Petrography of Some Granitic Bodies 

in the Northern Wl1ite Mountains, 

California-Nevada 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 775 

PETROGRAPHY OF 

SOME GRANITIC BODIES, 

NORTHERN WIDTE MOUNTAINS, 

CALIFORNIA-NEVADA 
View of the northern White Mountains showing the location of major granitic masses. The White Mountains have a maximum 

relief of 10,000 feet and are topped by White Mountain Peak (14,246 ft) . 
Petrography of Some Granitic Bodies 

in the Northern White Mountains, 

California-Nevada 

By DWIGHT F. CROWDER and DONALD C. ROSS 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 775 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1973 
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary 

GEOLOGICAL SURVEY 

V. E. McKelvey, Director 

Library of Congress catalog-card No. 73-600113 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402- Price 70c domestic postpaid or SOc GPO Bookstore 

Stock Number 2401-00332 
CONTENTS 

Page Page 

Abstract ---------------··----··---·--··-··--·-··----------·--·-·---····------------------------- 1 

Introduction ----------------·-----·-------·----·····------···------------------------------- 1 

Description of granitic rocks-Continued 

Granodiorite of Mount Barcroft ...................................... 13 

Description of granitic units --·-------------··---------·---------··------------- 3 

Granodiorite of the Benton Range ······----·--··------------------- 3 

Quartz monzonite and granite of Pellisier Flats -·-------- 5 

Quartz monzonite of Boundary Peak .............................. 17 

Chemical relations ---···-------------------········-------············-···········------ 18 

Anderson's granitization concept ............................................ 22 

Mixed metavolcanic and granitic rocks .......................... 11 Albitization ·····-·····--·-················-------------------------------------·------------- 23 

Diorite complex of Queen Canyon.................................... 12 References cited ·······-·······························--------------------··············· 28 

ILLUSTRATIONS 

Page 

FRONTISPIECE. Oblique aerial photograph of the northern White Mountains showing the location of major granitic masses. 

FIGURE 1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

14. 

15. 

16. 

17. 

18. 

19. 

20. 

21. 

22. 

23. 

24. 

25. 

Geologic sketch map of the northern White Mountains, California-Nevada -··············-···········------------------------··············· 1 

Photograph of contact of light-colored quartz monzonite of Boundary Peak with the dark-colored quartz 

monzonite and granite of Pellisier Flats ----·-·····················-·························-··························------------------·············-·······--· 4 

Map showing location of modally and chemically analyzed specimens .......................................................................... 6 

Photograph of granodiorite of the Benton Range ·····················-···----···········-··········-··--····--···············-···--------------··················· 7 

Ternary diagram showing modal distribution of quartz, K-feldspar, and plagioclase of the granodiorite of 

the Benton Range --------·······-··················----------·-··········-··································································-----···----------··················· 7 

Photomicrograph of fine-grained "aplitic" groundmass in granodiorite of the Benton Range...................................... 8 

Sketch map showing sample localities, dark-mineral content, and ratio of hornblende to biotite in the 

granodiorite of the Benton Range ------------·-···········--···············-··--·-········--------------·------------------------------------------------------------ 8 

Ternary diagram showing modal distribution of quartz, K-feldspar, and plagioclase in the quartz monzonite 

and granite of Pellisier Flats ----------------------------------·---····-····----········-----------------·----------------------------------------------------------------- 8 

Index map showing sample localities in the quartz monzonite and granite of Pellisier Flats and related 

albitized rocks -----------------------·-------------------------------------------------·······------------·--·····--·-------------·----------------------------------·--·-····----- 10 

Photomicrograph of aggregate of small biotite :Oakes and magnetite grains that probably pseudomorphs a 

hornblende crystal in quartz monzonite and granite of Pellisier Flats ----------------------··----·-------------··--------------------·--- 11 

Photomicrographs of fresh secondary albite with discontinuous and chessboard twinning in intensively 

albitized rocks of the Pellisier Flats unit--------------·--------------------·····------·----------------------------------------------------------------·---------- 12 

Photomicrographs of fresh secondary albite and saussuritized original plagioclase from same specimen, 

Pellisier Flats unit -----------------·--------------·-----------------··--·-·········---------------·-·······-----------------------------·----------------------------··---···--- 12 

Photograph of typical bouldery outcrop of granodiorite of Mount Barcroft----·--------------·-----·-----------------------------·-····--·--·- 14 

Ternary diagram showing modal distribution of quartz, K-feldspar, and plagioclase in samples from the 

granodiorite of Mount Barcroft ---------·----------·-········------···-··-······-·------------·-----·------------------------------------------------------------·--··- 14 

Photomicrograph of plagioclase crystal in the granodiorite of Mount Barcroft :flooded with sericite, 

epidote-zoisite, and biotite ----·---------------------------------·-----··--·-------······-----------·----·-----------------------------------------------------------------·- 16 

Photomicrograph of distinctive interstitial quartz in the granodiorite of Mount Barcroft----·-----·-------------------·------------- 16 

Photomicrograph of irregular aggregate of biotite, hornblende, and magnetite in granodiorite of Mount Barcroft... 16 

Ternary diagram showing modal distribution of quartz, K-feldspar, and plagioclase in samples from quartz 

monzonite of Boundary Peak ----------··----------------·-·····-····--·-···--··-····----·----·········-------·-------------------·------------------------------···----- 17 

Silica variation diagrams of granitic rocks, northern White Mountains -----·---------------------·-------·····-···--------------······---------- 21 

Silica variation diagrams comparing oxide contents of the granitic rocks of the northern White Mountains 

with other granitic suites ----------------------------------------·---:·----------------------------·-----------------------------------·------------------------------------- 22 

Graph showing Peacock index of granitic rocks, northern White Mountains -------------------·--------------------------------·----·-----··· 23 

Ternary diagrams showing selected oxides and normative minerals, northern White Mountains ----------------·------------- 24 

Ternary diagram comparing modal and normative fields for granitic rocks of the northern White Mountains -------- 25 

Histograms showing trace-element content of granitic rocks, northern White Mountains -------------------------------------------- 26 

Sketch map showing distribution of albitized rocks in the northern White Mountains ------------------------------------------------ 27 

v 
VI CONTENTS 

TABLES 

Page 

TABLES 1-8. Modes of1. Granodiorite of the Benton Range from Blind Spring Hill .............................................................................. 4 

2. Granodiorite of the Benton Range by Rinehart and Ross (1969, p. 43) .......................................................... 4 

3. Quartz monzonite and granite of Pellisier Flats................................................................................................ 9 

4. Diorite complex of Queen Canyon .......................................................................................................................... 13 

5. Granodiorite of Mount Barcroft ............................................................................................................................ 15 

6. Granodiorite of Mount Barcroft by Emerson (1959, p. 58-95) ........................................................................ 15 

7. Quartz monzonite of Boundary Peak .................................................................................................................... 18 

8. Quartz monzonite of Boundary Peak by Harris (1967, table 1) ...................................................................... 18 

9. Chemical analyses of granitic rocks in the northern White Mountains .. ...................................................................... 19 
PETROGRAPHY OF SOME GRANITIC BODIES IN THE 

NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

By DwiGHT F. CROWDER and DoNALD C. Ross 

ABSTRACT 

Mesozoic granitic rocks domi_nate the pre-Tertiary basement 

of the northern White Mountains. Although collectively called 

the lnyo batholith, there is little doubt that, under the Cenozoic 

overburden, they are physically continuous with the Sierra 

Nevada batholith to the west, rather than part of a separate 

body. These rocks are petrographically similar to the granodiorite and quartz monzonite of this region except that the 

granodiorite of Mount Barcroft is definitely quartz poor and 

the quartz monzonite and granite of Pellisier Flats is anomalously rich inK-feldspar. Both the Mount Barcroft and Pellisier Flats units are characterized by irregular patchy dark 

minerals that in part look secondary; these occurrences, patches 

of dark minerals in nearby metavolcanic wallrocks, and albitized granitic rocks suggest all were subject to some later, postmagmatic period of alteration. 

Chemical analyses of 11 samples from these bodies show that 

CaO content is markedly lower and K20 content markedly 

higher than in other granitic suites in California. A Peacock 

index of about 54 places these rocks well into the alkali-calcic 

field, in contrast to the calc-alkalic and calcic nature of other 

California granitic suites. 

The southern part of the quartz monzonite and granite of 

Pellisier Flats and the adjacent metavolcanic wallrocks have 

been extensively albitized over an area of at least 50 square 

miles. These rocks are characterized by fresh secondary albite 

(An1-s). The most intensely altered rocks are composed entirely 

of albite and quartz but retain a medium-grained granitic 

texture. 

The rocks of the northern White Mountains have long been 

considered a classic example of regional granitization. This 

report supports the conclusions of D. 0. Emerson that these 

granitic rocks are of magmatic intrusive origin, have assimilated wallrocks during intrusion, and were later subjected to 

alteration and albitization. The plutons of the White Mountains 

are typical of granitic rocks from this part of California and 

Nevada-they exhibit definite intrusive relations, relatively 

sharp contacts, and chemical characteristics compatible with 

magmatic origin, and they show only minor effects of assimilation, contamination, or granitization. 

INTRODUCTION 

From 1964 to 1969 Dwight F. Crowder made a 

detailed geologic study of the pre-Tertiary rocks of the 

White Mountain Peak and Benton quadrangles in the 

rugged northern White Mountains of California and 

Nevada. He had completed the geologic mapping, had 

nearly completed preparation of the geologic maps for 

publication, and was about to begin writing of the 

reports when, in April1970, he was killed in an automobile accident. I (Ross) was assigned the job of completing the maps for publication and preparing such 

reports as might be suitab1e. The field data for this 

report were almost entirely Dwight's. Unfortunately, 

the words and conclusions of the report had to be solely 

mine. This report is a synthesis of as much data as 

could be gleaned from Dwight's notes and my own 

study of hand specimens and thin sections. I made a 

2-week trip to the field area to familiarize myself with 

the rock units, but as anyone who knows the awesome 

topography of the White Mountains can appreciate, the 

limitations of such a brief visit are severe. In interpreting Dwight's data for the granitic rocks of the White 

Mountains, I hope that I have said, at least in part, 

what Dwight would have said. 

The northern White Mountains are underlain by 

large plutonic bodies (fig. 1) that are part of what has 

been termed the "Inyo batholith" (Anderson, 1937, 

p. 8). The petrography of these rocks and their almost 

certain connection beneath Cenozoic overburden with 

granitic rocks of the Sierra Nevada strongly suggests 

that they are part of the much larger composite Sierra 

Nevada batholith. Furthermore, the name "Inyo batholith" seems to imply a separate and distinct entity, 

which creates a false impression; for this reason, the 

term "Inyo batholith" is of dubious value. 

The granitic rocks of the northern White Mountains 

have received considerable attention since Anderson 

(1937, p. 66) proposed that one of the largest granitic 

masses, which he named the Pellisier Granite, originated by the granitization of metasedimentary rocks by 

solutions from a younger intrusive rock, which he called 

the Boundary Peak Granite (fig. 2). Since Anderson's 

paper, the northern White Mountains have been 

repeatedly cited in the literature as a prime example of 

large-scale granitization. 

In the 1940's and 1950's, detailed field studies were 

undertaken in the granitic terrane immediately to the 

west, where it was shown that the granitic rocks were 

dominantly of intrusive origin and that granitization 

had played only a minor role (Rinehart and Ross, 1957, 

1 
2 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

118°30' 

VOLCANIC 

WHITE MTN 

BISHOP QUADRANGLE 

TABLELAND 

Base from U.S. Geolog1ca I Survey 1:250,000 Mariposa, 1957-64; 

Goldfield, 1954-62; Walker Lake,1957-66 

0 

118°15' 

5 

DAVIS MOUNTAIN QUADRANGLE 

10 MILES 

-n 

iii 

:t 

FIGURE 1.-Northem White Mountains, California-Nevada. 

118·oo· 
DESCRIPTION OF GRANITIC lTNITS 3 

1964; Bateman, 1965; Moore, 1963). Reconnaissance 

studies in Nevada, immediately north and east of the 

White Mountains, led to similar conclusions (Ross, 

1961; Albers, 1964). The northern White Mountains 

lay virtually untouched, chiefly because of their rugged 

terrain and the lack of base maps, although Ross 

(1961) and Albers and Stewart (1965) worked along 

their edges. The first modern studies of the granitic 

basement of the northern White Mountains were begun 

in 1950 by D. 0. Emerson, who made a petrographic 

study of the granitic masses of the Mount Barcroft 

quadrangle (immediately east of the White Mountain 

Peak quadrangle) . Emerson's (1959, 1966) work 

showed that Anderson had included several discrete 

plutonic units as well as metamorphic rocks in his Pellisier Granite and that the granitic rocks of the quadrangle are predominantly intrusive (Emerson, 1966, 

p. 146-147). Subsequent geologic mapping of the 

Mount Barcroft quadrangle by Krauskopf (1968) corOther granitic 

rocks 

EXPLANATION 

D 

Volcanic and sedimentary 

rocks 

Quartz monzonite of 

Boundary Peak 

Quartz monzonite Granodiorite of 

and granite of Mount Barcroft 

Pe llisier Flats 

Diorite of 

Queen 

Ca nyon 

[] ' + + 

Granodiorite of the Be nton Range 

D < . 

