Lake Eleanor Quadrangle, Central Sierra 

Nevada, California--Analytical Data 

By F. C. W. DODGE and L. C. CALK 

U.S. GEOLOGICAL SURVEY BULLETIN 1585 
DEPARTMENT OF THE INTERIOR 

DONALD PAU'l H·ODEL, Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

UNITED STATES GOVERNMENT PRINTING OFFICE 1986 

For sale by the 

Books and Open-File Reports Section 

U.S. Geological Survey 

Federal Center, Box 25425 

Denver, CO 80225 

Library of Congress Cataloging-in-Publication Data 

Dodge, F. C. W. (Franklin, C. W.), 1934-

lake Eleanor quadrangle , central Sierra 

Nevada, California. 

(U.S. Geological Survey Bulletin 1585) 

Bibliography 

Supt. of Docs. no.: 119.3: 1585 

1. Rocks, Igneous-California, Eleanor, 

lake, Region-Analysis. 2. PetrologyCalifornia-Eleanor, lake, Region. 

3. Geology-California-Eleanor, lake, 

Region. I. Calk, l. C. II. Title. 

Ill. Series: United States. Geological 

Survey. Bulletin 1585. 

QE75.B9 no. 1585 557.3 s 

[QE461] [557.94'4) 

85-600350 
CONTENTS 

Abstract 1 

Introduction 1 

General geology 1 

Analytical data 2 

References cited 2 

FIGURES 

1. Index map of the Lake Eleanor quadrangle 4 

2-7. Simplified geologic maps of the Lake Eleanor quadrangle showing: 

2. Locations of chemically analyzed and isotopically dated samples 5 

3. Volume-percent quartz in plutonic rocks 6 

4. Volume-percent potassium feldspar in plutonic rocks 7 

5. Volume-percent plagioclase in plutonic rocks 8 

6. Volume-percent mafic minerals in plutonic rocks 9 

7. Bulk specific gravity of plutonic rocks 10 

8. Modal plots of grantic rocks .11 

9. Histograms of color index (volume-percent mafic minerals) of granitic rocks 13 

10. Histograms of bulk specific gravities of :granitic rocks 13 

11. Chondrite-normalized rare-earth elements in plutonic rocks 14 

TABLES 

1. Chemical and trace-element analyses, norms, modal·analyses, and .specific gravities 

of plutonic rocks 15 

2. ·Chemical and trace-element analyses and norms of trachyandesite 18 

3. Chemical and spectrographic analyses of metasedimentary rocks 19 

4. Uranium-lead age determinations on zircon from granitic rocks -20 

5. Potassium-argon age determinations of sample LE-1104 from the tonalite of Poopenaut Valley 20 

:Ill 
Lake Eleanor Quadrangle, Central Sierra 

Nevada, California--Analytical Data 

By F. C. W. Dodge and L. C. Calk 

ABSTRACT 

A variety of granitic, gabbroic, and 

metasedimentary rocks, covered locally with 

remnants of Cenozoic lava flows and glacial deposits, 

underlie the Lake Eleanor 15-minute quadrangle. 

More than 400 rock samples were collected during 

geologic mapping of the quadrangle. Modes were 

determined on 258 plutonic rock samples and bulk 

specific gravities on 262. Volume percentages of 

quartz, potassium feldspar, plagioclase, and mafic 

minerals and the bulk specific gravities are plotted 

on a simplified geologic map, and histograms of color 

index and specific gravities are plotted. Ternary 

plots of quartz, potassium feldspar, and plagioclase 

show that the compositions of the granitic rocks are 

predominantly granodiorite and tonalite, but range 

from granite to quartz diorite. Chemical analyses 

and assorted trace-element contents are tabulated 

for 28 of the plutonic rocks, 5 metasedimentary 

rocks, and 2 volcanic rocks. Zircon U-Pb ages are 

tabulated for 8 granitic rock samples and range from 

I 09 to 166 Ma.; however, younger granitic rocks crop 

out in the quadrangle. Biotite and hornblende K-Ar 

ages are tabulated for one of these samples. 

Chondrite-normalized rare-earth-element patterns of 

10 plutonic rocks are plotted. 

INTRODUCTION 

The Lake Eleanor 15-minute quadrangle covers 

an area of about 620 km2 on the western slope of the 

Sierra Nevada (fig. 1). The eastern third of the 

quadrangle is within Yosemite National Park. 

California Highway 120 crosses the southern part of 

the quadrangle, and branching roads provide access to 

much of the quadrangle. Elevations range from 610 

to 2,213 m. Large tracts are heavily forested, and in 

much of the quadrangle, outcrops of unweathered 

bedrock are sparse. 

The analytical data compiled herein, including 

chemical and modal analyses, specific gravities, and 

isotopic age determinations, supplement the geologic 

map of the Lake Eleanor quadrangle and were 

determined on samples collected during geologic 

mapping. Although some of these data have been 

reported elsewhere (for example, Bateman and 

others, 1984; Stern and others, 1981), for the sake of 

completeness, they are all brought together in the 

maps, diagrams, and tables of this report. Similar 

reports have been published for many of the 

other 15-minute quadrangles of the Mariposa 1° by 

2° sheet. 

GENERAL GEOLOGY 

Plutonic rocks of the Sierra Nevada batholith 

underlie three-quarters of the quadrangle, and 

prebatholithic rocks underlie the remaining quarter 

along the south edge. Cenozoic lava flows and 

glacial deposits locally overlie the crystalline rocks 

in the northern two-thirds of the quadrangle. 

Metasedimentary rocks, a part of the western 

metamorphic belt of the Sierra Nevada, have been 

assigned to two informal units. The quartzite and 

schist of Pilot Ridge is of early Paleozoic age. 

Fossils found in the phyllite and chert of Hites Cove 

immediately south of the Lake Eleanor quadrangle 

(Bateman and others, 1985) indicate an Early Triassic 

age. 

Plutonic rocks make up 19 intrusive units that 

range in composition from gabbro to leucogranite. 

Individual units consist of small plutons covering only 

a few square kilometers as well as parts of much 

larger bodies extending many kilometers beyond the 

quadrangle. Tonalites on the west side of the 

quadrangle have been radiometrically dated at 165 

Ma and are the oldest known granitic rocks within the 

western part of the main mass of the Sierra Nevada 

batholith. Granitoids to the east are generally 

progressively younger, some correlative with Early 

and Late Cretaceous rocks that crop out in Yosemite 

Valley. 

