 1960: U.S. G e o l o g i c a l Survey B u l l e t i n 1136, 116 p .

A v e r i t t , P a u l , and Lopez, Loreda , 1972, B i b l i o g r a p h y and index of U.S. G e o l o g i c a l Survey p u b l i c a t i o n s r e l a t i n g t o c o a l , 1882-1970: U.S. G e o l o g i c a l Survey B u l l e t i n 1377, 99 p .

Ayres , M . G . , 1964, Regional geology of t h e Cook I n l e t a r e a , A la ska ; A i n Guide- book: Alaska G e o l o g i c a l S o c i e t y , p. 28-36.

B a l l A s s o c i a t e s , L t d . , c o m p i l e r s , 1965, A la ska ; i n S u r f a c e and sha l low o i l - impregnated rocks and s h a l l o w o i l f i e l d s i n T h e Uni ted S t a t e s : U.S. Bureau of Mines Monograph 12, p . 18-41.

B a r n e s , F . F . , and Cobb, E . H . , 1959, Geology and c o a l r e s o u r c e s of t h e Homer d i s t r i c t , Kenai c o a l f i e l d , A la ska : U . S . G e o l o g i c a l Survey B u l l e t i n 1058-F, p. 217-260.

B a r n e s , F .F . , 1959, Geology and c o a l r e s o u r c e s of t h e L i t t l e S u s i t n a d i s t r i c t , Matanuska c o a l f i e l d , Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 1058-D, p . 121-138.

, 1961 , Coal f i e l d s of t h e Uni ted S t a t e s , s h . 2 - Alaska : U.S. G e o l o g i c a l Survey Map, s c a l e 1 : 5 , 0 0 0 , 0 0 0 .

B a r n e s , F . F . , 1962a , ~ e o l o g i c map of lower Matanuska V a l l e y , Alaska : U.S. G e o l o g i c a l Survey M i s c e l l a n e o u s Geo log ic I n v e n t o r y Map 1-359, 1 s h . , s c a l e 1 : 6 3 , 3 6 0 .

, 1962b, V a r i a t i o n i n r ank of T e r t i a r y c o a l s i n t h e Cook I n l e t b a s i n , A l a s k a ; i n G e o l o g i c a l Research 1962: U.S. G e o l o g i c a l Survey Pro- f e s s i o n a l p a p e r 4 5 0 - c , p . C14-C16.

, 1964, Coa l ; i n Minera l and wa te r r e s o u r c e s of A la ska : U.S. 8 8 t h Congress , Second s e s s i o n , Sena t e Committee I n t e r i o r and I n s u l a r A f f a i r s , -

Commercial P r i n t 31-068, p . 82-88. , 1966, Geology and c o a l r e s o u r c e s of t h e Beluga-Yentna r e g i o n ,

Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 1202-C, p. C1-C54. , 1967, Coal r e s o u r c e s of Alaska : U.S. Geo log ica l Survey B u l l e t i n

1242-B, p. R1-B36. , 1968 , G r a v i t y map of Alaska : U.S. Geo log ica l Survey P r o f e s s i o n a l

Pape r 600-A, p. A38-A39. B a r n e s , F.F . , and o t h e r s , 1951 , Coal i n v e s t i g a t i o n s i n s o u t h - c e n t r a l A la ska ,

1944-1946: U.S. G e o l o g i c a l Survey B u l l e t i n 963-E, p . 137-213. B a t t e l l e P a c i f i c Northwest L a b o r a t o r i e s , 1980, Beluga c o a l expor t market

s t u d y , p r epa red f o r t h e S t a t e of A la ska , O f f i c e of t h e Governor, ~ i v i s i o n o f P o l i c y Development and P l a n n i n g .

B e c h t e l , 1980, Execu t ive summary, p r e l i m i n a r y f e a s i b i l i t y s t u d y , c o a l e x p o r t program, Bass-Hunt-Wil son c o a l l e a s e s , Chui tna ~ i v e r F i e l d , A la ska .

Beikman, Helen , 1980, Geologic Map of A la ska , 2 s h . , s c a l e 1 : 2 , 5 0 0 , 0 0 0 . Berg , H . C . , J o n e s , D.L. , and R i c h t e r , D . H . , 1972, Gravina-Nutza t in b e l t .

Tec ton ic s i g n i f i c a n c e of an upper Mesozoic s ed imen ta ry and v o l c a n i c sequence i n s o u t h e r n and s o u t h e a s t e r n Alaska : U . S . Geo log ica l Survey Pro- f e s s i o n a l Pape r 800-D, p . Dl-D24.

B e r g q u i s t , H . R . , 1961 , E a r l y Cre t aceous (midd l e Neocomian) m i c r o f o s s i l s i n s o u t h - c e n t r a l A la ska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l P a p e r 424-D, p . D236-D237.

Brooks , A.H., 1911 , The Mount McKinley r e g i o n , w i t h d e s c r i p t i o n s of t h e i gneous r o c k s and of t h e B o n n i f i e l d and K a n t i s h n a d i s t r i c t s , by L.M. P r i n d l e : U.S. G e o l o g i c a l Su rvey P r o f e s s i o n a l Pape r 70 , 234 p .

, 1914, Alaska c o a l and i t s u t i l i z a t i o n : U.S. G e o l o g i c a l Su rvey B u l l e t i n 442-5, p . 47-100.

Bruhn, R .L . , 1979 , Holocene d i s p l a c e m e n t s measured by t r e n c h i n g t h e C a s t l e Mountain f a u l t n e a r Houston, A la ska : A la ska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Su rveys Geo log i c Repor t 6 1 , p. 1-4.

Buck, E . H . , A l l e n , Anda, O l shansky , R . B . , and P e n n e l l , S .H . , 1979, Comprehen- s i v e b i b 1 i og raphy and i ndex of env i ronmen ta l i n fo rma t i o n f o r t h e Beluga- S u s i t n a , Nenana, and w e s t e r n A r c t i c c o a l f i e l d s , 3 v . : U.S. Department of Ene rgy , A r c t i c Env i ronmen ta l I n f o r m a t i o n and Da ta C e n t e r .

Calderwood, K . W . , and F a c k l e r , W . C . , 1972 , Proposed s t r a t i g r a p h i c nomenc l a tu r e f o r Kenai Group, Cook I n l e t b a s i n , A la ska : B u l l e t i n of t h e American A s s o c i a t i o n o f P e t r o l e u m G e o l o g i s t s , v . 56 , no . 4 , p . 739-754.

Capps , S .R. , 1913 , The Yentna d i s t r i c t , Alaska : U.S. G e o l o g i c a l Su rvey B u l l e t i n 534 , 75 p .

, 1919a , Minera l r e s o u r c e s of t h e Upper C h u l i t n a r e g i o n : U.S. G e o l o g i c a l Survey B u l l e t i n 692 , p . 207-232.

, 1919b, Mine ra l r e s o u r c e s of t h e w e s t e r n T a l k e e t n a Mounta ins : U.S. G e o l o g i c a l Survey B u l l e t i n 692 , p . 187-205.

Capps , S .R. , 1925 , ~ n - e a r l y T e r t i a r y p l a c e r d e p o s i t i n t h e Yentna d i s t r i c t : U.S. G e o l o g i c a l Survey B u l l e t i n 773, p . 53-61.

, 1929 , The Skwentna r e g i o n , A la ska : U.S. G e o l o g i c a l Su rvey B u l l e t i n 797-B, p . 67-98.

, 1935, The s o u t h e r n A la ska Range: U.S. G e o l o g i c a l Su rvey B u l l e t i n 8 6 2 , 101 p .

, 1940, Geology of t h e A la ska R a i l r o a d r e g i o n : U.S. Geo log i ca l Survey B u l l e t i n 907 , 201 p .

C a r t e r , R . D . , and Adkison , W.L., 1972 , C o r r e l a t i o n of s u b s u r f a c e T e r t i a r y r o c k s , Cook I n l e t b a s i n , Alaska : U.S. G e o l o g i c a l Survey Open- f i l e Repor t 72-64, 8 p .

Chap in , Theodore , 1918 , The N e l c h i n a - S u s i t n a r e g i o n , A la ska : U.S. G e o l o g i c a l Survey B u l l e t i n 6 6 8 , 67 p .

Ch lebo rad , A .F . , Y e h l e , L.A. , Schmol l , H . R . , and G a r d n e r , C.A., 1980 , Pre- l i m i n a r y f i e l d g e o t e c h n i c a l and g e o p h y s i c a l l o g s from a d r i l l h o l e i n t h e Capps c o a l f i e l d , Cook I n l e t r e g i o n , A la ska : U.S. G e o l o g i c a l Su rvey Repor t 80-393, 17 p.

Church , R .E . , and L i a n , E . B . , 1970 , Geologic s e c t i o n , upper Cook I n l e t b a s i n : A la ska G e o l o g i c a l S o c i e t y , Anchorage.

C l a r d y , B . I . , 1978 , S t r a t i g r a p h y of t h e Matanuska-Sus i tna a r e a , n o r t h e a s t e r n Cook I n l e t b a s i n , A la ska : L o u i s i a n a Land and E x p l o r a t i o n Co. , Western D i v i s i o n , 1 5 p .

C l a r k , A.L., and Cobb, E . H . , 1972 , M e t a l l i c m i n e r a l r e s o u r c e s map of t h e T a l k e e t n a Quad rang le , A la ska : U.S. G e o l o g i c a l Survey M i s c e l l a n e o u s F i e l d S t u d i e s Map MF-369, 1 s h . , s c a l e 1 :250 ,000 .

C l a r k , A.L., and o t h e r s , 1972 , S i g n i f i c a n c e of upper P a l e o z o i c ocean c r u s t i n t h e Upper C h u l i t n a d i s t r i c t , w e s t - c e n t r a l A la ska Range: U.S. G e o l o g i c a l Survey P r o f e s s i o n a l P a p e r 800-C, p . C95-102.

Cobb, E.H. , 1969 , M e t a l l i c m i n e r a l r e s o u r c e s maps of 11 Alaska quad rang le s (Afognak, Beaver , Be r ing G l a c i e r , B e t t l e s , Ka r luk , Kenai , Middle ton I s l a n d , Tay lo r Mounta ins , T r i n i t y I s l a n d s , Tyonek, Y a k u t a t ) : U.S. G e o l o g i c a l Survey o p e n - f i l e r e p o r t , 20 p .

, 1972a , M e t a l l i c m i n e r a l r e s o u r c e s map of t h e T a l k e e t n a Mountains Quadrangle , Alaska : U.S. G e o l o g i c a l Survey Misce l l aneous F i e l d S t u d i e s Map MF-370, 1 s h . , s c a l e 1 :250 ,000 .

, 1972b, M e t a l l i c m i n e r a l r e s o u r c e s map of t h e Tyonek Quadrangle , A la ska : U.S. G e o l o g i c a l Survey Misce l l aneous F i e l d S t u d i e s Map MF-385, 1 s h . , s c a l e 1 : 2 5 0 , 0 0 0 .

, 1980, Summary of r e f e r e n c e s t o m i n e r a l o c c u r r e n c e s ( o t h e r t han m i n e r a l f u e l s and c o n s t r u c t i o n m a t e r i a l s ) i n t h e Kenai and Tyonek Quad- r a n g l e s , Alaska : U .S. G e o l o g i c a l Survey Open-f i le Report 80-86, 37 p .

Cobb, E.H., and C s e j t e y , Bk la , J r . , c o m p i l e r s , 1980, Summaries of d a t a on and l i s t s of r e f e r e n c e s t o m e t a l l i c and s e l e c t e d n o n m e t a l l i c m i n e r a l d e p o s i t s i n t h e T a l k e e t n a Mountains Quadrang le , Alaska : U.S. G e o l o g i c a l Survey Open- f i l e Repor t 80-167, 64 p ,

Cobb, E.H. and Reed, B.L. , 1980, Summaries of d a t a on and l i s t s of r e f e r e n c e s t o m e t a l l i c and s e l e c t e d n o n m e t a l l i c mine ra l d e p o s i t s i n t h e T a l k e e t n a Quadrang le , Alaska : U.S. G e o l o g i c a l Survey Open-f i le Report 80-884, 107 p.

Committee on Alaska Coal Mining and Rec lama t ion , and o t h e r s , 1980, S u r f a c e c o a l mining i n Alaska : An i n v e s t i g a t i o n of t h e S u r f a c e Mining Con t ro l and Reclamat ion Act of 1977 i n r e l a t i o n t o Alaskan c o n d i t i o n s , Minera l I n d u s t r y Research L a b o r a t o r y S p e c i a l P u b l i c a t i o n no. 4 , 328 p.

Conwell , C . N . , 1972, Alaskan c o a l s may prove a b i g p l u s i n f u t u r e e x p o r t s p i c t u r e ; i n Mining E n g i n e e r i n g , v . 24, no. 10 , p . 82-84.

, 1976 , Recla iming mined l a n d s i n A la ska ; AIME T r a n s a c t i o n s , v . 260, p . 81-84.

, 1977 , Energy r e s o u r c e map of Alaska : Alaska D i v i s i o n of Geo log ica l and Geophys ica l Su rveys , s c a l e 1 :2 ,500 ,000 . m i s c e l l a n e o u s pub1 i c a t i o n s .

C r o f f , C . , Lessman, J . , Bigelow, C . , and Ruz icka , J . , 1978, Uranium favor- a b i l i t y of t h e Cook I n l e t b a s i n , Alaska : U.S. Department of Energy , ~ ~ ~ ~ - 4 1 ( 7 8 ) , v . 1 and 2 .

C s e j t e y , B&la , J r . , 1974, Reconnaissance g e o l o g i c i n v e s t i g a t i o n s i n t h e T a l k e e t n a ~ o u n t a i n s , Alaska : U . S. G e o l o g i c a l Survey Open-f i le Repor t 74-147, 48 p .

C s e j t e y , la, J r . , and E v a r t s , R . C . , 1979, S e r p e n t i n i t e b o d i e s i n t h e Willow Creek d i s t r i c t , s o u t h w e s t e r n T a l k e e t n a Mountains, A la ska ; i n Johnson, K . M . , and W i l l i a m s , J . R . , e d s . , The Uni ted S t a t e s ~ e o l o ~ z a l Survey i n Alaska : Accomplishments d u r i n g 1978: U . S. G e o l o g i c a l Survey C i r c u l a r 804-B, p . B92-B94.

C s e j t e y , ~ k l a , J r . , and M i l l e r , R . J . , 1978 , Map and t a b l e d e s c r i b i n g m e t a l l i f e r o u s and s e l e c t e d n o n m e t a l l i f e r o u s m i n e r a l d e p o s i t s , T a l k e e t n a ~ o u n t a i n s Q u a d r a n g l e , Alaska : U.S. Geo log ica l Survey Open-f i le Report 78-558B, 20 p .

C s e j t e y , Bh la , J r . , Nelson , W.H., J o n e s , D.L., S i l b e r l i n g , N . J . , Dean, R.M. , M o r r i s , M.S., Lanphere , M.A . , Smi th , J . G . , and S i lbe rman , M.L., 1978, ~ e c o n n a i s s a n c e g e o l o g i c map and geochronology, T a l k e e t n a Mountains Quad- r a n g l e , n o r t h e r n p a r t o f Anchorage Quadrang le and southwes t c o r n e r of Healy Quadrang le , Alaska : U . S. Geo log ica l Survey Open- f i l e Report 78-558-A, 1 s h . , 6 2 p . , s c a l e 1 :250 ,000 .

D a l l , W . H . , 1896 , Report on c o a l and l i g n i t e of A la ska : U.S. G e o l o g i c a l Survey 1 7 t h Annual Repor t , p t . 1 , s e c . E , p . 763-906.

DalL, W . H . , and H a r r i s , G . D . , 1892, C o r r e l a t i o n p a p e r s ; Neocene: U.S. G e o l o g i c a l Survey B u l l e t i n 84 , p. 232-268.

Dames & Moore, 1974, Envi ronmenta l b a s e l i n e s t u d i e s , proposed c o a l mining o p e r a t i o n s , Cook I n l e t , A la ska , r e p o r t f o r P l a c e r Amex I n c . and S t a r k e y A . Wilson.