Mi xed metavolcanic and granitic rocks 

Metav

D 

olca nic rocks Volcaniclastic ~ 

metasediment ary 

rocks 

Meta• morphic rocks 

of proba ble 

Pa leozoic age 

Sedimentary rocks; in part 

metamorphosed 

Contact 

Fault 

u 

H 

(f) 

" ::J 

~0 

(f)l!J 

(f)U 

<(<( 

et:r-

::JW 

-,[t: 

. u U~ -et: 

~0 <(-

-o 

~z <( 

-

z 

<(0 

£rZz 

[D<(<( 

::?: -- <(Z~ 

u<(> 

w(rO 

o:mo 

o._::?:O: 

l!J<(o 

r-u 

<( 

.J 

roborated Emerson's findings, as did detailed studies 

of the quartz monzonite of Boundary Peak by Harris 

(1967). 

The dominantly granitic terrane of the west slope of 

the White Mountains, however, was still virtually 

unmapped, requiring a combination hard-rock geologist 

and mountaineer. In 1964 Dwight Crowder was persuaded to bring his ice ax from his beloved Cascade 

Mountains to the White Mountains, where he proceeded to map and study the rocks on this rugged 

mountain front. The work was halted by his death in 

1970. This report records some of Crowder's findings 

and helps refute the concept that the White Mountains 

are a locale of large-scale grauitization. 

The petrography and chemistry of these rocks are 

stressed in this report, which does not deal with the 

wallrocks or other aspects of the regional geology. For 

further information on the regional geology, the reader 

is referred to the following geologic quadrangle maps 

and accompanying explanatory texts: White Mountain 

Peak (Crowder and Sheridan, 1973),Benton (Crowder, 

Robinson, and Harris, 1973), Mount Barcroft (Krauskopf, 1971), Davis Mountain (Robinson and Crowder, 

1973), and Casa Diablo Mountain (Rinehart and Ross, 

1957). On both the White Mountai,n Peak and Benton 

maps, the term "adamellite" has been used, but it has 

been changed in this report to the equivalent term 

"quartz monzonite" for the comparable units, as that 

term is more commonly used in this region. 

Sample localities for modes and chemically analyzed 

rocks are shown in figure 3. Potassium-argon radiometric age dates for these granitic rocks are discussed 

in a report by Crowder, McKee, Ross, and Krauskopf 

(1973). The quartz monzonite of Boundary Peak is 

probably Late Cretaceous, and the Mount Barcroft and 

Pellisier Flats units are probably Triassic or Jurassic, 

although there are problems in dating these two altered 

granitic units. The granodiorite of the Benton Range 

is probably Triassic. 

DESCRIPTION OF GRANITIC UNITS 

GRANODIORITE OF TilE BENTON RANGE 

GEOLOGIC SETTING AND GENERAL DESCRIPTION 

Less than 10 square miles'of the granodiorite of the 

Benton Range is exposed in the southern part of Blind 

Spring Hill (frontispiece). These rocks are physically 

separate from, but texturally and mineralogically similar to, the granodiorite of the Benton Range abundantly exposed in the adjoining Casa Diablo Mountain 

quadrangle (Rinehart and Ross, 1957). Similar rocks 
4 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

FIGURE 2.-Contact of light-colored quartz monzonite of Boundary Peak with the dark-colored quartz monzonite and granite of 

Pellisier Flats. Taken from U.S. Highway 6; view southeastward into the White Mountains. High point on the skyline is 

Boundary Peak, 13,140 feet, the highest point in Nevada. The sage-covered valley floor is about 6,000 feet above sea level. 

are present to the northwest in the Glass Mountain 

quadrangle, but their extent is not known. This granodiorite is a major basement rock type underlying more 

than 200 square miles and possibly has a much greater 

area, as judged by probably correlative rocks in the 

Sierra Nevada (Rinehart and Ross, 1964, p. 47). Near 

the north end of Blind Spring Hill, it is intruded by the 

granite of Casa Diablo Mountain in a complicated contact zone containing abundant dioritic material and 

felsic dikes. 

The granodiorite IS medium to dark gray and 

strongly porphyritic in places, with euhedral K-feldspar 

phenocrysts as much as 50 mm long (fig. 4). Subhedral 

to euhedral"hornblende crystals as long as 10 mm, but 

more commonly 5 mm, are another striking characteristic. Ovoid dioritic inclusions are common. The few 

modes from Blind Spring Hill show a wide range (fig. 

5; table 1), as do the modes from the Casa Diablo quadrangle (table 2). Although this mass is indeed variable, 

it is easy to recognize in the field because the hornblende is so abundant and generally exceeds biotite, 

features which set this mass apart from other granitic 

bodies of the region. 

TABLE I.-Modes of granodiorite of the Benton Range from Blind Spring Hill 

Sample 

20 ........... . 21. .......... . 

22 ........... . 23 ........... . 24 ........... . 25 ........... . 

[n.d,=not determined] 

Plagioclase fel~~ar Quartz Biotite Hornblende 

40 

40 

40 

33 

50 

41 

33 

29 

34 

37 

18 

28 

15 

23 

15 

24 

9 

14 

1 

2 

1 

2 <I 

6 

'10 

6 

10 

4 

23 

11 

11 percent metallic opaque minerals. 

Specific 

gravity 

2.70 

2.68 

n.d. 2.66 

2.77 

2.73 

TABLE 2.-Modes of granodiorite of the Benton Range by 

Rinehart and Ross (1964, p. 43) 

Sample Plagioclase fel~~ar Quartz Biotite Hornblende ~i';,":;~i;r 

R-1. ........ . R-2 ......... . R-3 ......... . R-4 ......... . R-5 ......... . R-6 ......... . R-7 ......... . R-8 ......... . R-9 ......... . R-10 ....... . R-11 ....... . R-12 ....... . R-13 ....... . R-14 ....... . R-15 ....... . 

34 

48 

51 

50 

42 

53 

38 

58 

56 

40 

54 

57 

40 

31 

36 

17 

11 

7 

8 

26 

18 

30 

13 

13 

15 

10 

11 

26 

29 

21 

20 

25 

23 

21 

25 

8 

24 

15 

11 

34 

24 

20 

28 

36 

37 

12 

5 

7 

7 

2 

6 

4 

4 

10 

6 

8 

8 

4 

4 

6 

16 

9 

11 

13 

4 

14 

5 

9 

10 

3 

3 

2 

1 

2 

1 

1 

1 

1 

1 

2 

1 

2 

2 
DESCRIPTION OF GRANITIC UNITS 5 

In general the petrography of this mass, in particular 

the abundance of dark dioritic inclusions and euhedral 

hornblende, suggests a much greater affinity with Sierra 

Nevada granitic masses than with masses of the InyoWhite Mountains region. For some as yet unexplained 

reason, dark ovoid dioritic inclusions characteristic of 

large granodiorite masses of the Sierra Nevada are 

notably uncommon in rocks of the same general composition in the Inyo-White Mountains region. The contrast between the inclusion-poor Mount Barcroft and 

Pellisier Flats units and the inclusion-rich granodiorite 

of the Benton Range is striking. 

MICROSCOPIC DESCRIPTION 

The overall texture of the granodiorite of the Benton 

Range is hypautomorphic-granular, but sprinkles of 

rounded quartz crystals commonly give a somewhat 

aplitic aspect to the rock that culminates locally in an 

aplitic (or granoblastic) groundmass of quartz and 

feldspar in which much larger anhedral to euhedral 

crystals are set. Also present are square to rounded 

quartz crystals as large as 5 mm across that have been 

eaten into and embayed by the "aplitic" groundmass. 

Their general form suggests that they crystallized as 

beta quartz that formed discrete and in part euhedral 

crystals as large as, or larger than, the plagioclase 

crystals. In outcrop, the rocks with atypical aplitic 

groundmass resemble normal porphyritic granitic rock 

with euhedral hornblende. Thus, the texture, as it 

appears in thin section, is unexpected (fig. 6). A specimen from the Benton Range (specimen 2, Rinehart and 

Ross, 1964, p. 43) shows this same "aplitic" matrix 

inset with clean, well-formed crystals of feldspar and 

dark minerals. It seems likely that crystallization in 

most of the granodiorite of the Benton Range was completed, with no great change in conditions, and yielded 

a normal granitic texture. Locally, however, when the 

crystal mush was still bathed in liquid, a marked change 

in conditions of crystallization caused very rapid freezing to give the "aplitic" groundmass. 

Plagioclase is subhedral, remarkably fresh, and 

sharply twinned; oscillatory zoning with numerous 

small reversals is also characteristic. K-feldspar occurs 

in irregular grains of various size, but most strikingly 

as large poikiloblasts. Quartz is in irregular masses of 

various size and ranges from mosaicked grains with 

undulatory extinction to granulated, slivered aggregates. 

Biotite is a minor constituent in the rocks exposed 

in Blind Spring Hill but appears to be generally more 

abundant in correlative rocks in the Benton Range 

(Rinehart and Ross, 1964, p. 43). The small ragged 

crystals and intergrowths with hornblende are pleochroic from X= grayish yellow and orange to Z=moderate brown. 

Generally, hornblende overwhelmingly exceeds biotite in these rocks, and in part hornblende is the only 

dark mineral. Much of it is in large conspicuously subhedral to euhedral crystals, whereas other crystals are 

ragged and in part intergrown with biotite. In some 

specimens, hornblende occurs both as euhedral crystals 

and as fine-grained ragged aggregates. The hornblende 

has the following pleochroism: X=moderate greenish 

yellow, Y =light olive to light olive brown, and Z= 

grayish green to dark yellowish green. The dominance 

of hornblende appears to decrease to the south in the 

Benton Range, and the southernmost outcrops have 

none (fig. 7). 

Magnetite is scattered abundantly through these 

rocks and is particularly common in the hornblende. 

Apatite, sphene, and zircon are present, and allanite 

occurs in minor amounts. Sparse chlorite, epidote, and 

sericite are alteration products. 

QUARTZ MONZONITE AND GRANITE 

OF PELLISIER FLATS 

GEOLOGIC SETTING AND GENERAL DESCRIPTION 

The Pellisier Flats unit forms a belt of outcrop, as 

much as 8 miles wide at the latitude of Pellisier Flats, 

that is pierced by younger granitic rocks to the north; 

presumably correlative rocks extend to within 2 miles 

of the north boundary of the Benton quadrangle. The 

belt of outcrop also extends southward as far as Milner 

Canyon, where it fingers out. The irregular body and 

isolated small masses now cover an area somewhat less 

than 100 square miles. Although the main body of the 

Pellisier Flats unit closely approaches the largest mass 

of the Mount Barcroft unit, they are not in contact in 

the known exposures. Nearly all exposures are in the 

Benton and White Mountain Peak quadrangles; small 

areas protrude into the Mount Barcroft and Davis 

Mountain quadrangles. The term "Pellisier Granite" 

was first used on a geologic map by Anderson (1937) 

and included rocks on the east side of the range that 

Emerson (1966) and Krauskopf (1972) later found to 

be separate masses. The terms "quartz monzonite and 

granite of Pellisier Flats" or "Pellisier Flats unit" will 

be used throughout this report to avoid confusion with 

Pellisier Granite originally described by Anderson. 

The Pellisier Flats unit has a dull-gray cast and is 

characterized by abundant dark minerals. Much of this 

dull appearance is imparted by the dark minerals, 

which are rarely discrete shiny crystals but rather fuzzy 

aggregates and irregular shreds that give the rock a 

dirty, messy texture. The dark minerals tend to form 

very distinctive scattered ovoid clusters or clots several 

millimeters across. Dioritic inclusions, a few inches to 
6 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

.R- 1 

118°30' 1!8° 15' 38°00' .-----------------------------------------------,-, 

~0" ~R-12 

R-13 [\ 

'.\\~ 

R-14"', :: ( + R- 15 ~ 

~ ~ 0 2 4 Ml LES 

M-30~ 

31~~ 

FIGURE 3.-Location of modally and chemically analyzed specimens. 
DESCRIPTION OF GRANITIC UNITS 7 

2 or 3 feet across, are widespread and locally common, 

but in general are much less common than in Sierra 

Nevada granitic rocks of equivalent composition. 

The most noteworthy feature of hand specimens of 

this rock is the abundance of K-feldspar. Casual field 

observation suggests that the rock is a granodiorite; 

however, close observation reveals abundant pinkish 

feldspar in many specimens, and staining shows that 

K-feldspar predominates. The modes (fig. 8; table 3) 

show a field that blankets the quartz monzonite range 

and extends across much of the granite field. Because 

of the large number of points that fall within the granite 

field, the modal field is unusual in comparison with that 

of most other granitic bodies of the Sierra Nevada and 

the White and Inyo Mountains. 

