I 

I 

A Strontium f$9topic SlUdy of ~ 

Plute,ps and •.fl.·•·· •···· ••• ·· ;ociate ; Rocks o;t;t,the 

Southern Sierra~ Nevada; and Viclhity, 

Califo.rnia 

U.S. GEOLOGICAL SURVEY BULLETIN 1920 
AVAILABILITY OF BOOKS AND MAPS OF THE U.S. GEOLOGICAL SURVEY 

Instructions on ordering publications of the U.S. Geological Survey, along with prices of the last offerings, are given in the current-year issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices of available U.S. Geological Survey publications released prior to the current year are listed in the most recent annual "Price and Availability List" Publications 

that are listed in various U.S. Geological Survey catalogs (see back inside cover) but not listed in the most recent annual "Price and 

Availability List" are no longer available. 

Prices of reports released to the open files are given in the listing "U.S. Geological Survey Open-File Reports," updated monthly, which is for sale in microfiche from the U.S. Geological Survey, Books and Open-File Reports Section, Federal Center, Box 

25425, Denver, CO 80225. Reports released through the NTIS may be obtained by writing to the National Technical Information 

Service, U.S. Department of Commerce, Springfield, VA 22161; please include NTIS report number with inquiry. 

Order U.S. Geological Survey publications by mail or over the counter from the offices given below. 

BY MAIL 

Books 

Professional Papers, Bulletins, Water-Supply Papers, Techniques 

of Water-Resources Investigations, Circulars, publications of general interest (such as leaflets, pamphlets, booklets), single copies of Earthquakes 

& Volcanoes, Preliminary Determination of Epicenters, and some miscellaneous reports, including some of the foregoing series that have gone 

out of print at the Superintendent of Documents, are obtainable by mail 

from 

U.S. Geological Survey, Books and Open-File Reports 

Federal Center, Box 25425 

Denver, CO 80225 

Subscriptions to periodicals (Earthquakes & Volcanoes and 

Preliminary Determination of Epicenters) can be obtained ONLY from 

the 

Superintendent of Documents 

Government Printing omce 

Washington, D.C. 20402 

(Check or money order must be payable to Superintendent of Documents.) 

Maps 

For maps, address mail orders to 

U.S. Geological Survey, Map Distribution 

Federal Center, Box 25286 

Denver, CO 80225 

Residents of Alaska may order maps from 

Alaska Distribution Section, U.S. Geological Survey, 

New Federal Butlding -Box U 

101 Twelfth Ave., Fairbanks, AK 99701 

OVER THE COUNTER 

Books 

Books of the U.S. Geological Survey are available over the 

counter at the following Geological Survey Public Inquiries Offices, all 

of which are authorized agents of the Superintendent of Documents: 

• WASHINGTON, D.C.--Main Interior Bldg., 2600 corridor, 

18th and C Sts., NW. 

• DENVER, Colorado--FederalBldg., Rm.169, 1961 Stout St. 

• LOS ANGELES; California--Federal Bldg., Rm. 7638, 300 N. 

Los Angeles St. 

• MENLO PARK, California--Bldg. 3 (Stop 533), Rm. 3128, 

345 Middlefield Rd. 

• RESTON, Virginia--503 National Center, Rm. 1C402, 12201 

Sumise Valley Dr. 

• SALT LAKE CITY, Utah--Federal Bldg., Rm. 8105, 125 

South State St. 

• SAN FRANCISCO, California--Customhouse, Rm. 504, 555 

Battery St. 

• SPOKANE, Washington--U.S. Courthouse, Rm. 678, West 

920 Riverside Ave .. 

• ANCHORAGE, Alaska--Rm. 101, 4230 University Dr. 

• ANCHORAGE, Alaska--Federal Bldg, Rm. E-146, 701 C St. 

Maps 

Maps may be purchased over the counter at the U.S. Geological Survey offices where books are sold (all addresses in above list) and 

at the following Geological Survey offices: 

• ROLLA, Missouri--1400 Independence Rd. 

• DENVER, Colorado--Map Distribution, Bldg. 810, Federal 

Center 

• FAIRBANKS, Alaska--New Federal Bldg., 101 Twelfth Ave. 
A Strontium Isotopic Study of 

Plutons and Associated Rocks of the 

Southern Sierra Nevada and Vicinity, 

California 

By R.W. KISTLER and D.C. ROSS 

Rubidium and strontium concentrations and strontium isotopic 

compositions for granitic rocks of the southern Sierra Nevada and 

vicinity 

U.S. GEOLOGICAL SURVEY BULLETIN 1920 
DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, JR., Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

Any use of trade, product, or firm names in this publication 

is for descriptive purposes only and does not imply 

endorsement by the U.S. Government 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1990 

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 

Kistler, Ronald Wayne, 1931-

A strontium isotopic study of plutons and associated rocks of the southern 

Sierra Nevada vicinity, California I by R.W. Kistler and D.C. Ross. 

p. cm.-(U.S. Geological Survey bulletin; 1920) 

Includes bibliographical references (p. ). 

Supt. of Docs. no.: I 19.3:1920 

1. Rocks, Igneous-Sierra Nevada Mountains Region (Calif. and Nev.) 

2. Geology-Sierra Nevada Mountains Region (Calif. and Nev.) 3. Rubidiumstrontium dating. I. Ross, Donald Clarence, 1924- . II. Title. Ill. Series. 

QE75.89 no. 1920 557.3 s-dc20 90-3470 

[QE461] [552' .3'097944] CIP 
CONTENTS 

Abstract 1 

Introduction 1 

Analytical methods 1 

Observations 2 

Terrane boundary in the southern Sierra Nevada 2 

Isotopic and chemical characteristics of plutons in the southern 

Sierra Nevada 3 

Summary and conclusions 4 

References cited 4 

FIGURES 

1. Map of California and Nevada showing the Sri=0.706 isopleth determined for 

Mesozoic and Cenozoic plutons 9 

2. Map of the southern Sierra Nevada and El Paso Mountains strontium isotope 

isopleths and three age groups of plutons that crop out in the area 10 

3. Fields of Sri versus o

18 0 per mil for plutons in and peripheral to the 

Salinian-western Mojave terrane (Panthalassan lithosphere) in the southern 

Sierra Nevada and for plutons in the central Sierra Nevada and eastern 

Mojave Desert (North American lithosphere) ll 

4. Rb versus Sr for plutons with Sri< 0.706 peripheral to the Salinian-western 

Mojave terrane in Panthalassan lithosphere and peripheral to the Sierran 

terrane in North American lithosphere in the Walker Lake 1 o by 2° 

quadrangle 12 

TABLE 

1. Rubidium and strontium data for plutons and associated rocks of the southern 

Sierra Nevada and vicinity 13 

Contents Ill 

A Strontium Isotopic Study of 

Plutons and Associated Rocks of the 

Southern Sierra Nevada and Vicinity, California 

By R.W. Kistler and D.C. Ross 

Abstract 

Plutons and associated rocks in the southern Sierra 

Nevada and vicinity range in age from about 240 to 80 Ma. 

Triassic plutons form a narrow northwest-trending belt that 

lies between predominantly Middle Jurassic plutons on the 

east and Cretaceous plutons on the west. The belt of Triassic 

plutons is along a boundary between plutons with chemical 

and isotopic compositions that reflect source materials derived from two different lithospheres called North American 

and Panthalassan. The two lithospheres are in tectonic 

contact expressed by sheared plutons of the Middle Jurassic 

lnyo Mountains intrusive epoch, by sheared plutons in the 

Triassic belt, and by fault zones exposed in scattered roof 

pendants of metamorphosed sedimentary rocks of probable 

Paleozoic age. Late Cretaceous plutons engulf the tectonic 

contact along much of its length, and in the southern Sierra 

Nevada constrain the time of shearing to between about 160 

and 80 Ma. 

Oxygen isotopes are different in plutons with initial 87Sr/88Sr (Sri) values greater than 0.706 in the two lithosphere types, and they indicate a significantly greater sedimentary component in plutons with source materials in 

Panthalassan lithosphere than in plutons with source materials in North American lithosphere. In contrast to the North 

American lithosphere, there is no evidence that a Proterozoic 

sialic crystalline basement is present in the Panthalassan 

lithosphere. The plutons with Sr1 > 0. 706 and with source 

materials in Panthalassan lithosphere probably acquired that 

isotopic characteristic by assimilation of sediments derived 

from a Proterozoic sialic crust. Plutons with Sri< 0. 706 have 

chemical and Nd isotopic compositions that indicate timeintegrated depletion of large-ion-lithophile elements in the 

magma source regions in Panthalassan lithosphere relative 

to the magma source regions in North American lithosphere. 

INTRODUCTION 

Rubidium and strontium concentrations and 87Sr/ 86Sr values are documented herein for samples of plutons 

and associated rocks from 238 locations in the southern 

Manuscript approved for publication, December 8, 1989. 

Sierra Nevada and vicinity. The goals of this investigation 

were to determine ages of rock units, to aid in the 

separation of plutons in poorly exposed areas, to determine the pattern of variation of initial 87Srf6

Sr (hereafter called SrJ for plutons, and to constrain more 

rigorously the boundaries of the continental Sierran and 

Salinian-western Mojave terranes defined on the basis of 

the Sri of their plutons by Kistler (1978) and by Kistler 

and Peterman (1978). These new data expand the boundaries of the Salinian-western Mojave terrane and make it 

part of the Panthalassan lithosphere that lies west of the 

tectonic boundary, whereas the Sierran terrane is made 

part of the North American lithosphere that lies east of 

the tectonic boundary. 