Small patches of trachyandesite that trend 

southwesterly across the central part of the 

quadrangle are the erosional remnants of a Tertiary 

mudflow that originated far to the northeast. 

Trachyandesite samples of the same mudflow 

immediately northeast and southwest of the 

quadrangle have been dated at 9.1 and 9.2 Ma, 

respectively (Dalrymple, 1963, recalculated to the 

new decay constants recommended by Steiger and 

Jaeger, 197 7). Younger trachyandesite covers 5 

k mZ in the northeast corner of the quadrangle. 

Quaternary glacial deposits cover broad areas, 

particularly along Eleanor and Cherry Creeks and the 

Tuolumne River. These deposits are not shown on the 

simplified geologic map (fig. 2). 

1 
ANALYTICAL DATA 

A total of 420 rock samples were collected from 

the quadrangle during mapping. The generally poor 

exposure of unweathered bedrock precluded followi~g 

a regularly spaced sampling pattern. Of the plutomc 

rock samples collected, stained slabs (Norman, 1974) 

of 258 were modally analyzed (figs. ·3-6, 8), and 

powders of 28 were chemically analyzed (table 1), as 

were powders of 2 samples of Tertiary volcanic rocks 

(table 2) and 5 samples of metasedimentary rocks 

(table 3); assorted trace elements were determined 

by X-ray or emission spectrographic methods on all 

the chemically analyzed powders, and rare-earth 

elements were determined on 10 of the plutonic rock 

powders by neutron activation analysis (fig. _11). 

Whole-rock bulk specific gravities were determmed 

on 262 plutonic rock samples (figs. 7, 1 0), and 

densities were determined on the 5 chemically 

analyzed metasedimentary rock powders (table 3). 

Zircons separated from 8 plutonic rock samples were 

dated by the U-Pb method (table 4), and biotite and 

hornblende separated from 1 of these samples were 

dated by the K-Ar method (table 5). 

Systematic variations of modal constituents and 

bulk specific gravity within plutonic bodies are 

generally not apparent. This may in part simply 

reflect the lack of a regularly spaced sample pattern 

and the uncertainty of whether some samples are 

typical because of poor exposure. Isopleths .were 

drawn on figures 3-6 where the data permitted. 

Concentric zoning could not be demonstrated, and 

areas could only be contoured consistently in the 

granodiorite of Sawmill Mountain, the tonalite of 

Poopenaut Valley, and the granodiorite of Yosemite 

Creek. 

The percentage contents of quartz, potassium 

feldspar, and plagioclase in the granitic rocks 

recalculated to 100 are plotted on ternary diagrams 

(fig. 8). Ternary compositions lie within a broad band 

extending from the quartz diorite field across the 

tonalite and granodiorite fields into the granite field 

in the classification scheme of Streckeisen and others 

(1973). Histograms of color index (volume percent 

mafic minerals) and of specific gravity are shown in 

figures 9 and 10 for each of the granitic units. 

Rare-earth-element (REE) abundances 

normalized to chondrite values (composite of 9 of 

Haskin and others, 1968) of l 0 plutonic rocks are 

plotted in figure 10. Patterns of granitic :ock 

samples are similar to others of central S1erra 

Nevada granites (for example, Dodge and others, 

1982; Frey and others, 1978; Noyes and others, 1983; 

Sawka and others, 1984) with light REE abundances 

generally 50 to 100 times those of chondrites, heavy 

REE abundances about 10 times or less than those of 

chondrites, and no or only small negative europium 

anomalies. Gabbro samples (LE-96 and LE-1040) both 

show slight enrichment in intermediate REE 's, but 

only minor concentration of light relative to heavy 

REE's. 

REFERENCES CITED 

Bateman, 

P.E., 

2 

p .c. J 

1984, 

Dodge, 

Major 

F.C.W., and Bruggman, 

oxide analyses, CIPW 

norms modes and bulk specific gravities ' ' • 0 of plutonic rocks from the Mar1posa 1 by 

2° sheet, central Sierra Nevada, 

California: U.S. Geological Survey 

Open-File Report 84-162, 50 P• 

Bateman, P.C., Harris, A.G., Kistler, R.W., 

and Krauskopf, K.B., 1985, The Calaveras 

reversed: Westward younging is 

indicated: Geology, v. 13, no. 5, 

p. 338-341. 

Cross, Whitman, Iddings, J.P., Pirsson, L.V., 

and Washington, H.S., 1902, A quantitative 

chemica-mineralogical classification and 

nomenclature of igneous rocks: Journal of 

Geology, v. 10, p. 555-690. 

Dalrymple, G.B., 1963, Potassium-argon dates 

of some Cenozoic volcanic rocks of the 

Sierra Nevada, California: Geological 

Society of America Bulletin, v. 74, no. 4, 

p. 379-390. 

Dodge, F.c.w., Millard, H.T., Jr., and 

Elsheimer, H.N., 1982, Compositional 

variations and abundances of selected 

elements in granitoid rocks and 

constituent minerals, central Sierra 

Nevada batholith, California: U.S. 

Geological Survey Professional Paper 1248, 

24 p. 

Frey, F.A., Chappell, B.W., and Roy, S.D., 

1978, Fractionation of rare-earth elements 

in the Tuolumne intrusive series, Sierra 

Nevada batholith, California: Geology, 

v. 6, no. 4, p. 239-242. 

Haskin, L.A., Haskin, M.A., Frey, F .A., and 

Wildeman, T.R., 1968, Relative and 

absolute terrestrial abundances of the 

rare earths, in Ahrens, L.H., ed., Origin 

and distribution of the elements: Oxford, 

Pergamon Press, p. 889-912. 

Norman, M.B., 1974, 2d, Improved techniques 

for selective sta1n1ng of feldspar and 

other minerals using amaranth: U.S. 

Geological Survey Journal of Research, 

v. 2, no. 1, p. 73-79. 

Noyes, H.J., Frey, F.A., and Wones, D.R., 

1983, A tale of two plutons: geochemical 

evidence bearing on the or1g1n and 

differentiation of the Red Lake and Eagle 

Peak plutons, central Sierra Nevada, 

California: Journal of Geology, v. 91, 

no. 5, p. 487-509. 

Sawka, W.N., Chappell, B.W., and 

Keith, 1984, Light-rare-earthzoning in sphene and allanite 

granitoid fractionation: Geology, 

p. 131-134. 

Norrish, 

element 

during 

v. 12, 

Steiger, R.H., and Jaeger, E., Compilers, 

1977, Subcommission on geochronology; 

Convention on the use of decay constants 

in geo- and cosmochronology: Earth and 

Planetary Science Letters, v. 36, no. 3, 

p. 359-362. 