Qua rtz monzonite 

a nd g r anite of 

Pe llisier Flats 

Ove·rp1·int indicates 

albitized mixed 

metavolcanic and 

Pellisier· rocks 

EX PLANAT ION 

D 

Granodiorite 

of Mount 

Barcroft 

D + 

+ + 

D 

Quartz monzonite 

of Boundary Peak 

Granodiorite of the 

Benton Range 

Diorite complex 

Contact 

Fault 

SAMPLE LOCA LI TIES 

Numbers are keyed to tables in text 

128 0 

New mode 

1~ 7, dior-'itP cU'fnplex; 10 17, quar·tz monzon·ite of BoundaTy Peale; 

20 2-5, g·runodiorite of the Benton Range; 2, granodiorite 

of Mount BaTcTojl; 101~165. QlWTtz monzon-ite and gr·anite of 

Pellisier- Flats e H-20 

Mode from another source 

LetteT prefix keyed to •·efeTence list: E , Em.er·.•on (1959); H, 

Hcwri.• (1.967); R , Rinehar·t and Ro ss (1969, p. 4.7) ; M, Ross (1961 , p. 34) 

0 1s3 

Chemically analyzed sample 

ThTee specimens from Bounda,-y Peale (in paTentheses~116, 2 14, 

and 24 1) do not hcwe •rnodal analyses 

FIGURE 4.--Granodiorite of the Benton Range. Abundant 

euhedral K -feldspar phenocrysts, small dioritic inclusions, 

and euhedral hornblende crystals are visible. Quarter for 

scale. 

~ " Other 

,:}' 0 

f 

s-

~"'1o o"' 

""' 20 ,._., 

s 

,f 30 Q'<i 

EXPLANATION 

2 1 0 

New mode 

• Mode from Rin ehart 

and Ross (1964, p . 43 ) 

K-feldspar 

FIGURE 5.-Modal distribution of quartz, K-feldspar, and 

plagioclase of the granodiorite of the Benton Range. 
8 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

FIGURE G.-Photomicrograph of fine-grained "aplitic" groundmass of specimen 25 from the granodiorite of the Benton 

Range. 

37'45' 

0 

2.8 .1 -

1.!1 

3 MILES 

2211 

10 

25 17 

2 

Sample 18 i~i~~~:nhtornblende. number - '3 J- 6 Ratio of hornblende 

t.o biotite 

Sample locality 

Open circle, new rnnde; :wlid 

ciTcle, mode from Rinehart 

and Ro.s (1964, p. 43) 

FIGURE 7.-Sample localities, dark-mineral content, and ratio 

of hornblende to biotite in specimens in the granodiorite of 

the Benton Range. 

Quartz 

EXPLANATION 

0 

Normal gray facies 

0 

Coarse felsic facies 

. Other 

Plagioclase K- feldspar 

FIGURE 8.-Modal distribution of quartz, K-feldspar, and 

plagioclase in the quartz monzonite and granite of Pellisier 

Flats. 

TABLE 3.-Modes of quartz monzonite and granite of Pellisier Flats 

Sample 

103 ............ 104 ............ 105? .......... 106? .......... 108. ........... 109? .......... 110? .......... 111. ........... 117 ............ 121... ______ ___ 

122 ............ 124?... ....... 132 ............ 134 ............ 148?... ....... 150 ............ 151... ......... 153 ............ 154 ............ 155 ............ 156 ............ 157 ............ 158 ............ 159 ............ 160 ............ 161. ........... 162 ............ 163 ............ 164... ......... 165 ............ 

Avg ... 

[n.d.=not determined] 

Mafie m~nerals 

Plagioclase fel!-par Quartz ____ ..:..._ __ _ Biotite Hornblende 

Normal phase 

32 30 15 

41 22 17 

31 38 17 

40 37 12 

33 29 14 

35 42 15 

41 25 12 

37 25 17 

35 35 18 

41 24 17 

30 30 17 

20 44 23 

22 56 11 

20 45 27 

14 52 29 

24 45 19 

27 46 8 

23 50 15 

16 46 17 

24 47 11 

26 46 11 

28 39 8 

13 49 20 

18 62 12 

13 58 8 

21 48 9 

30 44 10 

24 39 12 

37 29 16 

39 27 17 

28 40 15 

18 

19 

5 

1± 

20 <I 

22 

18 

9 

9 

23 

13 

10 

8 

5 

12 

19 

12 

21 

18 

17 

25 

18 

8 

21 

22 

16 

25 

10 

11 

15 

5 

1 

'8 

10 

4 

8 

3 

3 

9 

1 

8 

'5 

2 

Specific 

gravity 

2.70 

2.69 

2.68 

2.65 

2.68 

2.64 

2.73 

2.73 

2.68 

2.70 

2.70 

2.62 

2.62 

2.62 

2.63 

2.64 

2.63 

2.62 

n.d. 

2.68 

2.67 

2.69 

2.65 

2.62 

2.69 

2.65 

2.65 

2.70 

2.70 

2.70 

2.66 
DESCRIPTION OF GRANITIC UNITS 9 

TABLE 3.-M odes of quartz monzonite and granite of 

Pellisier Flats-Continued 

K- Mafic minerals Specific Sample Plagioclase feldspar Quartz gravity Biotite Hornblende 

Coarse phase 

101? .......... 38 35 23 4 2.63 

102? .......... 39 28 21 12 2.66 

118 ............ 24 47 22 7 2.62 

119 ............ 22 49 22 7 <1 2.62 

123 ............ 25 42 24 9 2.64 

125 ............ 34 35 22 9 2.64 

126 ............ 27 46 22 5 2.62 

127?. ......... 36 38 18 8 2.65 

128 ............ 29 39 20 12 2.65 

129 ............ 23 40 28 9 2.64 

130? .......... 20 57 20 3 2.64 

131. ........... 12 61 24 3 2.60 

133 ............ 37 35 21 7 2.62 

135? .......... 35 32 26 7 2.63 

136? .......... 36 32 29 3 2.62 

137? .......... 40 28 28 4 2.64 

138 ............ 26 45 21 8 2.62 

139 ............ 29 44 20 7 2.62 

140? .......... 13 55 29 3 n.d. 141? .......... 15 61 15 9 2.63 

142?... ....... 16 46 17 21 2.60 

143? .......... 25 46 20 9 2.66 

Avg ... 29 41 22 8 2.63 

Other samples 

107?. ......... 65 1 18 16 2.64 

112 ............ 40 33 10 17 2.71 

113 ............ 50 13 17 19 1 2.70 

114 ............ 32 32 19 17 2.67 

115 ............ 39 32 9 1 19 2.73 

116 ............ 30 33 18 19 2.69 

120 ............ 68 0 25 7 2.60 

144 ............ 22 42 30 6 

145' ·········· 71 0 29 0 2.60 

146' .......... 22 49 23 6 2.62 

147' ·········· 8 57 30 '5 2.62 

149' .......... 8 61 29 2 2.63 

152 ............ 23 40 19 18 

Rocks of Harris (1967) 

H-L. ......... 43 28 27 2 

H-2 ............ 53 15 29 3 

H-3 ............ 39 29 26 6 

H-7 ............ 35 34 19 12 

H-8. ........... 54 15 24 7 

H-9 ............ 40 27 14 19 

H-10 .......... 39 28 13 20 

H-11 .......... 37 40 13 10 

H-21... ....... 28 49 22 1 

H-31... ....... 47 29 21 3 

Rocks of Ross (1961) 

M-30 .......... 30 39 23 8 

M-31... ....... 38 24 21 17 

11 percent metaUic opaque minerals and sphene. ' Albite g r a nit e (ty pe 1) . 3Albitized leucocratic Pellisier Flats (type 3). ' Altered t o chlorite. 

A coarser grained more felsic central core facies of the 

Pellisier Flats unit can be distinguished in the hand 

specimens collected. In the area of Mount Dubois, it 

forms a northeast-trending belt (fig. 9) that contains 

more quartz and fewer mafic minerals than the normal 

part of the Pellisier Flats unit. Both facies average on 

the granite side of the quartz monzonite field and have 

similar amounts of plagioclase and K-feldspar (fig. 8). 

The coarser facies was not mapped in the field, which 

suggests it is not an obviously separate intrusion. Moreover, outcrops of the Pellisier Flats unit north of the 

quartz monzonite Boundary Peak contain possibly 

transitional rocks that are coarser than the normal part 

of the Pellisier but contain more dark minerals than the 

coarser facies. Some rocks south of the quartz monzonite of Boundary Peak, as well as rocks tentatively 

assigned to the coarser facies west of this pluton, may 

be transitional. The dull-gray rock probably is normal 

Pellisier that grades to a coarser more felsic central core 

facies that crystallized last. On the other hand, the 

coarse felsic facies may represent nearly pure Pellisier, 

and the dull-gray Pellisier may be a contaminated 

altered variant as in the Pat Keyes pluton in the Inyo 

Mountains to the south (Ross, 1969,p.ll). The virtual 

absence of hornblende in the coarser facies, however, 

suggests that the dull-gray rock is typical of the Pellisier Flats unit. 

MICROSCOPIC DESCRIPTION 

Biotite occurs in shreds, slivers, and irregular aggregates or clots and is liberally sprinkled through altered 

plagioclase in these rocks. The distinctive clots seen in 

hand specimen are aggregates of biotite, meta1lic 

opaque minerals, sphene, and epidote. The shape of 

some biotite aggregates suggests pseudomorphs after 

hornblende (fig. 10). The biotite is rather uniformly 

pleochroic from X=grayish yellow or grayish orange to 

Z=light olive or light olive brown. 

Plagioclase is thinly twinned and commonly is richly 

peppered with sericite, epidote-zoisite, biotite, and 

some calcite. The pervasive saussuritization of what 

presumably was intermediate plagioclase has been very 

thorough, for all the plagioclase now seems to be albite 

(or oligoclase). Thin-section study of the plagioclase 

was supplemented by limited X-ray diffraction studies. 

The anorthite content of three specimens from the 

coarse felsic facies was about Anl-5 , although the patterns were somewhat irregular. Plagioclase from three 

typical rocks of the gray normal facies from the Benton 

quadrangle north of the coarse felsic facies showed 

An14, An20 , and An23 • These specimens probably are 

representative of the unalbitized parts of the Pellisier 

Flats unit. Four specimens from the gray normal facies 

of the Pellisier Flats unit south of the coarse felsic 

facies were picked; the specimens had intensely altered 

plagioclase, but no chessboard albite, and looked like 

dark normal rocks of the Pellisier Flats unit. These 
10 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

118°30' 

37°45' 

@Float 

0 Benton 

@Float 

BENTON QUADRA NGLE 

WH ITE MOUNTAIN PEAK 

EXPLAI\'ATION 

Coarse felsic facies Normal gray facies 

Quartz monzonite and granite of Pellisier Flats 

• 

(1) (2) (3) 

Albitized mixed metavolcanic and granitic rocks 

(1) Medium- to coarse-grained quartz-albite rocks 

(2) Albitized metavolcanic rocks 

(3) Albite granite with abundant K-feldspar 

0 

Hornblende-bearing specimen 

?: 1 

<1 

Ratio of plagioclase to K-feldspar 

--25--

Contour showing quartz content, in percent 

Contour interval 5 percent 

0 2 4 MILES 

118.15' 

. ' "' ' ' 

White Mountain 

f:c. Peak 

FIGURE 9.-Sample localities in the quartz monzonite and granite of Pellisier Flats and related 

albitize!l rocks. 
DESCRIPTION OF GRANITIC UNITS 11 

");. 

It' 

' · ' • f 

~·~,-I ¢!:4'> ~ .. :. ; 

. ·' ~ 

... 'iv • t • 

r~ ~·' -:.~ . " ... .. ., t • \. 

"" t ' . ._: ' h$ ·;. ~ :: • ;mm ~ 

FIGURE 10.-Photomicrograph of aggregate of small biotite 

flakes (bi) and magnetite grains (mgt) that probably pseudomorphs a hornblende crystal in quartz monzonite and granite 

of Pellisier Flats. 

rocks all showed X-ray diffraction patterns that suggest 

Ano-s, but the patterns were by no means conclusive for 

some specimens. The alteration products may mask the 

plagioclase peaks, or the alteration-product-soaked 

plagioclase may give w~aker-than-normalpeaks. Nevertheless, the plagioclase is probably sodic and probably 

albite in much of the area south of the coarse felsic facies. 

K-feldspar is dominant in most specimens, ranging 

from small interstitial grains to large irregular to subhedral crystals. Some is distinctly grid twinned; more 

characteristic is splotchy irregular perthite in which 

finely twinned albite is locally distinct. 

Quartz, though in part in fairly normal irregular 

crystals that show undulatory extinction and rather 

normal mosaicking, is typically in granular almost hornfelsic aggregates. The overall appearance is one of a 

metamorphic fabric, not a cataclastic one. Anderson 

( 1934, p. 185) noted this feature and suggested the 

term "pseudo-cataclastic" to identify it; he associated 

the texture with replacement. 

