GEOLOGY OF THE SODA LAKE GEOTHERMAL AREA

Bruce S. Sibbet t

December , 1979

EARTH SCIENCE LABORATORY UNIVERSITY OF UTAH RESEARCH INSTITUTE

420 Chipeta Nay, Suite 120 Sal t Lake City, UT 84108

DOE/ET/28392-34 79-1701.b.1.2.3

ESL-24

MSTPIQUnOH OF Tt!lS DOCUMENT K3 UNLIMITEO o h

DISCLAIMER

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CONTENTS

1 ' PAGE

ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 2 GEOLOGIC SETTING . . . . . . . . . . . . . . . . . . . . . . . . 2 IGNEOUS A C T I V I T Y . . . . . . . . . . . . . . . . . . . . . . . . 6 SUBSURFACE INFORMATION . . . . . . . . . . . . . . . . . . . . . SURFACE ALTERATION AND SINTER DEPOSITS . . . . . . . . . . . . . STRUCTURE . . . . . . . * HEAT FLOW AND TEMPERATURE . . . . . . . . . . . . . . . . . . . CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . .

L i t h o l o g i c l o g o f Chevron Resources Company Soda Lake 44-5

7

8

9

10

10

11

12

14

L i t h o l o g i c l o g of Chevron Resources Company Soda Lake 1-29

L i t h o l o g i c l o g o f Chevron Resources Company Soda Lake 11-33

L i t h o l o g i c l o g o f Chevron Resources Company Soda Lake 63-33

ILLUSTRATIONS

F i g u r e 1 Index map o f C h u r c h i l l County, Nevada . . . . . . . . 3 F i g u r e 2 Geology o f t he Soda Lake area, C h u r c h i l l County,

Nevada . . . . . . . . . . . . . .. . . . . . . . . . . 5 P l a t e 1 Soda Lake w e l l l o g c o r r e l a t i o n , C h u r c h i l l County,

N e v a d a . . . . . . . . . . . . . . . . . . . . . . . . i n p o c k e t

ABSTRACT

The Soda Lake geothermal area i s l o c a t e d i n t h e Carson Deser t ,

wes t - cen t ra l Nevada.

i n t h e pas t , r e s u l t i n g i n su r face d e p o s i t s which have m o t i v a t e d p resen t

geothermal exp l orat i .on. The geothermal anomaly i s i n Qua te rna ry c l a s t i c

sediments wh ich a r e as much as 4600 f e e t t h i c k . The sediments c o n s i s t o f

i n te rbedded d e l t a i c , l a c u s t r i n e , and a1 1 u v i a l sediments.

Hot s p r i n g s a c t i v i t y has occu r red i n t h e Soda Lake area

I

Quate rna ry b a s a l t i c igneous a c t i v i t y has produced c i n d e r cones, p h r e a t i c

exp los ions t h a t formed t h e maar occupied by Soda Lake, and p o s s i b l e d i kes .

Opal d e p o s i t i o n and s o i l a l t e r a t i o n a r e r e s t r i c t e d t o a smal l area two

m i l e s n o r t h o f Soda Lake. The l o c a t i o n o f h o t s p r i n g s a c t i v i t y and t h e

surface thermal anomaly may be p a r t i a l l y c o n t r o l l e d by nor th -no r theas t -

t r e n d i n g f a u l t s . I

1

INTRODUCTION

I

The Soda Lake geothermal a r e a i s l o c a t e d i n the Carson Desert, i n western

C h u r c h i 11 County, wes t -cent ra l Nevada (Figure 1 ) .

Thermal waters were f i r s t d iscovered i n the Carson Desert i n 1903 when a

well d r i l l e d a t the s i t e of an e x t i n c t h o t s p r i n g n o r t h e a s t o f Soda Lake h i t

h o t water a t a d e p t h of 60 f ee t (Gar s ide and S c h i l l i n g , 1979, P. 9 ) .

mixture o f steam and water produced by the well was used t o furnish steam t o a

bathhouse u n t i l sometime a f t e r 1950. The U. S. Bureau of Reclamation and the

U. S. Geological Survey d r i l l ed seve ra l t empera ture g r a d i e n t ho le s over the

Soda Lake anomaly du r ing 1972 and 1973. These h o l e s were d r i l l e d t o a d e p t h

of about 33 m and tempera ture and thermal g r a d i e n t s were measured.

and o t h e r s (1975) r e p o r t e d the results o f this program.