The Sri=0.706 isopleth (modified from Kistler, 

1983) determined for plutons in California and Nevada 

(fig. 1) was interpreted to approximate the position of the 

margin of Proterozoic sialic crust in the region (Kistler 

and Peterman, 1978). This isopleth was also used as a 

piercing point across faults, like the San Andreas and 

Garlock, to restore offsets of basement rocks along these 

structures (Kistler and others, 1973; Kistler and Peterman, 1978). A simplified bedrock map of the southern 

Sierra Nevada and the El Paso Mountains with numbered locations of samples analyzed for this report is 

shown in figure 2. Most of these same locations are 

shown on the more detailed basement map of the southern Sierra Nevada by Ross (1987). 'The area shown in 

figure 2 is entirely of Panthalassan lithosphere except fm 

an area of North American lithosphere in the eastern 

Sierra Nevada intruded predominantly by Jurassic plutons. 

Analytical Methods 

Analytical data are given in table 1. Concentrations 

of Rb and Sr were determined by energy-dispersive 

X-ray fluorescence using a direct-comparison method on 

standard samples of similar bulk composition. Uncertainties in Rb/Sr are in the range ±3 percent or less at 2 

sigma by this method. All Sr isotopic ratios were normalIntroduction 
ized to 86Srl8

Sr=0.1194. The measured 87Srl6Sr values 

have a coefficient of variation less than 0.01 percent and 

were obtained from a mass spectrometer that yielded 87Srl6

Sr values of 0.70800±3 and 0.71023±3 from replicate analyses of the E and A and NBS 987 SrC03 

standards, respectively. Values of Sri for plutons were 

determined from values of the intercept on the ordinate 

using York (1969) isochron regressions, by calculation 

for individual samples of known age, and by calculation 

for an assumed age of 100 Ma for those units with only 

one sample and no other age data. The decay constant for 

Rb is 1.42X 10-11 yr- 1 • Pluton names given in table 1 are 

from Ross (1987). 

OBSERVATIONS 

Ages of the plutons investigated range from about 

240 Ma to about 80 Ma. Triassic plutons (240 to 218 Ma) 

lie in a narrow northwest-trending belt (fig. 2) that 

extends from the El Paso Mountains through the Walker 

Pass area almost to Sherman Peak just north of the map 

area in the Hockett Peak quadrangle at about long. 118° 

22' W. These plutons are bounded on the east by plutons 

of Middle Jurassic age (177 ± 5 Ma) collectively called the 

Sacatar Quartz Diorite of Miller and Webb (1940), by 

isolated roof pendants of sedimentary rocks that contain 

bedded barite (Taylor, 1984) similar to the Paleozoic 

metamorphic rocks of the western Sierra Nevada foothills (Weber, 1963), and by scattered small felsic plutons 

of Late Cretaceous age. To the west of the belt of Triassic 

plutons, the bedrock is predominantly plutons of Cretaceous age (120 to 80 Ma) that intruded scattered roof 

pendants of sedimentary and volcanic rocks of Paleozoic 

and Mesozoic age called the Kings and Erskine Canyon 

sequences (Saleeby and Busby-Spera, 1986) and Pampa 

Schist of Dibblee and Chesterman (1953). 

The Sri=0.706 isopleth extends from the Garlock 

fault to the north margin of the map area in several 

northeast- and northwest-trending segments (fig. 2). The 

0.706 isopleth is offset about 9 km in a right-lateral sense 

by the Kern Canyon fault. The Sri values less than 0.706 

can be contoured. However, these isopleths do not 

parallel the 0.706 isopleth, and the 0.704 contours intersect the 0.706 contour at a 90° angle. This results in 

plutonic rocks with Sri of 0.70325 and 0.70656 (Nos. 97 

and 82, respectively, fig. 2) within 1 km of each other in 

the west-central part of the map area. The Sri values of 

the Triassic plutons, in the belt trending northwest from 

the El Paso Mountains to the vicinity of Sherman Peak 

just north of the map area, are all less than 0.706 and are 

as low as 0.70362 in the quartz diorite of Walker Pass and 

the quartz diorite and trondjhemite of the El Paso 

Mountains. Plutons of this age and isotopic characteristic 

are found in a narrow belt discontinuosly exposed for 240 

km from the Mineral King pendant in the north to near 

Barstow in the Mojave Desert to the south (fig. 1). The 

unradiogenic Sri values of these plutons are a major 

anomaly in the region of plutons with Sri >0.706 in 

California. 

Four samples in a traverse across the map area 

(Nos. 97, 82, 202, and 206, fig. 2 and table 1) with Sri 

values that range from 0.7032 to 0.7083 were investigated 

for Sm and Nd concentrations and initial 143Nd/ 44Nd 

values (DePaolo, 1981). Initial 143Nd/ 44Nd (Ndi) correlates negatively with Sri. The Ndi (epsilon Nd(T)) for 

sample 26-73 (No. 206, fig. 2 and table 1) from the 

quartz diorite of Walker Pass was recalculated to be +2.8 

at the emplacement age of 240 Ma given in this report, 

rather than +0.6 at the 86 MaK-Ar age for hornblende 

(Evernden and Kistler, 1970) used by DePaolo (1981). 

Oxygen isotopic compositions were determined for 

many of the same samples for which strontium isotopic 

data were already obtained (Masi and others, 1976, 1981; 

Saleeby and others, 1987). In the southern Sierra Nevada, there is a good correlation between strontium and 

oxygen isotope ratios, but there is a pronounced greater 

proportion of plutons with high-18 0 upper-crustal isotopic signatures relative to plutons in other parts of the 

Sierra Nevada and in the Mojave Desert (fig. 3). The 

high-18 0 signature is similar to that of plutons in the 

northwestern Mojave Desert and the Salinian block to 

the south and northwest, respectively (Masi and others, 

1976, 1981). 

Terrane Boundary in the 

Southern Sierra Nevada 

The narrow northwest -trending belt of Triassic 

plutons marks a boundary between two different terranes, each characterized by distinct metamorphosed 

sedimentary rocks in roof pendants. The boundary, 

where not engulfed by Cretaceous plutons, appears to be 

tectonic and is characterized by sheared and foliated 

plutons of Triassic and Jurassic age. The east margins of 

the Triassic plutons and the west margins of the Middle 

Jurassic plutons are sheared. This same boundary is 

exposed discontinuously northwestward as fault zones in 

the Mineral King and Boyden Cave roof pendants and is 

expressed as the Melones fault zone in the western 

foothills of the Sierra Nevada (fig. 1). The fault zone in 

the Mineral King roof pendant contains a mylonitic 

dacite with Sri of 0.7046 and a U/Pb zircon age of 240 Ma 

(Busby-Spera, 1983), whereas the fault zone in the 

Boyden Cave roof pendant contains badly deformed 

Triassic and Jurassic fossils (Moore and Dodge, 1962; 

Girty, 1985). South of the Garlock fault, the boundary 

can be followed almost to Barstow in the Mojave Desert 

as a narrow belt of plutons of Triassic and Jurassic age 

that have unradiogenic Sri< 0.706 (Kistler and Peterman, 1978; Kistler, unpublished data). The southern part 

2 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
of the boundary from the vicinity of Walker Pass in the 

southern Sierra Nevada to the vicinity of Barstow in the 

Mojave Desert is the same as the boundary between two 

terranes characterized by plutons with Sri> 0.706 called 

the Sierran and the Salinian-western Mojave by Kistler 

and Peterman (1978). 

These new data indicate that the Salinian-western 

Mojave terrane of Kistler and Peterman (1978) extends 

well into the Sierra Nevada and that wall rocks of plutons 

with Sri> 0. 706 include the metamorphosed sedimentary 

and volcanic rocks of early Mesozoic and mid-Cretaceous age called the Kings sequence and the Erskine 

Canyon sequence, respectively, near Lake Isabella (Saleeby and Busby-Spera, 1986). The expanded terrane is 

herein called the Salinian-western Mojave-Kings terrane. 

The Kings sequence was first defined for Upper Triassic 

and Lower Jurassic sedimentary and volcanic rocks exposed in the Kings River Canyon north of the map area 

of figure 2 in the Boyden Cave roof pendant (Bateman 

and Clark, 1974); rocks of similar age and lithology 

(Christensen, 1963) are also found in the Mineral King 

roof pendant between the Boyden Cave roof pendant and 

the map area of figure 2. The region in the Sierra Nevada 

batholith that contains metamorphosed sedimentary and 

volcanic rocks of the Kings sequence was called the Kings 

terrane by Nokleberg (1983). However, the eastern part 

of the Kings terrane and rocks in roof pendants in the 

eastern part of the southern Sierra Nevada assigned to 

the Kings sequence (Saleeby and others, 1978; Nokleberg, 1983) are in the Sierran terrane and are excluded 

from the combined Salinian-western Mojave-Kings terrane of this report. These metamorphosed sedimentary 

rocks of roof pendants on the west margin of the Sierran 

terrane are similar to those found to the north in the 

western Sierra Nevada foothills (Weber, 1963). These 

pendants contain bedded barite indicating a protolith of 

Paleozoic age (Taylor, 1984; Diggles and others, 1985). 