Hornblende is rare south of the coarser facies (fig. 9) 

but widespread north of the coarser facies and even 

dominant in some specimens (table 1). In some of the 

northern rocks, hornblende is in discrete subhedral 

crystals, but more commonly it is intergrown in clusters 

with fine-grained aggregates of biotite, metallic opaque 

minerals, and sphene. Although hornblende is rare in 

the southern rocks, the presence of scattered grains, as 

well as pseudomorphs after hornblende, suggests that 

the paucity of hornblende reflects a secondary effect 

related to alteration of the rocks, not a primary difference in the mineralogy. The hornblende is pleochroic 

from X=moderate greenish yellow and Y=grayish to 

dark yellowish green, to Z=various shades of blue 

green, yellowish green, and moderate green. 

Metallic opaque minerals present are sphene, apatite, 

and, less commonly, zircon. Sphene is abundant as 

irregular 1nasses in some rocks, and only rarely is in 

euhedral crystals . 

MIXED METAVOLCANIC AND GRANITIC ROCKS 

An "enclave" about 10 square miles in area has been 

called "mixed metavolcanic and granitic rocks" on the 

White Mountain Peak geologic map (Crowder and 

Sheridan, 1973). These rocks, exposed from Lone Tree 

Canyon north for several miles, were first thought to be 

a separate felsic intrusive. In fact, many of the outcrops 

are light colored and superficially resemble aplite and 

alaskite. Within this outcrop are patches and intrusive ( ?) areas of the Pellisier Flats unit. The "enclave" 

also contains abundant metavolcanic rocks with clearly 

recognizable porphyritic volcanic textures. 

It is here proposed that the "enclave" is an area of 

metavolcanic rocks that has been extensively intruded 

by the Pellisier Flats unit and, even more significant, 

has been drenched in the solutions that altered and 

albitized the southern part of the Pellisier Flats unit. In 

fact, some of the kinds of intensely albitized rocks common in the "enclave" are found some distance away 

within outcrops of the Pellisier Flats unit (fig. 9). 

Three main rock types make up the body of mixed 

metavolcanic and granitic rocks. The most abundant 

(judging by collected specimens) is a medium- to 

coarse-grained rock that looks alaskitic in hand specimen, but is composed almost entirely of albite and 

quartz. This rock is generally fresh looking in thin section and features cleanly twinned chessboard albite and 

thin discontinuous twins that seem to be a variant of 

chessboard twinning (fig. 11). It has no K-feldspar and 

virtually no dark minerals. Some specimens of the Pellisier Flats unit appear to be transitional to the albitequartz rocks (fig. 12), which may have originally been 

part of the Pellisier Flats unit. 

The next most abundant rock type is metavolcanic 

rock with striking porphyritic texture and a granablastic groundmass. Some phenocrysts as much as a 

few millimeters across are euhedral; they are now 

mostly chessboard albite to finely, discontinuously 

twinned albite. The fine-grained to dense groundmass 

is composed dominantly of quartz and albite; K-feldspar is abundant in the groundmass of some specimens. 

Flow structure is preserved in part, and some specimens 
12 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS. CALIFORNIA-NEVADA 

A 

B 

FIGURE !I.-Photomicrographs of fresh secondary albite (ab) 

with discontinuous and chessboard twinning in intensively 

albitized rocks of the Pellisier Flats unit. A, discontinuous 

twinning; B, chessboard twinning. 

look tuffaceous. The groundmass of some still has a 

felty aspect. There can be little doubt that these rocks 

were originally volcanic. In the field, some of these 

rocks are easily confused with quartzite or aplite, particularly where the original volcanic texture is subtle or 

absent. Abundance of aplite locally in this "enclave" of 

mixed rocks further complicates the problem of field 

identification. 

The other common rock type in the mixed area is 

albite granite with abundant K-feldspar. Its texture is 

granitic, but dark minerals are commonly minor or 

absent. Some specimens are aplitic to alaskitic, but 

have some chessboard-twinned albite. In these rocks, 

much of the albite is cloudy and only incompletely 

altered from the originally more calcic plagioclase. 

These rocks may represent a transitional stage on the 

way to albite-quartz rocks. 

A 

B 

FIGURE 12.-Photomicrographs of fresh seconqary albite and 

saussuritized original plagioclase from same specimen, Pellisier Flats unit. A, fresh secondary albite showing chessboard 

and discontinuous twinning; B, saussuritized plagioclase 

crystal liberally sprinkled with biotite shreds and flakes. 

The K-feldspar-bearing albite granites and the medium- to coarse-grained albite-quartz rocks occur not 

only in the "enclave" but also in the main mass of the 

Pellisier Flats unit, where they appear to be transitional to normal rocks of the Pellisier Flats unit, suggesting that these albite-rich rocks are variously altered 

Pellisier rocks mixed in with the metavolcanic rocks. 

DIORITE COMPLEX OF QUEEN CANYON 

Along the south side of Queen Canyon on the north 

side of the quartz monzonite of Boundary Peak is a 

4-mile-long belt of outcrop of various dioritic rocks 

mixed with felsic rocks (fig. 3; table 4) that may be 

related to the Pellisier Flats unit. Although some Pellisier-rocks are present, the complex also contains a 

variety of hornblende diorite and related rock types 
DESCRIPTION OF GRANITIC UNITS 13 

TABLE 4.-Modes of diorite complex of Queen Canyon 

[X indicates mineral p resent, but no mode run] 

Sample Plagioclase K-feldspar Quartz Biotite Hornblende ~~=~\~; 

1'.............. 50± 

2................ 60± <5 

3................ 60± 

4 ................ (similar to sample 5) ... . 5................ 36 29 11 

6................ X X X 

7................ 50± 

45± 

40± 

40± 

11 13 

X 

5-10 40-50 1Contains about 5 percent epidote ·in discrete crystals. 

2.96 

2.87 

2.87 

2.70 

2.72 

2.66 

2.89 

that make it distinctive from the main mass of the 

Pellisier Flats unit. Aplite, alaskite, pegmatite, and 

other felsic rocks make up as much as 50 percent of the 

complex. Presumably, these felsic types are largely 

offshoots of the quartz monzonite of Boundary Peak. 

In general, this complex contains dioritic rocks that are 

probably somewhat older than the Pellisier Flats unit, 

as well as Pellisier-like rocks and younger felsic rocks 

that are probably part of the quartz monzonite of 

Boundary Peak. 

Hornblende diorites of various grain sizes probably 

are the most abundant rock types in the complex. They 

range from fine-grained aplitic or granoblastic rocks to 

irregular-textured coarse rocks characterized by large 

hornblende crystals. The same kinds of hornblende 

diorite are relatively common in small masses in the 

granitic terranes of this region and are abundant in 

the Casa Diablo Mountain quadrangle to the west 

(Rinehart and Ross, 1957). These diorites are composed chiefly of about equal amounts of andesine and 

hornblende that is pleochroic from X= moderate greenish yellow and Y = various shades of olive and olive 

brown to Z=moderate to brilliant green. Small 

amounts of K-feldspar, quartz, and biotite (pleochroic 

from X = grayish yellow to Z=moderate reddish 

brown) are found in some specimens. Sphene is a relatively abundant accessory mineral; metallic opaque 

minerals are surprisingly rare or absent in most of these 

rocks. 

The diorite appears to grade into medium-gray 

medium-grained quartz monzonite containing biotite 

and hornblende in about equal amounts. The biotite is 

pleochroic in shades of olive and olive brown, and the 

hornblende has the same pleochroism as in the diorite. 

In these rocks, the plagioclase appears to be oligoclase. 

The quartz monzonite also has abundant accessory 

sphene; metallic opaque minerals are rare or absent. 

In addition to hornblende diorite and related rocks, 

the diorite complex contains granoblastic to gneissic 

rocks that have biotite but no hornblende and that are 

characterized by large pinkish K-feldspar crystals as 

much as 15 mm long. These rocks with strongly chloritized biotite do contain metallic opaque minerals, both 

as small particles in the chlorite and as discrete large 

crystals. 

The felsic members of the complex are aplite, 

alaskite, simple pegmatite, and coarse-grained biotite 

quartz monzonite that probably is related to the quartz 

monzonite of Boundary Peak. 

GRANODIORITE OF MOUNT BARCROFT 

GEOLOGIC SETIING AND GENERAL DESCRIPTION 

Outcrops of the Mount Barcroft unit extend (fig. 13) 

over an area of about 15 square miles in the southeastern part of the White Mountain Peak 15-minute quadrangle. They mark a profound structural break between 

Cambrian sedimentary rocks on the south and a mixed 

sequence of volcanic and sedimentary rocks of probable 

Mesozoic or late Paleozoic age on the north. The blunt 

dike-shaped mass extends northeastward into the 

Mount Barcroft quadrangle, where it covers ari additional 10 square miles (Krauskopf, 1971). A 5-square 

mile mass of correlative rocks (Emerson, 1966; Krauskopf, 1971) is exposed about 2 miles farther east along 

the same trend as the main mass. The two masses are 

separated by younger intrusive rocks. The profound 

structural break appears to swing north in the Mount 

Barcroft quadrangle, whereas the trend shown by the 

two masses of the Mount Barcroft unit cuts across the 

trend to the northeast. Nevertheless, the western mass 

of the granodiorite of Mount Barcroft probably is controlled by this major structural break. 

The Mount Barcroft unit is made up of medium-gray 

medium-grained rock that is generally equigranular; 

rare poikilitic K-feldspar crystals are as large as 10 mm. 

Along the north margin of the mass, the rocks are distinctly coarser grained than elsewhere. Fresh rocks are 

dark colored not only because of the abundance of dark 

minerals but because of dark-appearing feldspar. Some 

K-feldspar is a purplish pink. Quartz is not readily 

visible in most hand specimens. Dark minerals occur 

mostly as iregular aggregates that give a splotchy, 

messy texture to the rock; only locally are biotite and 

hornblende in discrete crystals. In some rocks, the dark 

minerals in part form distinctive rounded clots a few 

millimeters across. Dark rounded dioritic inclusions 

generally only a few inches across but as large as 2 feet 

in largest dimension are widely distributed and locally 

abundant, though in general much less abundant than 

one would expect in a granitic rock that contains 20-25 

percent dark minerals-at least in the region of the 

Sierra Nevada batholith. The relative abundance of 

K-feldspar in these rocks (most modes plot in the 

quartz monzonite field) is also surprising for rocks this 

dark. 
14 PETROGRAPHY OF SOME GRANITIC BODIES. NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

FIGURE 13.-Typical bouldery outcrop of granodiorite of Mount Barcroft. 

Other 

EXPLANATION 

0 

New mode 

• • Modes from Emerson 

( 1959, 1966) 

Trinng /.e. rock jro111 easter·n 

The modes (fig. 14; tables 5, 6) show a considerable 

spread but have a general clustering of most points in 

the quartz monzonite field. The tailing off of the field 

to quartz diorite in part represents plagioclase-rich 

rocks in the northeastern part of the western mass, but 

much of the variation has no obvious trend. Emerson 

(1959, p. 94) noted that the K.feldspar of these quartz 

diorite specimens has low triclinicity and a low albite 

to orthoclase ratio relative to the K-feldspar in other 

samples of the mass. The granodiorite of Mount Barcroft is quartz poor relative to most other granitic rocks 

in this region, and a number of points plot in the monzonite and syenodiorite fields. In general, the rocks 

along the southeastern side of the western mass and 

the western part of the eastern mass are slightly richer 

in quartz. 

The somber gray appearance and the fuzzy, splotchy 

look of the dark minerals are the most distinctive 

L _ _L ~~~:=__-:h-_....:::::.:.:.:::::=::.__-k _ _ _ _ _ i<K:t. -te;;;;ld:;;s-;;.'parr features of this mass in outcrop. Plagi - 10 

oc lase 90 

FIGURE 14.-Modal distribution of quartz, K-feldspar, and 

plagioclase in samples from the granodiorite of Mount 

Barcroft. 

MICROSCOPIC DESCRIPTION 

Plagioclase is generally well formed and well twinned; 

it ranges from fresh to highly altered grains rich in 
DESCRIPTION OF GRANITIC UNITS 15 

TABLE 5.-Modes of granodiorite of Mount Barcroft 

Mafic minerals 

Sample Plagioclase K-feldspar Quartz Metallic Specific gravity 

Biotite Hornblende Clinopyroxene opaque Undivided 

minerals 30 ____ ____________ 42 28 8 22 2.76 

31. ............... 34 38 8 20 "8 2.74 32 _______ __ ____ ___ 38 22 6 24 2.78 33 ________________ 43 25 4 15 9 2 2 2.76 34 ________________ 43 26 9 "8 22 2.76 35 ____________ ____ 32 37 10 10 1 2.72 36 ________________ 35 39 7 19 2.72 37 _____ ________ ___ 50 15 7 28 2.79 38 __ ___ ______ __ __ _ 33 32 6 12 16 1 2.74 39 __ ___ ______ __ ___ 46 7 5 42 2.83 40 __ _________ __ __ _ 49 11 6 <1 34 2.83 41. _______________ 39 30 8 <1 23 2.74 42 ________________ 34 36 16 8 5 <1 1 2.72 43 __ ____________ __ 37 29 9 25 2.76 44 ________________ 31 37 12 10 7 '2 1 2.74 45 __ ____ ____ ____ __ 42 28 7 15 7 <1 1 2.73 46 _____ ___________ 39 25 12 15 8 <1 1 2.73 47 ________________ 46 12 10 15 16 <1 1 2.78 48 ________ ____ __ __ 44 29 8 12 7 <1 2.73 49 ________________ 44 13 4 39 2.85 50 ____ __ _______ __ _ 36 31 8 25 2.76 51. _______________ 41 34 10 15 2.74 52 __ ______ _____ ___ 29 43 15 8 4 1 2.70 53 ________________ 36 36 12 16 2.74 54 __ ______________ 37 33 11 11 7 1 2.73 55 __ ___ _________ __ 39 29 8 24 2.75 56 ___ ________ _____ 36 28 19 17 2.74 57 __ ___________ __ _ 35 33 10 22 2.73 58. __ ___ __ __ ______ 37 29 11 23 2.72 59 __________ ____ __ 37 32 10 18 3 2.71 60 ______ ______ ___ _ 48 13 4 25 10 2.82 61. _______ ____ ____ 38 24 7 26 5 2.78 62 ______ ___ _____ __ 47 16 4 '33 2.82 

Avg. 39 27 10 16 7 1+ 25 2.75 

24 1Trace of orthopyroxene 2Contains clinopyroxene. 