Stern, T.W., Bateman, P.C., Morgan, B.A., 

Newell, M.F., and Peck, D.L., 1981, 

Isotopic U-Pb ages of zircon from the 

granitoids of the centra 1 Sierra Nevada, 
California: U.S. Geological Survey 

Professional Paper 1185, 17 p. 

Streckeisen, A.L., and others, 1973, Plutonic 

rocks: Classification and nomenclature 

recommended by the lUGS subcommission on 

the systematics of igneous rocks: 

Geotimes, v. 18, no. 10, p. 26-30. 

3 
4 

38! 2;.:0_• ~oo:...·--------..,...,..,...,..--r-------r~-----1-19---,·4s· 

oo· 

6 Pilot Peak 

10 

Lake Eleanor 

Hetch Hetchy Reservoir 

YOSEMITE 

___ 

1 

NATIONAL PARK 

20 30 KILOMETERS 

Figure 1. Index map of the Lake Eleanor 

quadrangle. 

EXPLANATION FOR FIGURE 2 

GJ Volcanic rocks 

G:J Felsic granitic rocks 

~ Sentinel Granodiorite 

~ Granodiorite of Yosemite Creek 

~ Granodiorite of Hodgdon Ranch 

Tonalite of North 

~ Crane Creek Tonalite of ~ Tamarack Creek 

Quartz diorite 

~ of Aspen Valley 

~ EJ ~ Granite of Rancheria Granite of Granite of Swamp Lake Mountain Bald Mountain 

El Capitan 

~ Granite 

~ Granodiorite ofTueeulala Falls 

~ ~ Granodiorite of Crane Flat 

L..:.:lli:l 

~ 

Granodiorite of Sawmill Mountain 

I K~(l 

Tonalite of Poopenaut Valley Granodiorite of Hazel Green Ranch 

{Porphyritic phase, stippled) (Contact phase, stippled) 

Mafic 

~ intrusive rocks 

Granite 

~ of Woods Ridge 

I Jv{l Tonalite of Granite Creek (Contact phase, stippled) 

GJ 

Metasedimentary rocks 

LE • 1040 LE· 36 

Chemically analyzed sample Isotopically dated sample 

(Symbols may be combined) 
12oo oo· 

38° 

oo· 

Tv 

Jgc 

ms 

Tv ci) LE-136 

JLE-133 )M Gl--Tv 

LE-134 

Ktf 

Kyc 

Kbm (\ 

~gr 

Figure 2. Locations of chemically analyzed and isotopically dated samples (see tables 1-4). 

Generalized geologic map of Lake Eleanor quadrangle from F .C. W. Dodge and L.C. Calk (unpub. 

data, 1985). 

119°45' 

5 
12oo oo· 

38° 

oo· 

37° 

45' 

Tv 

6 

ms 

• LE-160 

0 5 10 

.17 

e29 • 23 

32 • e26 

15 KILOMETERS 

• 19 LE-31 

M21 

Ktf 

Kyc 

Figure 3. Volume-percent quartz in plutonic rocks indicated by isopleths. Dot indicates location of 

sample. See figure 2 for explanation of generalized geology. 

119°45' 
120° 00' 

38° 

oo· 

37° 

45' 

Tv 

• 

Kyc 

Jgc 

ms 

• LE-160 

0 5 10 1 5 KILOMETERS 

Figure 4. Volume-percent potassium feldspar in plutonic rocks indicated by isopleths. Dot indicates 

location of sample; tr indicates trace amount. See figure 2 for explanation of generalized geology. 

1 19°4[)' 

7 
12oo oo· 38° 

00' 

Tv 

( 

J 

/).28 /Jr ~ 

37" 

45' 

e42 

Jgc 

ms 

• LE-160 

40 

ms 

0 5 10 15 KILOMETERS 

Figure 5. Volume-percent plagioclase in plutonic rocks indicated by isopleths. Dot indicates 

location of sample. See figure 2 for explanation of generalized geology. 

8 

119°45' 
120• oo· 

38° 

00' 

Tv 

e26 

Jwr 

.7 

Kyc 

Jgc 

ms 

0 5 10 15 KILOMETERS 

Figure 6. Volume-percent mafic minerals in plutonic rocks indicated by isopleths. Dot indicates 

location of sample. See figure 2 for explanation of generalized geology. 

119°45' 

9 
12oo oo· 38° 

00' 

37° 

45' 

2.53 2.78 ~:t· LE-1096 2.6~ .• /~ gr ·-.... e2.80 

2'9 • .2.69 2.74·2~7()?2-:'632.67 2.60~) Ji. 74 KJm• 2.74 • l -

.. ~.· 2.76 2.68 2.68 2.6~LE-1081 •2.71 e2.64 

' .2.62/ /~2.67 .2.73 .2.67 2.71~ 

I 

.2.71•2.71 • 2.69 \ Krm // 

• LE-258 • 2.71 / 

J .2.78 tt:~17 

• 2.53 / .2.71 •2.73 

\ ( 

\ .2.70 ·---

~/ (\ 2.63. '\ 2. 8 

// .2.77 ) ·--------.~-, 2.78 .2.82 2.78e \LE-36 2.64• 

( e2.70 f 2·

62 2.62', __ .!_ 2.77LE-208 ~ ~.69 Krm 

.2.59 

Jwr 

Ktf 

.2.64 

I 2.89e \' --t8

::-..., 2.6~~,---..!----266--- ~78 j .2.72 .2.66 .4'.til·\----~ . ~ . . 2 61 J Kpv 2.74• \ / • LE-111 \ ') ~2.63 LE-60 1 e • e 2.59 2.:;r1• • 2 .76 v 2.86 ~ K~l 65 2.~3 '\2.s_7'--...~2.80 ' 

2.7 . ...._,, 2.69e ( ~' KJm Tv .----" 2.79 •( LE-175 \ 

''·--."'- • 2.67 • 2.73 \ .2.71 . ....___/ 2 79 \\_ 

.2.78 "'-~/ ( \ / 2 76 2.68. . • /-

2.72. ~"'\,. . . \'- / 

2.80• LE122 / ', 2.78e ' 