To the south in the El Paso Mountains and along the 

west margin of the Sierran terrane into the central 

Mojave desert near Barstow, other metamorphic rock 

sequences crop out that are early and late Paleozoic in 

age and lithologically similar to the western facies rocks 

of west-central Nevada (Carr and others, 1981). 

Other metamorphosed wall rocks of the batholith 

in the western part of the southern Sierra Nevada are 

called the Pampa Schist, which consists of sillimanite and 

andalusite-bearing graphitic pelite interlayered with 

psammitic schist and local lenses of amphibolitic mafic to 

intermediate volcaniclastic rocks (Dibblee and Chesterman, 1953). This assemblage strongly resembles lower 

Mesozoic slaty rocks that lie depositionally above the 

Paleozoic Kings-Kaweah ophiolite belt about 50 km to 

the north (Saleeby, 1979). Blocks of quartzite and stratified sequences of quartz-rich turbidites intermixed with 

the Kings-Kaweah slaty strata suggest that these rocks 

and the Pampa Schist are a western facies of the Kings 

sequence (Saleeby and others, 1978). Basement rocks for 

the Kings sequence are unknown, except for the apparent 

westward overlap relation with Paleozoic ophiolitic rocks 

(Saleeby and others, 1978). Plagiogranite dikes that are 

about 300 Ma in age intruded the Paleozoic KingsKaweah ophiolite belt (Saleeby, 1982). Rocks mapped as 

the Kings sequence in the Tule River roof pendants 

(Saleeby and others, 1978) east of the Kaweah serpentinite melange (Saleeby, 1979) include 300-Ma volcanic 

rocks (Kistler and Sawlan, unpub. data, 1986). Other 

volcanic rocks in the Bean Canyon metamorphosed rocks 

section south of the Garlock fault and in the Salinianwestern Mojave terrane were tentatively dated at about 

300 Ma (R. J. Fleck, written commun., 1986) and give 

further support to a correlation of the metamorphosed 

sedimentary and volcanic rocks of the Salinian-western 

Mojave terrane with the Kings sequence. 

Isotopic and Chemical Characteristics of 

Plutons in the Southern Sierra Nevada 

The plutons that intruded the Salinian-western 

Mojave-Kings and Sierran terranes have isotopic and 

chemical characteristics that indicate different source 

materials for the magmas of each terrane. The lithospheres that include the Salinian-western Mojave-Kings 

and Sierran terranes are the Panthalassan and North 

American lithospheres, respectively. 

Plutons, in a northwest -trending belt in the western 

Sierra Nevada, which are described as strongly contaminated and reduced (Ague and Brimhall, 1987) on the 

basis of less than 6 mole percent Fe2 0 3 in their contained 

ilmenite and which lack hornblende and sphene in their 

mineral assemblages, have source materials in the Panthalassan lithosphere. Their chemical characteristics, 

unique in the Sierra Nevada, are interpreted to be due to 

assimilation of highly reducing pelites in the sedimentary 

rocks of the Kings sequence (Ague and Brimhall, 1987). 

The strongly contaminated and reduced plutons identified by Ague and Brimhall occur only in the restricted 

area of the Kings terrane as defined in this report. 

The high o18 0 values of plutons with source materials in Panthalassan lithosphere (Masi and others, 1976, 

1981; Ross, 1983; Saleeby and others, 1987), consistently 

greater than + 9 per mil in those with Sri > 0. 706 and 

often greater than +9 per mil in those with Sri< 0.706, 

also indicate significant sedimentary components in their 

parent magmas (fig. 3). In contrast, o180 values for all 

plutons with source materials in the North American 

lithosphere are less than +9 per mil (fig. 3). 

Concentrations of Rb in plutons having Sri< 0.706 

along the northern boundary of the Salinian-western 

Mojave-Kings terrane and derived from sources in Panthalassan lithosphere were consistently less than the 

concentrations of Rb in plutons having similar Sri values 

Observations 3 
along the margins of the Sierran terrane and derived 

from sources in North American lithosphere (Kistler and 

Peterman, 1978). This observation is still valid with the 

increased data now available. Rb is plotted against Sr for 

plutons with Sri< 0.706 that intruded the North American lithosphere in the Walker Lake 1° by 2° quadrangle 

(Robinson and Kistler, 1986) and intruded the Panthalassan lithosphere in the southern Sierra Nevada and 

vicinity (fig. 4). Plutons with these Sri< 0.706 values have, 

in general, Rb concentrations less than or greater than 

100 ppm in the Panthalassan and North American lithospheres, respectively. Also, in samples with Sri< 0.706, 

Sm and Nd concentrations are generally lower in plutons 

with source materials in the Panthalassan lithosphere 

than in plutons with source materials in North American 

lithosphere. In addition, the epsilon Nd values of plutons 

that intruded North American lithosphere are less positive than those for plutons with the same Sri (0.704) that 

intruded Panthalassan lithosphere. These chemical and 

isotopic characteristics indicate that the magma source 

for plutons with Sri< 0.706 is depleted in large-ionlithophile elements in the Panthalassan lithosphere relative to the North American lithosphere. 

Finally, a crustal model that compares near-surface 

geology with residual gravity, assuming perfect Airy-type 

isostasy, along a traverse from Visalia to Lone Pine 

across the southern Sierra Nevada (Oliver and Robbins, 

1982) crosses the tectonic boundary between the Panthalassan and North American lithospheres in the Mineral King roof pendant. In the Oliver and Robbins model, 

the depth to the Moho increases abruptly by 4 km, from 

about 30 to 34 km, across the subsurface projection of 

the lithospere boundary . This change indicates that the 

Panthalassan lithosphere is thinner. Therefore, the two 

lithospheres differ not only in chemical and isotopic 

characteristics but also in thickness. 

In the southernmost Sierra Nevada, distinctive 

gneisses are present that represent the deepest exposed 

levels of the Cretaceous Sierra Nevada batholithic belt 

(Sharry, 1981; Ross, 1985; Sams, 1986; Saleeby and 

others, 1987). Thermobarometric estimates of up to 8 kb 

for mineral equilibration in the gneiss complex and the 

plutons indicate that mid-crustal levels of the batholith 

are exposed here. These gneisses are predominantly 

Early Cretaceous (110-120 Ma) in age, and no direct 

remnants of Proterozoic sialic basement have been found 

at this level of the Panthalassan lithosphere (Sams, 1986; 

Saleeby and others, 1987). In contrast, strontium isotopic 

systematics of Phanerozoic plutons with Sri >0.706 and 

sources in the North American lithosphere are interpreted to indicate source materials for the plutons that are 

predominantly Proterozoic lower crust (Kistler and Peterman, 1978; Kistler and others, 1986). In addition, 

xenoliths entrained in Tertiary volcanic rocks that penetrate the North American lithosphere in the central 

Sierra Nevada include garnet granulites that represent a 

direct sample of the Proterozoic lower crust in that area 

(Domenick and others, 1983). 

SUMMARY AND CONCLUSIONS 

Three geographically distinct age groups of plutons 

were classified on the basis of this strontium isotopic 

study in the southern Sierra Nevada. In the study area, 

plutons in the eastern part are mostly Middle Jurassic in 

age (177±5 Ma), whereas plutons in the western part are 

mostly of Cretaceous age (120 to 80 Ma). A narrow 

northwest-trending belt of plutons of Triassic age (240 to 

218 Ma) lies between the Jurassic and Cretaceous plutons. 

The Triassic and Jurassic plutons are in tectonic 

contact along a shear zone that is engulfed by Late 

Cretaceous plutons along much of its length. The shear 

zone is exposed to the north as faults in pre-Jurassic wall 

rocks in the Mineral King and Boyden Cave roof pendants and as the Melones fault zone along the northwestern foothills of the Sierra Nevada. Distinct chemical, 

isotopic, and geophysical characteristics of the plutons on 

either side of this tectonic boundary permit the cryptic 

trace of the shear to be followed, even where it is 

destroyed by Cretaceous plutons. The profound differences in the chemical, isotopic, and geophysical characteristics of the plutons are interpreted to reflect magma 

sources in two different lithospheres called Panthalassan 

and North American on the west side and the east side of 

the tectonic boundary, respectively. 

REFERENCES CITED 

Ague, J.J., and Brimhall, G.H., 1987, Granites ofthe batholiths 

of California: Products of local assimilation and regionalscale crustal contamination: Geology, v. 15, p. 63-66. 

Bateman, P.C., and Clark, L.D., 1974, Stratigraphic and structural setting of the Sierra Nevada batholith, California: 

Pacific Geology, v. 8, p. 78-89. 

Busby-Spera, C.J., 1983, Paleogeographic reconstruction of a 

submarine volcanic center: geochronology, volcanology, 

and sedimentology of Mineral King roof pendant, Sierra 

Nevada, California: Ph.D. dissertation, Princeton, New 

Jersey, Princeton University, 290 p. 

Carr, M.D., Poole, F.G., Harris, A.G., Christiansen, R.L., 1981, 

Western facies Paleozoic rocks in the Mojave Desert, 

California: U.S. Geological Survey Open-File Report 

81-503, p. 15-17. 

Chen, J.H., and Moore, J.G., 1982, Uranium-lead isotopic ages 

from the Sierra Nevada batholith, California: Journal of 

Geophysical Research, v. 87, no. B6, p. 4761-4784. 

Christensen, M.N., 1963, Structure of the metamorphic rocks at 

Mineral King, California: California University Publications in Geological Sciences, Berkeley, California, v. 42, 

no. 4, p. 159-198. 