, 1476, Envi ronmenta l b a s e l i n e s t u d i e s , proposed c o a l mining o p e r a t i o n s , Cook I n l e t , Alaska , r e p o r t f o r P l a c e r Amex I n c . and S t a r k e y A. Wi lson , 53 p .

D a v i e s , J . , and Berg , E. , 1973, C r u s t a l morphology and p l a t e t e c t o n i c s i n s o u t h - c e n t r a l Alaska : B u l l e t i n of t h e S e i s m o l o g i c a l S o c i e t y of America, v . 6 3 , p. 673-677.

Dean, K . G . , 1980 , S u r f i c i a l geology of t h e S u s i t n a - C h u l i t n a R ive r a r e a , Alaska : Nor the rn Remote Sens ing L a b o r a t o r y , Geophys i ca l I n s t i t u t e , U n i v e r s i t y of A la ska , F a i r b a n k s , p r epa red f o r Alaska Department of N a t u r a l Resources , 35 p . , 1 4 s h . , s c a l e 1 :125 ,000 .

Decker , John , and K a r l , Susan , 1977, P r e l i m i n a r y aeromagnet i c map of e a s t e r n p a r t of s o u t h e r n Alaska : U.S. G e o l o g i c a l Survey Open-f i le Map 77-169-E.

Det te rman, R.L., 1963, Revised s t r a t i g r a p h i c nomencla ture and age of t h e Tuxedni Group i n t h e Cook I n l e t r e g i o n , A l a s k a ; i n G e o l o g i c a l Survey Research 1963: U.S. G e o l o g i c a l Survey ~ r o f e s s i o n x Paper 475-C, p. C30-C34.

Det te rman, R.L., and H a r t s o c k , J . K . , 1966 (19671, Geology of t h e I n i s k i n - Tuxedni r e g i o n , Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 512, 78 p .

Det te rman, R.L., Hudson, T r a v i s , P l a f k e r , George, T y s d a l , R . G . , and Hoare, J . M . , 1976, Reconnaissance g e o l o g i c map a long t h e Bruin Bay and Lake C l a r k f a u l t s i n Kenai and Tyonek Quadrang le s , Alaska : U.S. Geo log ica l Survey Open-f i le Repor t 76-477, 4 p.

De t t e rman , R.L., P l a f k e r , George, Hudson, T r a v i s , Tysda l , R . G . , and Pavon i , Naza r io , 1974, S u r f a c e geology and Holocene b r e a k s a long t h e S u s i t n a segment o f t h e C a s t l e Mountain F a u l t , Alaska : U.S. G e o l o g i c a l Survey Misce l l aneous F i e l d S t u d i e s Map MF-618, s c a l e 1 :24 ,000 .

Det te rman, R . L . , P l a f k e r , George, T y s d a l , R . G . , and Hudson, T r a v i s , 1976, Geology and s u r f a c e f e a t u r e s a long p a r t of t h e T a l k e e t n a segment of t h e C a s t l e Mountain-Caribou f a u l t sys tem, Alaska : U.S. Geo log ica l Survey Misce l l aneous F i e l d S t u d i e s Map MF-738, 1 s h . , s c a l e 1 :63 ,360 .

De t t e rman , R.L., Reed, B.L. , and Lanphe re , M . A . , 1965, J u r a s s i c p l u t o n i s m i n t h e Cook I n l e t r e g i o n , A la ska ; i n G e o l o g i c a l Research 1965: U.S. G e o l o g i c a l Survey P r o f e s s i o n a l P a p e r 525-D, p. D16-D21.

Dickenson, K . A . , and Campbell, J . A . , 1978, E p i g e n e t i c m i n e r a l i z a t i o n and a r e a s f a v o r a b l e f o r uranium e x p l o r a t i o n i n T e r t i a r y c o n t i n e n t a l s e d i m e n t a r y rock i n s o u t h - c e n t r a l A la ska -- A p r e l i m i n a r y r e p o r t : U.S. G e o l o g i c a l Survey Open- f i l e Report 78-757, 1 3 p .

Dickenson, K . A . , 1978, Sedimentary f a c i e s i n T e r t i a r y rocks i n t h e Tyonek Quadrangle [ a b s . ] : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Paper 1109 , p . 84 .

D ick inson , D . A . , 1977, Uranium and tho r ium d i s t r i b u t i o n i n c o n t i n e n t a l T e r t i a r y rocks of t h e Cook I n l e t b a s i n and some a d j a c e n t a r e a s , A la ska ; i n Campbell, J . A . , e d . , Sho r t p a p e r s of t h e U.S. Geo log ica l Survey - uranium-thorium symposium, 1977: U.S. G e o l o g i c a l Survey C i r c u l a r 753, p . 70-72.

Dobey, P . L . , McGee, D.L., and D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys s t a f f , 1976, Economic and g e o l o g i c s t u d i e s of t h e Beluga-Capps a r e a and g e o l o g i c r e s o u r c e o c c u r r e n c e s i n o t h e r a r e a s of t h e proposed Cook I n l e t Land Trade : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l Surveys Open- f i l e Report 9 4 , 86 p .

Dobey, P .L , Welch, J . . , and O'Connor, K . M . , 1975, Capps G lac i e r -Be luga c o a l economic r e s o u r c e a n a l y s i s : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l S u r v e y s , 1 8 p .

, 1976, P o t e n t i a l revenues from c o a l r o y a l t i e s i n t h e Capps G l a c i e r a r e a ; i n Dobey, P .L . , McGee, D.L., and Alaska D i v i s i o n of Geo log ica l and ~ e o ~ h ~ x c a l Surveys s t a f f , 1976, Economic and g e o l o g i c s t u d i e s of t h e Beluga-Capps a r e a and g e o l o g i c r e s o u r c e o c c u r r e n c e s i n o t h e r a r e a s of t h e proposed Cook I n l e t Land Trade : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l Surveys Open-f i le Repor t 94 , p . 13-28.

Dobrovolny, E r n e s t , and Schmol l , H . R . , 1966, Map of g e o l o g i c m a t e r i a l s , Anchorage and v i c i n i t y , Alaska : U .S . G e o l o g i c a l Survey open-f i l e map, 1 s h . , s c a l e 1 :24 ,000 .

Geolog E a k i n s , G . R

1973, S l o p e - s t a b i l i t y map of Anchorage and v i c i n i t y , Alaska : U.S. i c a l Survey o p e n - f i l e map, 1 s h . , s c a l e 1 : 24 ,000 . .. , 1975, I n v e s t i g a t i o n s of A l a s k a ' s uranium p o t e n t i a l , P a r t I: U.S.

Department of Energy , GJO-1627, 437 p . Ebasco S e r v i c e s I n c . , 1979, Cost s t u d y f o r a 400 MW c o a l - f i r e d power p l a n t -

North Fo re l and a r e a , Cook I n l e t , A la ska : Ebasco S e r v i c e s I n c . E l d r i d g e , G . H . , 1900, A r e c o n n a i s s a n c e i n t h e S u s h i t n a b a s i n and a d j a c e n t

t e r r i t o r y , Alaska , i n 1898: U.S. G e o l o g i c a l Survey 20th annual r e p o r t , p t . 7 , p. 1-29.

Evans , C . D . and o t h e r s , 1972, The Cook I n l e t Environment - A background s t u d y of a v a i l a b l e knowledge. P repa red by t h e U n i v e r s i t y of Alaska Resources and S c i e n c e S e r v i c e C e n t e r , Alaska Sea Grant Program, Anchorage, Alaska f o r t h e Alaska D i s t r i c t Corps of E n g i n e e r s .

F e r r i a n s , O . J . , J r . , 1965 , Pe rmaf ros t map of Alaska : U.S. G e o l o g i c a l Survey Misce l l aneous Geo log ic I n v e s t i g a t i o n s Map 1-445, s c a l e 1 :2 ,500 ,000 .

, Anchorage-Susi tna lowlands e a r t h q u a k e h a z a r d s mapping: U.S. Geologic a 1 Survey p r o j e c t i n p r o g r e s s , A r c t i c Environment a 1 In fo rma t i o n and Data C e n t e r , U n i v e r s i t y of A la ska , Anchorage.

F e u l n e r , A . J . , 1968, Data on w e l l s i n t h e Matanuska-Sus i tna Borough a r e a , Alaska : U.S. G e o l o g i c a l Survey o p e n - f i l e r e p o r t , 25 p .

, 1971, Water - resources r e c o n n a i s s a n c e of a p a r t of t h e Matanuska- S u s i t n a Borough, Alaska : U.S. Geo log ica l Survey Hydrologic I n v e s t i g a t i o n s A t l a s HA-364, 1 s h . , s c a l e 1 :250 ,000 , Washington, D . C .

F i s h e r , M . A . , and Magoon, L.B. , 1978 , Geologic framework of lower Cook I n l e t , Alaska : B u l l e t i n of t h e American A s s o c i a t i o n o f Pe t ro l eum G e o l o g i s t s , v . 62 , no. 3 , p . 373-402.

F o s t e r , H.L., and K a r l s t r o m , T . N . V . , 1967, Ground b reakage and a s s o c i a t e d e f f e c t s i n t h e Cook I n l e t a r e a , Alaska , r e s u l t i n g from t h e March 27, 1964, e a r t h q u a k e : U . S . Geo log ica l Survey P r o f e s s i o n a l Pape r 543-F, p. F23.

F r e e t h e y , G.W. , 1978, Guide t o ground-water d a t a , Cook I n l e t b a s i n , Alaska : U.S. G e o l o g i c a l Survey Open-f i le Repor t 78-439, 207 p.

F r e e t h e y , G . W . , and S c u l l y , D . R . , 1980, Water r e s o u r c e s of t h e Cook I n l e t b a s i n , Alaska : U . S . G e o l o g i c a l Survey Hydrologic I n v e s t i g a t i o n s A t l a s HA-620, 4 s h . , s c a l e 1 :1 ,000 ,000 .

F r i t t s , C.E., 1971a , B i b l i o g r a p h y of Alaskan geo logy , 1919-1949: Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l S u r v e y s , 92 p.

, 1971b, B i b l i o g r a p h y of Alaskan geo logy , 1950-1959 : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l S u r v e y s , 8 3 p .

, 1971c , B i b l i o g r a p h y of Alaskan geo logy , 1960-1964: Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l S u r v e y s , 8 1 p.

F r i t t s , C.E., and Brown, M.E., 1971, B i b l i o g r a p h y of Alaskan geo logy , 1831-1918: Alaska D i v i s i o n o f G e o l o g i c a l and Geophys ica l S u r v e y s , 8 8 p.

F r i t t s , C.E., and T u e l l , E . J . , 1972, B i b l i o g r a p h y of Alaskan geo logy , 1965-1968: Alaska D i v i s i o n o f G e o l o g i c a l and Geophys ica l S u r v e y s , 112 p.

F r i t t s , C.E. and o t h e r s , 1972, B i b l i o g r a p h y of Alaskan geology, 1969-1971 : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l S u r v e y s , 94 p.

Fuchs , W.A., 1980, T e r t i a r y t e c t o n i c h i s t o r y of t h e C a s t l e Mountain-Caribou f a u l t sys tem i n t h e T a l k e e t n a Mounta ins , Alaska : U n i v e r s i t y of Utah Ph . D . d i s s e r t a t i o n , Department of Geology and Geophys i c s , 152 p .

G a t e s , G . O . , 1946, Coal f i e l d s of Alaska , i n Analyses of Alaska c o a l s : U.S. Bureau of Mines T e c h n i c a l Pape r 682 , 7 1-9.

, 1964, Geologic and t e c t o n i c s e t t i n g ; i n Minera l and w a t e r r e s o u r c e s of Alaska : U.S. 8 8 t h Cong., 2nd s e s s i o n , S e n a t e Committee I n t e r i o r and I n s u l a r A f f a i r s , Commercial P r i n t 31-068, p. 32-39.

G a t e s , G . O . , and Gryc , G . , 1963, S t r u c t u r e and t e c t o n i c h i s t o r y of A la ska , i n 0 . E - C h i l d s and B.W. Beebe, e d s . , Backbone of t h e Americas: Memoir of t h e American A s s o c i a t i o n of P e t r o l e u m G e o l o g i s t s 2 , p. 264-277.

G a t t o , L.W., Merry, C . J . , McKim, H . L . , and Lawson, D.E. , 1980, Envi ronmenta l a n a l y s i s of t h e upper S u s i t n a R ive r b a s i n u s ing Landsa t imagery: U.S. Army Corps of E n g i n e e r s , Cold Regions Research and E n g i n e e r i n g L a b o r a t o r y , 41 p .

Gedney, L.D.; Vanwormer, J . D . , and S h a p i r o , Lewis, 1975, T e c t o n i c l i neamen t s and p l a t e t e c t o n i c s i n s o u t h - c e n t r a l Alaska : Geophys i ca l I n s t i t u t e Resea rch R e p o r t , F a i r b a n k s , U n i v e r s i t y of A la ska , 8 p .

Geer , M . R . , and Fennessy , F .D . , 1962, W a s h a b i l i t y of c o a l s from t h e Matanuska V a l l e y and Beluga R ive r f i e l d s , Alaska : U.S. Bureau of Mines Report of I n v e s t i g a t i o n s 6017, 3 3 p .

G e e r , M.R., S o k a s k i , Michae l , and J a c o b s e n , P . S . , 1962, Per formance of t a b l e s i n c l e a n i n g Alaska c o a l s : U.S. Bureau Mines Report of I n v e s t i g a t i o n s 6054, 26 p .

G r a n t z , A r t h u r , 1960a , Geologic map of T a l k e e t n a Mountains (A-2) Quadrang le , A la ska , and t h e c o n t i g u o u s a r e a t o t h e n o r t h and n o r t h w e s t : U.S. G e o l o g i c a l Survey Misce l l aneous Geo log ic I n v e s t i g a t i o n s Map 1-313, s c a l e 1 :48 ,000 .

, 1960b, Geologic map of T a l k e e t n a Mountains (A-1) Quadrangle and t h e s o u t h t h i r d of T a l k e e t n a Mountains (B-1) Quadrangle , Alaska : U.S. - .

G e o l o g i c a l Survey Misce l l aneous Geologic I n v e s t i g a t i o n s Map 1-314, s c a l e 1 :48 ,000 .

G r a n t z , A r t h u r , Thomas, Herman, S t e r n , T.W., and S h e f f e y , N . B . , 1963, Potas - sium-argon and l ead -a lpha ages f o r s t r a t i g r a p h i c a l l y b r a c k e t e d p l u t o n i c r o c k s i n t h e T a l k e e t n a Mounta ins , Alaska ; i n Shor t papers i n geo logy and hydro logy : U.S. G e o l o g i c a l Survey ~ r o f e s s i o n a l Pape r 475-By p. B56-B59.

G r a n t z , A r t h u r , Z i e t z , I s i d o r e , and Andreasen , G.E. , 1963, An aeromagnet ic r e c o n n a i s s a n c e of t h e Cook I n l e t a r e a , Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Paper 316-G, p. 117-134.

H a c k e t t , S.W., 1974, Analyses of f a u l t p a t t e r n s w i t h i n and a d j a c e n t t o t h e T o r d r i l l o b l o c k , s o u t h - c e n t r a l A la ska : F a i r b a n k s , U n i v e r s i t y of Alaska Geology Depar tment , unpub l i shed r e p o r t , 1 8 p.

H a c k e t t , S.W., 1976a , Regional g r a v i t y su rvey of Beluga Bas in and a d j a c e n t a r e a , Cook I n l e t r e g i o n , s o u t h - c e n t r a l Alaska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys Open- f i l e Report 100 , 38 p .

, 1976b, S p e c u l a t i v e t e c t o n i c e v o l u t i o n of t h e Cenozoic S h e l i k o f Trough, s o u t h - c e n t r a l A la ska ; i n Shor t n o t e s on Alaskan Geology - 1976: D i v i s i o n o f G e o l o g i c a l and ~ e o - & ~ s i c a l Surveys Geologic Repor t 51 , p . 13-17.

, 1977, G r a v i t y su rvey of Beluga b a s i n and a d j a c e n t a r e a , Cook I n l e t r e g i o n , s o u t h - c e n t r a l Alaska : A la ska D i v i s i o n of G e o l o g i c a l and Geophys ica l Surveys Geo log ic Report 4 9 , 26 p .