Company became interested i n the a r e a i n the e a r l y 1970s and has d r i l l e d

seve ra l e x p l o r a t i o n ho le s i n the Soda Lake a r e a (Hi1 1 and o t h e r s , 1979) .

Chevron encountered tempera tures i n excess o f 365OF i n e x p l o r a t o r y ho le s ( H i l l

and others, 1979) .

The

Olmsted

Chevron Resources

The p r e s e n t s t u d y was u n d e r t a k e n a s p a r t of t h e I n d u s t r y C o u p l e d C a s e

S t u d i e s Program of the Department o f Energy, D iv i s ion o f Geothermal Energy.

The o b j e c t i v e s of this s tudy a r e t o present the geo log ic set t ing of the YGRA

and the subsu r face informat ion a v a i l a b l e from the Chevron well cu t t ings .

GEOLOGIC SETTING

T h e rocks exposed w i t h i n the Carson Desert c o n s i s t of Quaternary t o

Recent , poor1 y consol i da ted sediments and m i nor basal t i c vol can i c rocks .

2

0 IO 20 30 MILES I I I I

N E V A D A

F i g u r e 1. index m a p of C h u r c h i l l C o u n t y , N e v a d a .

3

I

I

V

During the Quar te rnary the Carson Desert was f i l l e d w i t h l a c u s t r i n e

sediments, a l luvium, wind-blown sand , and i n the southwest p a r t by d e l t a i c and

f l u v i a l d e p o s i t s r e l a t e d t o the Carson River. Morrison (1964) r epor t ed on the

s u r f i c i a l d e p o s i t s . T h e c u r r e n t s tudy emphasizes the subsu r face deDosi ts

w i t h i n the b a s i n .

Lake Lahontan and younger l a k e sediments cover most o f the bas in . Recent

sand dunes, p l aya , and f l u v i a l sediments have covered o r reworked t h e

1 a c u s t r i ne d e p o s i t s i n some a r e a s . Morri son ( 1964) d i v i d e d the Lake Lahontan

d e p o s i t s i n t o seve ra l format ions . T h e Sehoo and Wyemaha formation c o n s i s t s of

l a c u s t r i n e sand , s i l t and c l a y , and the Fa l lon format ions c o n s i s t o f a l l u v i a l

sand and s i l t ( F i g u r e 2 ) . These . format ions could n o t be d i s t i n g u i s h e d i n

d r i 11 c u t t i n g s from ol der Qua te rna ry rocks pene t r a t ed i n the d r i 1 1 hol es.

Bouguer g r a v i t y studies (Wahl , 1965; E r w i n and Berg, 1977) i n d i c a t e t h a t

the depth o f a l l u v i a l f i l l v a r i e s cons ide rab ly a c r o s s the Carson Desert. Wahl

(1965) interpreted 1 ows o f 30 mil 1 i g a l s amp1 i t u d e w i t h i n the Carson Sink

(compared t o g r a v i t y va lues a long the western f r o n t o f the S t i l l w a t e r Range)

t o ind ica te about 10,000 f e e t of a l luvium. A low o f the same ampli tude i s

l o c a t e d s o u t h o f Fa l lon i n the Carson Lake a r e a . Between these two lows,

g r a v i t y and geo log ic d a t a i n d i c a t e a bedrock ridge under thinner a l l u v i a l

cover .

Soda Lake 44-5 and Carson Sink #1 ( F i g u r e 2 1 , l o c a t e d i n the southwest

p a r t of the Carson Desert, pene t r a t ed Quaternary sediments t o a d e p t h of 4600

f e e t .

4

I

To Reno (c T 15 N

a s

E X P L A N A T I O N

11 Opal cemented sand Fallon fm. alluvium-sand, silt

I Ovs 1 Volcanic sand Sehoo fm, Lake sediment sand, El silt, clay

O W J Wyemaha fm. Lake sed., sand r / Contacts generalized from

Morrison, 1964

,,)Linearr on aerial photos

6333 Chevron geothermal test wells Scale 1:62.500

as

/ /

I

036-78 0 63-33

- R 2 7 E . l R.28 E.

\ I \J

I I t

I I I

Os

Figure 2. Geology of the Soda bake area, Churchill Co., Nevada.

. . . . - . . - .. . . . - - . . . . . . .. . -. . . . . . . . . . . . . . . . . . . . . - - - ._ .