Collins, L.G., 1988, Hydrothermal differentiation and myrmekite-a clue to many geologic puzzles: Theophrastus Publications, S.A., Athens, Greece, 382 p. 

4 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
Cox, B.F., and Morton, J.L., 1980, Late Permian plutonism, El 

Paso Mountains, California: Geological Society of 

America Abstracts with Program, v. 12, no .3, p. 103. 

DePaolo, D.J., 1981, A neodymium and strontium isotopic 

study of the Mesozoic calc-alkaline granitic batholiths of 

the Sierra Nevada and Peninsular Ranges, California: 

Journal of Geophysical Research, v. 86, no. Bll, p. 

10470-10488. 

Dibblee, T.W., Jr., and Chesterman, C.W., 1953, Geology of the 

Breckenridge Mountain quadrangle, California: California Division of Mines and Geology, Bulletin 168, 56 p. 

Diggles, M.F., 1984, Peraluminous granite from the southern 

Sierra Nevada, California [abs.]: Geological Society of 

America Abstracts with Program, v. 16, no. 5, p. 278. 

Diggles, M.F., Tucker, R.E., Griscom, Andrew, Causey, J.D., 

and Gaps, R. S., 1985, Mineral Resources of the Owens 

Peak and Little Lake Canyon Wilderness Study Area, 

Inyo and Kern Counties, California: U. S. Geological 

Survey Bulletin 1708-B, 14 p. 

Domenick, M.A., Kistler, R.W., Dodge, F.C.W., Tatsumoto, 

Mitsunobu, 1983, Nd and Sr isotopic study of crustal and 

mantle inclusions from the Sierra Nevada and implications for batholith petrogenesis: Geological Society of 

America Bulletin, v. 94, p. 713-719. 

Evernden, J.F., and Kistler, R.W., 1970, Chronology of emplacement of Mesozoic batholithic complexes in California and western Nevada: U.S. Geological Survey 

Professional Paper 623, 42 p. 

Fox, L.K., 1981, Compositional variations and implications of 

petrogenesis of the Kernville pluton, southern Sierra 

Nevada, California: Unpublished senior thesis, Princeton 

University, Princeton, New Jersey, 77 p. 

Girty, G.H., 1985, Boyden Cave roof pendant, west-central 

Sierra Nevada, Madera and Tulare Counties: California 

Geology, v. 38, no. 3, p. 51-55. 

Griffis, R.A.,1987, Kern Knob pluton and other highly-evolved 

granitoids in east-central California: Ms dissertation, 

Northridge, California State University, Northridge, 305 

p. 

James, E.W., Kimbrough, David, and Mattinson, J.M., 1986, 

Evaluation of pre-Tertiary piercing points along the 

northern San Andreas fault using U/Pb zircon dating, 

initial Sr, and common Pb isotopic ratios [abs.]: Geological Society of America Abstracts with Programs, v. 18, p. 

121. 

Kistler, R.W., 1978, Mesozoic paleogeography of California: a 

viewpoint from isotope geology, in Howell, D.G. and 

McDougall, K.A., eds. Mesozoic paleogeography of the 

western United States: Society of Economic Paleontologists and Mineralogists Pacific Coast Paleogeography 

Symposium 2, Proceedings, p. 75-84. 

---1983, Isotope geochemistry of plutons in the northern 

Great Basin: Geothermal Resources Council Special 

Report 13, p. 3-8. 

Kistler, R.W., Chappell, B.W., Peck, D.L., and Bateman, P.C., 

1986, Isotopic variation in the Tuolumne Intrusive Suite, 

central Sierra Nevada, California: Contributions to Mineralogy and Petrology, v. 94, p. 205-220. 

Kistler, R.W., and Peterman, Z.E., 1973, Variations in Sr, Rb, 

K, Na, and initial 87Sr;B6Sr in Mesozoic granitic rocks 

and intruded wall rocks in central California: Geological 

Society of America Bulletin, v. 84, p. 3489-3512. 

---1978, Reconstruction of crustal blocks of California on 

the basis of initial strontium isotopic compositions of 

Mesozoic granitic rocks: U.S. Geological Survey Professional Paper 1071, 17 p. 

Kistler, R.W., Peterman, Z.E., Ross, D.C., and Gottfried, 

David., 1973, Strontium isotopes and the San Andreas 

fault, in Kovach, R.L. and Nur, Amos, eds., Proceedings 

of the conference on tectonic problems of the San 

Andreas fault system, Stanford University Publications 

in Geological Sciences, v. XIII, p. 339-347. 

Masi, Umberto, O'Neil, J.R., and Kistler, R.W., 1976, Stable 

isotope systematics in Mesozoic granites near the San 

Andreas and Garlock fault systems, California [ abs.]: 

Geological Society of America Abstracts with Programs, 

v. 8,no.6,p.998. 

---1981, Stable isotopes in Mesozoic granites of central and 

northern California and southwestern Oregon: Contributions to Mineralogy and Petrology, v. 76, p. 116-126. 

Miller, J.W., and Webb, R.W., 1940, Descriptive geology of the 

Kernville [30'] quadrangle, California: California Journal of Mines and Geology, v. 36, p. 343-378. 

Moore, J.G., and Dodge, F.C., 1962, Mesozoic age of metamorphic rocks in the Kings River area, southern Sierra 

Nevada, California, in Geological Survey Research 1962, 

U.S. Geological Survey Professional Paper 450-B, p. 

B19-B21. 

Moore, J.G., and duBray, Edward, 1978, Mapped offset on the 

right lateral Kern Canyon fault, southern Sierra Nevada, 

California: Geology, v. 6, p. 205-208. 

Nokleberg, W.J., 1983, Wallrocks of the central Sierra Nevada 

batholith, California: A collage of accreted tectonostratigraphic terranes: U.S. Geological Survey Professional Paper 1255, 28 p. 

Oliver, H.W., and Robbins, S.L., 1982, Bouguer gravity map of 

California, Fresno sheet: California Division of Mines 

and Geology, 23 p. 

Robinson, A.C., and Kistler, R.W., 1986, Maps showing isotopic dating in the Walker Lake 1 o by 2° quadrangle, 

California and Nevada, U.S. Geological Survey Miscellaneous Field Studies Map MF-1382-N. 

Ross, D.C., 1984, Generalized geologic map of the southern 

Sierra Nevada, California, showing the location of basement samples for which whole-rock 180 has been determined: U. S. Geological Survey Open-File Report 83-

904. 

---1985, Mafic gneiss complex (batholithic root?) in the 

southernmost Sierra Nevada, California: Geology, v. 13, 

p. 288-291. 

---1987, Generalized geologic map of the basement rocks 

of the southern Sierra Nevada: U.S. Geological Survey 

Open-File Report, 87-276. 

Ross, D.C., Wentworth, C.M., and McKee, E.H., 1973, Cretaceous mafic conglomerate near Gualala offset 350 miles 

by San Andreas fault from oceanic crustal source near 

Eagle Rest Peak, California: U. S. Geological Survey 

Journal Research, v. 1, no. 1, p. 45-52. 

Saleeby, J.B., 1979, Kaweah serpentinite melange, southwest 

Sierra Nevada foothills, California: Geological Society of 

America Bulletin, v. 90, p.29-46. 

---1982, Polygenetic ophiolite belt of the California Sierra 

References Cited 5 
Nevada-geochronologic and tectonostratigraphic development: Journal of Geophysical Research, v. 87, p. 

1803-1824. 

Saleeby, J.B., and Busby-Spera, C.J., 1986, Metamorphic 

framework rocks of the Lake Isabella area, southern 

Sierra Nevada, California, in Dunne, G .C., compiler, 

Mesozoic and Cenozoic structural evolution of selected 

areas, east-central California: Geological Society of 

America Annual Meeting, Cordilleran section, 82d, 

Guidebook, p. 81-94. 

Saleeby, J.B., Goodin, S.E., Sharp, W.D., and Busby, C.J., 1978, 

Early Mesozoic paleotectonic-paleogeographic reconstruction of the southern Sierra Nevada region, in Howell, D.G., and McDougall, K.A., eds., Mesozoic 

paleogeography of the western United States: Society of 

Economic Paleontologists and Mineralogists Pacific 

Coast Paleogeography Symposium 2, p. 311-336. 

Saleeby, J.B., Sams, D.B., Kistler, R.W., 1987, U/Pb zircon, 

strontium, and oxygen isotopic and geochronological 

study of the southernmost Sierra Nevada batholith, 

California: Journal of Geophysical Research, v. 92, no. 

BlO, p. 10443-10466. 

Saleeby, J.B., and Sharp, W.D., 1980, Chronology of the 

structural and petrologic development of the southwest 

Sierra Nevada foothills, California: Geological Society of 

America Bulletin, v. 91, Pt. 1, p. 317-320, pt. 2, p.1416-

1435. 

Sams, D.B., 1986, U/Pb geochronology, petrology, and structural geology of the crystalline rocks of the southernmost 

Sierra Nevada and Tehachapi Mountains, Kern County, 

California: Pasadena, California Institute of Technology, 

Ph.D. dissertation, 315 p. 

Sharry, James, 1981, The geology of the western Tehachapi 

Mountains, California: Ph.D. dissertation, Cambridge, 

Massachusetts Institute of Technology, 215 p. 

Taylor, G.C., 1984, Rockhouse basin wilderness study area, 

Kern and Tulare Counties: California Geology, v. 37, no. 

12, p. 263-272. 