, 1978a , Aeromagnetic map, Talkeetna-Kashwitna R ive r a r e a , A la ska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l Surveys Open-f i l e Report 107H, 1 s h . , s c a l e 1 :63 ,360 .

, 1978b, P r e l i m i n a r y g e o l o g i c a l i n t e r p r e t a t i o n (basement complex) of aeromagnet ic map, Ta lkee tna-Kashwi tna R ive r a r e a , Alaska : Alaska D i v i s i o n o f ~ e o i o ~ i c a l and Geophys ica l Surveys Open-f i le Report 1075, 1 s h . , s c a l e 1 :63 ,360 .

, 1978c , P r o v i s i o n a l g e o p h y s i c a l i n t e r p r e t a t i o n of s imple Bouguer g r a v i t y map, Ta lkee tna-Kashwi tna River a r e a , Alaska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l Surveys Open-f i le Report 1071, 1 sh . , s c a l e 1 : 63 ,360 .

, 1978d, Simple Bouguer map, Ta lkee tna-Kashwi tna River a r e a , Alaska : A la ska D i v i s i o n o f G e o l o g i c a l and Geophys ica l Surveys Open- f i l e Report - .

107G, 1 s h . , s c a l e 1 :63 ,360 . Hami l ton , P .A. , White , D . H . , J r . , Matson, T.K., 1975, The r e s e r v e base of U.S.

c o a l s by s u l f u r c o n t e n t ( i n two p a r t s ) ; 2 . The Western S t a t e s : Bureau of Mines I n f o r m a t i o n C i r c u l a r 8693, 322 p .

Hartman, D . C . , P e s s e l , G . H . , and McGee, D.L., 1974, Kenai Group of Cook I n l e t b a s i n , Alaska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l Surveys Open- f i l e Report 4 9 , 5 p.

Hawley, C . C . , 1978 , Minera l a p p r a i s a l o f l a n d s a d j a c e n t t o M t . McKinley N a t i o n a l Pa rk , Alaska : U.S. Bureau of Mines, Open- f i l e Repor t 24-78, 274 p .

Hawley, C . C . , and C l a r k A.L., 1968, Occurrences of go ld and o t h e r m e t a l s i n t h e Upper C h u l i t n a d i s t r i c t , A la ska : U.S. G e o l o g i c a l Survey C i r c u l a r 564, 21 p .

, 1973, Geology and m i n e r a l d e p o s i t s of t h e Chul i tna-Yentna m i n e r a l b e l t , Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 758-A, 10 p.

Hawley, C . C . , and C l a r k , A.L., 1974, Geology and mine ra l d e p o s i t s of t h e Upper C h u l i t n a d i s t r i c t , Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Paper 758-B, 47 p .

Hawley, C . C . , C l a r k , A.L., H e r d r i c k , M . H . , and C l a r k , S.H.B., 1969, R e s u l t s of g e o l o g i c a l and geochemica l i n v e s t i g a t i o n s i n an a r e a no r thwes t of t h e C h u l i t n a R i v e r , c e n t r a l A la ska Range: U.S. Geo log ica l Survey C i r c u l a r 617 , 19 p .

Hayes, J . B . , Harms, J . C . , and Wilson , T . , J r . , 1976, C o n t r a s t s between b r a i d e d and meandering s t r e a m d e p o s i t s , Beluga and S t e r l i n g orm mat ions ( ~ e r t i a r ~ ) , Cook I n l e t , A la ska , i n Recent and a n c i e n t s e d i m e n t a r y env i r - onments i n Alaska : Alaska ~ e o l o ~ z a l S o c i e t y Symposium, Anchorage, A l a s k a , A p r i l 2-4, 1975, P r o c e e d i n g s , p. 51-527.

Hennagin, B r i a n , D . , 1978, Cook I n l e t c o a l : Economics of mining and mar ine s l u r r y t r a n s p o r t : U.S. Bureau of Mines Open- f i l e Report 17 (2 ) -78 , 79 p .

H e r r e i d , Gordon, 1964, T e c t o n i c s and o r e d e p o s i t s i n A la ska , Alaska AIME Conference , C o l l e g e , Mar. 1 9 , 1964 , 7 p .

H i t e , D . M . , 1976 , Some s e d i m e n t a r y a s p e c t s of t h e Kenai Group, Cook I n l e t , A la ska , i n Recent and a n c i e n t s e d i m e n t a r y envi ronments i n Alaska : A la ska ~ z l o ~ i c a l S o c i e t y Symposium, Anchorage, A la ska , A p r i l 2-4, 1975, P r o c e e d i n g s , p . 11-123.

Hickman, R.G., 1974, S t r u c t u r a l geo logy and s t r a t i g r a p h y a long a segment of t h e D e n a l i f a u l t system: Madison, U n i v e r s i t y of Wiscons in , Ph.D. t h e s i s , 276 p .

H o l l i c k , A r t h u r , 1936, The T e r t i a r y f l o r a s of A la ska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 182 , 185 p .

H o l l i c k , C.A., 1911a , D i s c u s s i o n of t h e Cre t aceous and T e r t i a r y f l o r a s of A la ska [ a b s . ] : Washington Academy of S c i e n c e J o u r n a l , v . 1 , p . 142 .

, 1911b, R e s u l t s of a p r e l i m i n a r y s t u d y of t h e s o - c a l l e d Kenai f l o r a o f Alaska : American J o u r n a l of S c i e n c e , 4 t h s e r i e s , v . 31 , p . 327-330.

Holloway, C . D . , 1977, Map showing c o a l f i e l d s and distribution^ o i c o a l - b e a r i n g r o c k s i n t h e e a s t e r n p a r t of s o u t h e r n Alaska : U.S. G e o l o g i c a l Survey Open- f i l e Report 77-169D, 1 s h . , s c a l e 1 : 1 , 0 0 0 , 0 0 0 .

Hopkins, D . M . , 1951, L i g n i t e d e p o s i t s n e a r Broad Pass s t a t i o n , A la ska ; i n Coal i n v e s t i g a t i o n s i n s o u t h - c e n t r a l A la ska , 1944-46 : U.S. G e o l o g i c a l s u r v e y B u l l e t i n 963-D, p . 187-191.

Horne, J . C . and o t h e r s , 1978, D e p o s i t i o n a l models i n c o a l e x p l o r a t i o n and mine p l a n n i n g i n Appalachian r e g i o n : Bureau of t h e American A s s o c i a t i o n of Pe t ro l eum G e o l o g i s t s , v . 6 2 , no . 1 2 , p. 2379-2419.

Hutcheon, R . J . , 1972, Sea i c e c o n d i t i o n s i n t h e Cook I n l e t , Alaska , d u r i n g t h e 1970-71 w i n t e r . N a t i o n a l Oceanic and Atmospheric A d m i n i s t r a t i o n t e c h . mem. AR-7, 17 p .

J a c o b s e n , S . I . , Aamodt, P .L . , and S h a r p , R.R., J r . , 1979, Uranium hydrogeochemica l and s t r e a m sediment r e c o n n a i s s a n c e of t h e Lime H i l l s and Tyonek NTMS Quadrang le s , A la ska , i n c l u d i n g c o n c e n t r a t i o n s of f o r t y - t h r e e a d d i t i o n a l e l emen t s : U.S. Department of Energy, GJBX-29(79), 224 p.

J o i n t F e d e r a l S t a t e Land-Use P l a n n i n g Commission f o r A la ska , Resource P l a n n i n g Team, 1974, I n v e n t o r y Repor t -Mine ra l s , ene rgy and geo logy , S o u t h - c e n t r a l r e g i o n , p. 40-96.

J o n e s , D.L., 1973, S t r u c t u r a l e l emen t s and b i o s t r a t i g r a p h i c a l framework of lower Cre t aceous r o c k s i n s o u t h e r n A l a s k a ; i n t h e Borea l lower C r e t a c e o u s : See1 House p r e s s , L i v e r p o o l , ~ n s a n d ( i n c l . Ger. F r . , sum.) , p . 1-18.

J o n e s , D.L., S i l b e r l i n g , N . J . , C s e j t e y , B k l a , J r . , Nelson , W.H. , and Blome, C . D . , 1980, Age and s t r u c t u r a l s i g n i f i c a n c e of o p h i o l i t e and a d j o i n i n g r o c k s i n t h e upper C h u l i t n a d i s t r i c t , s o u t h - c e n t r a l A la ska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 1121-A, 21 p .

J o n e s , D.L., and S i l b e r l i n g , N . J . , 1979 , Mesozoic s t r a t i g r a p h y -- The key t o t e c t o n i c a n a l y s i s of s o u t h e r n and c e n t r a l Alaska : U.S. G e o l o g i c a l Survey Open- f i l e Report 79-1200, 41 p .

K a r l s t r o m , T.N.V., 1955 , L a t e P l e i s t o c e n e and r e c e n t g l a c i a l ch rono logy of s o u t h - c e n t r a l Alaska [cook I n l e t r e g i o n ] ; G e o l o g i c a l S o c i e t y of America B u l l e t i n , v . 6 6 , no. 1 2 , p t . 2 , p . 1581-1582.

, 1960, The Cook I n l e t , Alaska , g l a c i a l r eco rd and Q u a t e r n a r y c l a s s i f i c a t i o n ; i n G e o l o g i c a l Resea rch 1960: U.S. G e o l o g i c a l Survey Pro- f e s s i o n a l Pape r 400-B, p. B330-B332.

, 1964, Q u a t e r n a r y geology of t h e Kenai lowland and g l a c i a l h i s t o r y of t h e Cook I n l e t r e g i o n , Alaska : U .S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 443 , 69 p .

, 1965, ~ e s u m k o f t h e Q u a t e r n a r y geology of t h e upper Cook I n l e t a r e a and Matanuska R ive r v a l l e y , i n ~ d w k , T.L., e d . , Guidebook t o t h e Qua te rna ry geo logy , c e n t r a l and s o u t h - c e n t r a l Alaska (VII I N Q U A Congres s )

A la ska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Su rveys , p . 114-141.

Kar l s t rom, T.N.V. and o t h e r s , 1964, S u r f i c i a l geology of A la ska : U.S. G e o l o g i c a l Survey M i s c e l l a n e o u s Geo log ic I n v e s t i g a t i o n s Map 1-357, s c a l e 1 :1 ,584 ,000 .

K e l l y , T .E . , 1963, Geology and hydrocarbons i n Cook I n l e t b a s i n , Alaska , - i n C h i l d s , O.E., and Beebe, B.W. , e d s . , Backbone of t h e Americas - A symposium: American A s s o c i a t i o n of Pe t ro l eum G e o l o g i s t s Memoir 2 , p. 278-296, Houston G e o l o g i c a l S o c i e t y B u l l e t i n , v . 5 , no . 10 , p. 15-18.

K i r s c h n e r , C . E . , and Lyon, C . A . , 1973, S t r a t i g r a p h i c and t e c t o n i c development of Cook I n l e t pe t ro l eum p r o v i n c e ; i n A r c t i c Geology, M.G. P i t c h e r , e d . , American A s s o c i a t i o n of Pe t ro l eum G o l o g i s t s Memoir 1 9 , p. 396-407.

K l i n e , J . T . , 1978, Approximate s l o p e map of t h e Talkeetna-Kashwitna a r e a , S u s i t n a R ive r b a s i n , Alaska : Alaska D i v i s i o n of G e o l o g i c a l and Geophysi- c a l Surveys Open- f i l e Repor t 107C, 1 s h . , s c a l e 1 :63 ,360 .

LKB Resources , Inc . , 1978, NURE a e r i a l gamma-ray and magnet ic r e c o n n a i s s a n c e s u r v e y , Cook I n l e t , Alaska a r e a : P repa red f o r U.S. Department of Energy, G ~ ~ ~ - 1 0 8 ( 7 8 ) .

L a i r d , A.M. , 1977 , Beluga f i e l d p o t e n t i a l - Proposed c o a l o p e r a t i o n s , p. 143-152; i n W.C. McConkey, cha i rman, Alaskan c o a l and t h e P a c i f i c , J u n e a u , ~ G s k a Department of Commerce and Economic Development , and U .S. Energy Research and Development A d m i n i s t r a t i o n .

L o c k h a r t , Darcy, 1979 , S u s i t n a R ive r b a s i n r e s o u r c e b i b l i o g r a p h y - Supplement 1979: Alaska Department of N a t u r a l Resources , D i v i s i o n of Research and Development , Land and Resource P l a n n i n g S e c t i o n i n c o o p e r a t i o n wi th U.S. Department of A g r i c u l t u r e ( s o i l Conse rva t ion S e r v i c e , F o r e s t S e r v i c e , Economic Resea rch S e r v i c e ) , 244 p .

Long, W.E., Hydro log ica l b a s e l i n e s t u d i e s of Beluga c o a l a r e a ( i n p r o g r e s s ) : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l Su rveys .

L y l e , W . M . , Bragg, N . J . , 1974, Coal b i b l i o g r a p h y f o r Alaska : A la ska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Surveys Open- f i l e Report 4 1 , 31 p .

MacKevett, E.M., J r . , S i n g e r , D . A . , and Holloway, C . D . , 1978, Maps and t a b l e s d e s c r i b i n g met a l l i f e r o u s m i n e r a l r e s o u r c e p o t e n t i a l of s o u t h e r n A laska : U.S. G e o l o g i c a l Survey Open- f i l e Repor t 78-1-E, 4 5 p. and maps, s c a l e 1 :1 ,000 ,000 .

MacNeil, F . S . , Wolfe, J . A . , M i l l e r , D . J . , and Hopkins , D.M. , 1961, C o r r e l a t i o n of T e r t i a r y f o r m a t i o n s of Alaska: B u l l e t i n of t h e American A s s o c i a t i o n of Pe t ro l eum G e o l o g i s t s , v . 4 5 , no. 1 1 , p . 1801-1809.

Magoon, L.B., Adkison, W.L., and E g b e r t , R . M . , 1976, Map showing geo logy , w i l d c a t w e l l s , T e r t i a r y p l a n t f o s s i l l o c a l i t i e s , K-Ar age d a t e s , and pe t ro l eum o p e r a t i o n s , Cook I n l e t a r e a , Alaska : U.S. G e o l o g i c a l Survey Misce l l aneous I n v e s t i g a t i o n s Map 1-1019, 3 s h . , s c a l e 1 :250 ,000.

Maher, J . C . , and Tro l lman, W . M . , 1969, G e o l o g i c a l l i t e r a t u r e on t h e Cook I n l e t b a s i n and v i c i n i t y , Alaska : Alaska ~ i v i s i o n of G e o l o g i c a l and ~ e o p h y s i c a l Surveys i n c o o p e r a t i o n w i t h U.S. G e o l o g i c a l Su rvey , 8 2 p.

Maloney, R.P., 1958, Reconnaissance of t h e Beluga River c o a l f i e l d , Alaska : U.S. Bureau o f Mines Repor t I n v . 5430, 1 8 p .

M a r t i n , G . C . , 1926, The Mesozoic s t r a t i g r a p h y of A la ska : U.S. Geo log ica l Sur- vey ~ u l l e t i n 776, p . 232-240.

M a r t i n , G . C . , and K a t z , F . J . , 1912, Geology and c o a l f i e l d s of t h e lower Matanuska V a l l e y , Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 500 , 98 p .

May, R . R . , and W a r f i e l d , R. S . , 1957 , ~ n v e s t i g a t i o n of subbi tuminous-coa l beds n e a r Houston, westward e x t r e m i t y of Matanuska c o a l f i e l d , Alaska : U.S. Bureau of Mines Report Tnv. 5350, 20 p .

McGee, D.L., 1973, Coal r e s e r v e s s t u d y ; Beluga , Chu i tna River and Capps G l a c i e r a r e a s , Alaska : D i v i s i o n of G e o l o g i c a l and Geophys i ca l Su rveys Open- f i l e Report 30 , 7 p .

, 1976, Coal r e s o u r c e a p p r a i s a l o f t h e Beluga-Capps g l a c i e r a r e a ; - i n Dobey, P.L., McGee, D.L., and D i v i s i o n o f G e o l o g i c a l and Geophys ica l Su rveys s t a f f , 1976 , Economic and g e o l o g i c s t u d i e s of t h e Beluga-Capps a r e a and g e o l o g i c r e s o u r c e o c c u r r e n c e s i n o t h e r a r e a s of t h e proposed Cook I n l e t l and t r a d e : Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Sur- v e y s Open- f i l e Repor t 94 , p . 4-12.