Subsurface i n f o r m a t i o n i n t h e Soda Lake area comes f rom s i x ho les,

Chevron 's Soda Lake 44-5, 1-29, 53-33, 11-33, 36-78 and t h e Carson Sink W1

uranium e x p l o r a t i o n h o l e ( F i g u r e 2 ) .

Appendix. The sediments i n t h e d r i l l h o l e s a r e p o o r l y s o r t e d l i t h i c and

a r k o s i c sand, s i l t , t u f f a c e o u s mudstone, c l a y , and g r a v e l . The c o a r s e r

sediments a r e p r o b a b l y d e l t a i c and a l l u v i a l f a n d e p o s i t s o f t h e Carson R i v e r ,

whereas s It, wudstone, and c l a y i n t e r b e d s a r e p r o b a b l y l a c u s t r i n e and p l a y a

sediments

Logs f o r t h e Chevron h o l e s a r e i n t h e

IGNEOUS A C T I V I T Y

Igneous r o c k s i n t h e Soda Lake area c o n s i s t o f b a s a l t i c c i n d e r cones and

d i k e s o r f l ows .

Upsal Hogback, seven m i l e s n o r t h e a s t o f Soda Lake, i s composed o f

o v e r l a p p i n g b a s a l t i c t u f f cones. M o r r i s o n (1964, p. 38) suggested t h a t t h e

cones were o f Wyemaha age (30,000 t o 45,000 y e a r s o l d ) . The b a s a l t i c t u f f i s

o l i v i n e - r i c h , m o s t l y sand t o p e b b l e - s i t e , and was d e p o s i t e d s u b a e r i a l l y

(Mor r ison , 1964, p. 38) .

Soda and L i t t l e Soda Lakes occupy c r a t e r s formed b y r n u l t i o l e p h r e a t i c

e x p l o s i o n s and v o l c a n i c e r u p t i o n s .

l a p i l l i , and l a c u s t r i n e d e p o s i t s (Mor r ison , 1964, u . 71) .

was s u b a e r i a l and pos t -da ted t h e l a s t l a k e r i s e t o t h a t l e v e l .

The c r a t e r r i m c o n s i s t s o f v o l c a n i c sand,

The l a s t e r u p t i o n

A sample o f b a s a l t f rom R a t t l e Snake H i l l , n o r t h o f F a l l o n ( F i g u r e 11,

y i e l d e d a whole-rock potassium-argon age o f 1.05

personal communication , 1979).

0.05 m.y. ( S t a n Evans,

6

Subsurface b a s a l t i c rocks w i t h i n the Quaternary a l luv ium were o e n e t r a t e d

9 ’ i n Soda Lake 1-29, 11-33, and 63-33. The igneous rocks consist of

non-porphyri t i c pyroxene b a s a l t w i t h t r a c h y t i c texture. No evidence o f

vesicles or amygdaloids i n the b a s a l t was found i n the c u t t i n g s , and the

sediments i n c o n t a c t w i t h the t h i c k b a s a l t intercept i n Soda Lake 1-29 a r e \

a l t e r e d above and below the b a s a l t . T h i s sugges t s t h a t the b a s a l t occu r s as

d i k e s rather t h a n f lows. The b a s a l t s i n Soda Lake 63-33 and 11-33 are

p e t r o l o g i c a l l y i d e n t i c a l t o the basal ts i n Soda Lake 1-29 and d i f f e r e n t from

the b a s a l t of the P l e i s t o c e n e b a s a l t f lows pene t r a t ed i n Soda Lake 44-5.

SUBSURFACE INFORMATION

Subsurface s t r a t i g r a p h i c informat ion i n the Soda Lake a r e a i s based on

i n t e r p r e t a t i o n o f d r i l l c u t t i n g s from six holes: Soda Lake 44-5, 1-29, 11-33,

56-33, and 36-78, d r i l l e d by Chevron (Earth Sc ience Labora tory , 1979) , and

Carson Sink #1 (Hor ton , 1978) .

11-33, and 66-33 a r e inc luded i n the Appendix and a l og summary i s presented

on Plate 1.

C i thology l o g s f o r Soda Lake 44-5, 1-29,

Soda Lake 44-5 and Carson S i n k #1 each penetrated 4,600 f e e t o f

Quaternary sed iments ( P l a t e 1) . Below t h e s e sed iments i s a sequence of t h i c k ,

v e s i c u l a r , o l i v i n e and a u g i t e b a s a l t f lows.

the P1 iocene t o e a r l y P l e i s t o c e n e Bunejug formation (Morrison, 1964, p . 1 4 ) .