Weber, H.F., Jr., 1963, Barite in California: Mineral Information Service, California Division of Mines and Geology, 

v. 16,no. 10,p. 1-10. 

York, Derek, 1969, Least-squares fitting of a straight line with 

correlated errors: Earth and Planetary Science Letters, v. 

5, p. 320-324. 

6 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
FIGURES 1-4; TABLE 1 

·-··-··-··-··-··-··-··-"-··-··-··-·····-.. -.. _··-··-··-··-··-··-··-··-··-··-··-.. -··-··-

CALIFORNIA 

EXPLANATION 

Sri= 0.706 isopleth 

}~~t}tt~J Sri> 0.706 

~ - • Fault-Showing relative 

~ horizontal direction of 

movemenL Dashed 

33° where approximately 

located 

0 100 200 KILOMETERS 

1 

I 

I NEVADA 

Figure 1. Map of California and Nevada showing the Sr1=0.706 isopleth determined for Mesozoic and Cenozoic plutons. 

Shaded area has plutons with Sr1>0.706. 

Figures 1-4; Table 1 9 
119°30' 119000' 

~000'.-------------------------~~--r-------,-----~~ 

EXPLANATION m Cenozoic rocks 

D Cretaceous plutons 

§ Jurassic plutons 

- Triassic plutons 

Contact 

.706 

I' I Strontium isotope isopleth 

Sample location- Numbers 

refer to table 1 

Fault-Dashed where 

approximate; dotted 

where concealed 

Shear 

~ «,;s ~ . .:f.o ••.. ·· 

~<v .•• •• .:f.~ .• ••· .... ·· 

118°30' 

34°45 ~------------------------~----------~----------~--------~ 

0 15 KILOMETERS 

Figure 2. Map of the southern Sierra Nevada and El Paso Mountains showing strontium isotope isopleths and the three age 

groups of plutons that crop out in the area. Shaded area has plutons with Sri> 0. 706. 

10 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
0.710 

Central 

Sierra 

Nevada, Salinian-western 

eastern Mojave Mojave 

:::i! 0.708 

Desert 

::::> 

i= 

z 

0 

a: 

~ 

en 

I 

~ ::::> 0.706 

i= 

z 

0 

a: 

~ 

,..en 

~ 

< 

E 

z 0.704 

Mantle 

0.702 

5 7 9 11 13 

6 180 PER MIL 

Figure 3. Fields of Sri versus o180 per mil for plutons in and peripheral to the Salinian-western Mojave terrane (Panthalassan 

lithosphere) in the southern Sierra Nevada and for plutons in the central Sierra Nevada and eastern Mojave Desert (North 

American lithosphere). 

Figures 1-4; Table 1 11 
z 

0 100 

::; 

...J 

~ 

a: 

w 

a. Southern Sierra Nevada------..-,;=:;.,. 

~ a: 

< a. 

z 

~ :::> 

25 10 

m 

:::> 

a: 

1 ~-----~---~---~-~~~~~~~-----~~----~--~--~--~~~~~ 

10 100 1000 

STRONTIUM, IN PARTS PER MILLION 

Figure 4. Rb versus Sr for plutons with Sr1 < 0.706 peripheral to the Salinian-western Mojave terrane in Panthalassan 

lithosphere and peripheral to the Sierran terrane in North American lithosphere in the Walker Lake 1° by 2° quadrangle. Each 

data point represents a single sample. Open triangles are samples from North American lithosphere. Closed circles are 

samples from Panthalassan lithosphere. 

12 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
Table 1. Rubidium and strontium data for plutons and associated rocks of the southern Sierra 

Nevada and vicinity 

[Pluton names and symbols from Ross (1987); n, number of samples tested; T, age in millions of years before present; 

MSWD, mean squares of weighted deviates; Sri> initial 87Srf8

Sr value calculated;--, Sri determined from isochron] 

Map no. Sample Rb Sr Rb/Sr 87Rbf8

Sr 87Srf6Sr Sri (fig.2) no. (ppm) (ppm) 

Granodiorite of Gato-Montes (Kgm) 

[T=96.3±8.7 Ma, Sr;=0.70786±0.00016, n= 10, MSWD=2.4, * sample not used for isochron] 

1 DR-3356 80.4 632 0.127 0.368 0.70833 

2 DR-3534B 129 416 .310 .897 .70895 

3 DR-3733A 82.7 618 .134 .387 .70840 

4 DR-3756A* 131 370 .357 1.032 .70991 0.70850 

5 DR-3740 113 844 .134 .388 .70837 

6 DR-3745 137 590 .232 .671 .70878 

7 DR-3746 98.5 579 .170 .492 .70865 

8 DR-3747A 84.1 744 .113 .327 .70831 

9 DR-3818 90.2 582 .155 .449 .70837 

10 DR-3819 89.9 632 .142 .411 .70848 

11 DR-3820* 90.7 358 .253 .732 .70716 .70681 

12 DR-3829A* 110 449 .245 .709 .70952 .70855 

Granite of Tejon Lookout (Ktj) 

[T=96.0± 1.9 Ma, Sr;=0.70727±0.00010, n=3, MSWD= 1.2] 

13 DR-3401 173 79.3 2.18 6.32 0.71578 

14 DR-3466 191 89.2 2.14 6.20 .71583 

15 DR-3752 172 307 .560 1.62 .70948 

Mafic inclusion in granite of Tejon Lookout (Ktj) 

16 DR-3754 146 353 0.414 1.20 0.70775 0.70612 

17 1Sr12-73 80.1 612 .131 0.381 .7062 .70568 

Granodiorite of Lebec (Kie) 

18 2DR-698 127 376 0.338 0.978 0.70930 

19 DR-3088 93.2 659 .14 .41 .70797 0.70741 

20 DR-3181 89.9 489 .184 .53 .70814 .70742 

This pluton is equivalent to and offset from the granodiorite of Gato-Montes by the Garlock Fault. Sample DR-698 used in the 

Gato-Montes isochron. 

Granite of Brush Mountain (Kbm) 

[T=91.1±1.6 Ma, Sr;=0.70846±0.00010, n=2. T=98 Ma, U/Pb zircon (James and others, 1986)] 

21 DR-3221 237 13.6 17.4 50.8 0.77414 

22 DR-3005 170 78.4 2.17 6.28 .71658 

Tona1ite of Antimony Peak (KJap) 

23 DR-3023 <5 603 <0.01 <0.024 0.70337 0.70334 

Diorite Gneiss (Kset) 

24 DR-3097 2.4 261 0.01 0.026 0.70364 0.70360 

25 DR-3098A 16.6 289 .06 .166 .70446 .70422 

26 8PC-129 40.6 332 .122 .352 .70650 .70593 

----- Tonalite of Bear Valley Springs (Kbv) 

[T= 100 Ma, U/Pb zircon (Sams, 1986)] 

27 8CM-9 104 388 0.268 0.775 0.70785 0.70677 

28 8CM-25 55.9 399 .140 .405 .70648 .70591 

29 8CM-26 69.2 392 .177 .512 .70708 .70637 

Figures 1-4; Table 1 13 
Table 1. Rubidium and strontium data for plutons and associated rocks of the southern Sierra 

Nevada and vicinity-Continued 

Map no. Sample Rb Sr Rb/Sr 87Rbf8

Sr 87Srf8Sr Sri (fig.2) no. (ppm) (ppm) 

Tonalite of Bear Valley Springs (Kbv) -Continued 

30 ~C-15 18.5 360 .051 .148 .70603 .70583 

31 ~C-42 30.8 341 .090 .261 .70606 .70570 

32 1Sr14-73 55.0 347 .158 .460 .7055 .70485 

. 33 DR-3427B 63.0 297 .212 .614 .70649 .70562 

34 DR-3575 85.5 346 .247 .715 .70701 .70600 

35 DR-3837 81.8 250 .327 .947 .70725 .70591 

36 DR-3670 63.2 313 .202 .584 .70684 .70601 

37 DR-3791 41.4 344 .120 .348 .70546 .70497 

38 DR-3858 72.6 285 .255 .737 .70616 .70512 

39 DR-4181 62.7 378 .165 .480 .70493 .70425 

40 DR-4184 53.8 323 .167 .481 .70498 .70430 

41 DR-4281 86.2 274 .315 .910 .70722 .70593 

42 DR-6300 48.9 348 .141 .41 .70529 .70471 

43 Dr-6336 52.3 295 .177 .51 .70552 .70480 

44 DR-6356 44.9 370 .121 .35 .70474 .70424 

45 DR-6369 44.6 284 .157 .45 .70587 .70523 

Granodiorite of Keene (Kk) 

46 1Sr15-73 53.8 341 0.158 0.460 0.7060 0.70535 

TonaJite of Mount Adelaide (Kma) 

[T=100 Ma, U/Pb zircon (Sams, 1986)] 

47 3BM-684 19.6 455 0.043 0.125 0.70458 0.70440 

48 DR-4189 35.2 418 .084 .243 .70483 .70449 

49 DR-3631 57.8 640 .090 .261 .70462 .70427 

Quartz diorite of Caliente (Kca) 

50 Dr-3635 36.4 417 0.087 0.253 0.70479 0.70443 

Mafic gneiss complex of San Emigdio and Tehachapi Mountains (Kset) 

[T=116.7±2.45 Ma, Sr;=0.70488±0.00019, n=13, MSWD=63.1. T=ll?-110 Ma, U/Pb zircon (Sams, 1986)] 