, 1977, Alaskan c o a l - An overv iew, p. 36-51; i n W.C. McConkey, cha i rman, Alaskan c o a l and t h e P a c i f i c , Juneau , ~ l a z a Department of Com- merce and Economic Development and U .S. Energy Research and Development A d m i n i s t r a t i o n .

1978, Bedrock geology and c o a l o c c u r r e n c e s , Ta lkee tna-Kashwi tna a r e a , S u s i t n a River b a s i n : A la ska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l . .

S u r v e y s , Alaska Open- f i l e Report 107E, s c a l e 1 :63 ,360 . McGee, D.L., Emmel, K.S., Coonrod, P.L. , and C l a u t i c e , K . H . , 1977, B i b l i o -

graphy of t h e Cook I n l e t , 1969-1976: Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Su rveys , 3 3 p.

McGee, D.L., and Henning, M . W . , 1977 , Reconnaissance geology --- S o u t h - c e n t r a l T a l k e e t n a Mounta ins , Alaska : A la ska D i v i s i o n of G e o l o g i c a l and Geophysi- c a l Surveys Open- f i l e Repor t 103 , 1 s h . , s c a l e 1 :63 ,360 .

McGee, D.L., and 0 ' Connor, K . M . , 1974, Mine ra l r e s o u r c e s of Alaska and t h e impact of f e d e r a l land p o l i c i e s on t h e i r a v a i l a b i l i t y - Coa l : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Surveys Open-f i le Repor t 51 , 29 p .

, 1975, Cook I n l e t b a s i n s u b s u r f a c e c o a l r e s e r v e s t u d y : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Su rveys Open- f i l e Repor t 74 , 24 p .

M e r t i e , J . B . , J r . , 1919, P l a t i num-bea r ing gold p l a c e r s of t h e K a h i l t n a V a l l e y : U.S. G e o l o g i c a l Survey B u l l e t i n 692-D, p . 233-264.

M i l l e r , D . J . , Payne , T .G. , and Gryc , George, 1959, Geology of p o s s i b l e petroleurn p r o v i n c e s i n Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 1094, 127 p .

M i l l e r , R . D . , and Dobrovolny, E r n e s t , 1959, S u r f i c i a l geology of Anchorage and v i c i n i t y , Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 1093, 128 p.

M i l l e r , T .P . , e d . , 1976 , Recent and a n c i e n t s ed imen ta ry envi ronments i n Alaska : Alaska G e o l o g i c a l S o c i e t y Symposium, Anchorage, A la ska , A p r i l 2-4, 1975.

M o f f i t t , F.H. and Pogue, J . E . , 1915, The Broad P a s s r e g i o n , U.S. G e o l o g i c a l Survey B u l l e t i n 608 , 8 0 p.

Mul l i gan , J . J . , W a r f i e l d , R .S . , and Wel l s , R . R . , 1967, Sampling a gold-copper d e p o s i t , Golden Zone Mine, s o u t h - c e n t r a l Alaska : U .S. Bureau of Mines Open- f i l e Repor t 9-67, 59 p .

NWS ( ~ a t i o n a l Weather S e r v i c e ) , 1973a , [Map o f ] A l a s k a [ showing] mean annual p r e c i p i t a t i o n : U.S. Department o f Commerce, Na t iona l Weather S e r v i c e i n c o o p e r a t i o n w i t h U .S. G e o l o g i c a l Survey , Anchorage, A la ska .

Nelson, S.W., and Reed, B.L., 1978, S u r f i c i a l d e p o s i t s , T a l k e e t n a Quadrangle , Alaska : U.S. G e o l o g i c a l Survey Misce l l aneous F i e l d S t u d i e s Map MF-870-J.

Page , R . A . , and Lahr , J . C . , 1971, Measurement of f a u l t s l i p on t h e D e n a l i , •

F a i r w e a t h e r and C a s t l e Mountain f a u l t s , Alaska : J o u r n a l of Geophys ica l Resea rch , v . 76, no . 35, p . 8534-8543.

P a t s c h , B . J . G . , Beluga c o a l p r o j e c t ( i n p r o g r e s s ) : [ c o n t a c t Benno J . G . P a t s c h , P r o j e c t E n g i n e e r , 2500-One C a l i f o r n i a S t r e e t , San F r a n c i s c o , CA 94111.1

P a t s c h , B . J . G . , 1974, P r o j e c t e n g i n e e r , P l a c e r Amex, s t a t e m e n t s on Beluga c o a l s , Alaska : P r e s e n t a t i o n a t F e d e r a l A d m i n i s t r a t i o n P r o j e c t Independence P u b l i c H e a r i n g s i n Anchorage, September 9-10. , 1977, Beluga f i e l d p o t e n t i a l - t h e r e s o u r c e , p. 126-142, i n W . C . McConkey, cha i rman, Alaskan c o a l and t h e P a c i f i c , J u n e a u , ~ c s k a - .

Department of Commerce and Economic Development, and U.S. Energy Research and Development Admin i s t r a t i o n .

P a t s c h , B.J.G., and P l a c e r Amex, I n c . , 1975, E x p l o r a t i o n and development of t h e Beluga c o a l f i e l d , p . 72-83; i n Rao, P .D. , and Wolf f , E . N . , e d s . , Focus on A l a s k a ' s Coal - 1975, c o n f e r e n c e , Fa i rbanks [ A l a s k a ] , October 15-17, 1975, P roceed ings : F a i r b a n k s , U n i v e r s i t y of Alaska Mine ra l I n d u s t r i e s Research L a b o r a t o r y Report 3 7 .

Payne, T.G. , 1955, Mesozoic and Cenozoic t e c t o n i c e l emen t s of Alaska: U.S. G e o l o g i c a l Survey Misce l l aneous Geologic I n v e s t i g a t i o n s Map 1-84, s c a l e 1 :5 ,000 ,000 .

Pkwk, T .L . , e d . , 1965, Guidebook t o t h e Q u a t e r n a r y geo logy , c e n t r a l and s o u t h - c e n t r a l Alaska (VII INQUA Congress) : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l S u r v e y s , 141 p . , 1975 , Qua te rna ry geology of Alaska : U.S. Geo log ica l Survey P r o f e s s i o n a l Pape r 835 , 145 p .

P l a c e r Amex, I n c . , 1976, Beluga ( an Alaskan c o a l f i e l d , not a wha le ) , - i n Western Miner , Oc t . 1976, p . 82-84. , 1977 , Beluga c o a l p r o j e c t s t a t u s r e p o r t , 1977: P l a c e r Amex, I n c . , 58

P . , 1979, Beluga c o a l p r o j e c t s t a t u s r e p o r t , S e p t . 1979, 63 p .

P l a f k e r , G . , 1971, P a c i f i c margin T e r t i a r y b a s i n , i n F u t u r e Pe t ro l eum pro- v i n c e s of Nor th America: American ~ s s o c i a t i o n o f Pe t ro l eum G e o l o g i s t s Memoir 15 , p . 120-135.

P o s t , Aus t in and Mayo, L .R . , G l a c i e r dammed l a k e s and o u t b u r s t f l o o d s i n Alaska : U . S . G e o l o g i c a l Survey Hydro log ic 1 n v e s t i g a t i ons A t l a s HA-455, 10 p . , 3 s h . , s c a l e 1 : 1 , 0 0 0 , 0 0 0 .

Race , W . H . , 1962, The m i n e r a l i n d u s t r y of t h e Kenai-Cook I n l e t - S u s i t n a r e g i o n : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Surveys m i s c e l l a n e o u s p u b l i c a t i o n , 42 p .

Ramsey, J . P . , 1981, Chu i tna c o a l is w a i t i n g on marke t : Alaska I n d u s t r y , May 1981, p . 12 .

Rao, P .D . , 1975, C h a r a c t e r i z a t i o n of Alaskan c o a l s , Focus on A l a s k a ' s Coal- 1975, P roceed ings of t h e c o n f e r e n c e h e l d a t t h e U n i v e r s i t y of A la ska , F a i r b a n k s , October 15-17, 1975, U n i v e r s i t y of Alaska Minera l I n d u s t r i e s Research Labora to ry Repor t 37, p . 33-47.

Rao, P .D . , and Wol f f , E . N . , e d s . , 1976, Focus on A l a s k a ' s Coal - 1975, P roceed ings of t h e c o n f e r e n c e h e l d a t t h e U n i v e r s i t y of Alaska , F a i r b a n k s , 1975 ( sponso red by U n i v e r s i t y of Alaska School of Minera l I n d u s t r y and F e d e r a l Energy A d m i n i s t r a t i o n ) , Mine ra l I n d u s t r y Research L a b o r a t o r y Report 37 , 281 p . , 1980 , C h a r a c t e r i z a t i o n and e v a l u a t i o n of w a s h a b i l i t y of Alaskan c o a l s , f i n a l t e c h n i c a l r e p o r t f o r phase 11: M i n e r a l I n d u s t r y Research L a b o r a t o r y , U n i v e r s i t y of A la ska , F a i r b a n k s , 47 p .

Reed, B . L . , and E l l i o t t , R.L. , 1970, Reconnaissance g e o l o g i c map, a n a l y s e s o f bedrock and s t r e a m sediment samples and an aeromagnet ic map of p a r t s of t h e s o u t h e r n Alaska Range: U.S. G e o l o g i c a l Survey Open- f i l e Repor t 70-271, 145 p . , s c a l e 1 :250 ,000.

Reed, B.L. , and Lanphe re , M.A., 1969, Age and c h e m i s t r y of t h e Mesozoic and T e r t i a r y p l u t o n i c r o c k s i n s o u t h - c e n t r a l Alaska : G e o l o g i c a l S o c i e t y of America B u l l e t i n , v . 8 0 , no. 1 , p . 23-44.

, 1973, P l u t o n i c r o c k s of t h e Alaska-Aleut ian Range B a t h o l i t h , i n A r c t i c Geology, American A s s o c i a t i o n of P e t r o l e u m G e o l o g i s t s Memoir 1 9 , p . 421-428.

Reed, B.L., and M i l l e r , T .P . , 1980, Uranium and thor ium c o n t e n t of some T e r t i a r y g r a n i t i c r o c k s i n t h e s o u t h e r n Alaska Range: U .S. G e o l o g i c a l Su rvey Open- f i l e Repor t 80-1052, 16 p .

Reed, B.L. , and Nelson, S.W., 1980, Geologic map of t h e T a l k e e t n a Quadrang le , A la ska : U . S . G e o l o g i c a l Survey Misce l l aneous Geologic I n v e s t i g a t i o n s Map 1-1174, s c a l e 1 :250 ,000.

Reed, John C . , 1961, Geology of t h e Mount McKinley Quadrangle , A la ska : U.S, G e o l o g i c a l Survey B u l l e t i n 1108-A, 36 p.

Reger , R . D . , S u r f i c i a l geology and g e o l o g i c h a z a r d s of t h e s o u t h w e s t e r n T a l k e e t n a Mountains: A la ska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Sur- veys p r o j e c t i n p r o g r e s s , Arc t i c Envi ronmenta l I n f o r m a t i o n and Data C e n t e r , U n i v e r s i t y of A la ska , Anchorage.

, 1978a , Reconnaissance geology of t h e new c a p i t a l s i t e and v i c i n i t y , Anchorage Quadrangle and v i c i n i t y , Alaska : A la ska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Surveys Open-f i le Report 113A, 1 s h . , s c a l e 1 :63 ,360 .

, 1978b, Reconnaissance geo logy of t h e Talkee tna-Kashwi tna a r e a , S u s i t n a River b a s i n , Alaska: A la ska D i v i s i o n of G e o l o g i c a l and Geophysi- c a l S u r v e y s , Alaska Open- f i l e Repor t 107A, s c a l e 1 :63 ,360 .

Reger , R . D . , and Ca rve r , C .L. , 1978a, Reconnaissance g e o l o g i c m a t e r i a l s map o f t h e new c a p i t a l s i t e and v i c i n i t y , Anchorage Quadrang le , Alaska : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Surveys Open- f i l e Repor t 113B, 1 s h . , s c a l e 1 :63 ,360 .

, 1978b, Reconnaissance g e o l o g i c m a t e r i a l s map of t h e Ta lkee tna - Kashwitna a r e a , S u s i t n a River b a s i n , Alaska : Alaska D i v i s i o n of Geologi- c a l and Geophys i ca l Surveys Open- f i l e Report 107B, 1 s h . , s c a l e 1 :63 ,360 .

R i c h a r d s , G . H . , 1974, T e c t o n i c e v o l u t i o n o f Alaska : B u l l e t i n of t h e American A s s o c i a t i o n o f P e t r o l e u m G e o l o g i s t s , v . 58 , no. 1 , p . 79-105.

R i c h t e r , D . H . , 1963, Geology of t h e P o r t a g e Creek-Sus i tna R ive r a r e a : Alaska D i v i s i o n o f G e o l o g i c a l and Geophys i ca l Su rveys Geo log ic Repor t 3 .

Robinson , G . D . , Wedow, H . , J r . , and Lyons, J . B . , 1955, R a d i o a c t i v i t y i n v e s t i - g a t i o n s i n t h e Cache Creek a r e a , Yentna D i s t r i c t , A la ska , 1945: U.S. G e o l o g i c a l Survey B u l l e t i n 1024-A, 23 p .

Ross, C.P. , 1933, Mine ra l d e p o s i t s n e a r t h e West Fork of t h e C h u l i t n a R i v e r , Alaska : U.S. G e o l o g i c a l Survey B u l l e t i n 849-E, p. 289-333.

Ru t l edge , F.A., Thorne, R.L., and o t h e r s , 1953, P r e l i m i n a r y r e p o r t - Non- m e t a l l i c d e p o s i t s a c c e s s i b l e t o t h e Alaska r a i l r o a d a s p o s s i b l e s o u r c e s o f raw m a t e r i a l s f o r t h e c o n s t r u c t i o n i n d u s t r y : U.S. Bureau of Mines Report o f I n v e s t i g a t i o n s 4932, 129 p .

Sande r s , R . B . , I n v e n t o r y of r e c l a m a t i o n needs of abandoned c o a l mines i n Alaska . A la ska D i v i s i o n of M i n e r a l s and Energy Management p r o j e c t i n p r o g r e s s , A r c t i c Env i ronmen ta l I n f o r m a t i o n and Data C e n t e r , U n i v e r s i t y o f A l a s k a , Anchorage.

, 1976, Coal r e s o u r c e s of Alaska - 1975, i n Focus on A l a s k a ' s Coal ' 7 5 , P roceed ings of t h e c o n f e r e n c e he ld a t t he?n ive r s i t y of A la ska , F a i r b a n k s , October 15-17, 1975 , U n i v e r s i t y of Alaska Minera l I n d u s t r i e s Research L a b o r a t o r i e s Repor t 37, p . 21-32.

Schmol l , H . R . , and Yeh le , L.A., 1978, Gene ra l i zed phys iography and geology of t h e Beluga c o a l f i e l d and v i c i n i t y , s o u t h - c e n t r a l A la ska ; i n U.S. - G e o l o g i c a l Survey C i r c u l a r 772-B, p. B73-B76.

Schmol l , H . R . , Yeh le , L.A., and Gardner , C . A . , 1981, P r e l i m i n a r y g e o l o g i c map of t h e Congahbuna a r e a , Cook I n l e t r e g i o n , Alaska : U.S. G e o l o g i c a l Survey Open-f i le Repor t 81-429, 8 p . , 1 s h . , s c a l e 1 :63 ,360 and 1 ,000 ,000 .

S e l k r e g g , L .L. , e d . , 1976, Alaska r e g i o n a l p r o f i l e s , s o u t h - c e n t r a l r e g i o n : U n i v e r s i t y of A la ska , A r c t i c Envi ronmenta l I n f o r m a t i o n and Data C e n t e r , C o l l e g e , Alaska 255 p .

S e l v i g , W.A., Ode, W.H. , and D a v i s , J . D . , 1944, Low t e m p e r a t u r e c a r b o n i z a t i o n o f Alaska c o a l s : U.S. Bureau of Mines T e c h n i c a l P a p e r 668 , 16 p.