The Carson Sink f l hole pene t r a t ed over 3000 feet of b a s a l t and a n d e s i t e f lows

(Horton, 1978) .

These f lows a r e i n t e r p r e t e d t o be

Below the b a s a l t f lows i s an a l t e r e d , welded ash-flow t u f f .

Soda Lake 1-29 encountered a pyroxene gabbro below the sediments a t a depth o f

3940 f e e t .

7

I

Tuffs and tuffaceous sand and mudstone are Dredominant below a depth of

2400 fee t . The basal e ight hundred f e e t of Quaternary sediments are poorly

sorted mudstone, sand, s i l t , and tu f f . These a re overlain by organic-rich,

laminated mudstone which may represent the f i r s t lake event or a del ta ic

swamp. A channel gravel has replaced most of the mudstone u n i t i n Soda Lake

44-5 (P la t e 1) . Above the organic-rich mudstone i s 250 f e e t of sand and

mudstone, which may also be lacustr ine, overlain by 230 f e e t of mudstone,

s i l t s tone , and shale with organic carbon. In the next 2000 f e e t , between a

depth o f 3000 f e e t and 1000 f ee t , individual beds cannot be correlated. In

general, sand and gravel predoqinate i n the Carson S i n k #1 hole and

finer-grained sand t o clay are present i n the holes no r th of Soda Lake.

The basal t intercepts between 1300 and 2000 f e e t i n Soda Lake 1-29,

11-33, and 63-33 are petrographically ident ical .

be dikes and were discussed in the Igneous A c t i v i t , y section of t h i s report.

The basa l t ic crystal ash a t 1520 f ee t i n Soda Lake 44-5 has tabular p l a g i o -

c lase phenocryst and i s d i s t i n c t from basal t dikes.

These basal ts are thought t o

A uni t consisting o f shale, mudstone, and f ine sand occurs between a

depth o f 700 and 1000 f ee t i n the four d r i l l holes i n which cut t ings are

available for t h i s interval (P la te 1). These rocks probably formed i n a deep

lake environment. The Lake Lahontan formations probably account for only the

upper 400 f ee t of sediments (Morrison, 1964) .

SURFACE ALTERATION AND SINTER DEPOSITS

Hot springs deposits and a l te ra t ion are r e s t r i c t ed t o several small areas

8

two miles n o r t h of Soda Lake (Figure 2 ) .

kaol ini te , i r o n oxides, and hydroxides (Olmsted and others , 1975, p . 103).

The a l te ra t ion extends a b o u t two hundred f e e t t o the section l i n e road west of

an abandoned steam well and approximately one hundred f e e t t o the eas t where

i t i s covered by a sand dune.

Here the soil has been a1 tered t o

Shallow hand-dug p i t s have exposed b r i g h t l y

colored a l te ra t ion a few inches be

steam we1 1 .

The hot springs deposits cons

ow the surface i n the low area around the

s t of small areas o f opal-cemented sand i n

the SE 1 /4 of section 29 and the NE 1/4 of section 32 (Figure 2 ) .

replaced grass stems are abundant local ly and opallized b r u s h stems are also

present, while opal-f i l led fractures were found a t one location.

opal-cemented sand i s deeply eroded and sand dunes have par t ly covered some

outcrops.

Opal

The

Alteration coloration was n o t evident i n the sinter-cemented

outcrops.

STRUCTURE

The dominant f a u l t trend around the Carson Desert i s northeast. Linears

on aer ia l photographs o f the Soda Lake area have a north-northeast trend

(Figure 21, and several short l inears were found near Soda Lake 1-29 and

11-33.

o l d steam well (Figure 2 ) . T h i s photo l i nea r coincides w i t h the thermal plume

and a NE-SW-trending f a u l t , defined from seismic ref lect ion (Hill and others,

1979) .

(Figure 2 ) .

formed the boundary of a NE-trending graben.

One l inear extends from opa1;cemented sand t o the al tered area of the

The surface expression indicates r e l a t ive movement down t o the SE

vi1 1 and others ( 1979) concl uded t h a t the f a u l t dipped SE and

Offset on the pho to l inears

9

I

appears t o be a few f e e t a t most.

c u t t i n g s i n t h e fo rm o f gouge and s l i c k e n s i d e su r faces on ch ips ; l o c a t i o n s of

t h e p o s s i b l e f a u l t i n t e r c e p t s a r e shown on P l a t e 1. There a re no marker beds

which c o u l d be used t o demonstrate o f f s e t between ho les . The sedimentary

f a c i e s c o r r e l a t e d between h o l e s c o u l d be o f f s e t a few t e n s o f feet .