~ \)•2.16 (? ~~· 66 ·,~ ~2~ia31 . '·,'!. 2.74 

·-~ ;1-Tvk.-J ' • 2.77 / 

ms ') 2.77 • 2.74 ____ ..--~ .... , V 2.76"" \ • 2 .79 

2· 

7

8/ 

2.69e 2 77 • _.,......, ./ \ ·, '\.. • !---

f\ . •/2.59 I __..-/ LE-249 '·,, '\.. 2 ·

78 / 2 65 

~ """ l \i ------- J // 2 .6~ \ "" "" // • . ' r. •2.57 \1 2.74 \ •2.66~ .2.84// . 1''- • .76 .2.69 2.68.~_9-15 • ~·2.6ff.E·28 \ / 

LE-153'"'-·.J ms • '- .. ms ~.6~ LE- 68 / 2 73\ '\ 2.77 ) "'----p LE-183 f • 2.65 • . \ 

• 2.83 \ •2. 75 \ • 2 ·65 

Jgc ( .2.66 .2.71• •2.75 e2.68 \ Kblj1 

.2. 73 2.641. \ 2.62 

c..-n.~· 2 ·

65 2 61 • 2.68 \ '\ • 2

·

68 2.8o 

2.82e. -,~ •2.90 : _..}'!v 

1

./' \ '\ • /·1 77 .2.6~ 

Kyc 

2 79 • ms .;/\ Ksm ~ [./'~ 2.65 \ , ~~ ~s . 2.79.;:·~·~Jm 2.62 • 2.71 /;'.---·" .. , • 2.70 \ \2-l7 2 6 

Tv (eJ •LE-136 l'e3!Jo67 :_yTv "' e2.79 2.71• •2.71 '\2".64• , Kbrn Kgr2.~7 

JLE-13~ ·~~ ~.::~~ E~~3/ •

2

·

65 jJ ms \, 2.l8 .2.82 2.i1•

2

.

68 LE-134 2.65 \. j 2.66e \ ( __ ') • 2.82 • 2.72 

... '5\ 

\

~ 

2.62 f'¥60 ·~ 8 

f)-Tv ve 2 ·

68 Ksm "-~---- 2.81 • 2.71~. • --.2.~.3·<.. 2.:,75 2.8o/ 

.2.73 \ .2.64 .2.66 • 2 ·

6 5 '" -· • 2.79 --,__ •. 2.78 • ' 

2.78e ~ '·---y;-;.9~'--, ~Jm "4~;,.7~~~~5 

e2.74 2 .67 2.70'1 LE-1040 \ /rr:s~~~--- ?Sb• • I LE-1008 

2.64• • 2.67 •/{ \ ' / LE-1044 '"- 2 • l •2.72 • j ~ \" KJ ;- • 2 74 ., 2 7. ~ • 2.61 2.66 2.67• / {27~ m £-z. . "" 2.6 e/ . K 

::::::<'{])it;~,~-~ 2 70 )~··r~~;;2.8a;''2(~55 ms \ '~;~~ . ~~-~?J>LE-96 '\!l . 2 .• 66 2.~5 / -~-80 "2.69 li~ ~\•2.78 2.71e 2.72~\\ (2.7~;. L~:~62o • 

- ~ ..-- ..- Jgc LE-244 ~.79e/) 2 67• \ \2. • 2 75 

~ ,..---- 2.76• 2.77 -----2.76 \, . ~ 2.'78 Kav . 

10 

Q._:v··•2.79 • 2.77 • !'- \ 2 12• 2 67 \ • 

• 2. 76 ,- ---~--~, I ..,LE-6 \ . 2.63 • • ~ ·r:~9 .--

\..._ c.-------.. ---------.. \1 \ II -L. 64 \ 2 .• 7 8 K cc \ • ~· 6 7 2. 7 8 ~--~ ' • 2.77 \2.60 

2 9-z~ ' KJm \1 J 2.61 I 2.7'0 2.77 Ktc 

· \ •12

·

81 Khr ~ 2 72 \ • • • ' ) 2 89 • . • \ 2. 7 6\ -.""'-~----· \ • 2.71 .2.69 • 2 \ 

~ ') --.... ,, \ • 2. 77 .66 \ '"' \ 

KgrA'./1 \ ..J, \ \ ' \ "'LE-143 \2 •. 74•2.67 \ e2.74 \ """\ 

• '\ "~-. 2~~~1---~------- 2. 74 • _______________ LE-3 / /) • 2.69 ,,.. ""~· 2,\7i 

~/-~-;-.6~"'~--._/'\__ ______ -· 2~Kgr ·------ 2.71 ,{E-41 

~-// Khg • • 2·

62 ') ms /''\ LE-1104{~72 /~2.65 LE-8/!f~l J,L~jgo 2.68 \ ( \._ ~3:~ ~ ~:()/ c: \ Kct.J7o--y------/ Kec 

ms 

• LE-160 

0 5 10 1 5 KILOMETERS 

Figure 7. Bulk specific gravity of plutonic rocks. Dot indicates location of sample. See figure 2 for 

explanation of generalized geology. 
35 

35 

35 

65 90 

X Sentinel Granodiorite 

• Granodiorite of Yosemite Creek 

65 

• 04artz diorite of Aspen Valley 

65 

x Tonalite of Tueeulala Falls 

+ Granodiorite of Crane Flat 

90 

90 

• Granodiorite of Hazel Green Ranch 

35 

35 

35 

65 90 

X Granodiorite of Hodgdon Ranch 

• Tonalite of North Crane Creek 

+ Tonalite of Tamarack Creek 

65 

+ Granite of Swamp lake 

x Granite of Bald Mountain 

Granite of Rancheria Mountain 

c::. El Capitan Granite 

65 

90 

90 

• Granodiorite of Sawmill Mountain 

Figure 8. Modal plots of granitic rocks in the Lake Eleanor quadrangle. Explanation 

found on page 12. 

11 
35 65 90 

• Tonalite of Poopenaut Valley 

p 35 65 90 

• Granite of Woods Ridge 

Figure 8. Continued. 

12 

35 65 90 

• Tonalite of Granite Creek 

0 

EXPLANATION 

Q Quartz 

A Alkali feldspar 

including plagioclase 

(An 0 • 5 average 

composition) 

P Plagioclase 

(Ans-loo) 

Diorite 

and 

5 gabbro 

A~--~----------~------------+-~~~~~~~p 

10 35 65 90 
I/) 

w 

0 

0 

~ 

u. 