Sharma, G . D . , and B u r r e l l , D . C . , 1970, Sedimentary environment and sed imen t s o f Cook I n l e t , Alaska : B u l l e t i n of t h e American A s s o c i a t i o n o f Pe t ro l eum G e o l o g i s t s , v . 5 4 , no. 4 , p. 647-654.

S i n g e r , D . A . , C s e j t e y , B&la , J r . , and M i l l e r , R . J . , 1978, Map and d i s c u s s i o n of t h e m e t a l l i f e r o u s and s e l e c t e d n o n m e t a l l i f e r o u s m i n e r a l r e s o u r c e s of t h e T a l k e e t n a Mountains Quadrang le , Alaska : U.S. G e o l o g i c a l Survey Open- f i l e Repor t 78-558-4, 32 p . , s c a l e 1 :250 ,000.

Smi th , P .S . , 1939, Area l geology of Alaska : U.S. Geo log ica l Survey Pro- f e s s i o n a l Pape r 192 , 100 p .

S p u r r , J . E . , 1900, A r e c o n n a i s s a n c e i n sou thwes t e rn Alaska i n 1898 : U.S. G e o l o g i c a l Survey 20 th Annual Report p t . 7 , p. 31-268.

S t a n f o r d Research I n s t i t u t e , 1974, The p o t e n t i a l f o r deve lop ing Alaskan c o a l s f o r c l e a n e x p o r t f u e l s , i n Dobey, P .L . , McGee, D.L., and Alaska D i v i s i o n of G e o l o g i c a l and ~ e o ~ h ~ x c a l s t a f f , 1976, Economic and g e o l o g i c s t u d i e s o f t h e Beluga-Capps a r e a and g e o l o g i c r e s o u r c e o c c u r r e n c e s i n o t h e r a r e a s o f t h e proposed Cook I n l e t l and t r a d e : Alaska D i v i s i o n of G e o l o g i c a l and Geophys ica l Surveys Open- f i l e Repor t 94, p . 65-86.

S t e e l e , W . C . , and LeCompte, J . R . , 1978, Map showing i n t e r p r e t a t i o n of LANDSAT imagery of t h e T a l k e e t n a Mountains Quadrangle , Alaska : U.S. G e o l o g i c a l Survey Open- f i l e Repor t 78-558D, 2 s h .

S t i l l , P . J . , 1980, Index of s t r eamf low and w a t e r - q u a l i t y r e c o r d s t o September 3 0 , 1978 , s o u t h - c e n t r a l A la ska : U.S. Geo log ica l Survey Open-f i le Report 80-600, 54 p.

S t o n e , R.W., 1906, Coal f i e l d s of t h e Kachemak Bay r eg ion : U.S. Geo log ica l Survey B u l l e t i n 277, p . 53-73.

Toenges , A.L., and J o l l e y , T.R. , 1949, I n v e s t i g a t i o n s of c o a l d e p o s i t s i n s o u t h - c e n t r a l Alaska and t h e Kenai P e n i n s u l a : U.S. Bureau of Mines Repor t o f I n v e s t i g a t i o n s 4520, 37 p .

T r i p l e h o r n , D.M. , 1976, ~ o n t r i b u t i o n s t o c l a y mine ra logy and p e t r o l o g y , Cook I n l e t b a s i n , A la ska : Alaska D i v i s i o n of G e o l o g i c a l and Geophys i ca l Sur- veys Open-f i le Report 102 , 18 p .

Tuck, Ralph , 1934 , The Curry d i s t r i c t , Alaska : U.S. Geo log ica l Survey B u l l e t i n 857 , p . 99-140.

U .S. Army Corps of E n g i n e e r s , 1972, Flood p l a i n i n f o r m a t i o n , T a l k e e t n a River- R i v e r - S u s i t n a ~ i v e r - C h u l i t n a ~ i v e r : Report f o r t h e ~ a t a n u s k a - S u s i t n a Borough, 28 p .

U.S. Department of Commerce, 1968, C l ima te s of t h e s t a t e s , Alaska : Environ- m e n t a l S c i e n c e S e r v i c e s A d m i n i s t r a t i o n , ~ l i m a t o g r a p h y of t h e Uni ted S t a t e s no. 60-49, 23 p .

U.S. Department of Energy th rough Alaska Department of Commerce and Economic Development under c o n t r a c t t o p a c i f i c Northwest Labora to ry , ~ i c h l a n d , Washington, May 1979, Beluga Coal F i e l d ~ e v e l o p m e n t - s o c i a l e f f e c t s and management a l t e r n a t i v e s ( P N L - R A P - ~ ~ / u c ~ ~ ) .

U.S. G e o l o g i c a l Survey , 1954, T a l k e e t n a Mountains Quadrang le , A la ska : U.S. G e o l o g i c a l Survey Alaska Topog. S e r . Map, s c a l e 1 :250 ,000.

U.S. G e o l o g i c a l Survey , 1958 , T a l k e e t n a Quadrang le , Alaska : U.S. G e o l o g i c a l Survey Alaska Topog. S e r . Map, s c a l e 1 :250 ,000.

U .S . G e o l o g i c a l Su rvey , 1962, Anchorage Quadrang le , Alaska : U.S. G e o l o g i c a l Survey Alaska Topog. S e r . Map, s c a l e 1 :250 ,000.

Vanwormer, J . D . , D a v i e s , J . , and Gedney, L .D. , 1974, S e i s m i c i t y and p l a t e t e c t o n i c s i n s o u t h - c e n t r a l Alaska : B u l l e t i n of t h e S e i s m o l o g i c a l S o c i e t y of America, v . 6 4 , p . 1467-1475.

Wahrha f t i g , C . , 1965 , P h y s i o g r a p h i c d i v i s i o n s of A la ska : U.S. G e o l o g i c a l Sur- v e y P r o f e s s i o n a l Pape r 482 , 5 2 p.

Walker , F.K., 1975, B i b l i o g r a p h y and index of U.S. G e o l o g i c a l Survey pub l i ca - t i o n s r e l a t i n g t o c o a l , J a n u a r y 1971-June 1974: U.S. G e o l o g i c a l Survey C i r c u l a r 709 , 14 p .

War f i e l d , R. S . , 1963, I n v e s t i g a t i o n of a subbi tuminous c o a l d e p o s i t s u i t a b l e f o r open c u t min ing , Beluga River c o a l f i e l d , Alaska : U.S. Bureau o f Mines Report of I n v e s t i g a t i o n s 6238, 100 p .

Wari.ng, G . A . , 1947, N o n m e t a l l i f e r o u s d e p o s i t s i n t h e Alaska R a i l r o a d b e l t : U.S. G e o l o g i c a l Survey C i r c u l a r 1 8 , 10 p .

Weber, F . R . , 1961, Reconnaissance e n g i n e e r i n g geology f o r s e l e c t i o n of highway r o u t e from T a l k e e t n a t o McGrath, A la ska : U.S. Geo log ica l Survey Open-f i le Map 61-169, 2 s h . , s c a l e 1 :250 ,000.

W i l l i a m s , J . R., 1970, Ground wa te r i n t h e pe rmaf ros t r e g i o n s of A la ska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 696 , 8 3 p .

Wolfe, J . A . , 1966, T e r t i a r y p l a n t s from t h e Cook I n l e t r e g i o n , A la ska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l P a p e r 398-B, p . B1-B32.

Wolfe, J . A . , Hopkins, D . M . , and Leopold , E . B . , 1966, T e r t i a r y s t r a t i g r a p h y and pa l eobo tany of t h e Cook I n l e t r e g i o n , Alaska: U.S. G e o l o g i c a l Survey Pro- f e s s i o n a l Pape r 398-A, 29 p .

Wolfe , J . A . , ancl T a n a i , T . , 1980, The Miocene S e l d o v i a P o i n t f l o r a from t h e Kenai Group, Alaska : U.S. G e o l o g i c a l Survey P r o f e s s i o n a l Pape r 1105, 52 p .

Z i e t z , I s i d o r e , Andreasen , G.E., and G r a n t z , A r t h u r , 1957, Aeromagnetic recon- n a i s s a n c e of t h e Cook I n l e t a r e a , A la ska [ a b s . ] : G e o l o g i c a l S o c i e t y of America B u l l e t i n , v . 6 8 , no. 1 2 , p t . 2 , p . 1910.

Z u f f a , G . G . , N i l s e n , T.H. , and Wink le r , G . R . , 1980, Rock-fragment p e t r o g r a p h y o f t h e Upper C r e t a c e o u s Chugach t e r r a n e , s o u t h e r n A laska : U.S. Geo log ica l Survey O p e n r f i l e Repor t 80-713, 31 p.

APPENDIX A - COAL lDCALBS

Outc rop Ho. o f Haximum Loca le Loca le Loca le s e c t i o n c o a l c o a l bed

no . name code Township Range S e c t i o n t h i c k n e s s b e d s t h i c k n e s s Dip

1 Beluga Rive r BR 13 11 14 Approximately Over 12 1 0 f t 35' 150 f t de- o b s e r v e d ; s c r i b e d 7 d e s c r i b e d

i n s e c t i o n

2 Besh ta Bay BB

3 Camp Creek CPC ( F a i r v i e w Htn a r e a )

4 Canyon Creek CnCl

5 Canyon Creek CnC2

19 13 6 Approx 150 f c . o n l y p a r t o f s e c t i o n d e s c r i b e d

19 13 7 2 U f t exposed

L 5 f t 37' exposed

l o f t 35' h e r e bedded, l o c a l l y c o n t o r t e d

G e n e r a l c o m e n t s

Numerous S e d U exposed l a t e r a l l y a long r i v e r . C o a l s appea r t o be of good q u a l i t y . p r e d o m i n a n t l y d u l l , b l o c k y , and h a r d ; l o c a l l y p l a t y and bony. T h i c k e r seams toward b a s a l p o r t i o n of s e c t i o n

L P.

have t h i n c l a y s t o n e p a r t i n g s . Underc lays t y p i c a l l y medium-gray sandy c l a y s t o n e s . Sand x" c o n t e n t g e n e r a l l y i n c r e a s e s upward i n t h e sec - z. t i o n . S e e app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g 2. s e c t i o n . 0

D u l l , b locky c o a l wi th o c c a s i o n a l t h i n v i t r a i n bands ; seam exposed a l o n g c o a s t f o r n e a r l y 10

; g m i l e s . Overburden and s e a t r o c k c o n s i s t p re -

fi w d o m i n a n t l y of pebb ly aandsconr and c o n g l u u e r a l r ; aandscone , l i g h t brown. medium g r a i n e d . l o c a l l y c l a y e y . Top of s e c t i o n c o n t a i n s v e r y l a r g e b o u l d e r a t o s e v e r a l f e e t i n d i a m e t e r .

! 8 s g P r r d o m i n d r ~ t l y d u l l , p l a t y c o a l . becoming b locky toward b a s a l p o r t i o n . l o c a l l y bony. High ly

; * weathe red on s u r f a c e o u t c r o p . Exposed f o r abou t 'Il 5 200 f t a l o n g C a p Creek. Overburden and a e a t r o c k not exposed . 2

3 Predominan t ly d u l l , b locky c o a l but wi th abundant 0 t h i n v i t r a i n banda. I s o l a t e d b lock of T e r t i a r y Kenai s t r a t a su r rounded by Mesozoic igneous 2 i n t r u s i v e a . Grave l ( w i t h c o b b l e s g e n e r a l l y Less t h a n 1 f t i n . d i a m e t e r ) covera overburden s e c t i o n .

s Y

HrLdmorphosed c o a l bed l o c a l l y s e v e r e l y c o n t o r t e d a s r e s u l t of s u r r o u n d i n g i n t r u s i v e s . Rim of h i g h l y a x l d i z e d i r o n s t o n e ( h e m a t i t e ) o c c u r s a s a u r e o l e between c o a l and i n t r u s i v e b o d i e s .

O u t c r o p Loca le Loca le Loca le s e c t i o n

no. name code Townsh ie Range S e c t i o n t h i c k n e s s

6 Canyon Creek CnC3 19 13 7 - -

No. o f Haximum c o a l c o a l bed

t h i c k n e s s Dip beds

7 Canyon Creek CnC4 19 I 3 7 60-80 f t 1

8 Canyon Creek CnCS 19 1 3 6 5 0 f t 1 exposed

9 Canyon Creek CnC6 20 14 35 Only 10- 1 I5 f t t o f i r s t t e r - r a c e above s t r e a m

10 Canyon Creek CnC7 20 13 19 2 5 f t I

11 Canyon Creek CnC8 20 1 3 19 V a r i e s 1 L a t e r a l l y

Over 20 S l i g h t f t d i p

Approx 15' 20 It exposed

6 f t Near ly exposed hoc i - t o c r e e k z o n t a l l e v e l

1 0 f t S t e e p

1 4 f t S t r o n g

G e n e r a l comments

G r a d a t i o n a l zones of burn a s s o c i a t e d wi th metamorphic a u r e o l e s e p a r a t i n g Mesozoic i n t r u s i v e 8 and m r t a s e d i m r n t a from T e r t i a r y Kenai s t r a t a . The zones i n c l u d e : a ) l i g h t - g r a baked c l a y s t o n e wi th abundant p l a n t f o s s i l s ; b! cream-colored ( b e i e ) baked c l a y s t o n e ; c ) pink t o l i g h t - r e d c l i n k e r t i s c o r i a c e o u s ) w i t h abundant h e m a t i t e ; and d) da rk - red t o maroon burn ( p u r e h e m a t i t e . l o c a l l y s p e c u l a r ) .

S i t e abou t 50 yd s o u t h of t h e l a r g e burn a r e a a t CnC3. Coal t h e r m a l l y a l t e r e d ( b r i g h t , v i t r e o u e , w i t h c o n c h o i d a l f r a c t u r e ) . La rge t a l u s s l o p e b e n e a t h t h e c o a l p r e v e n t b o t h e x a c t d e t e r m i n a t i o n o f t h i c k n e s s and smnpl ing t h e a e a t r o c k .

Loca le i s j u a r s o u t h o f CnCI. Good exposure o f s e a t r o c k . See app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

S e a e x t e n d s below s t r e a m . L o c a l l y s l i g h t l y s lumped. Roof and f l o o r not exposed .

S u r f a c e w e a t h e r i n g p d t t e r n on c o a l v e r y d i s - tinctive---similar t o d r u s y q u a r t z . P o s s i b l e v o l c a n i c ash p a r t i n g ( t o n s t e i n ) . S e e app. B f o r d e s c r i p t i o n o f c o a l - b e a r i n g s e c t i o n .

Complete seam t h i c k n e s s exposed wi th c l a y s t o n e overburden and s e a t r o c k . Q u a l i t y of seam d e t e r i o r a t e * n o t i c e a b l y i n b a s a l 2-3 f t . S e e app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

- . - m

4 YI 3 u . u a

P .-r a "3 4 a u 0 Y Y I Y Y .