Some evidence f o r f a u l t i n g was found i n t h e

HEAT FLOW AND TEMPERATURE

Olmsted and o t h e r s (1975, p. 115) es t ima ted a conduc t i ve hea t d ischarge

o f 3.2 x 106 c a l / s e c as a minimum f rom t h e Soda Lake thermal anomaly enclosed

by t h e 2OOC i so the rm a t a depth o f 30 m.

severa l water samples f rom two i n t e r v a l s i n Chevron 's Soda Lake 1-29 t e s t h o l e

( E a r t h Science Labora to ry , 1979). Cal c u l a t e d r e s e r v o i r t e m e r a t u r e s u s i n g t h e

s i l i c a geothermorneter averaged 183oC f o r b o t h t e s t i n t e r v a l s w i t h a range o f

176' t o 192OC f o r 6 samples. The measured temperature i n t h e l ower i n t e r v a l ,

1008-1531 f e e t deeo, averaged 174OC.

r e s e r v o i r tempera ture i n excess o f 4 0 0 0 ~ ( 1 9 0 0 ~ ) .

Chemical analyses were made o f

H i l l and o t h e r s (1979) es t ima ted a

CONCLUSIONS

The Soda Cake thermal anomaly i s l o c a t e d i n t h i c k Qua te rna ry c l a s t i c

sediments. I n general t h e sediments a r e coa rse r t o t h e southwest and f i n e r t o

t h e n o r t h and n o r t h e a s t . The g r a v e l s found i n Soda Lake 44-5 and Carson S ink

Y 1 a r e p robab ly channel d e p o s i t s w h i l e t h e few c l e a n sand zones may be beach

depos i t s .

44-5, which a r e f i v e m i l e s a p a r t , than between Soda Lake 44-5 and Soda Lake

1-29, which a re o n l y 2 m i l e s apar t . T h i s i s p robab ly because Carson Sink #1

There i s a g r e a t e r s i m i l a r i t y between Carson Sink f l and Soda Lake

10

#

and Soda Lake 44-5 a r e both i n the d e l t a - a l l u v i a l f an f a c i e s , b u t Soda Lake

1-29, 11-33, and 63-33 a r e i n the lake-p laya f a c i e s o f d e p o s i t i o n . The a rea

of d e l t a i c o r l a c u s t r i n e depos i t i on s h i f t e d a t times due t o rise and f a l l o f

the bas in l a k e , b u t the d e l t a - a l l u v i a l f an g e n e r a l l y extended from the

southwest t o just nor th of Soda Lake.

3 '

I

Soda Lake 1-29, 63-33, and 11-33 a r e i n f iner sediments than Soda Lake

44-5 and Carson S i n k #1 t o the south . Most of the c u t t i n g s from Soda Lake

1-29 a r e of s i l t y and sandy mudstone derived from t u f f a c e o u s m a t e r i a l . All of

the t u f f s intercepted have undergone f l u v i a1 t r a n s p o r t .

The Qua te rna ry sediments a r e 4600 feet t h i c k and ove r l ay b a s a l t f low

under Soda Lake and t o the west.

over1 a i n by the sediments.

Two miles nor th of Soda Lake gabbro i s

ACKNOWLEDGEMENTS

I wish t o c red i t Ed C . B ing le r f o r the l i t h o l o g i c l o g o f the Carson Sink

#1 Borehole w h i c h was publ i shed i n the Bendix r e p o r t (Hor ton , 1978) and was

used i n this r e p o r t . Helpful c o n s u l t a t i o n on c u t t i n g s i n t e r p r e t a t i o n was

provided by Je f f Hulen. Valuable guidance i n the p repa ra t ion o f this r e p o r t

was given by Joe Moore, and the c r i t i c a l reviews o f the manuscript by J o e

Moore and Howard Ross a r e apprec i a t ed . The d r a f t i n g was done by Oawnetta

B o l a r i s and Connie P ix ton and typ ing by Lucy S t o u t .

11

3 '

BIBLIOGRAPHY

Axel rod , D. I . , 1956, Mio-P1 iocene Floras from wes t -cent ra l Flevada: Geol. S c i . , v . 33.