0 

a: 

w 

co 

~ 

:::> 

z 

0 Sentinel Granodiorite 

10 • Granodiorite of Yosemite Creek 

5 

0 

0 Granodiorite of Hodgdon Ranch 

8 Tonalite of North Crane Creek 

10 8 Tonalite of Tamarack Creek 

• Quartz diorite of Aspen Valley 

5 

0 

0 Granite of Swamp Lake 

8 Granite of Bald Mountain 

10 • Granite of Rancheria Mountain 

181 El Capitan Granite 

5 

0 

8 Tonalite of Tueeulala Falls 

0 Granodiorite of Crane Flat 

10 • Granodiorite of Sawmill Mountain 

5 

0 

0 Granodiorite of Hazel Green Ranch 

• Tonalite of Poopenaut Valley 

10 

5 

0 

10

05 

[ ___ ·~JG.ra•n•i~te~o-f•VV~o~o-d_s_R-id~g-e----'----~----~--~ - .!1 -1 

] • Tonalite of Granite Creek 

., IIIII • I 

5 10 15 20 25 30 35 40 

COLOR INDEX 

Figure 9. Histogrfims of color index 

(volume-percent mafic minerals) of 

granitic rocks. 

0 Sentinel Granodiorite 

10 • Granodiorite of Yosemite Creek 

5 

0 

0 Granodiorite of Hodgdon Ranch 

El Tonalite of North Crane Creek 

10 181 Tonalite ofTamarack Creek 

• Quartz diorite of Aspen Valley 

5 

0 

0 Granite of Swamp Lake 

[!] Granite of Bald Mountain 

10 • Granite of Rancheria Mountain 

181 El Capitan Granite 

5 

0 

El Tonalite of Tueeulala Falls 

0 Granodiorite of Crane Flat (f) • w Granodiorite of Sawmill Mountain 

'I ...J 

a.. 

~ 

<{ 

(f) 

u. 

0 

a: [?)[?) w 

co 

~ 

:::> 

z 0 Granodiorite of Hazel Green Ranch 

• Tonalite of Poopenaut Valley 

10 

5 

0 

Granite of VVoods Ridge 

] • Tonalite of Granite Creek 

.. 

2.55 2.60 2.65 2.70 2. 75 2.80 2.85 2.90 

SPECIFIC GRAVITY 

Figure 10. Histograms of bulk 

specific gravities of granitic rocks. 

13 
10 

w 

t: 

a: 

0 

z 

0 

z 

u 

en 

..... 

z 1000 w 

:2 

w 

...J 

w 

z 

..... 100 a: 

<( 

w 

w 

a: 

<( 

a: 

- 10 

~ 

u 

0 

a: 

en 

..... 

z 

w 

:2 

w 

...J 

w 

z 

..... 

a: 

<( 1000 w 

w 

a: 

<( 

a: 

100 

10 

14 

Granite of Rancheria Mountain 

LaCe Pr NdPmSm Eu Gd Tb Dy Ho Er Tm Yb Lu 

Granodiorite of Sawmill Mountain 

LaCe PrNd PmSm Eu Gd Tb Dy Ho Er Tm Yb Lu 

Tonalite of Granite Creek 

0 LE-244 

0 LE-153 

" LE-96 

La Ce Pr Nd PmSm Eu Gd Tb Dy Ho Er Tm Yb Lu 

Tonalite of Poopenaut Valley 

1000 c-r-r-r-r-r-r-.-.-.-.-.-.-.-.-~ 

100 

10 

w 

t: 

a: 

0 

z 

0 

z 

u 

en 

..... 

z 1000 w 

:2 

w 

...J 

w 

z 

..... 

a: 100 

<( 

w 

w 

a: 

<( 

ll: 

- 10 ~ 

u 

0 

0::: 

en 

..... 

z 

w 

~ 

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...J 

w 

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a: 

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a: 

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10 

CHEMICAL ELEMENTS 

o LE-1104 

o LE-258 

\l LE-31 

LaCe Pr NdPmSm Eu Gd Tb Dy Ho Er Tm Yb Lu 

Granite of Woods Ridge 

LaCe Pr Nd PmSmEu Gd Tb Dy Ho Er Tm Yb Lu 

Gabbro 

La Ce Pr Nd PmSm Eu Gd Tb Dy Ho Er Tm Yb Lu 

Figure 11. Chondrite-normalized rare-earth elements in plutonic rocks (see figure 

2 for location of samples). Instrumental neutron activation analyses of all samples 

by L.J. Schwarz. 
Table 1. Chemical and trace element analyses, norms, modal analyses, and specific 

gravities of plutonic rocks 

[Chemical analyses by V.F. McDaniel and P.E. Bristow using a combination of X-ray fluorescence and 

chemical methods. Trace-element analyses by V.F. McDaniel using X-ray fluorescence methods. Modal 

analyses and specific gravities by Oleg Polovtzoff. CIPW norm (Cross and others, 1902)). 