TABLE 6.-Modes of granodiorite of Mount Barcroft by Emerson (1959, p. 58, 95) 1 

Sample Plagioclase K-feldspar Quartz Biotite Hornblende Accessory Chlorite Opaque Accessory and minerals minerals opaque minerals 

E-8F ____ __ ______ 42.7 21.9 13.6 9.8 9.9 0.6 0.6 0.9 E-8G ______ ____ __ 35.1 24.2 13.9 12.9 11.6 .6 .6 1.1 E-8H ______ ____ __ 40.4 25.9 8.6 12.5 11.1 .4 1.1 E-10A __________ 50.4 18.6 5.4 19.5 3.6 1.4 .1 1.0 E-lOB __________ 56.3 7.0 12.8 21.7 .6 1.5 .1 E-10C __________ 41.0 24.7 5.5 10.1 16.3 .9 .5 1.0 E-llA __________ 46.1 18.1 5.4 12.1 16.5 .2 1.6 E-llB __________ 40.3 18.9 8.0 17.9 13.9 .3 .7 E-llC __________ 36.2 25.1 17.0 14.5 5.7 .6 .9 

E-12A __________ 39.8 22.2 14.2 10.6 '10.0 .2 3.0 E-12B. _________ 30.7 30.3 17.3 9.2 '6.5 '4.4 .8 .8 E-13A __________ 44.1 14.6 8.9 22.6 8.8 .3 .7 E-19 ________ ____ 38.4 20.4 4.2 12.9 22.9 1.2 E-20 ____________ 45.8 12.9 5.9 16.7 17.2 1.5 E-23 ____________ 42.9 4.4 7.5 16.2 27.9 1.1 E-25 ______ __ ____ 55.3 3.3 12.1 9.7 17.3 2.3 E-26 ____ _____ __ _ 52.3 9.6 8.0 29.8 .3 E-29 __ _____ ____ _ 35.3 22.6 15.9 18.4 5.3 2.5 

E-30 ------------ 37.6 31.5 14.6 8.1 5.7 2.5 E-31 ___ __ __ __ ___ 39.7 25.7 13.1 11.4 7.8 2.3 E-32 ____________ 35.9 31.8 12.9 4.9 11.5 3.0 

Avg. 42.2 19.2 10.8 13.3 12.4 2.1 1

About 20 percent of sections studied contain augite along with hornblende (Emerson, 1969, p. 60) . 

'Predominantly augite. 01 percent hypersthene, abundant augite, less than 1 percent hornblende. 

'Predominantly secondary pyrite. 
16 -PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

sericite and epidote-zoisite and is liberally sprinkled 

with biotite flakes (fig. 15). Zoning, in part oscillatory, 

is mostly in the andesine range; however, some cores 

are sodic labradorite, and some rims lap over to oligoclase. K-feldspar is generally in irregular interstitial 

grains of various sizes that grade up to poikilitic 

crystals several millimeters in diameter than engulf all 

other minerals in the rock. 

Quartz is mostly in thin vermicular but in part 

straight-sided crystals (fig. 16). All the quartz is somewhat strained and shows a range from grains with unduFIGURE 15.-Photomicrograph of plagioclase crystal in the 

granodiorite of Mount Barcroft flooded with sericite, epidotezoisite, and biotite. 

FIGURE 16.-Photomicrograph of distinctive interstitial quartz 

in the granodiorite of Mount Barcroft. 

latory extinction through mosaic grains with sutured 

contacts to granulated and slivered grains. 

The dark minerals show the irregular splotchy nature 

noted in hand specimen. Biotite is mostly in ragged to 

slivery patches that are pleochroic from grayish orange 

to various shades of olive and brown. Alteration to 

chlorite is common. Many crystals that appear 

unaltered have trains of sphene droplets concentrated 

on cleavages; needles that may be rutile are common 

in the biotite in three directions 120° apart. Much biotite is in greenish aggregates with much epidote and 

chlorite; some of these aggregates contain remnants of 

the olive to brown biotite. Hornblende remnants in 

some indicate they were probably originally hornblende, and the shape of similar biotite aggregates 

strongly suggests they also were once hornblende. 

Hornblende occurs most commonly in ragged clusters 

with biotite, sphene, apatite, and metallic opaque minerals; rarely, hornblende is found in discrete nearly subhedral crystals. Cores of some hornblende crystals 

contain remnants of clinopyroxene that are in part iron 

stained, accounting for the reddish spots and cores seen 

in hornblende in hand specimen. One specimen contains 

orthopyroxene ( ?) in a hornblende crystal. Fresh hornblende is green and has the following pleochroism: 

X=moderate greenish yellow, Y =light olive, and 

Z=light olive to grayish green and less commonly moderate to dark yellowish green. 

The shredded aggregates of biotite that are in part 

pseudomorphs after hornblende, the overall messy 

appearance of both hornblende and biotite, and the 

small dark clots, dominantly biotite (fig. 17), together 

give some of these rocks a megascopic resemblance to 

some of the rock of the Pellisier Flats unit. Although 

FIGURE 17.-Photomicrograph of irregular aggregate of biotite, 

hornblende, and magnetite in granodiorite of Mount Barcroft. 
DESCRIPTION OF GRANITIC UNITS 17 

there are significant petrographic differences between 

the two masses and they are definitely not correlative, 

the similarities of their dark minerals suggest that both 

masses have undergone similar alteration. The Mount 

Barcroft unit was less affected, for most specimens still 

bear hornblende; although the plagioclase is somewhat 

altered, the average speCimen is generally more calcic 

than the rocks in the Pellisier Flats unit. 

Metallic opaque minerals are abundant and are most 

commonly associated with the dark mineral clusters. 

Well-formed crystals of apatite and irregular grains of 

sphene are widespread. Allanite and zircon are present 

but rare. Bluish pleochroic tourmaline is widely 

scattered in trace amounts. 

QUARTZ MONZONITE OF BOUNDARY PEAK 

GEOLOGIC SETTING AND GENERAL DESCRIPTION 

The Boundary Peak unit crops out over some 25 

square miles in the northern White Mountains. The 

mass underlies some very rugged terrain, culminating 

at 13,140 feet elevation in Boundary Peak. The dazzling white outcrops led Harris (1967) to liken the 

Boundary Peak unit to "a shining white fortress set in 

the somber colored northern White Mountains," an 

apt description of this vivid contrast (fig. 1). The 

quartz monzonite of Boundary Peak looks in gross 

aspect like a great dike whose west-northwest trend 

sharply cuts across the dominant, more northerly, 

structural grain of the region. Harris (1967) believed 

that the Boundary Peak unit is somewhat sheetlike and 

that it rose from a root zone near the west limit of 

present outcrops, then spread eastward. The gently 

dipping roof of granitic and metamorphic rocks certainly suggests that the Boundary Peak unit might be 

tabular, but this cannot be determined, as the lower 

contact is not exposed. 

The Boundary Peak unit is medium to coarse grained 

and light gray to dazzling white in outcrop but in part 

weathers to various shades of tan and buff. In many 

fresh outcrops, pinkish K-feldspar is easily distinguished from white plagioclase. Coarse masses of clear 

quartz are evident, and scattered wisps and flakes of 

biotite are present. Much of the rock, particularly along 

the west side of the outcrop area, is foliated to gneissic. 

Where best developed, this foliation is shown by strungout biotite that gives the rocks an anastomosing structure. Harris (1967) noted that in some of the western 

outcrops, the quartz grains are sheared into subparallel 

bands. 

The granitic rock is remarkably uniform in appearance, and the compositional homogeneity is shown by 

the compactness of the modal field in figure 18. (See 

also tables 7 and 8.) The ratio of plagioclase to K-feldspar is somewhat higher along the west side of the mass, 

Quartz 

EXPLANATION 

. New mode 

Mode from Harris 11967) 

FIGURE 18.-Modal distribution of quartz, K-feldspar, and 

plagioclase in samples from quartz monzonite of Boundary 

Peak. 

which is also slightly lower in quartz, but the differences 

are not great. Aplite and pegmatite dikes are surprisingly rare. Harris ( 1967) noted them at only one locality 

about 1 mile northeast of Boundary Peak. Aplite and 

pegmatite are also present about 2 miles north of 

Boundary Peak. Inclusions are virtually absent, except 

for fairly obvious wallrock inclusions from the Pellisier 

Flats unit and from the diorite complex bodies near 

contacts. 

MICROSCOPIC DESCRIPTION 

The plagioclase ranges from fresh to strongly saussuritized and is in part oscillatorily zoned. Harris 

( 1967), using the angular separation of the 131-131 

reflections by X-ray diffractometer, reported a range of 

An1o to about An30 • The plagioclase tends to be a bit 

more felsic to the southeast. Harris also determined the 

index of refraction of a number of fused glass beads of 

plagioclase and reported a range of about An1o-An25, 

using the curve of Schairer, Smith, and Chayes (1956, 

p. 196). 

Irregular masses of K-feldspar, somewhat less abundant than plagioclase, generally are grid twinned and 

in part perthitic. Harris (1967, p. 47) analyzed several 

K-feldspars. Those from the quartz monzonite of 

Boundary Peak show 84-91 percent orthoclase, 8-14 

percent albite, and 1-2 percent anorthite. The orthoclase content is possibly a bit higher in the western, 

"fat" end of the mass, but very subtly so. Contrastingly, 

four K-feldspars from the Pellisier Flats unit just north 
18 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

TABLE 7.-Modes of quartz monzonite of Boundary Peak 

Plagioclase felf~ar Mafic minerals Specific Sample Quartz 

Biotite Hornblende gravity 

10 .............. 41 36 20 13 2.63 

.11 .............. 41 32 24 3 2.64 

12 .............. 43 34 19 4 <1 2.62 

13 .............. 45 33 18 4 2.65 

14 .............. 40 33 22 15 2.63 

15 .............. 48 31 18 3 <1 2.65 

16 .............. 50 30 17 3 <1 2.65 

17 .............. 45 30 22 3 <1 2.65 1Also contains 1 percent muscovite. 

TABLE 8.-Modes of quartz monzonite of Boundary Peak by 

Harris (1967, table 1) 

Sample Plagioclase K-feldspar Quartz Other 

H-4 .............. 43.8 27.6 25.8 2.8 

H-5 .............. 42.4 31.2 24.4 2.0 

H-6 .............. 39.6 33.2 25.2 2.0 

H-12 ............ 42.0 30.1 24.6 3.1 

H-13 ............ 42.6 31.6 23.6 2.6 

H-14 ............ 43.8 30.5 23.0 2.8 

H-15 ............ 48.6 24.3 25.0 2.2 

H-16 ............ 42.4 31.2 23.5 3.1 

H-17 ............ 41.1 31.2 23.8 3.9 

H-18 ............ 42.4 30.0 25.0 2.6 

H-19 ............ 43.2 28.9 25.6 2.2 

H-20 ............ 40.8 30.7 26.0 2.4 

H-22 ............ 43.8 30.0 24.1 2.2 

H-23 ............ 39.0 33.6 25.8 1.6 

H-24 ............ 39.0 30.5 28.5 2.0 

H-25 ............ 41.8 32.1 22.4 3.7 

H-26 ............ 43.3 28.8 25.2 2.6 

H-27 ............ 44.7 28.6 23.5 3.2 

H-28 ............ 44.4 29.4 23.3 3.0 

H-29 ............ 47.0 27.6 21.0 4.3 

H-30 ............ 36.2 36.3 25.8 1.7 

H-32 ............ 45.8 28.6 23.0 2.6 

H-33 ............ 44.1 29.0 24.0 2.8 

H-34 ............ 51.6 25.7 18.8 3.8 

H-35 ............ 47.8 27.6 21.3 3.2 

H-36 ............ 44.0 30.3 23.4 2.3 

H-37 ............ 43.5 28.1 26.9 1.5 

H-38 ............ 50.2 26.2 20.1 3.5 

H-39 ............ 45.2 30.0 21;9 3.0 

H-40 ............ 52.4 28.8 15.1 3.7 

H-41.. .......... 41.6 28.8 25.2 4.3 

H-42 ............ 43.7 30.0 22.6 3.6 

H-43 ............ 44.2 28.2 24.8 2.7 

H-44 ............ 45.4 29.0 21.4 4.2 

H-45 ............ 44.8 31.7 21.0 2.6 

H-46 ............ 45.4 25.8 25.6 3.2 

H-47 ............ 45.0 27.0 24.1 3.8 

H-48 ............ 43.5 29.2 22.3 5.0 

H-49 ............ 44.6 28.6 24.2 2.6 

H-50 ............ 43.8 29.0 24.8 2.4 

H-51.. .......... 41.6 30.8 23.9 3.6 

H-53 ............ 41.8 28.2 26.2 3.8 

H-54 ............ 38.2 33.2 26.5 2.1 

H-55 ............ 41.6 31.3 24.9 2.2 

H-56 ............ 41.3 31.0 25.0 2.8 

H-57 ............ 49.2 27.1 20.2 3.5 

H-58 ............ 46.5 26.8 24.2 2.4 

H-59 ............ 46.0 27.7 24.0 2.4 

H-60 ............ 42.8 27.2 27.6 2.4 

of the Boundary Peak unit have 78-81 percent orthoclase, 17-26 percent albite, and 2-4 percent anorthite. 