Bing le r , E . C . 1978, Abandonment of the name Har t ford Hill Rhyol i t e Tuff and adopt ion of new formation names f o r Yiddle Tertiary Ash-Flow T u f f s i n the Carson C i t y - S i l v e r C i t y Area, Nevada: IJ. S. Geol . Survey Bull . 1457-D, 19 p.

Bonham, Harold F., 1969, Geology and mineral d e p o s i t s of Washoe and S to rey Counties, Nevada: Nev. Bur. Mines, Bu l l . 70, 140- P .

Ear th Sc ience Labora tory , 1979, Chevron Resources ComDany d a t a f o r Soda Lake: S a l t Lake C i t y , Open-f i le release, March, 1979, C2C 8-9.

E r w i n , J . W . , and Berg, J . C . , 1977, Bouquer g r a v i t y map o f Nevada, Reno Shee t : Nev. Bur. Mines, Geol . Map 58.

Gars ide , L . * I . , and S c h i l l i n g , J . H . , 1979, Thermal waters o f Nevada: Nev. Bur. o f Mines, Bul l . 91, 163 p .

Gars ide , L . J . , 1974, Geothermal e x p l o r a t i o n and development i n Nevada throuqh 1973: Nev. Bur. o f Mines, Rept. 21, 12 p .

H i l l , D. G . , Layman, E . R . , S w i f t , C . Y . , and Yunqul, S . H . , 1979, Soda Lake, Nevada, thermal anomaly: Geoth. Res. Counci l , T r a n s a c t i o n s , v . 3 , p . 305-308.

Horton, Robert C . , 1978, L i t h o l o g i c 1oq and i n t e r p r e t a t i o n of instrument l o g s , N U R E Project, Carson Sink , Nevada, Bore Hole: Bendix F i e l d Enq. C o r p . , GJBX - 53(78) , 36 p.

Langenheim, R . L . J r . , and Larson E . R . , 1973, C o r r e l a t i o n o f Grea t Basin S t r a t i g r a P h i c units: Nev. Bur. o f Mines, B u l l . 72, 36 p .

Mariner , R. H., Rapp, J . B., Willey, L . M . , and Presser, T. S . , 1974, T h e chemical composi t ion and e s t ima ted m i n i m u m thermal reservoir temperatures of the p r i n c i p a l h o t s p r i n g s of no r the rn and c e n t r a l Nevada: U. S. Geol . Survey, Ooen-File Report 74-1066, 32 p .

Moore, James G . , 1969, Geology and mineral d e p o s i t s of Lyon, Douglas, and Ormsby Count ies , Nevada: Nev. Bur. Mines, Bu l l . 75, 45 D .

;4orr ison, R . B . , 1964, Lake Lahontan: Geology o f Southern Carson g e s e r t , Nevada: U. S. Geol . Survey, Prof . Paper 401.

Nielson, R . L . , 1954, Righ t - l a t e ra l s t r ike-s l ip f a u l t i n g i n the Nalker Lane, wes t -cent ra l Nevada: Geol . SOC. o f Am. B u l l . , v . 75, p . 1301-1308.

12

Olmsted, F. H., 1977, Use of temperature surveys a t a depth o f 1 meter i n geothermal e x p l o r a t i o n i n Nevada: U . S . %eo1 . Survey, P r o f . P . 1044-6, 25 p.

Olmsted, F. H . , Glaney, P . A . , H a r r i l l , J . R., R u s h , F. E., and Van Denburgh, A. S. , 1975 , Prel iminary hydrogeol o g i c a p p r a i s a l o f s e l e c t e d hydrothermal systems i n northern and central Nevada: U . S. Geol. Survey, Open-File Rept. 75-56, 267 p .

Church i l l County, Nevada: Nev. Bur. Mines, Geol . Map 28. Page, B . M . , 1965, P re l imina ry geologic map of a p a r t of the S t i l l w a t e r Range, I

Riehle , J . R . , McKee, E . H . , and Speed, R . C . , 1972, A T e r t i a r y vo lcan ic

R u s h , F. E . , 1972, Hydrologic reconnaissance of Big and L i t t l e Soda Lakes,

center, west-central Nevada: Geol. SOC. Am. Bu l l . , v . 8 3 , p . 1383-1396.

Church i l l County, Nevada: Nevada S t a t e , Dept. Cons. and Nat. Res., D i v . Water Res., Rept. 11.