- V ] C m 0 P '3 .- U YI . U m w u c m a m o u m s

0 0 X 4 P M w c x c - .- 0 .- + U 4 MYI m > c w Y 0 Y P a, -P I P 4 A

u - 4 C 4 0 l o 0 U m X U O C U

i 4 U 0 O U O

C S m o ii.2

U U A . 4 U * = 8 ' - v

a! a.C In > au Y k 4 v U u- YI - r

n u r 3 0 0 o w -

u .. 4 w - C m C w- M

3"": Y I P U S * o u r m o nu Y Y X 4 - 3 * o Y u c n U

Y a 12- - 3 4 > * 20 U u . 4 - m Z I O ' Y B

d L 1 X 3 . 4 Y - . - > U X d m 4 u w 4

u r Y y l C " r c 4 0 Y Y I d - 4 . m m u -22 3 * - X U u,? m ' 4 0 - 3 . C D M 34 4 . , a - C

X U a m.- m w v 3 3 c a+ u .4 u .4

P d 4 V 0 4 4 4 C Y r . Y u >.- f i n m

4 n m . *4.-

n Y m 4 * n o > o u 4 Y U O O o r 8 Y

u ur v z O m C - r 0.4 0

u n C U L. 9 M.4 a u c c m m .- U O u r u.- a o r s n . X 4 P C " ,"a:" 2

- 4 c u o u 4 Y m U m v 1 7 i 4 0 m Y a n 01 Y . 4 u m m I.- 0 4 . y) - " c c w C

4 .- a, .d

~ P V Y C * 0 5 - r b . 4 o m o m a a ) 'a- > an n

u

3 - m 4 . 3

' O Y O U P

- a, - YI c - - - a o - n - 4 n 4 . 4

Y I - a . - " . m V L U m I m 0 9 1 f i m m I n u w 4 u u

N;::;: '

n c YI o o u i.* C U U * U U v 3 w . -

o p e

a, w 1 -

g ": :.2 r u o 'n n n.0 YI P Y - i X C U - = N w 4 u

Outc rop No. o f Maximum I.ocale L o c a l e Loca le aec t i on c o a l c o a l bed

no. name code Township Range S e c t i o n thickness beds t h i c k n e s s Dip

19 Chu i tna R i v e r CR3 13 13 28 1 0 f t 1 Approx 30' 6 f t exposed

20 Chu i tna R ive r CR4 13 1 3 28 Usua l ly l e s s 1 V a r i e s , 30' t h a n 10 f t g e n e r a l l y

4-6 f t exposed

21 Chu i tna R ive r CRS 12 1 3 24 2 0 f t 2 8 f t 4 '

22 Chu i tna R ive r CH6 12 1 3 6 Up t o 80 f t 1 Over 20 Nearly exposed bu t f c h o r i - l a r g e l y z o n t a l i n a c c e s s i b l e

23 Chu i tna R i v e r CR7 12 1 3 35 - -

24 Chu i tna R ive r CR8 12 13 1 6 0 f t

2 5 C h u ~ t n a Rive r CR9 12 13 1 8 0 f t 30 f t Less than 5 '


Exposure of C h u i t n a bed a long s t r e a m d r a i n a g e ; one l imb of a n t i c l i n e on bot tom of s t r e a m bed . See app. 5 f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

Coal a t t h i s l o c a l e is c o n t a i n e d w i t h i n t h e n o r t h e a s t - t r e n d i n g a n t i c l i n e d e s c r i b e d a t CR2 and CR3.

T w s e a m o r one s e p a r a t e d by a 1 .5 - fc p a r c l n g o f c l a y s t o n e . Coal e x t r e m e l y weathered a t t h i s e x p o s u r e . See app . 6 f o r d e s c r i p t i o n o f c o a l - b e a r i n g s e c t i o n .

Ou tc rop of s e a t r o c k o f Chu i tna bed -- weathe red , f r i a b l e s a n d s t o n e and l o o s e sand . r e l a t i v e l y c l e a n , f i n e t o medium-grained, p redominan t ly q u a r t z bu t wi th d i s s e m i n a t e d b l a c k o r g a n i c m a t t e r and e x t r e m e l y f i n e muscov i t e f l a k e s .

Ou tc rop of baked s a n d s t o n e and s h a l e w i t h i m p r i n t s of l e a f f o s s i l s . Burn m a t e r i a l -- s c o r i a , p o r c e l l a n i t e , c l i n k e r , "red dog." Di f - f e r e n t a t a g e s of o x i d a t i o n and v a r i e t i e s of v e s i - c u l a r h e m a t i t e ; l o c a l a d m i x t u r e s o f p y r o l u s i t e ( Mn02 ) . D i s t i n c t i v e d i f f e r e n t i a l wea the r ing s u r f a c e s ( a n a s t a m o s e s ) on s a n d s t o n e roof rock oC Chuicna c o a l bed. The b a s a l p o r t i o n of t h e c o a l bed (1-2 f t ) a p p e a r s t o be burned . Desc r ibed from a c r o s s r l v r r . See app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

Good exposure of C h u i t n a bed a long sou thuesc w a l l o f promontory. P o s s i b l e v o l c a n i c ash p a r t i n g w i t h i n c o a l seam. See app. B f o r d e e c r i p t i o n o f c o a l - b e a r i n g s e c t i o n .

U

J 0

d

5 2

x . o m 0 3 1 n u .- m u) Y u ) "2 Y o

'5 0 C 4

.3 I , a - m N M - L

4 m a - U

n W 0 a L

1I u L13

2 0

0 n . X w Q Y

v u 0 > 0 0 il U

O u t c r o p No. of Loca le Loca le L o c a l e s e c t i o n c o a l

no. name code T o u n s h i e Range S e c t i o n t h i c k n e s s b e d s

33 F r i d a y Creek FC 19 13 35 20 f t 1

34 Johnson Creek JC1

35 Johnson Creek JC2

r n I 36 Johnson Creek JC3

37 P r t e r a v i l l e PA1 a r e a

2 3 15 21 2 0 0 f t o r - - more; o n l y b a s a l 20 f t d e s c r i b e d

23 14 30 5 0 f t exposed

3, o n l y lower bed a c c e s s i b l e

Haximum c o a l bed t h i c k n e s s

12 f t exposed down t o c r e e k l e v e l

- -

Less t h a n 1 f t

6 f c

1 f t

D ip

Near ly h o r i - z o n t a l

- -

25-

13'

Moderate


Coal h a r d , p l a t y , a s h y , l o c a l l y v i t r a i n - b a n d e d bu t p r e d o m i n a n t l y d u l l . Roof and f l o o r unexposed.

Lower s e c t i o n of e x p o s u r e is composed of da rk - g r a y g r a p h i t i c c l a y s c o n e and g r a p h i t e wi th d i i t e q u a r t z v e i n s . f r a c t u r e f i l l s . and n o d u l e s . A zone o f * i t e c a l c i t e and a n aquamar ine v r a t h e r - i n g r i m forma t h e boundary between t h e g r a p h i t e and t h e q u a r t z .

Coal t h e r m a l l y a l t e r e d v i t r e o u s , c o n c h o i d a l f r a c t u r e . ~ a r b o n a c e o < s s h a l e roof and f l o o r . See app . B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

Crops o u t i n s o u t h wa l l o f c r e e k . P r e d o m i n a n t l y a d u l l , p l a t y c o a l bu t u i t h f e u i n t e r b a n d e d b r i g h t c o a l l a y e r s . Loca ted a t t h e base of a q u a r t z - p e b b l e c o n g l o m e r a t e and p e b b l y , s a n d s t o n e sequence . Coal bed h a s a t h i n ca rbonaceous c l a y - s t o n e p a r t i n g toward t h e b a s a l p o r t i o n . I ron- s t o n e nodu les occur l o c a l l y wi th t h e roof and f l o o r m a t e r i a l s . S m e burn w i t h i n immediate a r e a . S e e app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

Ou tc rop l o c a t e d on west w a l l of S h o r t Creek, a sou thward- f lowing t r i b u t a r y of Cache Creek. Rapid v e r t i c a l and l a t e r a l changes i n l i t h o l o g i c f a c i e s . C o a l s t h i n , h a r d , d u l l , and b locky . Overburden i n c l u d e s a c l a y s t o n e w i t h d i s t i n c t i v e c o a l i f i e d r o o t l e t s toward t h e f o p of t h e a t r a t i - g r a p h i c sequence . S e e app. B f o r d e s c r i p t i o n o f c o a l - b e a r i n g s e c t i o n .

Outc rop No. of Maximum Loca le L o c a l e Loca le s e c t ion c o a l c o a l bed

no . name code Townsh ie Range S e c t i o n t h i c k n e s s beds t h i c k n e s s Dip

38 P r t e r s v i l l e PA2 2 7 8 I 8 V a r i e s 1 4 f t Near a r e a l a t e r a l l y v e r t i c a l

G e n e r a l cormnents

P o s s i b l e v o l c a n i c a sh p a r t i n g i n c e n t e r of c o a l seam. Coal woody. A da rk -g ray ca rbonaceous , f e l d s p a t h i c graywacke s t a n d s i n r e l i e f abou t 1 5 f t above c o a l bed. Exposure on sou thwes t u a l l of t r i b u t a r y of Sou th Fork Creek on t h e s o u t h e a s t f l a n k of P e t e r s H i l l s . See app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

39 P e t e r s v i l l e PA3 2 7 8 a r e a

2 f t o f 45' c o a l s e p a r a t e d by 0 . 5 - f t p a r t i n g

Outc rop l o c a t e d on P e t e r s Creek n e a r Lampoon Pond. Pebb ly . c o a r s e - g r a i n e d s a n d s t o n e roof and f l o o r exposed .

40 S a t u r d a y SCI 18 13 1 15 f t Creek

Banded c l a y s t o n e u n i t benea th c o a l exposed a t l o c a l e SC2. Ttir u n i t c o n t a i n s l a r g e ova l - shaped c o n c r e t i o n s ( u p t o 5 f t i n d i a m e t e r ) u i t h ha rd s a n d s t o n e c e n t e r s . Some of t h e c o n c r r t i o u v have abundant c o a l band ing and ca rbonaceous r o o t , b r a n c h , and l e a f i m p r e s s i o n s , o t h e r s have i r o n - r i c h ( h e m a t i t e ) c o r e s .

41 S a t u r d a y SC2 18 I 3 2 50 f t Creek

P o b s i b l e f l o w - r o l l ( b a l l and p i l l o w ) s t r u c t u r e s e x h i b i t e d a t a ~ r o m i n e n t l edge abou t 6 f t below t h e b o t t u o of t h e c o a l seam. See app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

42 S a t u r d a y SC3 18 I 3 2 4 0 f t Creek

-4 1 43 S a t u r d a y SC4 18 13 2 90 f t

Creek

Channel c u t - o u t ( exposed i n c r o s s s e c t i o n ) a t t h e u e s t s i d e of t h e o u t c r o p ; c h a n n e l f i l l e d u i t h s a n d s t o n e and c o n g l o m e r a t e . See app. B fo r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

3 f t ; cop 25' 2 b e d s s e p a r a t e d by 2 - f t p a r t i n g

Ovsrburden l a r g e l y covered bu t c l a y s t o n e roof o f t o p seam exposed by t r e n c h i n g . One t h i n ( 0 . 3 f t ) s t r i n g e r of e x t r e m e l y ha rd c o a l e x h i b i t s con- c h o i d a l f r a c t u r e -- p o s s i b l y a canne l c o a l . See app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

44 Skuen tna SH 22 15 23 6 0 f t ?.,only Upper 6' R ive r exposed upper seam 2 f t ;

Sean ac- lower seam c e s s i b l e approx

5 f t exposed

Second seivo o f c o a l c r o p s out abou t 100 yd t o u e s t a t s t r e a m l e v e l . C l a y s t o n e roof and c a r - bonaceous s h a l e f l o o r exposed . Coal pre- d o m i n a n t l y d u l l , p l a t y . l o c a l l y bony; q u a l i t y d e t e r i o r a t e s t o w ~ r d b a s e of seam. S e e app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

45 Sunf lower SC 2 7 12 26 7 0 f t Creek

I Over Top 25'. 50 f t b a s a l

p a r t o f bed

;gPrrox

Lower p o r t i o n o f bed s lumped. Roof and s e a t r o c k o f coa l not e x p o s e d . Appears t o be ve ry l o c a l i z e d , Lying nea r Mesozoic r o c k s . See app 8 f o r d e s c r i p r i o r ~ of c o a l - b e a r i n g s e c t i o n .

46 T a l a c h u l i t n a TR 19 12 21 l o f t I R ive r

Metamorphosed J u r a s s i c - C r e t a c e o u s g r e e n s t o n e r o c k s a r e f a u l t e d and jux taposed a g a i n s t coa l abou t 100 f t ups t ream. See app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

Located n o r t h e r n e x t r e m i t y of Mount S u s i t n a . Two seams exposed bu t s e c t i o n p robab ly r e p e a t e d . C l a y s t o n e roof dnd f l o o r we l l exposed . See dpp . B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

47 Wolver ine WCI 17 9 1 V a r i e s 2 Creek l a t e r a l l y

7 f t Nearly v e r t i c a l

C l a y s t o n e roof of upper s e m c o n t a i n s d i s t i n c t i v e i r o n - r i c h ( h e m a t i t e c o r e ; l i m o n i t e r im) s e p t a r i a n nodu les t o 2 - in . i n d i a m e t e r . See app. B f o r d e s c r i p t i o n of c o a l - b e a r i n g s e c t i o n .

48 Wolver ine UC2 I7 9 24 V a r i e s 2 Creek l a t e r a l l y

2 f t S t e e p

APPENDIX B Geologic columns of described coal-bearing sections within the Kenai Group.

BELUGA RIVER SEAMS SITE: BR1

LITHOLOGIC DESCRIPTION

23 Coal (inaccessible): section discontinued.

22 Sandstone, clayey, medium-gray (N5), medium-grained, firm.

21 Claystone, slightly sandy, lightolivegray (5Y6/1), streaked olive-gray (5Y4/1), firm.

20 Coal, brownish-black, dull, bony, hard.

1 9 Sandstone. slightly clayey, olive-gray (5Y4/1) with grayish-black (N2) coak inclusions. medium-grained with disseminated, very fine muscovite, friable.

18 Claystone. slightly sandy, light-olive-gray (5Y611) with medium-olivegray (5Y 511) t o olive-gray (5Y4/1) streaks. finely disseminated black orgmic matter and threadlike stringers of coal, locally iron-oxide-stained.

1 7 coal. black, dull, platy, bony. hard.

1 6 Sandstone, lightolive-gray (5Y611) with black (Nl ) coaly inclusions, mediunraained, organic, firm.

1 6 Sandstone, clayey, lightolive-gray (5Y5/1), medium- grained, disseminated black organic matter and flne muscovite, locally friable.

1 4 Sandstone, medium-gray (N5), medium- t o coarse-grained. abundant disseminated black organic matter ("salt and pepper"), friable, soft.

1 3 Claystone, sandy, lightolive-gray (5Y611) with Pale yel- 1owish;orange (10YR8/6) mottling, firm but weathered soft locally.

1 2 Coal, black. dull, platy. hard. bony.

11 Sandstone. medium-oiivegray (5Y5/1), speckled white (N9) and black (Nl), organic, medium-grained, hard with coal spars at top: below sandstone. medium gray (N5). medium grained, weathered. friable, soft.

1 0 Claydone, sandy, medium-olive-gray (5Y 511) wlth olive- black (5Y211) streaks, predominantly. and sandstone. clayey. medium-gray (N5), medium-aained, firm, in te r bedded with few thin (less 0.5 ft) coal stringers.

9 Shale, carbonaceous, brownish-gray (5Y4/1), firm to hard, iron-rich, slightly W e .

8 Coal. black, dull. hard. bony.

7 Claystone, sandy, medium-olive-gray (5Y511) with fine brownish-black (5YR2/1) coaly inclusions, firm, Pre- dominantly, but interbedded with sandstone, clayey, medium-gray (N5), medium-grained, locally weathered and friable, and thin (less 0.5 ft) coal stringers.

6 Coal (inaccessible).

5 Sandstone, medium-gray , medium- to coarse-grained. hiable, firm.

4 Coal (inaccessible).

3 Claystone, sandy, medium-gray, firm, and sandstone, clayey, medium-gray. medium-grained, soft to firm interbedded.

2 Parting, claystone, sandy, brownish-gray (5YR4/1) with dark-gray (N3) coaly inclusions, h.

1 Coal, black, dull, platy, woody, locally bony.

CANYON CREEK SEAM SITE CnC5


7 Roof covered and inaccessible.

6 Canyon Bed: coal. black. dull. blocky with few vitrain bands. hard; locally platy and ashy.

SEATROCK 5 Claystone. sandy, olive-black (5Y/1). carbonaceous, firm.

4 Claystone, pinkish-Bay (5YR811) with grayish-black (N2) to black ( N l ) coaly inclusions, locally carbonaceous. rooted, weathered and soft.

3 Shale, carbonaceous, black (Nl ) , fissile, higbly weathered, soft.

2 Claystone, slightly sandy, pinkish-gray (5YR811) with grayish-black (N2) coaly inclusions and black (Nl ) dis seminated organic matter. firm; 0.2 ft band of shale, carbonaceous, black (Nl) , fissile, highly weathered and soft in center of unit.

1 Claystone, slightly sandy, pinkish-gray (5Y R8/1) with black (Nl ) coaly inclusions and local dark-yellowish- orange (lOYR616) mottlhg. firm.