51 3

PC-31 52.1 215 0.242 0.700 0.70627 

52 3

PC-32 145 79.1 1.83 5.30 .71336 

53 3

PC-34 33.3 352 .095 .273 .70511 

54 3PC-35 149 49.5 3.01 8.72 .71965 

55 3

PC-36 11.2 324 .035 .100 .70515 

56 3

PC-37 69.7 222 .314 .908 .70613 

57 3

WR-30/2 1.9 447 .004 .012 ·.70480 

58 3

WR-39 2.4 696 .003 .010 .70501 

59 3WR-40 56.7 138 .411 1.18 .70670 

60 3

WR-91A 18.7 353 .053 .153 .70560 

61 3

WR-171 35.8 308 .116 .336 .70518 

62 3

CM-630 36.1 257 .140 .405 .70534 

63 3WR-643 21.0 367 .057 .165 .70545 

Metagabbro of Tunis Creek (Ktmg) 

[T=94.1± 12.5 Ma, Sr;=0.70499±0.00003, n=S, MSWD=2.84. T= 102-101 Ma, U-Pb zircon (Sams, 1986)] 

64 3

PC-227 4.2 709 0.006 0.017 0.70495 

65 3WR-190 5.7 500 .011 .033 .70504 

66 3WR-84 3.7 583 .006 .018 .70502 

67 3

WR-86 2.2 504 .004 .013 .70506 

67a ~L-197 36.6 330 .111 .321 .70542 

14 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
Table 1. Rubidium and strontium data for plutons and associated rocks of the southern Sierra 

Nevada and vicinity-Continued 

Map no. Sample Rb Sr Rb/Sr 87Rbf8

Sr 87Sr/sesr Sri (fig.2) no. (ppm) (ppm) 

Gabbro of Eagle Rest Peak (Jer) 

[Minimum age is 161 Ma, U/Pb zircon, James and others (1986). Maximum age is 200 Ma, K/AI hornblende (Ross and others, 1973)] 

68 2

DR-1182C 8.8 228 0.016 0.046 0.7042 0.70407 

69 2DR-671B <2 147 .7031 .7031 

69 2DR-671Pl 4.2 293 .014 .041 .7035 .70337 

Gneiss of Tweedy Creek (Kset) 

[f= 110 Ma, U/Pb zircon (Sams, 1986)] 

70 s.rc-12A 66.7 216 0.309 0.890 0.70818 0.70679 

Inclusion in the tonalite of Bear Valley Springs (Kbv) 

71 8CM-22B 16.0 265 0.060 0.173 0.70629 0.70604 

Paragneiss of Cummings Mountain (Kset) 

72 8CM-110 110 165 0.667 1.931 0.71442 0.71168 

Quartzite in the Tehachipi metasedimentary belt of Ross (1987) 

73 8CM-640 32.3 90.3 0.358 1.037 0.72581 0.72434 

Granodiorite of Poso Flat (Kpf) 

[f=100 Ma. Probable facies of tonalite of Bear Valley Springs] 

74 DR-6292 80.5 227 0.291 0.84 0.70609 0.70490 

75 DR-6297 52.3 285 .183 .53 .70534 .70459 

76 DR-6359 61 300 .205 .59 .70587 .70503 

77 DR--6373 53.6 310 .172 .50 .70549 .70478 

Granodiorite of Alder Creek (Kal) 

[f=91 Ma. Probable facies of tonalite of DunL'lp Meadow) 

78 DR-5236 108 328 0.329 0.953 0.70812 0.70677 

79 DR-5261 116 305 .380 1.10 .70831 .70675 

80 DR-6245 123 232 .530 1.53 .70855 .70638 

81 DR-6269 117 220 .532 1.54 .70861 .70644 

82 1

Sr4-73 146 249 .586 1.69 .7089 .70656 

83 1Sr5-73 154 238 .646 1.86 .7084 .70576 

Tonalite of Walt Klein Ranch (Kwk) 

[f=l11±2.5 Ma, K/AI hornblende (Evemden and Kistler, 1970)] 

84 DR--6061 33.1 294 0.113 0.326 0.70433 0.70382 

85 DR--6088 46.1 311 .148 .429 .70485 .70417 

86 DR--6096 60.6 295 .205 .594 .70485 .70391 

87 DR-6281A 37.7 423 .089 .26 .70460 ... 70419 

88 DR-6314-1 79.3 288 .275 .80 .70540 .70414 

89 DR-6321 42.4 349 .121 .35 .70476 .70421 

90 1

Sr1-73 77.2 360 .215 .62 .7048 :70382 

91 1

Sr2-73 57.7 399 .145 .42 .7050 .70434 

Tonalite of Fountain Springs (Kfs) 

[f= 102 Ma, U/Pb zircon (Saleeby and Sharp, 1980)] 

92 DR-6024 34.6 341 0.101 0.293 0.70432 0.70390 

93 DR-6106 34.4 281 .122 .354 .70441 .70390 

Figures 1-4; Table 1 15 
Table 1. Rubidium and strontium data for plutons and associated rocks of the southern Sierra 

Nevada and vicinity-Continued 

Map no. Sample Rb Sr Rb/Sr 87Rbf8

Sr 87Srf8Sr Sri (fig.2) no. (ppm) (ppm) 

Granite of Arrastre Creek (Kac) 

94 DR-6093 73.8 140 0.527 1.53 0.70620 0.70403 

Tonalite of Carver Bowen Ranch (Kcb) 

95 DR-5980 44.9 282 0.159 0.459 0.70447 0.70382 

96 DR-6079A 70.8 282 .251 .726 .70493 .70390 

97 1Sr3-73 44.0 514 .086 .25 .7036 .70325 

Granodiorite of Deer Creek (Kdc) 

98 DR-6030 77.6 230 0.337 0.976 0.70546 0.70408 

99 DR-6117 74.1 195 .380 1.10 .70567 .70411 

Tonalite of Zumwalt Ranch (Kzr) 

100 DR-6123 41.1 320 0.128 0.371 0.70419 0.70366 

Granite of Portuguese Pass (Kpp) 

[T= 105.6±9.2 Ma, Sri=0.70628±0.00049, n=3, MSWD=36.2] 

101 DR-5017 116 141 0.823 2.38 0.70951 

102 DR-5062 189 94.7 1.996 5.78 .71504 

103 DR-5592B 76.7 168 .457 1.32 .70852 

Granodiorite of Pyles Camp 

(Hockett Peak quadrangle north of map at 36° 06' 15" N. L'lt, 118° 28' 01 " W. long) 

DR-4692 106 403 0.293 0.761 0.70720 0.70623 

Tonalite of Dunlap Meadow (Kdm) 

104 DR-5871 51.4 326 0.158 0.456 0.70697 

105 DR-5887 59.8 377 .159 .459 .70665 

106 DR-5922 45.6 398 .115 .331 .70663 

107 DR-5008 70.0 296 .236 .684 .70706 

108 DR-5285 62.6 305 .205 .594 .70710 

109 DR-5974 84.1 321 .262 .758 .70717 

110 DR-6004 59.3 461 .129 .372 .70658 

Granodiorite of Pine Flat (Kpi) 

[Combined tonalite of Dunlap Meadow and granodiorite of Pine Flat. T=91.4±113 Ma, Sri=0.70618±0.00024, n=10, MSWD=4.0) 

111 DR-5801R 71.1 451 0.158 0.456 0.70669 

112 DR-5946 94.3 300 .314 .909 .70731 

113 DR-5965 113 343 .329 .953 .70742 

Granodiorite of Hatchet Peak (Khp) 

114 DR-5865A 121 174 0.695 2.01 0.70966 0.70681 

Granodior·:- of Peppermint Meadow (Kpm) 

[T= 106.7±21.1 Ma, Sri=0.70616±0.00023, n=4, MSWD=24.3. DR-4688 is north of map in Hockett Peak quadrangle at 36° 08' 50" 

N.lat, 118° 29' 50" W. long) 

115 DR-4995 78.7 614 0.128 0.371 0.70664 

116 DR-5034 79.1 577 .137 .397 .70706 

117 DR-5852 76.6 621 .123 .357 .70649 

DR-4688 134 277 .484 1.40 .70827 

Granodiorite of Brush Creek (Kbru) 

[1'=90.0±2.0 Ma, K/Ar biotite (Evemden and Kistler, 1970)] 

118 DR-5031 133 408 0.325 0.943 0.70746 0.70625 

16 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
Table 1. Rubidium and strontium data tor plutons and associated rocks of the southern Sierra 

Nevada and vicinity-Continued 

Map no. Sample Rb Sr Rb/Sr 87Rb/sesr 87Sr/sasr Sri (fig.2) no. (ppm) (ppm) 

Granodiorite of Alta Sierra (Kas) 

[f=89.0±2.1 Ma, K/Ar biotite (Evemden and Kistler, 1970)) 

119 DR-5423 60.1 527 0.114 0.330 0.70658 0.70616 

120 DR-5425 42.6 676 .063 .182 .70676 .70653 

121 DR-4796-1 63.1 567 .111 .321 .70660 .70619 

122 DR-4789A 63.7 541 .118 .341 .70670 .70626 

Granite of Kern River (Kkr) 

[f=87 and 89 Ma, K/Ar biotite (Evemden and Kistler, 1970). T=81.1±11.1 Ma, Sri=0.70810±0.00039, n=4, MSWD=12.6, Rb/Sr 

whole-rock isochron) 

