DEPARTMENT OF THE INTERIOR
UNITED STATES GEOLOGICAL SURVEY

sggwon

Prepared in cooperation with the

NEVADA BUREAU OF MINES AND GEOLOGY

YOR HUN TOOW LITTLE TACKS TEELS BASALT MILLER BELLE VILLE-
* VALLEY HUNTOON SPRING MARSH MOUIVTAIN - CAN DE LARIA
VALLEY coLuMBus (Speed and Cog bill ,/979)
(STewart, 1979) Tt/0
€
TESS Tesk Tess Tesh —
Tts 75 ——4 tts —— Tts Tts Tes eee aint
33000". N | Tésa Ttsa Ttsa Ttsa <*oe
ie T#3b Tt3b
Tt 2b Tt 3h a 2 Té3e mas
Sy Tt 3e Tt3 |_Té 3a 23) T#3a [| -——__|
p3 TE?
a Ng - Té2d Té 2d Belleville
é3z Teh
Ttad Ttad
re- Te r
Tead Té2b i Te2, Tes
Ttab ie Tes
Pre - iia Fault Ter — a, —
rocks == Te.
T42
—” von Pre-Tertiary zs kX
LOCAT/IC©CN OF QUADRANGLES io Oa BaP 24 rocks Te vr
3e°1s' 2. Little Hentoon Valley
Pre-Tertiar Tez
2 4 6 B 3. Tacks Spring eee 7
1 % Teels Marsh tall
"a 5. Basalt Pre- were)
7 rocks
eat cfs) Si ¥ ’ 3 Ss % | 6. Belle vile
38° 00' 7 Miller Movntain
116° 45! 18° 00° @ Candelaria
9. Columbus

Figure |--CORRELATIONW DIAGRAM FOR OLIGOCENE AND MIOCENE TUFF UNITS

SHOWING MAP SYMBOLS USED IN PUVADRANGES

IN SOUTHWESTERN PART OF WALKER “LAKE 2° PUADRANGLE. THICKNESSES NOT TO SCALE

CORRELATION OF MAP UNITS :

SURFICIAL DEPOSITS bial
Qea | Qes | Qsd | Qpla Qf
3 | Qfs.5 |
Qis | Qf, Qt + QUATERNARY all
of
24
ar,

VOLCANIC AND SEDIMENTARY ROCKS

VOLCANIC ROCKS OF =) el

N

“A
4

(HAWTHORNE

N

27060.

“
agg0a0

Base from U.S. Geological Survey, 1956.

|
1 wevans |

QUADRANGLE oA

Tach | aNCHORITE PASS AREA
[Tea Thap | lreselrcep] [TOb|Tbe| [7 . | [te] Ta
Li? Qla
Thi
| TERTIARY
Ta
Qqis
Tsb
Tts
Tt [tts |Tbp
PLUTONIC ROCKS
= a,
Khv + CRETACEOUS
Kow? | Kae | CRETACEOUS OR
JURASSIC
SEDIMENTARY AND VOLCANIC ROCKS
MePep | MePey | MESOZOIC OR
_} PALEOZOIC
OF a2
} JURASSIC
+ PERMIAN a,
| PENNSYLVANIAN
Sa
SOURCES OF GEOLOGIC MAPPING
1. Bedrock geologic mapping by J. H. Stewart, 6
D. C. Johannesen, and F. J. Kleinhampl, |
1978-1979; surficial geology by J. C.
Dohrenwend, 1979-1980
2. Mapping of pre~Tertiary rocks largely by
R. C. Speed, 1977-1978
3.  Photogeology by D. C. Johannesen based on
mapping by Gilbert and others (1968) with
additions and modifications by J. H.
Stewart and D. C. Johannesen (1978-1979);
@ surficial geology by J. C. Dohrenwend,
1979-1980.
Tach
Taap

DESCRIPTION OF MAP UNITS.
SURFICIAL DEPOSITS

FOLIAN AND ALLUVIAL DEPOSITS, MOSTLY VOLCANICLASTIC--Predominantly
air-fall tuff reworked by both eolian and fluvial processes.
Includes some alluvial fan and playa deposits. Occurs in numerous
small valleys and fault bounded depressions in the Fxcelsior
Mountains and Anchorite Hills

BOLIAN SAND--Well sorted to moderately well sorted sand and silt.
Thin sheets and veneers over other surficial deposits and bedrock
leeward of actively forming playas and the distal fringes of
large, young alluvial fans. fxtensive deposits occur only on the
southeast side of Huntoon Valley .