Boulders (diamicton) up to several feet in diameter.

Parting. claystone (possibly volcanic ash). pdeyellowish- orange (10Y R8/6) to dark-yellowish-omnge (10Y R6/6). firm .

Coal, black. dull, very hard, platy, with distinctive sur flcial-weatheling pattern similar to drusy quartz in ap- pearance.

SEATROCK (underclay): claystone, slightly sandy, light olivegray (5Y6/1) with dazk-yellowish-brown (10YR412) organic inclusions, carbonaceous plant fragments, micaceous, firm.



Covered interval directly above roof but includes boulders (diamicton) to several feet in diameter toward tap of section.

Roof; claystone, slightly sandy, olive-gray (6Y4/1), carbonaceous, soft

Coal. black. dull. block^. hard, quality of coal deteri- orates significantly in basal 2-3 it.

SEATROCK Shale. carbonaceous, brownish-black (5YR2/1), soft, smutty. Claystone, sandy. Uto l ive-gray (5Y6/1), slightly carbonaceous, especially toward top, micaceous, soft to firm.

CAPPS COAL SEAM SITE C G3


Surficial cover; predominantly a brown sandy loam.

Claystone, olive-black (5Y2/1) t o brownishmay (5YR4/1), carbonaceous, breaks with blocky conchoidal fracture. firm, locally has gale-yellowish-orange (10YR8/6) to light-brown (5YR5/6) goethite staining along weathered surfaces and fracture planes.

Shale, carbonaceous, brownish-black (5YR2/1) to olive black (5Y2/1) to grayish-black (N2). firm to soh. locally fissile with thin interbedded lenses (less 1 in.) of sandstone, medium-gray (N5). coarse-aalned, and coal ( a p proximately 1 in. thick), black, bony, platy, soft and weathered.

Claystone, slightly sandy to sandy, medium-gray (N5). massive, firm, blocky conchoidal hacture and abundant iron-oxide staining along hacture planes and weathering surfaces.

Sandstone, light.olivegray (5Y6/1) to medium-olive-gray (5Y511). coarse-grained, vew hard, calcareous, with abundant plantleaf fossils, pale-yellowish-orange (10YR8/6) iron-oxide staining along central (2 in. thick) band.

Clay stone. olive-black (5Y 2/1), massive, firm, with abundant black, carbonaceous. fossil-leaf films, l o c d y with moderatered (5R4/6) to dusky-red (5R3/4) hematitic oxidation staining.

1 Shale, black (Nl ) to brownish-black (5YR2/1), slightly carbonaceous, fissile, soft to firm, locally highly weathered.

2 Claystone, moderate-brown (5YR3/4) with black (Nl ) coaly inclusions, soft to firm, breaks with conchoidal fracture, rounded limonite on hematite nodules t o 2 in. diameter, thin streaks and contorted laminae of black carbonaceous shale.

3 Shale. carbonaceous. black (Nl ) with light-brown (5YR5/6)-weathering stains, f k d e , soft.

4 Claystone, olive-say (5Y4/1) to olive-black (5Y2/1), firm t o soft. with blocky fracture pattern.

Capps Seam: coal, black, dull. firm to hard, locally with thin (less 3 in.) vitrain bands, surfaces and fractures covered with abundant iron-oxide and sulfate stains, local siderite.

CAPPS SEAM SITE CG4


Surtlcial cover; unconsolidated light-brown sand and sandy loam.

Coal (top 2 ft), black, soft, highly weathered, and shale. carbonaceous. black (Nl), fissile, firm.

Partin& claystone, dark-may, carbonaceous, soft.

Capps Seam; coal. black, predominantly dull and blocky but locally bony and platy with increasing vitrain bands toward basal portion.

Parting: claystone (possibly volcanic ash). lightbrowniah- Way (5YR6/1), finn.

SEATROCK (underclay) Claystone. medium-olivegray (5Y511) with grayish-black (N2) carbonaceous inclusions, locally slightly W e , soft to tirm.

Section down to level of Capps Creek largely covered with talus and regolith but predominantl~ sandstone, medium-gray (N5). medium-grained. friable but firm, and claystone, sandy. medium-gray (N5), soft to firm, breaks with conchoidal fracture.

CAPPS CREEK SEAMS CAPPS GLACIER AREA

SITE CG6


Surflcial cover.

Sandstone, medium-gray, medium- to coarse-!grained. hard, weathered with light-brown to orange-iron~xide staining.

Waterfall Seam.

Claystone, medium-gray. firm.

Capps Seam.

Lower extent of section down to level of Capps Creek.

CHUITNA RIVER SEAM SITE CR3


Baked shale and varicolored clays weathering from it.

Chuitna Bed (partid exposure, basal portion); coal, black, dull. block^, highly weathered.

SEATR OCK (underclay) Claystone, sandy, medium-lighbaay (NB), black carbonaceous leaf impression% soft.

Section discontinued at water level.



Coal, black, dull, blocky, highly weathered with abundant orange-limonite staining.

PARTING Claystone, light-olive-gray (5Y6/1), locally carbonaceous, iron-oxide staining. firm.

Coal, black, dull, blocky, hard.

Section discontinued at creek level.

CHUITNA RIVER SEAM SITE CRS


ROOF: Sandstone. Wt-grayish-yellow, medium- t o coarse- grained, weathered, locally limonite-stained, pockmarked differential-weathers surfaces (anastarnosis).

Chuitna Bed; coal, black. dull. hard, blocky, basal 1 ft appears burned.

SEATROCK (underclay) Claystone, sandy, medium-gray, firm.

Sandstone, medium-gray, medium- t o coarsegrained, hard, with quartz-pebbleconglomerate interbeds, local yellow to orange iron-oxide staining.

Covered interval to water level.



Roof of coal inaccessible.

Chuitna Bed; coal. black, hard, platy. dull, locally bony.

Parting (possibly volcanic ash): claystone, silty. olive- black (6Y2/1), weathers t o grayish-red (10R412). firm. breaks with conchoidal fracture.

Coal below parting predominantly dull and blocky, ash content appears significantly less than in upper portion; local minor pyrite and weathered-sulfate coatings.

SEATROCK Sandstone, Light-olive-gray (5Y 611) t o pinkish-gray (5YR8/1), medium-grained, relatively clean, predominantly quartz with disseminated black organic matter, subrounded t o angular grains, friable, weathered, soft. Minor (near 0.5 ft) partings of quartz-pebble conglomerate and conglomeratic sandstone toward top of section beneath coal bed.

CHUITNA RIVER SEAM SITE CRlO

v v v V V " V V V i

V V V V V

.Q 0 o'', '.~'o'~" 0 . 0 0. a' 0 . a . . . . . . . . . . . I " ' , I


Surficial cover; brown sandy loam, sand, and gravel.

Burn (clinker, "red do&" scoria, porcellanite).

Cod, predominantly dull and blocky with thin (less 2 in.) vitrain bands and bony layers (to 0.5 it), hard.

Shale, carbonaceous. olivegray (5Y4/1) with lightbrown (5YR5/6)-oxidation staining, firm.

Claystone, dark-'&ray (N3). carbonaceous, soft, 1ocaJ.l~ weathered with lightbrown (6YR5/6 )-limonite staining.

Sandstone, medium-gray (N5), medium- to coarse-grained, locally conglomeratic with interbedded quartz-pebbleconglomerate bands, especially toward the basal portion of outcrop and light-brown (5YR5/6)-iron-oxide staining.

COAL CREEK SEAM SITE CC2

LITHOLOGIC DESCRIPTlON

Surficial cover: sand, loamy, medium-grayish-brown. soft with abundant rootlets.

Diamicton: boulders and cobbles predominantly less than 1 ft in diameter.

Shale, carbonaceous, black, flssile, soft to firm, locally goethite-stained.

Coal, black, hard, dull. blocky.

Claystone, sandy, lightgray, soft to firm.

Sandstone, lightsray, medium- to coarse-grained, friable, firm.

Section discontinued at Coal Creek water level.

FAIRVIEW MOUNTAIN SEAMS SITE FM1

Sheet 1 of 7 LITHOLOGIC DESCRIPTION

Surficial cover; loam, sand, brown, disseminated black- organic matter, soft, rooted.

Sand, yellowish-gray , m e d i u m - m e d , slightly clayey. soft, yellow- to orange-iron-oxide mottling. rare extremely fine disseminated muscovite.

Claystone, lightgray, soft, with abundant yellow-iron- oxide staining.

Claystone, sandy, medium-gray, fine disseminated muscovite and black organic matter, firm; thin (1 in.) stringer of coal, black, dull. very hard forming base.

Sand, yellowish-gray. coarse-grained, locally contains d b seminated organic matter and abundant threadlike stringers of black carbonaceous material. weathered. loose.

Conglomerate. petromictic, light to medium-aay: sand matrix, coarse-grained. angular kagments, poorly cemented to loose, predominantly quartz and chert: "gravel" mostly in size range less 0.5 ft and includes various igneous lithologies. coal gravels, and cobbles: interspersed within unit are thin (less 2 in,) stringers and pockets of clay, light- to medium-gray. soft, plastic. Thin coal stringer (less 1 in.) at base of conglomerate.

FAIRVIEW MOUNTAIN SEAMS SITE FMl


1 Clay stone, dark-gray, slightly sandy, carbonaceous, firm.

2 Shale, carbonaceous, black, M e , soft to firm, weathered.

3 Claystone, medium-brownish gray, slightly carbonaceous and sandy. firm.

4 Claystone, medium-gray, very sandy, firm.

6 Sand. medium-gray, medium-, to coarse-grained with abundant limonitic and hematitic staining and black coaly stringers and bands.

6 Conglomerate, petromictic (as above) but with abundant coal cobbles and gravel inclusions: few graphite nodules t o 0.5 ft diameter near base directly above coal: also contains few clean orthoquartzite-sandstone cobbles.

7 Shale. carbonaceous, black (Nl), M e , firm, weathered with abundant iron-oxide staining.

F Seam

8 Coal, black. dull. platy, ashy, weathered, poor-quality.

9 Partings, claystone, olive-black (5Y2/1), carbonaceous, slightly sandy, firm, thin (less 2 in.) coal bed in basal portion.


Sheet 3 of 7


F Seam Coal, black, dull, platy, bony, poor quality with thin laminae of claystone, sandy, medium-gray, soft and shale, carbonaceous, black, fissile, soft, intercalated for top 2 ft; lower 0.5 f t dull. blocky, hard coal.

SEATROCK (underclay) Claystone, sandy, medium-light (N6)-gray, firm, limonite surface stains, breaks with conchoidal fracture ;becomes more sandy toward basal portion with few interspersed sand lenses (less 1 in.), light t o medium-gray, medium- grained, micaceous, locally limonite-stained.

Sand, yellowish-gray, fine- t o medium-pained. soft, loose with disseminated fine black organic matter and musco-- vite; also smutty coal stringers (around 0.5 in.) locally.

Conglomerate, petromictic pebble-cobble, with coarse- grained. poorly lithified sand matrix; pebbles and cobbles predominantly 2 in. t o less than 0.5 ft of various igneous lithologies (including aanite), abundant coal, quartz. chert, and clean orthoquartzite sandstone; pebbly sandstone lenses to 1 ft thick locally throughout this section.


Sheet 4 of 7


Shale, carbonaceouq black lN1) with light-brown (5YR516) weathering stains, fissiie, firm.

E Seam Coal, top 2 12, black, dull, platy, weathered, firm; basal portion dull. blocky, bony, hard.

SEATROCK (underclay) Claystone, olive-gray (5Y4/1) with black (Nl ) coaly in- clusion and local light-brown (6YR516) mottling. firm. breaks with conchoidal hacture.

Sandstone. medium-gray, fine-grained. friable, stightly clayey. with fine disseminated muscovite and black organic fragments.

Sand. medium-gray, medium-grained, loose, soft with dis seminated, extremely fine muscovite and black organic matter, locally limonite-stained.



Claystone, sandy to very sandy. medium-gray, firm with abundant limonite staining.

Sand, light- to medium-gray, fine- to medium-grained. slightly clayey, soft, with disseminated fine muscovite flakes and black organic matter.

Clay stone, sandy, medium-grayish-brown. firm, local iron-oxide staining.

Claystone, very sandy, light-gray, firm.

Sandstone, clayey, light-gray, medium-grained, Biable soft, with tine disseminated black organic matter and coaly streaks.

Claystone, sandy. light-gray, firm, with weathered iron- stone nodules t o 2 in. diameter.

Shale, carbonaceous, dark-gray (N3) t o black (Nl) , clayey. f W e . soft.

D Seam Coal. black, dull. hard, platy, bony.

SEATROCK (underclay) Claystone, sandy, olive-gray (5Y411) with grayish-black (N2)-threadlike stringers, firm, breaks with conchoidal fzactue, locally limonite-stained.


Sheet 6 of 7


ROOF Shale, carbonaceous, brownish-black (5YR2/1), fissile, weathered. soft.

C Seam Coal, black, dull, hard, blocky at top to bony and platy at basal portion

SEATROCK (underclay) Clay stone, very sandy, light-olivegray (5Y 611). firm.

Claystone, sandy, medium-gray, tirm, with very tine dkt seminated muscovite.

Sand, medium-gray, very coarse-grained, angular to subangular grains, disseminated black fine coal fragments, friable. loose, weathered.

Conglomerate, petromictic, pebble-cobble (including coal): sand matrix, very coarse-grained. poorly lithified with fine disseminated coal fragments: local coarse grained pebbly sand lavers up to 1 ft thick.


Sheet 7 of 7


Claystone, medium-gray but grades to dark-gray and carbonaceous in basal portion, soft to firm: pockets and stringers of coal near bottom.

Section discontinued but remaining section includes two poorly exposed and highly weathered coal seams (A and B); see FM2.



Surficiciat cover predominantly a sandy loam grading to sand at base.

B Seam 1 & 2 Coal. top 0.5 ft black. very soft. smutty: bottom 3 f t

very hard and bony, breaks blocky and locally with conchoidal fracture,

3 Shale. carbonaceous, bmwn, black (6Y2/1), clayey. soft.

4 Claystone, olive-eray (5Y411) with moderate-brown (6YR414) plant-fragment inclusions. slightly silty, soft t o firm,

6 Claystone, sandy. Ilghtgray, soft, with very fhe d* seminated muscovite.

6 Claystone, medium-gray (N5) with black (N1) inclusions and dark-yellowish-orange (10YR616) mottling. slightly sandy and carbonaceous, firm.

A Seam 7 Coal, black to brownish-black. lignitic toward base, poor

quality: thin (less 1 in.) partings of claystone, brown. firm, and shale, carbonaceous, black, fisnile, firm, toward top.

8 Claystone, sandy, olivegray (5Y411) with grayish-brown (5YR312) and blackish-red (5R2/2) plant-bagment inclusions, disseminated extremely fine muscovite, firm.

9 Coal stringer, black, hard, woody.

1 0 Claystone. very sandy, medium-gray (N5), extremely fine disseminated muscovite, firm.

11 Conglomerate, petromictic, pebblecobble; pebbles, gravel% and cobbles predominantly less than 3 in. in diameter consisting of quartz, chert, orthoquartzite sandstone, coal, and granite in a poorly lithified, coarse grained, sand matrix; also includes pebbly. coarse-grained- sand intervals to several feet thick, yellowish-gray, an- t o subangular with disseminated black organic matter.

Section described down to level of Cottonwood Creek.

JOHNSON CREEK SEAM SITE JC2


Section includes 50-ft ledge of sandstone, conglomerate, two other thin coal beds, gravel, and surficial cover.

Shale, carbonaceous, black, hard. fkdle, local iron-oxide staining.

Coal, black, very hard, bright, glwy fracture, semian- thracitic, conchoidal fracture.

Shale, carbonaceous, olive-black (5Y2/1) to black (Nl). tissile, firm.

Claystone, olive-black (5Y2/1) with black (Nl) coaly stringers, firm. Approximately 8 ft of claystone is followed downsection to creek level by sandstone, medium-gray, medium-grained, hard.

JOHNSON CREEK SEAMS SITE JC3


Overburden section of approximately 30 ft of pebbly sandstone, conglomerate, and unconsoLidated surficial cover, locally highly washed and eroded with covered intends.