124 DR-5006 127 200 0.635 1.84 0.70999 0.70767 

125 DR-4763 155 147 1.054 3.05 .71158 .70773 

126 DR-4819A 155 148 1.047 3.03 .71169 .70767 

127 4

24-73 105 203 .516 1.49 _7100 .70812 

Granodiorite ofWagy Flat(Kwl) 

128 DR-4273 74.1 623 0.119 0.344 0.70698 0.70649 

129 DR-4294 59.5 583 .102 .295 .70722 .70680 

Granite of Saddle Springs (Kss) 

[mafic inclusions] 

130 DR-5089 50.1 387 0.129 0.373 0.70724 0.70671 

131 DR-5153 56.7 480 .118 .341 .70656 .70608 

Granodiorite of Rabbit Island (Kri) 

[f=99 Ma, U!Pb zircon (Saleeby and Busby-Spera, 1986)] 

132 DR-4848 107 604 0.177 0.512 0.70712 0.70639 

133 DR-5421 70.6 530 .133 .385 .70648 .70593 

134 DR-5407 108 623 .173 .502 .70716 .70645 

135 5

LGC-4 82.9 732 .113 .328 .70713 .70664 

136 5

LGC-5 107 615 .174 .503 .70746 .70675 

137 5

LGC-6 69.3 776 .089 .258 .70706 .70669 

138 5

LGC-7 116 378 .307 .888 .70805 .70679 

139 5

LGC-8 124 480 .258 .747 .70813 .70707 

140 DR-5191A 56.7 956 .059 .171 .70814 .70790 

Granodiorite of Castle Rock (Kcr) 

141 DR-4528 117 449 0.261 0.754 0.70909 0.70813 

142 DR-4402 89.9 573 .157 .454 .70851 .70793 

143 DR-4354 99.4 526 .189 .547 .70852 .70782 

144 DR-4341 82.0 603 .136 .393 .70850 .70800 

145 DR-5356 101 456 .221 .641 .70752 .70671 

146 DR-4093 81.3 652 .125 .361 .70864 .70818 

147 5

LGC-3 195 470 .415 1.200 .70875 .70706 

148 1

Sr6-73 140 349 .401 1.16 .7073 .70582 

149 1

Sr8-73 98 737 .133 .384 .7080 .70751 

150 1

Sr9-73 81.8 695 .118 .341 .7084 .70746 

151 DR-5133R 182 75.5 2.41 6.98 .71654 .70762 

152 DR-5403 130 460 .283 .818 .70791 .70687 

153 DR-6539 94.9 713 .133 .385 .70786 .70731 

154 DR-4686 170 511 .333 .962 .70783 .70660 

Wbiterock facies of the granodiorite of Castle Rock (Kcw) 

[f=90 Ma, U!Pb zircon (Sams, 1986)} 

155 DR-4314 103 552 0.187 0.540 0.70835 0.70766 

156 DR-4102A 96.6 504 .192 .554 .70817 .70746 

157 DR-3737 86.0 893 .096 .279 .70813 .70777 

Figures 1-4; Table 1 17 
Table 1. Rubidium and strontium data for plutons and associated rocks of the southern Sierra 

Nevada and vicinity-Continued 

Map no. Sample Rb Sr Rb/Sr 87Rbf8

Sr 87Srf8Sr Sri (fig.2) no. (ppm) (ppm) 

Wbiterock facies of the granodiorite of Castle Rock (Kcw) -Continued 

158 So-rC-27 71.2 562 .127 .367 .70777 .70730 

159 So-rC-40 48.1 578 .083 .241 .70735 .70704 

Dikes in Isabella roof pendant in the Long Canyon metasedimentary belt of Ross (1987) 

160 PM-505 123 186 0.661 1.91 0.71701 0.71443 

161 PM-536 144 289 .498 1.44 .70981 .70787 

162 DR-5629 67.5 621 .109 .315 .70725 .70683 

Volcanic rocks of Piute Peak in the Erskine Canyon sequence of Saleeby and Busby-Spera (1986) 

[f=97.3±0.5 Ma, Sr;=0.70576±0.00011, n=3, MSWD=O.Ol. T=98 Ma, U!Pb zircon (Saleeby and Busby-Spera, 1986)) 

163 EM-10 77.6 136 0.571 1.651 0.70804 

163 EM-lOB 71.8 232 .309 .895 .70699 

163 EM-10C 58.2 242 .240 .696 .70672 

Volcanic rocks in Erskine Canyon sequence of Saleeby and Busby-Spera (1986) 

[f=102 Ma, U/Pb zircon (Saleeby and Busby-Spera, 1986)] 

164 82SS7 137 143 0.958 2.77 0.71038 0.70637 

Granite of Bodfish Canyon (Kbo) 

165 DR-5071 194 41.1 4.72 13.7 0.72647 0.70896 

Tonalite of Hoffman Canyon (Kbc) 

166 1

Sr10-73 89.6 634 0.141 0.408 0.7076 0.70708 

Amphibolite of Jawbone Canyon (KJc) 

167 DR-4497B 29.8 662 0.045 0.130 0.70814 0.70793 

168 DR-4498B 64.5 237 .272 .787 .70877 .70750 

169 DR-4499 33.1 719 .046 .133 .70779 .70758 

Granite of Bishop Ranch (Kbr) 

170 DR-4472 93.1 665 0.140 0.405 0.70904 0.70852 

Granite of Cannell Creek (Kcc) 

[f=80±2 Ma, U!Pb zircon (Saleeby and Busby-Spera, 1986)] 

171 '1._GC-9 99 366 0.270 0.783 0.70854 0.70743 

172 5LGC-11 195 29.6 6.59 19.1 .73642 .70930 

173 5LGC-17 57.7 517 .117 .323 .70768 .70723 

174 5

LGC-18 148 318 .465 1.35 .70925 .70734 

175 5LGC-23 171 392 .436 1.26 .70904 .70725 

176 5LGC-25 133 28.9 4.60 13.34 .73010 .71116 

Quartz diorite of Cyrus Flat (Kcl) (Unit "A" Fox, 1981) 

177 5LGC-12 10.0 780 0.013 0.037 0.70681 0.70676 

178 5

LGC-13 13.5 623 .027 .063 .70686 .70677 

Quartz diorite of Cyrus Flat (Kcl) 

[f= 100 Ma, U/Pb zircon (Saleeby and Busby-Spera, 1986)] 

179 5LGC-14 117 408 0.287 0.830 0.70814 0.70796 

180 5

LGC-15 110 407 .270 .782 .70811 .70700 

181 5LGC-16 113 384 .294 .851 .70770 .70650 

18 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 
Table 1. Rubidium and strontium data for plutons and associated rocks of the southern Sierra 

Nevada and vicinity-Continued 

Map no. Sample Rb Sr Rb/Sr 87Rb/86Sr 87Srf8

Sr Sri (fig.2) no. (ppm) (ppm) 

Quartz diorite of Cyrus Flat (Kcl)-Continued 

182 5LGC-20 57.7 471 .123 .354 .70821 .70771 

183 5

LGC-21 103 366 .281 .814 .70908 .70793 

184 5

LGC-22 99.5 306 .325 .941 .70918 .70785 

185 5

LGC-24 91.2 521 .175 .506 .70763 .70691 

186 5

LI-33 74.8 498 .150 .435 .70813 .70751 

187 5LI-34 46.9 683 .069 .199 .70827 .70799 

188 5

LI-35 203 198 1.025 2.97 .71134 .70712 

189 5

LI-36 195 243 .802 2.32 .70951 .70622 

190 5LI-37 218 249 .876 2.53 .71104 .70745 

191 5

LI-38 105 569 .184 .534 .70887 .70811 

192 5

LI-39 102 579 .176 .510 .70848 .70776 

193 5

LI-40 93.4 445 .210 .607 .70857 .70771 

194 5

LI-41 129 265 .487 1.41 .70937 .70737 

195 5

LI-42 125 406 .308 .891 .70886 .70760 

196 5LI-43 180 242 .744 2.15 .71044 .70739 

197 5

LI-44 59.0 511 .115 .334 .70776 .70729 

Sedimentary rocks south of the quartz diorite of Cyrus Flat in the Long Canyon metasedimentary belt of Ross (1987) 

198 5LGC-1 67.5 445 0.152 0.439 0.72032 0.71970 

199 5LGC-2 123 165 .745 2.16 .73827 .73520 

200 5LGC-10 122 35.6 3.43 9.96 .75232 .73818 

201 5LGC-19 71.6 459 .156 .451 .70917 .70853 

Granite of Onyx 

(T=81 Ma, K/Ar biotite (Evemden and Kistler, 1970)] 

202 425-73 170 343 0.496 1.435 0.7098 0.70801 

Quartz diorite of Freeman Junction (Trtj) 

[T=222 Ma, Sr1=0.70428, n=2) 

203 DR-6438A 35.5 531 0.067 0.19 0.70488 

204 DR-6439 49.8 456 .109 .32 .70529 

Quartz diorite of Walker Pass, unsheared part (Trwp) 

(T=240.4±14 Ma, Sr1=0.70362±0.00007, n=lO, MSWD=4.06. lsochron from these and unsheared quartz diorites and trondjhemites 

of the El Paso Mountains] 

205 DR-6226 35.0 599 0.058 0.169 0.70434 

206 4

26-73 76.8 396 .194 .561 .7056 

207 DR-6179 30.8 694 .044 .128 .70411 

208 DR-6391 33.0 762 .043 .13 .70416 

209 DR-6217 70.8 633 .111 .324 .70475 

Quartz diorite of Walker Pass, sheared part (Trwps) 

[Samples do not yield an isochron) 

210 DR-6220 43.4 539 0.081 0.233 0.70475 0.70396 

211 DR-6394A 27.2 714 .038 .110 .70440 .70403 

212 DR-6400 30.6 668 .045 .132 .70452 .70407 

213 DR-6176A 36.1 577 .062 .181 .70460 .70398 

214 DR-6174D 26.9 643 .042 .121 .70441 .70400 

215 DR-6385A 73.5 654 .112 .325 .70538 .70428 

Gray gneiss in the summit gabbro of Miller and Webb (1940) (JTrsg) 

(T=218 Ma, Sr1=0.70366] 

216 DR-6511 58.2 616 0.094 0.273 0.70451 

217 DR-6516 93.2 446 .209 .605 .70554 

Figures 1-4; Table 1 19 
Table 1. Rubidium and strontium data for plutons and associated rocks of the southern Sierra 

Nevada and vicinity-Continued 

Map no. 