Quartz ranges from irregular masses with undulatory 

extinction to mosaicked and sutured crystals. In more 

sheared rocks, the quartz is definitely granulated and 

slivered into anastomosing trains. Some quartz is 

sprinkled through the rock in rounded crystals, giving 

an aplitic look to the rock. Biotite is invariably present 

in scattered irregular grains. It is pleochroic from X== 

grayish yellow and grayish orange to Z==light olive to 

light olive brown. Gray-green to moderate-green hornblende is present in trace amounts in several specimens. 

Metallic opaque minerals, sphene, apatite, zircon, and 

allanite (in part rimmed with epidote) are scattered 

through the mass. The alteration products chlorite, 

sericite, and epidote are present in variable amounts. 

Most thin sections, though structureless, do show 

some quartz strain and locally have bent and fractured 

feldspar crystals. Locally rocks of the Boundary Peak 

unit are foliated and gneissic. Harris (1967, p. 20) 

noted that deformation was most intense near the 

western contact and attributed this largely to forcible 

injection (Harris, 1967, p. 40), speculating that the 

Boundary Peak unit may have been forcibly emplaced 

along an early fault zone near its west margin. A rather 

strong north-trending foliation in the bounding rocks 

of the Pellisier Flats unit to the west could be a reflection of such a zone of weakness. 

CHEMICAL RELATIONS 

During the geologic mapping, Crowder obtained 

chemical analyses of specimen 44 of the granodiorite of 

Mount Barcroft, specimens 124 and 134 of the quartz 

monzonite and granite of Pellisier Flat, and specimens 

116, 214, and 241 of the quartz monzonite of Boundary 

Peak (table 9). Unfortunately, except for specimen 44, 

thin sections are not available, and the specimens are 

missing. Owing to fading or illegibility of labels, anumber of specimens from Crowder's collection could not 

be identified and had to be thrown out. Presumably, the 

missing chemically analyzed specimens were in this 

group. Nonetheless, it seems worthwhile to record the 

analyses, even though their petrography is unknown. 

The remaining five chemical analyses given in table 9 

were obtained by Ross from specimens collected for 

radiometric age dating. The 11 chemical analyses represent a very small and probably unrepresentative 

sample of the intrusive bodies, as can be seen from 

figure 3. 

The study of numerous thin sections indicates that 

the chemical analyses of the granodiorite of Mount 

Barcroft probably represent fairly well the rock type 

of at least the western mass and that those of the 

quartz monzonite of Boundary Peak probably represent this unit fairly well. The large, variable, and muchaltered Pellisier Flats unit, on the other hand, is far less 

representatively sampled by the four analyses of table 

9. We do not know what specimens 124 and 134 represent; their field location suggests they are part of the 
CHEMICAL RELATIONS 19 

TABLE 9.-Chemical analyses of granitic rocks in the northern White Mountains 

[Chemical analyses by rapid rock method; analysts: P. L. D. Elmore, Lowell Artis, J. L. Glenn, Gillison Chloe, Hezekiah Smith, and James Kelsey. Semiquantative spectrographic analyses by Chris Heropoulos. Results are to be identified with geometric brackets whose boundaries are 1.2, 0.83, 0.56, 0.38, 0.26, 

0.18, 0.12 ... , but are reported arbitrarily as midpoints of these brackets, 1, 0.7, 0.5, 0.3, 0.2, 0.15, 0.1 ... The precision of a reported value is approximately plus or minus one bracket at 68 percent, or two brackets at 95 percent confidence. Looked for, but not found: Ag, As, Au, Bi, Cd, Mo, Pd, Pt, Sb, 

Sn, Te, U, W, Zn, Ge, Hf, In, Li, Re, Ta, Th, Tl, Pr, Sm, Eu] 

Granodiorite of Mount Barcroft Quartz monzonite and granite of Pellisier Flats Quartz monzonite of Boundary Peak 

44 61 62 124 134 163 165 16 116 214 241 

Chemical analyses (weight percent) 

Si02 ........................ 62.6 60.1 57.8 70.0 70.0 64.8 66.1 68.7 71.4 72.4 70.4 AhOa ...................... 16.5 17.3 17.1 14.7 15.0 16.4 15.8 16.8 15.4 15.3 15.7 F~Oa ...................... 1.9 2.1 2.2 1.4 1.2 1.8 1.5 1.0 .87 .82 1.0 FeO ........................ 3.2 3.6 4.5 1.2 1.1 2.6 2.4 .96 .57 .44 .42 MgO ...................... 2.2 2.5 3.4 .70 .61 1.6 1.5 .43 .24 .22 .24 CaO ........................ 3.9 4.6 6.0 1.3 1.2 2.8 8.0 2.4 1.7 1.3 2.0 Na20 ...................... 3.2 3.2 2.9 4.0 3.8 3.7 3.5 4.4 4.3 4.1 4.3 K20 ........................ 4.4 4.3 3.6 4.7 4.9 5.0 4.6 4.2 3.8 4.0 3.8 H20- ...................... 0 1.0 1.0 .06 .05 .81 .60 .35 .03 .08 .10 H20+ ...................... .90 .08 .10 .92 .58 .12 .07 .08 .57 .92 .76 Ti02 ...................... .70 .80 .86 .43 .44 .80 .62 .34 .18 .16 .21 P205 ........................ .28 .33 .42 .12 .12 .24 .18 .08 .05 .04 .08 MnO ........................ .10 .11 .11 .05 .04 .11 .07 .05 .04 .04 .05 <.05 .10 <.05 .05 

99.79 99.25 99.82 99.11 

C02 .......................... __ <.::.;·:..::0.::.5 ___ <..::.:..;.0:..::5 ___ _.::.;:.;:..;:_ __ __;:,_;_::_::.__ __ __;:=..:::..__ __ ---:~:..__---::~---~;..:.-----:~;..:.-----:-:"'-::::-----::7-:-:--

Total .......... 99.88 100.02 

<.05 <.05 <.05 .15 <.05 

99.99. 99.58 99.04 99.83 99.32 

B ··················~--~········ Ba ......................... . 

Be --~---·········--·-··-···· Ce ........................... . Co ........................... . Cr ........................... . Cu ........................... . Ga ......................... . La ........................... . Nb ......................... . Nd ......................... . Ni ........................... . Pb ........................... . Sc ........................... . Sr ........................... . 

v ···························· y ........................... . Yb ......................... . Zr ........................... . 

Q ........................... . or ........................... . ab ........................... . an ........................... . wo ........................... . en ........................... . fs ........................... . mt ........................... . hm ......................... . il ............................. . 

ap ············-------········· c ............................. . cc ........................... . 

70 1,000 3 

150 

20 

30 

70 

15 

50 

15 

20 

15 

15 

700 

150 

30 

3 150 

14.9 

26.3 

27.4}A 17.7 ns9 

5.5 

3.4 

2.8 

1.3 

.7 

.1 

10 1,500 

150 

10 

20 

30 

15 

70 

10 

15 

15 1,000 70 

20 

2 

100 

10.9 

25.7 

27.4}A 20.4 n43 

.2 

6.3 

3.8 

3.1 

1.5 

.8 

Semiquantitative spectrographic analyses (ppm) 

10 1,000 700 700 1,500 1,500 5 5 2 100 150 100 200 150 20 5 5 7 7 50 1 15 15 70 7 5 20 15 15 15 15 15 15 50 70 100 100 70 15 15 15 10 70 20 7 10 7 20 20 30 10 20 7 5 10 10 1,000 200 200 500 700 150 30 50 50 70 20 30 30 30 30 2 3 3 3 2 150 150 150 200 150 

CIPW norms (weight percent) 

9.0 25.4 26.2 15.5 19.1 21.5 28.2 29.4 29.9 27.4 

24.8}A 23.3 n4s 34.3~ 5.7fAnu 32.7l An 5.3f 14 31.7}A 11.5 n27 29.8}A 13.8 ns2 

1.7 

8.6 1.8 1.5 3.8 3.8 5.3 .4 .4 2.6 2.3 3.2 2.1 1.8 1.9 2.2 

1.7 .8 .8 1.5 1.2 1.0 .3 .3 .6 .4 1.0 1.6 .7 

10 7 2,000 1,000 1,000 1,500 2 2 3 150 

7 3 2 2 20 20 20 20 70 30 ...... iii 10 10 

20 30 30 30 

1,500 700 1,000 ·iooo 20 10 20 10 15 10 

100 150 100 150 

21.4 28.6 30.6 27.0 25.0 22.8 23.9 22.9 37.5~ 

11 _

51 An2s 36.9}An 

7.6 17 35.1}An 6.3 15 ~:~}An2o 

1.1 .6 .6 .6 .5 .1 1.5 1.3 1.1 .9 .1 .4 .7 .3 .3 .4 .2 .1 .1 .2 .8 1.5 2.0 1.2 .2 .1 

100.0 100.1 99.9 Total .......... --=-1-=-o-=-o.-=-1-----:-:-::-::---___:_:::-::--:::.:.:.;..--___:_::.:.:-::.:.::-.:.--=::-::--::=-:---=~:-::---==::-:::::-::---1~0:-:0:-.2-::------:-::-::--:------::-:-::---:------:::-::--

si --··········--····---~---····· al ........................... . fm ......................... . c ............................. . alk ......................... . 

q'i!: ····--··--·-··-------····--- k ............................. . mg ......................... . 

Plagioclase ........... . K-feldspar ........... . Quartz ................... . Biotite ................... . Hornblende ......... . Clinopyroxene ..... . Metallic 

opaque minerals 

229.5 

35.6 

27.4 

15.3 

21.7 

42.8 .5 

.4 

2.74 

31 

37 

12 

10 

7 

22 

38 

24 

7 

26 

5 

20 

44 

f~ 

20 

45 

27 

8 

1Mixed biotite, hornblende, and clinopyroxene with epidote and chlorite. 2Trace of orthopyroxene. 

24 

39 

12 

25 

Specimen localities (parentheses enclose California Grid System coordinates, zone 4) : 

44. T. 4 S., R. 33 E., (2,638,000 E., 391,500 N.), White Mountain Peak quadrangle. 

61. Sec. 3, T. 5 S., R. 33 E., (2,628,800 E., 388,000 N.), White Mountain Peak quardangle. 

39 

27 

17 

11 

5 

62. Sec. 33, T. 4 S., R. 33 E., (2,627,200 E., 393,800 N.), White Mountain Peak quadrangle. 

124. T. 2 S., R. 33 E., (2,627,200 E., 482,000 N.), Benton quadrangle. 

134. T. 2 S., R. 33 E., (2,625,000 E., 470,700 N.), Benton quadrangle. 

163. (Float) T. 3 S., R. 33 E., (2,623,000 E., 422,700 N.), White Mountain Peak quadrangle. 

165. (Float) T. 1 S., R. 32 E., (2,596,300 E., 491,000 N.), Benton quadrangle. 

16. (Float) T. 1 S., R. 32 E., (2,596,300 E., 491,000 N.), Benton quadrangle. 

116. T. 1 S., R. 33 E., (2,614,500 E., 506,800 N.), Benton quadrangle. 

214. T. 2 S., R. 33 E., (2,629,300 E., 489,700 N.), Benton quadrangle. 

241. T. 1 S., R. 33 E., (2,629,500 E., 502,600 N.), Benton quadrangle. 

317.3 

45.7 

10.3 

11.9 

32.1 

89.0 .4 

.3 

2.61 

50 

30 

17 

3 

<1 

375.6 

47.7 

8.0 

9.6 

34.7 

136.9 .4 

.2 

n.d. 

396.0 361.2 49.3 47.5 7.4 7.7 7.6 11.0 35.7 33.8 

153.2 125.9 .4 .4 .2 .2 

2.61 2.68 
20 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

coarse felsic facies, although Crowder's field notes 

describe both localities as "typical Pellisier." Specimen 

163 is typical gray Pellisier with abundant K-feldspar, 

highly altered plagioclase, shredded scattered biotite, 

and no hornblende, a composition associated with the 

area of widespread albitization, and is probably a representative sample of the Pellisier Flats unit south of the 

coarse felsic facies. Specimen 165, in contrast, retains 

original hornblende, has much less altered plagioclase, 

and is a fair sample of the less altered Pellisier Flats 

unit north of the coarse felsic facies. 