Coal, black, dull. hard, bony, locally platy and weathered with iron-oxide staining.

, Parting: claystone. light-brownish gray (5YR611) with dark-gray (N3) carbonaceous inclusions and coal stringers, firm.

Coal as above.

Claystone, sandy. light-olive-gray (5Y6/1) with olive- black (5Y2/1) carbonaceous inclusions and dark-yellowish-orange (10YR616) mottling; becomes less sandy and more silty toward base.

Claystone, dark-yellowish-brown (10YR4/2) with dark- gray (N3) carbonaceous stringers and dark-yellowish- orange (10YR616) mottling. firm.

Coal, black, hard, dull, bony, platy.

Claystone, sandy. llght-olive-gray (5Y611) with black (Nl ) coaly inclusions and local dark-yellowish-orange (10YR6/6) mottling, firm.

PETERSVILLE AREA SEAMS SITE PA1


1 Sandstone and sand, light-olivegray (5Y6/1) with black (N1) coaly inclusions and local pale-yellowish-orange (10YR8/6) mottling, coarse-grained, angular to subrounded, predominantly quartz but arkosic. weathered. friable. soft.

2 Claystone, sandy, moderate-yellowish-brown (10YR5/4) dark-yellowish-orange (10YR616) and pale-yellowish- orange (10YR8/6) streaked, soft t o firm, with distinctive gravels of brown amber and codified wood laths.

3 Clay, lightolive-gray (5Y6/1). very soft, plastic. pliable.

4 Claystone, medium-gray (N5) with grayish-black (N2) coaly inclusions, firm. breaks in conchoidal blocks.

5 Coal. black. hard, dull, bony.

Shale, carbonaceous, medium-gray (N5) to grayish-black (N2). firm with transitions to claystone, m e d i m - to dark- gray, locallv carbonaceous. silty to sandy, soft to firm.

Claystone, light-olive-gray (5Y6/1) with dark-gray (N3) to black (Nl ) coaly inclusions and lightbrown (5YR5/6) to moderate-brown (5YR3/4)-oxidation staining. slightly sandy, soft, with few inches of shale, grayish-purple (5P412). bounding top and basal portions.

Sand, clayey, lightolive-gray (5Y6/1), medium-grained, soft. loose.

Claystone, sandy, light-olive-gray (5Y6/1), soft.

Sandstone, lightolive-gray (5Y6/1) with medium-dark- gray (N4) carbonaceous plant fragments and films, firm, clayey, with interbedded claystone, sandy, medium-gray (N5). local iron-oxide staining.

Sandstone, light-olive-gray (5Y6/1) predominant (but "salt and pepper"), coarse-grained, subangular to wb- rounded grains, locally iron-stained (limonitic) bands, fi'iable, soft; thin (4 in.) layer of claystone, light-gray (N7). silty, soft in center. .

Claystone, sandy, medium-olive-gray (5Y 511) and dark- yellowish-brown (10YR4/2) streaked, and black (Nl ) threadlike coal stringers and fragments, soft; grades t o claystone, medium-gray (N5) to moderateyellowish- brown (10YR514) at base with stringers of codified wood.

Claystone, pale-yellowish-orange (10YR8/6) to yellowish- gray (5Y7/2) with light-brown (5YR5/6)-weathering streaks. firm.

Sandstone, yellowish-gray (5Y7/2) with local dark-yellowish-orange (10YR6/6) mottling. medium-grained, hiable, firm.

Claystone, very sandy, light-olive-gray (5Y6/1) with fine grayish-black (N2) and light-brown (5YR5/6) inclusions. soft.

Claystone, oliveblack (5Y2/1) with grayish-black (N2) coaly inclusions, firm.

Claystone. sandy, grayish-yellow (5Y814) to yellowish- gray (5Y7/2), soft; sandstone, light (N7)- to medium- gray (N6). medium-grained, hiable, soft. with abundant limonite staining, and weathered loose sand, medium- to coarse-grained with iron-oxide staining.

Claystone, sandy, light-olivegray (5Y6/1), £inn, with a thin (approximately 0.5 in.) coal stringer along top.

Sandstone, yellowish-gray (5Y7/2). medi&- to coarse- grained. friable, soft to firm.

Claystone, olivegray (5Y4/1). slightly sandy, soft to firm.

Sandstone, yellowish-gray (5Y8/1) with grayish-black (N2) inclusions ("salt and Pepper"), medium-grained, soft, and claystone, sandy, firm.

Claystone, lightolivegray (5Y6/1), firm, lo call^ silty to slightly sandy with common hematitic surface staining.

Claystone and shale, interbanded, carbonaceous, dark- gray (N3) to olive-black (5Y2/1), fkn.

PETERSVILLE AREA SEAMS SITE PAI

Sheet 2 of 3


Sandstone and weathered loose sand, yellowish-gray (5Y7/2) with pale-yellowish-orange (10YR8/6) mottling. medium-grained, with disseminated black organic matter: grades to coarse-grained, loose, dark-yellowish- orange (10YR6/6),sand at base.

Claystone, olive-gray (5Y4/1), slightly sandy, firm with abundant limonite and hematite staining.

Sandstone. light-olivegray (5Y6/1) with dark-yellowish- orange (10YR6/6)-weathering stains, medium-grained, locally slightly clayey, friable.

Claystone. light-olive-gray (5Y6/1) to medium-olive- a a ~ (5Y5/1), slightly silty, firm.

Shale. carbonaceo& medium-gray (N5) to grayish-black (N2). M e . firm. Sandstone, clayey, light-olivegray (5Y6/1) with l ight brown (5YR5/6) mottling. abundant disseminated black organic matter and muscovite.

- Sand. yellowish-gray (5Y7/2), medium-grained, soft. loose with abundant limonite staining.

Claystone, light-gray (N7). slightly sandy, soft.

Coal, black, firm, dull, platy.

Claystone, light-gray (N7). slightly silty, soft.

Coal, black, dull, hard, bony. . -

clay;one, sandy, light-gray (N7) with black ( N l ) coaly inclusions and local gale-yellowish-orange (10YR8/6) mottling, and soft, at top: grades to sand. medium-gray (N5), finegrained, clayey, loose, soft toward basal portion.

Sand. grayish-orange (10YR7/4) and light-olivegray (5Y6/1), medium-grained, soft with abundant limonite staining and disseminated black organic matter.

Claystone, medium-olive-gray (5Y5/1), slightly sandy to sandy, fum-soft.

PETERSVILLE AREA SEAMS SITE PAl -

Sheet 3 of 3


C -

Claystone, sandy. light-gray (N7). firm.

Section discontinued at Short Creek level.

PETERSWLLE AREA SEAM SITE PA2


Claystone. medium-gray (N5), firm.

Graywacke, predominantly olive-gray (5Y4/1) with lightolivegray (5Y 611) inclusions, carbonaceous, feld- spathic; stands in relief within softer claystone unit.

Claystone, medium-gray (N5). slightly carbonaceous and silty. firm.

Shale, carbonaceous, black (Nl ) , W e , firm.

Coal, black, dull, hard. blocky in center section, woody toward top and basal portions.

Claystone (possibly volcanic ash), medium-light-gray (N6) with grayish-black (N2) coaly inclusions and dark- yellowish-orange (10YR6/6) mottling. firm.

SEATROCK (underclay) Claystone, sandy, medium-gray (NS), firm, locallY limo- nitestained.

- - . . . . . . . a . . . . . . . . .o. .. I::. . . . . . . . : ? ' I

PETERSVILLE AREA SEAM SITE PA3


ROOF Sandstone, pebbly (quartzlchert), moderate-brownish- Bray (6YR511). coarse-grained, granular. friable.

Coal, brownish-black, dull. woody. h.

Parting, shale, carbonaceous, olive-black (5Y211) with grayish-black (N2) coaly inclusions and moderate-brown (6YR414)-weathering stains, W e , iirm, and claystone. dark-gray (N3). carbonaceous, soft, and smut, black (Nl) .

Coal, as above.

SEATROCK Sandstone, pebbly, as in roof.

SATURDAY CREEK SEAM SITE SC2


1 Surficial cover, brown sandy loam.

2 Sandstone, medium-gray, medium-grained. with yellow- iron-oxide staining locally; interbands of quartz-pebble conglomerate (pebbles to 2 in. diameter) up to 0.5 ft thick.

3 Conglomerate, monomictic, quartz-pebble, hard, well- cemented.

4 Sandstone, medium-yellowish-gray, medium-grained. hard, with surficial iron-oxide-weathering stains.

5 Claystone, dark-gray, carbonaceous, firm.

6 Claystone, sandy, light-gray, firm.

7 Claystone, medium-light-my (N6) with black (Nl) coaly inclusions and lightbrown (5YR5/6)-weathering stains. firm. breaks conchoidal fracture.

8 Coal. black, blocky, hard; middle has black. carbonaceous shale partings.

SEATROCK (underclay) 9 claystone, light-gray, sl iehtl~ sandy, firm.

10 Sandstone, medium-yellowish-gray, medium-grained. very hard, surficial iron-oxide-weathering stains.

SATURDAY CREEK SEAM SITE SC3


Roof not exposed: covered interval.

Coal, black, dull, platy, bony, highly weathered on surface.

SEATROCK Claystone, brownish-gray (5YR4/1), locally carbonaceous, firm t o soft, with light-bmwn (5YR5/6) iron- oxide staining : interbedded with shale, carbonaceous, black (Nl), fissile, firm.

Claystone, light-gray (N7) t o lightolive-gray (5Y6/1), locally slightly carbonaceous, firm to soft, breaks with conchoidal &actwe.

Sandstone and sand, yellowish-gray (5Y 712) to lighG ' olive-gray (5Y6/1), medium- t o coarse-grained, angular

to subrounded grains, disseminated fine black organic matter and muscovite, but predominantly quartz sand, h b l e to loose.

SATURDAY CREEK SEAMS SITE SC4


Covered interval for 30 ft to top of ridge.

Claystone, sandy, olive-gray (5Y4/1) with dark-yellowish-orange (10YR616)- to light-brown (5YR5/6)- weathering mottles.

Coal. black, hard, bright, blocky.

Claystone. grayish-black (N2). carbonaceous, firm. rooted, and shale, carbonaceous, dark-gray (N3) t o black (Nl), fissile and firm, intercalated.

Coal, black, bright, hard, platy; becomes bony toward basal portion.

Claystone, sandy, lightolive-gray (6Y6/1) with black (Nl ) coaly inclusions and local ddk-yellowish-orange (10YR616) weather banding, firm.

Shale. carbonaeous. gray--black (N2). fissile. weathered and soft. Coal. black, very hard, breaks conchoidal fracture, polr sibly cannel coal.

Shale, carbonaceous, medium-dark-gray (N4) to black (Nl). fis9ile. firm. Claystone, lightolivegray (6Y6/1), with disseminated black organic matter. rooted, hematite-stained, soft.

Claystone, lightolivegray (5Y611) with medium-dark gray (N4) coaly inclusions and local dark-yellowish- orange (10YR6/6) mottling. slightly sandy. breaks with conchoidal fracture. Claystone, medium-olive-gray (5Y511) with black ( N l ) coaly inclusions and local dark-yellowish-orange (10YR616) mottling. firm.

Coal. black. dull, hard, platy. bony.

Claystone, olive-gray (5Y4/1) with dark-gray (N3) coaly inclusions, slightly sandy. firm, locally limonite-stained.

Covered interval for 30 f t down to creek level.

SKWENTNA RIVER SEAM SITE SR1


Surflcial cover; lightbrown sandy loam.

Sand, light-yellow to brownish-yellow, medium-grained, loose, soft, weathered with iron-oxide staining.

Claystone, medium-olive gray (5Y5/1), slightly carbonaceous, firm, breaks with conchoidal fracture.

1 Coal. black. dull. thinly plated. bony. 2 Shale, carbonaceous, dark-gray (N3) to grayish-black

(N2). M e . hinhlv w.eathered. soft. 3 Claystone, sandy, hght-olive-gray (5Y611) with olive-

gray (5Y4/1) streaks, carbonaceous, firm. 4 Sand, yellow to orange, medium-gdned, h w y weath-

ered with iron-oxide staining. disseminated black organic matter. micaceous, loose.

Claystone. sandy, dark-gray, carbonaceous, soft-firm.

SUNFLOWER CREEK SEAM SITE SuCl


Diamicton.

Coal. brownish-black, woody, d m , without partings; lower part of bed (dipping at 50°) probably slumped since upper part of bed dips at only 25O.

Covered interval down to creek level.

TALACHULITNA RIVER SEAM SITE TR1


ROOF Claystone, medium-olivegray (5Y 5/1), abundant limonite and hematite staining, weathers t o yellow and orange shingles and conchoidal blocks, soft.

Coal, brownish-black, dull, woody, ashy, locally U t l Y contorted.

SEATROCK (underclay) Claystone, lightolivegray (5Y6/1) with local light-brown (5YR5/6) mottling and staining.

Section discontinued at water level. Metamorphosed JK greenstone faulted and juxtaposed against coal approximately 100 ft upstream.

WOLVERINE CREEK SEAM SITE WC1


Sandstone, light-olive-gray (5Y6/1) speckled ("salt and pepper") with white (N9) and medium-light-gray (N6). coarse-grained, angular to subangular grains, £riable. sofbfirm.

Claystone, sandy, medium-light-gray (N 6) streaked medium-dark-gray (N4). soft, breaks in blocks, abundant limonite stains along surfaces and joints.

Claystone, grayish-black (N2) with olive-gray (5Y4/1) streaks, carbonaceous, soft, and shale, carbonaceous, black (Nl) , fissile, soft.

Coal, black, predominantly bright, hard, blocky: basal 3 f t highly weathered and limonite-stained.

SEATROCK (underclay) Claystone, medium-gray (N5) with abundant dark-yellowish-orange (10Y R6/6) staining, soft.

WOLVERINE CREEK SEAMS SITE WC2


1 Sandstone, light-gray (N7) with dark-yellowish-orange (10YR6//) mottles, coarse-grained, locally clayey and slightly carbonaceous, "salt and pepper."

2 Claystone, olive-gray (5Y4/1), soft to firm, breaks in blocky masses, abundant iron-rich (limonite rim, hematite core) septarian nodules.

3 Claystone, brownish-gray (5YR4/1) with grayish-black (N2) streaks and inclusions. soft.

4 Coal stringer, black. hard, platy t o slightly blocky.

5 Shale, carbonaceous, olive-black (5Y211) with dark- yellowish-orange (10YR6/6) mottles, fissile. firm. inter- layered with claystone, brownish-gray (5YR4/1), locally silty, abundant limonite stains along surfaces and bedding planes; central (0.5 ft) layer of sandstone, grayish-brown (5YR3/2), medium-gmhed, hard, iron-stained.

6 Claystone, olive-gray (5Y4/1) with light-brown (5YR5/6) mottles, locally slightly carbonaceous and iron-stained. soft t o firm.

7 Shale, carbonaceous, dark-gray (N3) with lightbrown (5YR5/6)-weathering stains, W e , soft to firm, interbanded with claystone, dark-gray (N3). carbonaceous. soft.

8 .Claystone, dark-yellowish-brown (10YR4/2), slightly silty and carbonaceous, soft.

Coal, black, dull, firm to hard, blocky, weathered locally with abundant iron-oxide staining.

Claystone, very sandy, light-olive-gray (5Y 611). soft, locally with abundant iron-oxide staining; interbanded with sand lenses. light-gray (N7), medium-grained, micaceous. friable. soft.

Sandstone, light-olivegray (5Y6/1) streaked olive-gray, medium-grained, friable, soft, abundant limonite staining; thin (approximately 1 in. thick) interbands of claystone. medium gray (N5). silty, soft. toward top.

Claystone, light.gray (N7). breaks with blocky, conchoidal fracture, abundant iron-oxide staining.

Coal, black, dull. hard, blocky, locally weathered with abundant limonite staining.

Claystone, light-olivegray (5Y6/1), silty, soft.

DIVISION OF GEOLOGICAL AND GEOPHYSICAL SURVEYS · 2006. 11. 5. · potential geologic hazards to...

Documents

Transcript of DIVISION OF GEOLOGICAL AND GEOPHYSICAL SURVEYS · 2006. 11. 5. · potential geologic hazards to...