(fig.2) 

Sam pte 

no. 

Rb 

(ppm) 

Sr 

(ppm) Rb/Sr 

Quartz diorite and trondjhemite of El Paso Mountains (frPe) 

(T=240±14 Ma, Sri=0.70362±0.00007, n=10, MSWD=4.1. T=247-223 Ma, K/Ar hornblende (Cox and Morton. 1980)] 

218 GR-151 42 604 0.069 0.200 0.70424 

219 GR-152 26 574 .045 .130 .70392 

220 1

Sr1Cr73 98.1 382 .257 .743 .7062 

221 S28-84 67.8 500 .136 .393 .70477 

222 S31-84 67.0 512 .131 .379 .70489 

Quartz diorite of Long VaHey (frlv) 

223 DR-6509A 43.4 925 0.047 0.136 0.70558 0.70512 

Granodiorite of Five Fingers (Kll) 

(T=90 Ma, estimnted from Rb/Sr data] 

224 DR-6535 92.7 799 0.116 0.336 0.70721 0.70679 

225 DR-6415 76.6 809 .095 .27 .70716 .70682 

226 DR-6208 93.2 544 .171 .496 .70738 .70675 

Sacatar quartz diorite of MiJier and Webb (1940) (Js) 

[T=1TI.4±4.9 Ma, Sri=0.70718±0.00015, MSWD=12.5, n=l9. T> 170 Ma, U/Pb zircon preferred intrusive age (Chen and Moore, 

1982) for unit 6 of Moore and DuBray (1978), which is Sacatar Quartz Diorite equivalent in the Hockett Peak quadrangle north of map 

(fig. 2)] 

227 DR-6483A 94.2 659 0.143 0.413 0.70883 

228 DR-6472A 88.7 525 .169 .489 .70847 

229 DR-6523A 132 460 .287 .830 .70952 

230 DR-6425 105 532 .197 .57 .70861 

231 S6Cr84 137 470 .291 .843 .70963 

231 S66A-84 178 132 1.35 3.90 .71710 

232 S67-84 188 348 .540 1.56 .71117 

Granite of No Name Canyon (Knc) 

(T=80.5±1.7 Ma, Sri=0.70880±0.00008, MSWD=0.17, n=4. T=80.1±5.3 Ma, K/Ar muscovite (Diggles, 1984). Samples are from 

Griffis (1987)] 

233 NM-4A 366 5.54 66.06 195.3 0.93265 

234 NM-4B 329 11.8 27.88 81.40 .80172 

235 NM-30 119 478 .25 .720 .70960 

236 NM-31 155 462 .335 .971 .70993 

Granite of Tehachapi Airport (Kta) 

237 DR-4100A 165 78.7 2.097 6.07 0.71645 

Granodiorite of Little Lake (JII) 

(T== 175±5 Ma, Rb/Sr whole-rock isochron from 5 samples outside map area] 

238 Sr20-73 

1

Kistler and Peterman (1978) 2

Kistler and others (1973) 8

Sams (1986) 4Kistler and Peterman (1973) 5

Collins (1988) 

132 339 0.389 1.126 

20 Strontium Isotopic Study, Plutons and Associated Rocks, Sierra Nevada, California 

0.7089 

0.70955 

0.7061 
SELECTED SERIES OF U.S. GEOLOGICAL SURVEY PUBLICATIONS 

Periodicals 

Earthquakes & Volcanoes (issued bimonthly). 

Preliminary Determination of Epicenters (issued monthly). 

Technical Books and Repons 

Professional Papers are mainly comprehensive scientific reports of 

wide and lasting interest and importance to professional scientists and engineers. Included are reports on the results of resource studies and of 

topographic, hydrologic, and geologic investigations. They also include 

collections of related papers addressing different aspects of a single scientific topic. 

Bulletins contain significant data and interpretations that are of lasting scientific interest but are generally more limited in scope or 

geographic coverage than Professional Papers. They include the results 

of resource studies and of geologic and topographic investigations; as well 

as collections of short papers related to a specific topic. 

Water-Supply Papers are comprehensive reports that present significant interpretive results of hydrologic investigations of wide interest 

to professional geologists, hydrologists, and engineers. The series covers 

investigations in all phases of hydrology. including hydrogeology, 

availability of water, quality of water, and use of water. 

Cb'culars present administrative information or important scientific 

information of wide popular interest in a format designed for distribution 

at no cost to the public. Information is usually of short-term interest. 

Water-Resources Investigations Reports are papers of an interpretive nature made available to the public outside the formal USGS publications series. Copies are reproduced on request unlike formal USGS 

publications, and they are also available for public inspection at 

depositories indicated in USGS catalogs. 

Open-Flle Reports include unpublished manuscript reports, maps, 

and other material that are made available for public consultation at 

depositories. They are a nonpermanent form of publication that may be 

cited in other publications as sources of information. 

Maps 

Geologic Quadrangle Maps are multicolor geologic maps on 

topographic bases in 7 ln.- or 15-minute quadrangle formats (scales mainly 1:24,000 or 1 :62,500) showing bedrock. surficial, or engineering geology. Maps generally include brief texts; some maps include structure 

and columnar sections only. 

Geophysical Investigations Maps are on topographic or planimetric 

bases at various scales; they show results of surveys using geophysical 

techniques, such as gravity, magnetic, seismic, or radioactivity, which 

reflect subsurface structures that are of economic or geologic significance. 

Many maps include correlations with the geology. 

Miscellaneous Investigations Series Maps are on planimetric or 

topographic bases of regular and irregular areas at various scales; they 

present a wide variety of format and subject matter. The series also includes 7 1/2-minute quadrangle photogeologic maps on planimetric bases 

which show geology as interpreted from aerial photographs. Series also 

includes maps of Mars and the Moon. 

Coal Investigations Maps are geologic maps on topographic or 

planimetric bases at various scales showing bedrock or surficial geology, stratigraphy, and structural relations in certain coal-resource areas. 

Oil and Gas Investigations Charts show stratigraphic information 

for certain oil and gas fields and other areas having petroleum potential. 

Miscellaneous Field Studies Maps are multicolor or black-andwhite maps on topographic or planimetric bases on quadrangle or irregular areas at various scales. Pre-1971 maps show bedrock geology 

in relation to specific mining or mineral-deposit problems; post-1971 

maps are primarily black-and-white maps on various subjects such as 

environmental studies or wilderness mineral investigations. 

Hydrologic Investigations Atlases are multicolored or black-andwhite maps on topographic or planimetri(.. bases presenting a wide range 

of geohydrologic dataofboth regular and irregular areas; principal scale 

is 1:24,000 and regional studies are at 1:250,000 scale or smaller. 

Catalogs 

Permanent catalogs, as well as some others, giving comprehensive listings of U.S. Geological Survey publications are available under 

the conditions indicated below from the U.S. Geological Survey, Books 

and Open-File Reports Section, Federal Center, Box 25425, Denver, 

CO 80225. (See latest Price and Availability List) 

"Publications of the Geological Survey, 1879-1961" may be purchased by mail and over the counter in paperback book form and as a 

set of microfiche. 

"Publications of the Geological Survey, 1962- 1970" may be purchased by mail and over the counter in paperback book form and as a 

set of microfiche. 

"Publications of the U.S. Geological Survey, 1971-1981" may be 

purchased by mail and over the counter in paperback book form (two 

volumes, publications listing and index) and as a set of microfiche. 

Supplements for 1982, 1983, 1984, 1985,1986, and for subsequent 

years since the last permanent catalog may be purchased by mail and 

over the counter in paperback book form. 

State catalogs, "List of U.S. Geological Survey Geologic and 

Water-Supply Reports and Maps For (State)," may be purchased by mail 

and over the counter in paperback booklet form only. 

"Price and A vailabillty List of U.S. Geological Survey Publications," issued armually, is available free of charge in paperback booklet form only. 

Selected copies of a monthly catalog "New Publications of the U.S. 

Geological Survey" available free of charge by mail or may be obtained 

over the counter in paperback booklet form only. Those wishing a free 

subscription to the monthly catalog "New Publications of the U.S. 

Geological Survey" should write to the U.S. Geological Survey, 582 

National Center, Reston, VA 22092. 

Note.--Prices of Government publications listed in older catalogs, 

announcements, and publications may be incorrect. Therefore, the 

prices charged may differ from the prices in catalogs, announcements, 

and publications.