Sample------

sio2--------- Al2o3--------

Fe203--------

Fe0----------

MgO----------

CaO----------

Na 2o---------

~~~;::::::::: 

H2o----------

Tio2---------

P2o5---------

Mno----------

C02----------

Total------

Ba----------

Ni---------- Rb----------

Sr----------

Y-----------

Q-----------

c-----------

or----------

ab----------

an----------

ne----------

di----------

hy----------

ol----------

mt----------

il----------

ap----------

Total---

Quartz-------

Potassium 

feldspar---

Plagioclase--

Ma fie--------

minerals---

Total------

Pyroxenite 

LE-1044 

42.60 

9.66 

3.93 

6.16 

22.02 

7.93 

.98 

.13 

4.89 

.08 

.42 

.ll 

.149 

.08 

99.14 

55 

470 

<5 

106 

12 

.82 

8.81 

22.93 

14.30 

12.48 

33.49 

6.06 

.85 

.28 

100.01 

3.01 

Tonalite of Granite Creek 

Gabbro 

LE-1040 LE-1096 LE.'-103 

Contact 

facies 

LE-96 

Chemical analyses (weight percent) 

42.54 

20.53 

3.92 

5.88 

8.36 

13.07 

2.02 

.34 

1. 79 

.15 

1. 76 

.08 

.107 

.06 

100.61 

43.07 

19.33 

2.81 

5.52 

11.56 

12.16 

1.38 

.35 

2.89 

.25 

1.07 

.ll 

.us 

.05 

100.6 7 

43.50 

16.41 

5.98 

7.67 

7.66 

13.10 

1.53 

.36 

1. 70 

.16 

1.20 

.17 

.163 

.05 

99.65 

44.40 

12.98 

1.19 

11.30 

10.98 

10.98 

2.06 

.62 

2.06 

.07 

1.95 

.15 

.188 

.29 

99.09 

Main 

facies 

LE-153 

59.21 

16.66 

.82 

6.00 

3.55 

6.31 

2.49 

2.13 

1.51 

.09 

.75 

.19 

.118 

.23 

100.06 

LE-244 

61.69 

15.86 

.94 

5.23 

2.89 

6.21 

2.43 

2.44 

.68 

.10 

.68 

.17 

.120 

.07 

99.51 

Trace-element analyses (parts per million) 

ll2 

40 

<5 

610 

11 

2.04 

9.28 

46.60 

4.36 

14.18 

13.57 

5.76 

3.39 

.19 

100.01 

2.98 

76 

94 

5 

620 

<5 

80 

29 

<5 

425 

7 

177 

49 

ll 

163 

33 

CIPW norms (weight percent) 

2.12 

10.73 

46.69 

6.79 

11.48 

21.77 

4.18 

2.09 

.27 

100.01 

2.18 

13.24 

37.70 

22.25 

4.20 

8.84 

8.87 

2.33 

.41 

100.01 

3.79 

14.13 

25.18 

2.12 

24.02 

24.80 

1. 79 

3.83 

.37 

100.01 

Modal analyses (volume percent) 

Bulk specific gravities 

2.95 3.02 3.08 

840 

28 

75 

335 

13 

14.77 

12.81 

21.45 

28.50 

1. 75 

17.62 

1.21 

1.45 

.46 

100.01 

27 

1 

43 

29 

100 

2.81 

920 

21 

76 

335 

14 

18.71 

14.61 

20.84 

25.50 

3.82 

13.43 

1.38 

1.31 

.41 

100.01 

22 

2 

49 

28 

101 

2. 79 

Granite 

of 

Woods 

~ LE-1092 

73.76 

14.02 

.73 

.96 

.57 

2.32 

2.93 

4.14 

.30 

.12 

.24 

.os 

.033 

.15 

100.35 

1550 

12 

56 

295 

<5 

34.98 

.69 

24.52 

24.85 

u.o1 

2.25 

1.06 

.46 

.19 

100.01 

34 

28 

31 

8 

101 

2.65 

15 
Table 1. Chemical and trace element anal~ses 2 norms2 modal anal~ses 2 and s12ecific 

gravities of (2lutonic rocks-Continued 

Grano- GranoTonalite Grano- Grano- diorite Tonalite Tonalite Tonalite diorite Sentine 1 

of diorite diorite of of of of of GranoTueeulala of Bald of Swamp Rancheria Aspen Tamarack N Crane Hodgdon diorite 

Falls Mountain Lake Mountain ~ Creek Creek Ranch 

Sample------ LE-60 LE-28 LE-111 LE-175 LE-1020 LE-41 ~ LE-6 LE-1008 

Chemical analyses (weight percent) 

Si02--------- 68.40 71.08 72.54 72.18 62.16 62.79 64.16 67.56 64.69 

Al203-------- 15.62 14.93 14.86 14.61 17.42 16.77 16.46 16.07 16.86 

Fe2or------- 1.66 .85 .88 .78 1.99 2.11 1.81 1.58 1.92 

FeO---------- 2.04 1.48 1.32 1.44 3.22 3.08 2.56 1.68 2.14 

MgO---------- 1.32 .59 .so .46 2.32 2.21 2.06 1.31 1.54 cao---------- 3.69 2.57 2.23 2.10 5.68 5.30 5.24 3.06 5.00 

Na20--------- 3.86 3.31 3.48 3.86 3.68 3.62 3.73 3.37 4.00 

~~g;::::::::: 2.38 3.70 3.96 3.07 1.58 2.00 1.84 2.95 2.06 

.60 .39 .35 .34 .69 .82 .72 1.02 .54 

H2o---------- .10 .19 .05 .04 .11 .20 .14 .79 .16 

Ti02--------- .52 .33 .31 .32 .64 .70 .74 .59 .73 

P2os--------- .13 .10 .12 .11 .25 .21 .21 .21 .21 

MnO---------- .100 .069 .054 .063 .107 .105 .077 .061 .on C02---------- .05 .09 .07 .07 .06 .09 .11 .12 .06 

Total------ 100.4 7 99.68 100.72 99.44 99.91 100.01 99.86 100.32 99.98 

Trace element analyses (parts per million) 

Ba----------- 820 980 860 1050 680 820 780 940 800 

Ni----------- 25 22 16 18 21 19 24 17 21 

Rb----------- 86 95 111 98 43 57 37 82 54 

Sr----------- 310 265 215 265 530 460 590 485 640 

Y------------ 8 <5 <5 5 <5 5 <5 8 <5 

CIPW norms (weight percent) 

Q------------ 26.64 31.15 31.30 32.71 18.45 19.18 21.40 28.79 21.03 

c------------ .30 1.06 1.08 1.40 2.31 

or----------- 14.10 22.08 23.34 18.33 9.43 11.95 11.00 17.71 12.27 

ab----------- 32.75 28.29 29.37 32.99 31.44 30.97 31.92 28.97 34.11 

an----------- 17.51 12.22 10.25 9.80 26.60 23.87 22.99 14.03 22.14 ne-----------

di----------- .16 1.08 1.54 1.19 

by----------- s.oo 3.10 2.52 2.76 9.20 8.03 6.60 4.25 4.58 

ol-----------