I

Silberman, M . L . , and McKee, E . H., 1972, A summary o f r ad iomet r i c age

C a l i f o r n i a : P a r t 11, Western Nevada: Isochron/West, no. 4 , Aug. , de te rmina t ions on T e r t i a r y vo lcan ic rocks from Nevada and eastern

Speed, R . C . , 1975 , Carbonate b r e c c i a (rauhwacke) nappes o f the Carson S i n k

S t a n l e y , W . D., Wahl, R . R . , and Rosenbaum, J . G . , 1976, A magne to - t e l lu r i c

r eg ion , Nevada: Geol . SOC. America B u l l . , v . 8 6 , p. 473-486.

s tudy of S t i l lwa te r -Soda Lake, Nevada geothermal a r e a : U . S . Geol. Survey, Open-File Report 75-80, 38 p .

Swanberg, C . A . , and Alexander, S . , 1979, Use of water q u a l i t y f i l e WATSTORE i n geothermal expl o r a t i o n : C a l i f o r n i a : Geol. , v . 7 , p . 108-111.

An exampl e from the Imperi a1 Val 1 ey ,

T r e x l e r , D. T. , Bel 1 , E. J . , and Roguemore, G . R . , 1978, Eva1 ua t ion of l ineament a n a l y s i s a s an e x p l o r a t i o n technique f o r geothermal energy , western and central Nevada: Nev. Bur. M i n . , DOE Contract E-Y -76-5-08-0671 , 78 p.

Vanderburg, W . O . , 1940, Reconnaissance o f mining d i s t r i c t s i n Churchi l l County, Nevada: U . S., Bur . Mines, I n f . Circ. 7093.

Wahl , Ronald R . , 1965, An i n t e r p r e t a t i o n o f g r a v i t y d a t a from the Carson Sink a r e a , Nevada: S t an fo rd U n i v . , Dept. of Geophysics, unpub. report, 38 p.

Willden, R . , and Speed, R . C . , 1974, Geology and mineral d e p o s i t s of Church i l l County Nevada: Nev. Bur. M i n . , Bu l l . 83.

Zohdy, A. A . , and Bisdorf , R . J . , 1977, D e l i n e a t i n g a b a s a l t i c a q u i f e r w i t h Schl umberger soundings near Fa1 l o n , Nevada: Geophysics, v . '42 , no. 7 , p. 1550.

13

APPEND I X

LITHOLOGIC LOGS

OF

CHEVRON RESOURCES COMPANY WELLS

Soda Lake 44-S Soda Lake 1-29 Soda Lake 11-33 Soda Lake 63-33

14

NU m.@ Soda Lake 44-5 LQCXZZON Center Sec. 5. Tf9N.. R 28 E. m p LY Sl'&bett

3

WLL IYOL* Soda Lake 44-5 L4=lZZ??

. . . - . - . . - . . - . . . . - . . - .. .- -

3

AWZL NO Soda Lake 44-5 L o c p T o N a p Sibbett

I

. . . . . . . .- - - . -. -. . . . - . . - .. - . . -

3

I

I

DWLL UOL& Soda Luke /k33 tomiox7 See. 33, T.2ON.. R. 28 E.

3

DRILL U O L ~ Soda Luke 1 1 - 3 3

P -

I i

P I I

D ~ L & HOL# Soda Luke 63-33 L O C ~ T / ~ ~ ~ Y NE94 Sec. 33, T: 2 0 N , R. 28 E.

D ? Z & HOL& Sodo Lake 63-33 tm’%oN N E h Sec. 33, T. ZON, R. 28 E.

CARSON SINK #1 generalized from

Horton, 1978 Elev. 4060' 4-4--- 5 mi.,-hv-w EL EVA T/ON --- --- \

SODA LAKE SODA LAKE 44-6 + 2 mi.+ 1-28 4000'

SODA LAKE 11-83 3980'

SODA LAKE 6a-83 3976'

4000'- - 3990' Sand

coarse 8

gravel arkosic

sand c. - m.

qtz. B l ithic coarse- pebbly

arkosic

gravel pebbles

370' Detaic deposits

no cuttings no cuttings FI uvlal? 400' 400'

490' sand m.- c. gravel pebble

-_. .. ,. , L sqhd If -.c.'..

gravel 8

sand

silt zone

120' /? /

/-

20'- 60' -7

-? * iz L sand ark0 se l i thic

6 0' ~~

silt 8 clay 90'

150'

Coarse -jebblj ark0 ic arkose

med - coar. Lithic, pebbt)

- - ?=.mu dstoiiez -

Es/rsIe Je&s gravel

sond fine - silty clay- zones organic beds

coarse sand lithic, volc.