Despite the limitations of these chemical data, generalizations can be made about the northern White 

Mountains granitic rocks. The silica variation diagrams 

(fig. 19) have remarkably linear plots. If Anderson's 

analyses (1937) were similarly plotted, they would 

show wide divergences from the trends of figure 19. The 

variation diagrams reflect the high K-feldspar content 

of specimens 124, 134, and 163 of the Pellisier Flats unit 

by their low CaO content and correspondingly high 

K20 content. But as these specimens are not enriched 

in Na20, it appears that, even though their plagioclase 

is strongly altered, they are not strongly albitized, for 

were they, the NaO would be enriched, probably at the 

expense of K20 as well as CaO. 

The trends of the oxides in the variation diagrams 

show that CaO is markedly lower and that K20 is 

markedly higher than in similar plots for other granitic 

suites (fig. 20). These proportions mean that not only 

is the Pellisier Flats unit extremely high inK-feldspar, 

but also the entire granitic suite is rich in K20 relative 

to other granitic suites in the western batholithic belt. 

Compared with the other granitic suites, the northern 

White Mountains rocks seem to become relatively 

enriched in both N azO and Al203 as Si02 increases. 

The northern White Mountains rocks have a low 

Peacock index, about 54, which puts them well into the 

alkali-calcic field (fig. 21). The eastern and central 

Sierra Nevada granitic rocks have a Peacock index of 

about 60, the Coast Ranges about 61, the western 

Sierra about 63, the Southern California batholith 

about 65, and the Klamath Mountains about 63 (Ross, 

1972; P. E. Hotz, oral commun., 1971). It appears that 

the entire northern White Mountains suite is rich in 

alkalis and poor in lime, apparently reflecting a regional 

trend rather than a local alteration effect. Bateman and 

Dodge (1970) noted that KzO increases eastward 

across the Sierra Nevada batholith and that CaO may 

decrease eastward. 

About 40 miles south of the northern White Mountains in the lnyo Mountains is a suite of granitic rocks 

in which the KzO is somewhat higher than in comparable rocks in the Sierra Nevada to the west (Ross, 

1969, p. 34, 36). Yet both soda and lime were comparable for the lnyo Mountains and the Sierra. Evidence so far collected shows that the granitic rocks of 

the In yo-White Mountains are high in KzO and that 

the north end of the range is, in addition, strikingly low 

inCaO. 

Ternary plots of selected oxides and normative minerals show restricted and separate fields for each of the 

triangles (fig. 22). The pronounced linear trend on the 

Alk-F-M diagram directly reflects color index. The 

closest comparison that can be made between modes 

and norms is the ternary diagram that plots the normative quartz and feldspars (quartz-orthoclase-albite plus 

anorthite). The northern White Mountains granitic 

rocks cluster closely near the border between granodiorite and quartz monzonite (if the modal rock classification is superimposed on the normative diagram) 

(fig. 23). The Mount Barcroft unit, as expected from 

modes, is lowest in normative quartz. The normative 

field falls over the center and average values of the 

modal field. The normative field of the Boundary Peak 

unit is only slightly displaced away from the K-feldspar 

corner as compared with the modal field, which probably means the extra KzO from biotite that becomes 

orthoclase in the norm is more than compensated for 

by the albite molecule in the K-feldspar that shows up 

as albite plus anorthite in the normative plot. As these 

rocks are very low in dark minerals, this distribution is 

expectable. The tightness of the normative field of the 

Pellisier Flats unit in comparison to the great spread 

of the modal field largely reflects sampling; the chemically analyzed specimens are relatively unaltered, 

whereas the modal field includes a great variety of 

altered rocks. 

The trace-element contents listed in table 9 and represented by the histograms of figure 24 show mainly 

that the granodiorite of Mount Barcroft is relatively 

richer in Co, Cr, Cu, Ni, Sc, and V than the Boundary 

Peak and Pellisier Flats units, which almost certainly 

reflects the higher content of dark minerals in the 

Mount Barcroft unit, with which these trace elements 

are most commonly associated. Boron was below the 

detection limit (7 ppm) in all four samples from the 

Pellisier Flats unit yet ranged from 10 to 70 ppm in the 

Mount Barcroft unit. 
Sample 62 61 

18 

17 

16 

15 

14 

7 

6 

4 

3 

5 

4 

1- 3 z 

UJ 2 (.) 

0::: 

UJ 

a.. 

~ 

...: 0 

z 

UJ 

1-

z 

0 6 (.) 0 

UJ 

0 

x 

0 4 

3 

2 

0 

6 

5 

4 -

3 -o 

2 

6 

0 4 0 

3 

1 

56 60 

CHEMICAL RELATIONS 

44 163 165 

Na,O 

a 

0 0 

0 

0 0 

K,O 

64 

SILICA CONTENT, IN 

124 

134 

16 241 116 214 

0 0 a 

--tr 0 

0 

8 

0 0 0 

68 72 

PERCENT 

-

-

76 

FIGURE 19.-Silica variation diagrams of granitic rocks, northern White Mountains. 

21 
22 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

8.-----------~----------------------~ 

1- 6 z 

w 

(.) 

0:: 

w 

a.. 

z 4 

r: 

z 

w 

1-

z 

0 2 (.) 

w 

0 

x 

0 

CaO 

6.-----------------------------------~ 

Na,O 

4 1-- Wes~:~~~!erra~~ -~an~s~ve~rs~e~R~an~g~es~~~~i~----~~~-~ ~ _1\ Coast Ranges 

/-- Eastern Sierra Nevada Southern California batholith 

21-- -

o~----~~----~~------~~----~~----~ 

6.-----------------------------------~ 

K,O 

SILICA CONTENT, IN PERCENT 

FIGURE 20.-Silica variation diagrams comparing o:x;ide 

contents of the granitic rocks of the northern White 

Mountains (heavy line) with other granitic suites. 

ANDERSON'S GRANITIZATION CONCEPT 

Anderson (1937, p. 1-74), from his study of the 

northern White Mountains, concluded that two extensive granitic formations, his Pellisier and Boundary 

Peak Granites, made up most of the granitic basement. 

He further concluded that the Pellisier Granite originated by granitization of sediments as a result of heat, 

pressure, and solutions from the magma that eventually 

crystallized as the Boundary Peak Granite. The principal lines of evidence cited by Anderson (1937, p. 46) 

are gradational contacts, partially digested xenoliths, 

variable composition and texture of the Pellisier 

Granite, pseudosedimentary layering in the Pellisier 

Granite, and increased mafic content in the Pellisier 

Granite near wallrock contacts. 

Emerson (1966, p. 146) showed that the purported 

relict sedimentary bedding in the Pellisier Granite of 

Anderson is not related to, nor traceable into, the wallrock. Emerson (1966, p. 146), Krauskopf (1971), and 

Crowder mapped intrusive contacts of Anderson's Pellisier Granite with its wallrocks as generally distinct 

and relatively sharp, although Krauskopf (1971) did 

note narrow zones of migmatite at some contacts. 

Anderson lumped other granitic masses in the Mount 

Barcroft quadrangle with his Pellisier Granite (Emerson, 1966; Krauskopf, 1971), which accounts for some 

of the variability he attributed to this unit. Nonetheless, the part of Anderson's Pellisier Granite now called 

the Pellisier Flats unit is variable; digestion of metavolcanic wallrock material is evident in the White 

Mountain Peak quadrangle as well as in the migmatitic 

border zones in the Mount Barcroft quadrangle (Krauskopf, 1971). Yet the normal facies of the Pellisier Flats 

unit, with its small biotite clots and dull-gray color, is 

relatively similar over a large area. The coarse felsic 

facies of the Pellisier Flats unit looks like either a somewhat younger core facies or a somewhat less contaminated core facies; it is distinctive and recognizable over 

a large area. 

It seems that Anderson, in his reconnaissance study 

of the granitic rocks of the northern White Mountains, 

may have extrapolated too much from marginal contamination effects. And his emphasis on broad gradational contacts may have been based on very local 

observations, for there is a general pattern of relatively 

sharp contacts of the Pellisier Flats unit with its wallrocks. Anderson was certainly handicapped by the lack 

of a good topographic base map and aerial photographs, 

and his study therefore must have stressed thin section 

petrography rather than field relations. The pitfalls he 

faced in trying to evaluate hand specimens and thin 

sections without an adequate understanding of field 

relations are apparent and serve as a good lesson for 

any petrographer. 
ALBITIZATION 23 

1-8 

z 

LU 

u 

a:: 

LU 

a.. 

z6 

t-=" 

z 

LU 

1-

~ 4 u 

LU 

0 

x 

0 2 

ALKALIC CALC-ALKALIC 

51 

52 56 60 64 68 72 

SILICA CONTENT, IN PERCENT 

FIGURE 21.-Peacock index of granitic rocks, northern White Mountains. 

ALBITIZATION 

Both granitic and metavolcanic rocks are albitized 

over an area of some 50 square miles. Essentially all the 

bedrock north ofMilner Canyon (fig. 1) in the White 

Mountain Peak quadrangle, except for some of the 

metasedimentary rocks, is altered. In thin section, 

rocks from this area show a considerable amount of 

clean fresh secondary albfte. Sample localities of these 

rocks are shown in figure 25. Not all rocks within the 

area are equally albitized, but the extent of alteration 

in some degree is striking. 

The most intensely albitized rocks can be divided 

into three types: ( 1) medium- to coarse-grained "alaskitic" rocks composed almost entirely of fresh-looking 

albite and quartz, (2) similar medium- to coarsegrained rocks containing abundant K-feldspar in addition to albite and quartz, and (3) rocks with well-preserved porphyritic volcanic texture that are almost 

entirely fresh-looking albite and quartz. The first two 

types most likely are intensely altered rocks of the 

Pellisier Flats unit, for transitional rocks that grade 

into typical rocks of the Pellisier Flats unit are present. 

The third type is quite obviously the result of albitization of the meta volcanic section. 

To confirm the anorthite content of these albitic 

rocks, X-ray diffraction patterns were run on three 

typical samples from each of the three varieties. All are 

more sodic than An:;, and most are about An1 , nearly 

pure albite. It has been suggested that such nearly pure 

albite cannot be a normal primary magmatic product 

(Gilluly, 1933, p. 74). 

The coarse-grained "alaskitic" rocks and some of the 

finer grained metavolcanic rocks seem at first glance to 

be alaskite and aplite. Closer study reveals abundant 

strange chessboard albite twinning and a complete 

absence of K-feldspar. These features, together with 

preserved volcanic textures in the "aplitic" rocks and 

gradation of the "alaskite" to rocks of the Pellisier 

Flats unit, leave little doubt about the parent rocks of 

these strange alaskites and aplites. 

In addition to these three types of intensely albitized 

rocks, the Pellisier Flats unit contains abundant evidence of probably related alteration in the same area. 

Invariably, thin sections of these rocks show intensely 

saussuritized plagioclase liberally sprinkled to choked 

with sericite, epidote, and biotite and scattered shreds 

and aggregates of biotite, but they do not show any 

amphibole. Some clean fresh albite is found, part of 

which has chessboard twinning (fig. 12). 

The pattern of present distribution suggests that all 

rocks of the Pellisier Flats unit south of the coarse felsic 

facies (fig. 9) underwent considerable alteration of 

original plagioclase and dark minerals. Within the 

coarse felsic facies and in the normal gray rocks north 

of the coarse facies, intense albitization is not found; 

moreover, the gray rocks of the Pellisier Flats unit 

north of the coarse facies contain hornblende, which 

must surely have been originally present in the rocks 

of the Pellisier Flats unit south of the coarse facies. The 

most intense alteration of metavolcanic rocks generally 

coincides with the area of alteration of the Pellisier 

Flats unit. These relations suggest we are dealing with 
24 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

An 

F=FeO+MnO+ 

Mg0+2Fe"o3-

Ti02 

Q EXPLANATION 

A 

Or 

Quartz monzonite of Boundary Peak 

• Granodiorite of Mount Barcroft 

• Quartz monzonite and granite of 

Pellisier Flats 

Ab+An Or Ab An 

FIGURE 22.-Distribution of selected oxides and normative minerals, northern White Mountains. 

a pervasive process that affected a volcanic and granitic 

terrane of some 50 square miles. 