mt----------- 2.41 1.25 1.27 1.14 2.91 3.09 2.65 2.33 2.81 

il----------- .99 .63 .59 .61 1.23 1.34 1.42 1.14 i.40 

ap----------- .31 .24 .28 .26 .60 .50 .so .51 .so 

Total---- 100.01 100.01 100.01 100.01 100.01 100.01 100.01 100.01 100.01 

Modal analyses (volume percent) 

Quartz------- 25 32 25 35 20 28 24 31 22 

Potassium 11 21 30 20 1 6 5 14 5 

feldspar---

Plagioclase-- 52 39 38 39 61 51 56 47 59 

Mafic-------- 12 8 8 6 19 16 15 7 13 

minerals---

Total----- 100 101 101 100 101 101 100 99 99 

Bulk specific gravities 

2. 70 2.66 2.64 2.67 2.75 2.75 2.74 2.64 2. 72 

16 
Table 1. Chemical and trace element analyses, norms, modal ·analyses, and specific 

gravities of plutonic rocks-Continued 

Sample------

Si02---------

Al203--------

Fe203--------

Fe0----------

MgO----------

CaO----------

Na 2o--------- K2o----------

H2o+--------- H2o----------

Ti02---------

P20s---------

Mn0----------

C02----------

Total------

Ba-----------

Ni-----------

Rb-----------

Sr-----------

Y------------

Q------------

c------------

or-----------

ab-----------

an-----------

ne-----------

di-----------

hy-----------

ol-----------

mt-----------

il-----------

ap-----------

Total----

Quartz-------

Potassium 

feldspar---

Plagioclase--

Mafic--------

minerals---

Total-----

LE-31 

60.23 

17.16 

1.95 

4.17 

2.84 

6.32 

3.42 

1.85 

.77 

.09 

.81 

• 21 

.112 

.os 

99.89 

670 

17 

58 

480 

18 

14.83 

11.03 

29.21 

26.25 

3.28 

10.50 

2.85 

1.55 

.so 

100.01 

21 

2 

50 

27 

100 

2.78 

Tonalite of Poopenaut Valley 

Granodiorite of 

Hazel Green Ranch 

LE-208 

61.37 

17.74 

1. 78 

3.60 

2.28 

5.78 

3.98 

1.83 

.89 

.09 

.77 

.22 

.092 

.06 

100.48 

1050 

21 

62 

500 

20 

14.75 

10.87 

33.86 

25.28 

1. 73 

8.93 

2.60 

1.47 

.52 

100.01 

19 

1 

56 

23 

99 

2.77 

LE-122 

62.65 

16.84 

1.93 

3.16 

2.39 

5.70 

3. 70 

1.77 

.93 

.11 

.as 

.24 

.080 

.06 

100.41 

740 

34 

32 

680 

<5 

18.60 

10.53 

31.52 

24.28 

2.12 

7.94 

2.82 

1.63 

.57 

100.01 

17 

4 

57 

22 

100 

2.76 

Contact Main 

facies 

LE-258 LE-1104 LE-1081 LE-86 

Chemical analyses (weight percent) 

63.99 

16.81 

1.55 

2.56 

2.03 

5.03 

3.83 

2.32 

.66 

.10 

.67 

.19 

.072 

.04 

99.85 

65.39 

16.60 

1.02 

3.16 

1.50 

4.21 

3.96 

2.46 

.sa 

.12 

.62 

.19 

.084 

.os 

99.94 

71.34 

15.05 

.88 

1.18 

.71 

2. 73 

3.73 

3.44 

.42 

.12 

.40 

.12 

.051 

.06 

100.23 

48.65 

24.97 

.16 

3.90 

5.10 

14.24 

1.90 

.35 

1.00 

.10 

.22 

.13 

.085 

.48 

101.29 

Trace-element analyses (parts per million) 

1100 

29 

50 

630 

6 

1100 

17 

62 

375 

<5 

1350 

18 

69 

425 

<5 

CIPW norms (weight percent) 

19.04 

13.84 

32.72 

22.03 

1.54 

6.83 

2.27 

1.29 

.45 

100.01 

20.53 

.23 

14.66 

33.78 

19.80 

1.49 

1.19 

.45 

100.01 

29.62 

.52 

20.40 

31.68 

12.81 

2.65 

1.28 

• 76 

.29 

100.01 

245 

46 

<5 

760 

<5 

2.07 

16.12 

58.74 

9.13 

7.22 

s. 76 

.23 

.42 

.31 

100.01 

Modal analyses (volume percent) 

19 

5 

56 

20 

100 

22 

4 

55 

19 

100 

29 

18 

45 

8 

100 

Bulk specific gravities 

2.73 2. 72 2.66 

11 

0 

77 

12 

100 

2.81 

facies 

LE-90 

63.74 

16.29 

1.49 

3.00 

2.45 

5.13 

3.29 

2.26 

.88 

.16 

.60 

.17 

.084 

.06 

99.60 

710 

28 

81 

405 

14 

20.82 

13.56 

28.26 

23.36 

1.10 

9.16 

2.19 

1.16 

.41 

100.01 

26 

7 

48 

20 

101 

2. 73 

Granodiorite of 

Sawmill Mountain 

LE-1036 

69.99 

15.18 

1.05 

1. 74 

.87 

2.92 

4.20 

2.34 

.sa 

.16 

.36 

.17 

.082 

.06 

99.70 

960 

22 

51 

335 

<5 

28.99 

.85 

13.98 

35.93 

13.52 

4.10 

1.54 

.69 

.41 

100.01 

31 

9 

51 

10 

101 

2.65 

LE-249 

71.48 

15.10 

.as 

1.40 

.52 

2.16 

2.94 

4.14 

.75 

.37 

.29 

.13 

.065 

.31 

100.51 

940 

11 

120 

235 

<5 

33.12 

2.19 

24.69 

25.11 

9.96 

2.83 

1.24 

.56 

.31 

100.01 

26 

30 

37 

7 

100 

2.63 

LE-183 

72.12 

14.26 

1.04 

1.28 

.39 

1. 71 

3.76 

4.19 

.52 

.10 

.32 

.10 

.oso 

.07 

99.91 

920 

16 

75 

165 

<5 

30.01 

.68 

24.95 

32.06 

7.89 

2.04 

1.52 

.61 

.24 

100.01 

30 

28 

38 

4 

100 

2.65 

17 
18 

Table 2. Chemical and trace-element 

analyses and norms of trachyandesite 

IChemical analyses by B.W. King, L.F. 

·Espos, and M.J. Cremer using a combination 

of X-ray fluorescence and chemical 

me'thods-. Ba, Rb, S, -Sr, Y, Zn, and Zr 

determined by x-ray fluorescence methods by 

B.W. King and ·L.F. Espo·s. Co, Cr, Cu, Sc, 

and V determined by quantitative 

spectrographic methods by Chris 

Heropoulos. CIPW norm (Cross and others, 

1902)]. 

Sample------ LE-136 LE-134 