- - _ _ _ - - - - . - _ . _ _ - - . =--- - - -:sandy-=>Z -_

arkose 2 6 0 ' Deltaic deposits

no' Ybturns 540' 2 IO' 12d

120' graywacke 40' 4 0'

100'

60'

50'

20' / sand

3000' - gray Wac &e - -?-.7-

calcite % - - anhydrite - - no returns

sand K E. - m, with clay=

s i l t 8 gravel

360' Lake Preclpitotes

SO'

graywacke arkose 320'

graywacke 160' - -?+.- . . . .sat?d'.' loo' '/tn(c arkose .. sand 8

s i l t

Deltaic deposits .sand . . 140

70'

80' Fault

Fault !OO'

Fault

00'

20'

160'

Fault

!40'

150'

5 0' 4 0'

170'-200

1 I 0'-I 40'

40'

70'

Fault

60' . arkose. . l ithic - .

sand m. - f. tuffaceous graywacke ?80' sand

granules

Poor sorting

silts tone

(mudstone?)

graywacke 160'

40'

190'

20' 7 30' * 80' rault 20' ' D 2,000

- 7 00' -?

basaltic :rystal ash slit - sand v. fL

tu f f sed. 100' 2 0'

Fault

160' - - - - -basaft- ? ,--? Ptt7ynwke- I 4- 80'- --- --

- D 2,000

l ithic arkose-

i

Lacustrine? fay-tuf faceou 8 sand

8w pebbles

tuffaceous siliceous

graywacke 4 graywacke

~~ ~~

gravel Pebble- sand tu f f sed 4 0'

2000' - sandstone

few pebbles silt zones

sulfides. py- mar

tuffoceous sond

vitric tuff , 370' 50'

50' 5 0'

thic sand iy-tuffaceous gravel Deltaic?

Y f f . bosaltic l i thic sand

gnite grains 30 si l tstone

8

sandstone

.- - -- tuffaceous mudstone

cloy 60' 2 5'

-35' 60'

-? b - -

------- 7 -& Channel - - - deposit? - - - EXPLANATION

scmd med- fine v i t r i c tu f f

oft to cloy 750'

Silt 8 clay or shale- with possible lateral extent.

7nd8 clay

nterbedded tu/ f aceous

Basaltic-andesite dikes or flows - plagioclase laths in biotite-chlorite matrix.

1 7 Clean sand. 30' 0 % carbon IOOO'

Bunejug formation- basalt, witti olivine crystals. 5 ' l imestone sandstone tuffaceous , fignite grains

cloys-

30' . - Vegetation- -

event / Faults from slicken sides & gouge; dip & offset not known.

i i t r i c tuff rlt sulfiabs IO'

vein

10'

m.- c. r mudston

s hale

grave/

sand

s-ome s i l t 8

pebbles

240'

sandstone ru ffaceous

aft. clays

\ -- .-- -

mudstone carbon silty banded

u f f X I 8 vitr. ril icif led nudston2 - - - - --

gabbro d pyroxene

aft.

dstone&da sand 1 EARTH SCIENCE n. - C. rtr a l i thic

clay zones LABORATORY UNIVERSITY of UTAH &L RESEARCH INSTITUTE

BRUCE SIBBETT, 1979

mudstone 8

sand SEA LE VEL - ----

Fault

Fault 50'

100' rkose, muds

bands

3 5' 50' :ault

00' :auk

---------------------- E:-- - - 2 0

=ault

D 4,300

1 andesite flow-

soil-

PLATE I ff 6 sand I 85' SODA LAKE WELL LOG CORRELATION 230'

CHURCHILL CO., NEVADA f lows rsdt f/ow

T D 5 , 0 6 9 f t .

Ll T D 8,502ft.

ABSTRACTINTRODUCTIONGEOLOGIC SETTINGIGNEOUS ACTIVITYSUBSURFACE INFORMATIONSURFACE ALTERATION AND SINTER DEPOSITSHEAT FLOW AND TEMPERATURECONCLUSIONSACKNOWLEDGEMENTSBIBLIOGRAPHYAPPENDIXLithologic log of Chevron Resources Company Soda Lake

Figure 1 Index map of Churchill County NevadaNevada