Anderson (1937, p. 50, 72) was the first to recognize 

the albitization in the White Mountains, but he apparently concentrated his attention on the granitic rocks, 

because he did not mention the similar intense albitization of associated metavolcanic rocks. He did note that 

metasediments in contact with what he regarded as 

Pellisier Granite are similarly albitized (p. 52), probably referring to what are now known to be metavolcanic rocks, but there is little further mention of 

albitization in the wallrocks. Anderson suggested that 

the Pellisier Granite formed by replacement; he postulated that the Boundary Peak Granite furnished active 

granitizing and albitizing solutions that converted sediments into Pellisier Granite by metasomatism. The 

distribution of the most intensely albitized rocks clearly 

argues against this thesis. The rocks of the Pellisier 

Flats unit nearest the quartz monzonite of Boundary 

Peak are much less albitized and otherwise altered than 
ALBITIZATION 25 

(Ab+An) 

Plagioclase 

(Q) 

Quartz 

EXPLANATION 

Modal 

field 

Normative 

field 

fBP; '-/ 

Quartz monzonite of Boundary 

Peak 

----.........,_ 

c~~-~~s_e~!~l_:;~c_!~<:!~~1 (·; ~ ~orm~ay faci~ \._ .... 

Quartz monzonite and granite 

of Pellisier Flats 

0 

Granodiorite of Mount 

Barcroft 

(Or) 

K-feldspar 

FIGURE 23.-Modal and normative fields for granitic rocks of 

the northern White Mountains. 

the rocks of the Pellisier Flats unit and associated 

volcanic rocks some distance to the south. It appears 

that the Boundary Peak unit was not the source of 

albitizing solutions. 

Anderson (1937, p. 15, 41, 67, 70) listed chemical 

analyses for four samples of Pellisier Granite described 

as albitized. These rocks contain from 2. 7 to 4.6 percent 

Na20, 2.5 to 4.8 percent K20, and 1.1 to 3.8 percent 

CaO. It is frustrating that there are no modal data for 

these specimens, but the general chemical character of 

the rocks is closer to that of the strongly saussuritized 

rocks that retain their original granitic character than 

to the intensely albitized rocks with clean secondary 

albite. Anderson (1937, p. 45) listed chemical analyses 

for two samples from albite-rich bodies that he believed 

to be replacement bodies in the "metasediments" near 

the main batholith. These rocks contain about 6 percent Na20 and about 1 percent each K20 and CaO. 

Anderson described them as being composed almost 

entirely of chessboard albite and quartz, with minor 

amounts of biotite, sphene, and magnetite. These rocks 

probably are part of the intensely albitized terrane. 

Although no textures are mentioned, they would seem 

from the setting described to be albitiz~d metavolcanic 

rock, but they could be albitized rocks of the Pellisier 

Flats unit that became mobilized and were squirted 

into the adjacent wallrocks. 

Anderson ( 1934) described and illustrated a texture 

in these albitized rocks that he called "pseudo-cataclastic." It looks cataclastic, but because the rock contains abundant fresh secondary material, Anderson 

believed it was a replacement texture. Gilluly (1933) 

noted that cataclastic rocks were easier prey for 

replacement solutions in a vast albitized terrane in 

Oregon. He further noted that in other areas albitization was more common in rocks that had been crushed. 

Crowder, in his field notes on the White Mountains 

rocks, was torn between calling these rocks hornfelsed 

or cataclastically deformed. Nevertheless, many of these 

intensely albitized rocks show remarkably well preserved original granitic or volcanic textures; therefore, 

pervasive shearing was not necessary for the albitization. But there is abundant evidence of shearing in this 

terrane, and it seems likely that numerous channelways 

were available to albitizing solutions. How or why the 

area of most intense albitization was localized is not 

clear. It is tempting to speculate that there is some 

connection with the White Mountain fault zone (fig. 1). 

In summary, the Pellisier Flats unit, with highly 

altered plagioclase, shredded aggregates of biotite, and 

loss of hornblende throughout the southern part of the 

body, probably underwent considerable change since 

its intrusion. The anomalous abundance of K-feldspar 

also attests to an unusual, and probably not original, 

composition. It is perhaps significant that within the 

area where intense albitization produced rocks from 

which all the K-feldspar was driven, the granitic rocks 

of the Pellisier Flats unit are extremely rich in K-feldspar. Possibly the K-feldspar was redistributed in the 

alteration process, for it seems unlikely that the original magma that produced the Pellisier Flats unit was 

as rich in potassium as present modes suggest. 

It also seems evident that the nearby metavolcanic 

rocks underwent the same kind of alteration as the 

Pellisier Flats unit. The metavolcanic rocks were 

intensely albitized, they lost their original pyroxene 

and amphibole, and they now contain scattered shreds 

and aggregates of biotite, in part in the altered plagioclase, much like the Pellisier Flats unit. It is not lik~ly 

that the Pellisier Flats unit was the "altering agent"; 

rather, some younger unit probably provided solutions 

that transformed both the Pellisier Flats intrusive and 

its metavolcanic wallrocks. Also, the distribution of 

altered rocks suggests the presently exposed Boundary 

Peak rocks were not the source of the altering solution. 

It may be worth noting that the most intense albitization seems to be associated with the area of the mixed 

Pellisier Flats unit and metavolcanic rocks and that the 

granitic rocks are most altered where the elongate 

prong of the Pellisier Flats unit protrudes into the 

metavolcanic wallrocks. 
1 

or---------~~~------~~----------------~ 0 ~--~~~~L-~~~~~~------------------~ 

4 

7 

6 

1 

or-----------------------------------~~~~~ 

4 

3 

2 

1 

en 

w 

~ 3 

::2: 2 <( 

en 1 

LL. 0 

0 

0::: 

w 

m 

::2: 

::::> 

z 3 

0 ~------------~~~~--------------------------~ 

4 

3 

1 

0 ~----------------~~-L~~----------------~ 

4 

3 

1 

0 r---------~~~~------------------------~ 

1 

0 ~--------~~~~~------------------------~ 

4 

3 

~~NM~~s~~~~~§~~~~Rg~gg ~~NM~~0~00000000000000 ~ ~~NM~~o~oooooooo 

...... .-.N("f)LO"'OLnOO ...... .-t N M .-. ...... N ('I') 

CONCENTRATION, IN PARTS PER MILLION CONCENTRATION, IN PARTS PER MILLION 

D 

Quartz monzonite 

of Boundary Peak 

EXPLANATION 

D 

Quartz monzonite and granite 

of Pellisier Flats 

[JEJ 

Granodiorite of 

Mount Barcroft 

or-------~~~~~~------------------------__, 

4 

3 

1 

o 1 1 1 1 J r HI 1 

1 

0~------------~-L~~~~~~~------------__, 

5 

4 

3 

2 

1 

0~----------~~~~-L----------------------~ 

4 

3 

1 

or---~~~----------------------------------~ 

7 

6 

2 

OLJ-L~~~~-L~~~~~~~~-L~~ 

~~NM~~s~~~~~§~~~~R§~gg .-t.-INM 

CONCENTRATION, IN PARTS PER MILLION 

FIGURE 24.-Trace-element content of granitic rocks, northern White Mountains. 

Averages for granodiorite (grd) and granite (gr) are from Taylor (1965). 

~ 

0) 

i-t:l 

t;rj 

> 

~ ~ 

= ~ 

0 

~ 

r.n 

0 

s= 

t;rj 

~ > z 

::3 

1-4 

0 

ttl 

0 

t:l 

1-4 

t;rj 

~r.n 

z 

0 

~ 

= t;rj 

~ 

z 

~ 

= 1-4 

@ 

s= 

0 

c:: 

1-4 

~ z 

~r.n 

0 

> t'"4 

1-4 

~ 

1-4 

~ > I 

z 

t;rj 

~ t:l 

"> 
118"30' 

37"45' 

EXPLANATION 

Ld f- :J r::::::l } <( lfl 

Quartz monzonite of Boundary Peak 5 ~ 

Normal gray Coarse felsic 

facies facies 

Quartz monzonite and granite of 

Pellisier Flats 

EJ . , 

, 

Mixed metavolcanic and granitic 

rocks 

Metavolcanic 

rocks 

Volcaniclastic 

sedimentary rocks 

Probable extent of most intense 

albitization 

• • Granitic Metavolcanic 

Sample localities 

Thin sections of .~;~amples f rorn these 

localiti es contain abunda,nt fresh 

secondary albite 

}I 

ALBITIZATION 

118° 15' 

BENTON QUADRANGLE 

• Mount Barcroft 

0 2 4 Ml LES 

L----L--~----~~ 

WHIT E MOUNTAIN 

FIGURE 25.-Distribution of albitized rocks in the northern White Mountains. 

27 
28 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA-NEVADA 

REFERENCES CITED 

Albers, J.P., 1964, Structural and stratigraphic environment of 

granitic plutons in Esmeralda County, Nevada, in Advancing frontiers in geology and geophysics: H yderabad, India, 

Osmonia Univ. Press, p. 352- 360. 

Albers, J . P ., and Stewart, J . H., 1965, Preliminary geologic 

map of Esmeralda County, Nevada: U.S. Geol. Survey 

Mineral Inv. Field Studies Map MF - 298, scale 1: 200,000. 

Anderson, G. H ., 1934, Pseudo-cataclastic texture of replacement origin in igneous rocks: Am. Mineralogist, v. 19, nv. 

5, p. 185-193. 

--- 1937, Granitization, albitization, and related phenomena 

in the northern lnyo Range of California-Nevada : Geol. 

Soc. America Bull., v. 48, p. 1-74. 

Bateman, P . C., 1965, Geology and tungsten mineralization of 

the Bishop district, California : U.S. Geol. Survey Prof. 

Paper 470, 208 p. 

Bateman, P. C., and Dodge, F . C. W., 1970, Variations of major 

chemical constituents across the central Sierra Nevada 

batholith: Geol. Soc. America Bull., v. 81 , p. 409-420. 

Crowder, D. F ., McKee, E . H., Ross, D . C., and Krauskopf, 

K. B., 1973, Granitic rocks of the White Mountains area, 

California-Nevada: Age and regional significance : Geol. 

Soc. America Bull., v. 84, p. 285-296. 

Crowde r, D . F ., Robinson, P . T., and Harris, D . L., 1973, Geologic map of the Benton quadrangle, California-Nevada : 

U.S. Geol. Survey Geol. Quad. Map GQ-1013, scale 

1: 62,500. 

Crowder, D . F., and Sheridan, M . F., 1973, Geologic ma p of 

the White Mountain Peak quadrangle, California: U.S. 

Geol. Survey Geol. Quad. Map GQ-1012, scale 1:62,500. 

Emerson, D . 0 ., 1959, Granitic rocks of the northern portion 

of the lnyo batholith: Pennsylvania State Univ., State College, Ph.D. thesis, 140 p. 

---1966, Granitic rocks of the Mount Barcroft quadrangle, 

lnyo batholith, California-Nevada : Geol. Soc. America 

Bull., v. 77, no. 2, p. 127-152. 

Gilluly, James, 1933, Replacement origin of the albite granite 

near Sparta, Oregon : U.S. Geol. Survey Prof. Paper 175-C, 

p. 65-81. 

Harris, D. L., 1967, Petrology of the Boundary Peak adamellite 

pluton in the Benton quadrangle, Mono and Esmeralda 

Counties, Nevada: California Univ. (Davis), M .A. thesis, 

57p. 

Krauskopf, K. B., 1968, A tale of ten plutons: Geol. Soc. 

America Bull., v. 79, p. 1-18. 

- --1971, Geologic map of the Mount Barcroft quadrangle, 

California-Nevada: U .S. Geol. Survey Geol. Quad. Map 

GQ- 960, scale 1: 62,500. 

Moore, J . G., 1963, Geology of the Mount Pinchot quadrangle, 

southern Sierra Nevada, California: U.S. Geol. Survey 

Bull. 1130, 152 p. 

Rinehart, C. D ., and Ross, D . C., 1957, Geology of the Casa 

Diablo Mountain quadrangle, California: U.S. Geol. Survey Geol. Quad. Map GQ- 99, scale 1: 62,500. 

---1964, Geology and mineral deposits of the Mount Morrison quadrangle, Sierra Nevada , California: U.S. Geol. Survey Prof. Paper 385, 106 p. 

Robinson, P . T., and Crowder, D . F., 1973, Geologic map of the 

Davis Mountain quadrangle, Nevada-California: U.S. 

Geol. Survey Geol. Quad. Map GQ-1078, scale 1: 62,500. 

(in press). 

Ross, D. C., 1961, Geology and mineral deposits of Mineral 

County, Nevada : Nevada Bur. Mines Bull. 58, 98 p. 

--- 1969, Descriptive petrography of three large granitic 

bodies in the lnyo Mountains, California : U.S. Geol. Survey Prof. Paper 601, 47 p. 

---1972, Petrographic and chemical reconnaissance of some 

granitic and gneissic rocks near the San Andreas fault from 

Bodega Head to Cajon Pass, California: U.S. Geol. Survey 

Prof. Paper 698, 92 p. 

Schairer, J. F., Smith, J . R., and Chayes, F., 1956, Refractive 

indices of plagioclase glasses: Carnegie lnst. Washington 

Year Book, Ann. Rept. Director Geophys. Lab. no. 55, 

p. 195. 

Taylor, S. R., 1965, The application of trace-element data to 

problems in petrology, in Ahrens, L. H., Rankama, K ., and 

Runcorn, S. K., eds., Physics and Chemistry of the earth, 

v. 6: Oxford, Pergamon Press, p. 133-213. 

f< U .S . GOVERNMENT PRINTING OFFICE: 1973 -515- 658/ 45