Chemical analyses (weight percent) 

s i02_.;. ______ _ 

Al203--------

Fe203--------

FeO----------

MgO----------

Cao----------

Na --EJ---------

K20---------- :H

2

o+ ________ _ 

:RiO----------

T i 0;l---------

P20s---------

Mri0-----------

C02----------

Total------

5'6.16 

17.29 

2.62 

3.96 

3.91 

6.59 

3.37 

2.99 

.4'5 

.20 

.98 

.44 

.113 

.07 

99.14 

56.17 

17.32 

3.80 

2.78 

4.07 

6.61 

3.41 

2.46 

.89 

.52 

.88 

.43 

.114 

.18 

99.63 

Trace-element analyses (parts per million) 

Ba----------- 1.,300 l-,500 

·Co----------- 19 22 

·c r----------- 56 170 

Cu------------- 40 78 

·Rb----------- 65 48 

s------------ <7 30 

Sc----------- 14 13 

s·r----------- 840 960 

v------------ 130 160 

Y------------ 18 18 

Zn----------- 83 8"2 

Zr----------- 220 215 

CIPW norms (weight .percent) 

"Q------------ 6.2'5 8.90 

or------------ :1'7 o-95 14;83 

·ab----------- 28.97 29.43 

an----------- 23.59 ·25.18 

·d i ----------- 5.39 4.24 

by----------- .U.06 9.10 

nit----------- 3.86 5•62 

i"l----------- 1.89 1.'-tl 

ap----------- 1.06 1.04 

Total---- 100.03 100.02 
Table 3. Chemical and spectrographic analyses of metasedimentary 

rocks 

[Chemical analyses by P.L.D. Elmoc-e, Gillison Chloe, J.L. Kelsey, Hezekiah 

Smith, and James Glen, using ~apid-~ock methods. Semiquantitative 

spect~og~aphic analyses by R.E. Mays. Results dete~ined spect~og~aphically 

a~e identified with geomet~ic b~ackets whose bound~ies a~e 1.2, 0.83, 0.56, 

0.38, 0.26, 0.18, 0.12, and so on, but a~e ~epo~ted a~bit~adly as midpoints 

of these b~ackets, that is, 1, 0.7, 0.5, 0.3, 0.2, 0.15, 0.1, and so on. The 

p~ecision of a ~epo~ted value is app~oximately plus o~ minus one b~acket at 68 

pe~cent, o~ two b~ackets at 95 pe~cent confidence. H = not detected. Looked 

fo~. but not detected in any samples: Ag, As, Au, Be, Bi, Cd, Ce, Co, Eu, Ge, 

Hf, In, Li, Ko, Hb, Pb, Pd, Pt, Re, Sbl7Sn, Ta, Te, Th, Tl, U, V, W, Zn] 

Black Banded Qua~tz-mica 

slate ho~nfels schist Qua~tzite 

Sample------ LE-160 LE-68 LE-143 LE-99 LE-133 

Chemical analyses (weight pe~cent) 

Si02--------- 73.7 79.1 91.1 92.5 95.0 

Al203-------- 14.4 6.4 3.9 3.2 2.5 

Fe2o3-------- 2.2 1.0 1.0 .00 .00 

FeO---------- .36 1.6 .24 .27 .31 

KgO---------- .77 1.9 .20 .46 .08 

CaO---------- .06 6.4 .06 .10 .08 

Ha2o--------- .15 1.1 .12 .11 .08 

K20---------- 4.0 .29 .85 1.5 .63 

H2o+-··------- 2.7 .75 1.3 .72 .25 

~f~~=~-======= .26 .11 .09 .06 .06 

.87 .31 .28 .14 .18 

P2o5-·-------- .07 .57 .03 .04 .00 

KnO--· -------- .00 .10 .00 .00 .oo 

C02---------- <.05 <.05 <.05 <.05 <.05 

Total------ 100 100 99 99 99 

Powde~ 

density 

(gm/cm8 ) 2.76 2.76 2.72 2.72 2.72 

Semiquantitative spec t~og~aphic analyses (pa~ts pe~ million) 

B----------- 100 H H H H 

Ba---·------- 2000 200 150 200 500 

c~---------- 70 100 15 10 3 

Cu---------- 20 10 7 7 H 

Ga---------- 15 N H H H 

Hi---------- H 70 H H H 

Sc---------- 15 3 y H N 

s~----------- 30 200 y 10 H 

V----------- 100 100 N H y 

Y----------- 20 20 H H y 

Yb---------- 2 2 H H H 

z~---------- 100 50 150 70 70 

19 
Table 4. Uranium-lead age determinations on zircon from granitic rocks 

[Determinations by T.W. Stern. Constants used: 258U/ 255U=l37.88; 238A=0.155xlo-9 years. Analytical uncertainties 

"'±3 percent] 

Sample------

Parts Pb 

per u million Th 

Atomic z o aPb/ z o &pb 

ratios 207pbf20&pb 

2 o -Pb/ z o &pb 

Age zoapbj2S2Th 

(Ma) 207pbj2S5ij 

206pbj2S8ij 

20 

Grano- GranoGranite diorite Tonalite diorite of 

Tonalite of of of Hazel 

·of Woods Sawmill Poopenaut Green 

Granite Creek Ridge Mountain Valley Ranch 

LE-153 LE-244 LE-1092 LE-1036 LE-31 LE-1104 LE-90 

16.26 20.99 19.40 7.45 8.62 10.24 14.64 

635.7 841.9 811.5 408.9 435.5 533.2 5ll.8 

137.2 172.1 249.2 126.7 204.3 204.1 1161 

.07992 .07518 .09887 .09928 .19289 .13779 .75710 

.05549 .05374 .05958 .05440 .06566 .05456 .05730 

.00033 .00029 .00067 .00059 .oo 125 .00038 .00069 

158.8 156.6 111.2 89.3 109.9 117.5 114.8 

169.6 163.1 15 2.8 110.7 111.7 120.1 112.6 

165.7 162.6 150.9 116.1 114.1 118.8 115.3 

Table 5. Potassium-argon age determinations of sample LE-1104 from the 

tonalite of Poopenaut Valley 

[Potassium measu~ements by P.R. Klock. 

Constants used: ~~=4.962x10- 10y~·l; 

~c=0.58lxl0- 10 y~- ; 4°K/IK=l.l67xl0-14 ) 

Radiogenic 

K20 4oA~ 

Kine~al (weight '-> (mol/gm) 

Biotite 8.48 t26.3xl011 

Ho~nblende 0.905 153.7x1012 

A~gon measu~ements by J.C. Von Essen. 

Radiogenic 40A~ Age 

<'-> (Ka) 

65.2 100.6±0.7 

84.6 114.3±0.7 

Tonalite 

of 

Tueeulala 

Falls 

LE-36 

23.37 

1260 

663.3 

.19556 

.05717 

.00060 

109.9 

109.0 

108.7 

687-049/45024 
Dodge and Calk-LAKE ELEANOR QUADRANGLE, CENTRAL 'SIERRA NEVAdA, CALIFORNIA-ANALYTICAL DATA-U.S. Geological Survey Bulletin 1585 I