SAND DUNE DEPOSITS--Well-sorted medium to fine sand. Formed leeward
of playas and the distal fringes of large young alluvial fans.
Commonly stabilized, at least in part, by sparse to moderate
densities of low shrubs and grasses. Limited to the area
surrounding Huntoon Valley playa and the central part of Little
Whiskey Flat

ACTIVELY FORMING PLAYA DEPOSITS--Brownish- to grayish-white clay,
silt, and very fine sand with associated evaporite salts. Occurs
along basin axes in lowland areas and in small structurally
controlled depressions in upland areas. Occurs in Huntoon Valley
playa and in several fault-bounded depressions in the Excelsior
Mountains and the Anchorite Hills

LANDSLIDE DEPOSITS--Chaotic masses of unsorted, angular, boulder- to
clay~size debris. Includes some talus and colluvium where these
materfals overlap or are intermixed with landslide debris. Forms
hummocky terrain in steeply sloping upland areas underlain by
Tertiary volcanic rocks. large landslides are lipited to a
probable rock slide complex (approximately 2.5 km* in area)
southwest of Anchorite Pass, and a highly dissected old
landslide(?) west of Huntoon Valley. Rock units that occur within
landslide are indicated in parentheses

YOUNG ALLUVIAL FAN DEPOSITS--Poorly sorted deposits of boulders,
cobbles, gravel, sand, and silt. Clast size generally decreases
and sorting generally improves downfan. Includes some
fine-grained basin-fill deposits where distal fan limits are
gradational and poorly defined. Fan surfaces undissected to only
slightly dissected with few, if any, well-defined drainage
channels.  Constructional surfaces generally unweathered with
weak, if any, soil profile development. Drainage distributary,
radiating from the fan apex

YOUNG AND INTERMEDIATE AGE ALLUVIAL FAN DEPOSITS, UNDIFFERENTIATED--
Mapped in areas where young and intermediate age fan surfaces are
too complexly interrelated to be mapped separately. Includes fans
for which more precise age relationships could not be determined

INTERMEDIATE AGE ALLUVIAL FAN DEPOSITS--Lithologically and
sedimentologically similar to young alluvial fan deposits.
Contacts with young alluvial fan deposits commonly gradational and
poorly defined. Intermediate alluvial fan surfaces slightly to
moderately dissected with numerous well-defined drainage
channels. Drainage predominantly distributary, but some drainage
channels head on fan surfaces. Relief due to dissection generally
less than 5m. Constructional surfaces slightly to moderately
weathered with weak to moderate soil profile development and
distinct desert pavement

INTERMEDIATE AND OLD ALLUVIAL FAN DEPOSITS, UNDIFFERENTIATED--tMapped
in areas where intermediate and old alluvial fan deposits are too
complexly interrelated to be mapped separately. Includes fans for
which more precise age relationships could not be determined

OLD ALLUVIAL FAN DEPOSITS--Similar lithologically to young and
intermediate alluvial fan deposits. Fan surfaces deeply dissected
by well-developed subparallel drainage that heads on the fan
surface. Relief due to dissection commonly 10 to 30 m. Commonly
separated from younger depositional surfaces by abrupt erosional
scarps-  Constructional fan surfaces strongly weathered with
moderately well to well developed soil profiles and well-developed
desert pavement

VOLCANIC AND SEDIMENTARY ROCKS

ANDFSITE IN CEDAR HILL-TRENCH CANYON AREA-
(1968, p- 294-296)

“See Gilbert and others

VOLCANIC ROCKS OF ANCHORITE PASS ARFA (see Gilbert and others 1968,
p- 293-294)

Andesite--Phenocrysts of andesine together with variable amounts
of biotite, hornblende, augite, olivine. Abundant inclusions of
hornblende-plagioclase rock. As used by Gilbert and others
(1968), andesite and latite rocks im Anchorite Pass area are
classed as andesite if sanidine is absent and as latite of
sanidine is present

Tlap

‘Tap

Teap

Tob

Tli

Tsb

Tts

Tt3b

mit

Khv

KJwe

KJa

Jd

Latite--Phenocrysts of andesine together with variable amounts of
biotite hornblende, argite, olivine, and sanidine. Abundant
inclusions of hornblende-plagioclase rock. As used by Gilbert
and others (1968), andesite and latite rocks in Anchorite Pass
area are classed as andesite if sanidine is absent and as latite
if sanidine is present. ‘The most distinctive latite is biotite
perlite (Gilbert and others, (1968), in which sanidine is almost
as abundant as oligoclase andesine, and biotite is much more
abundant than other ferromagnesian minerals

Basalt
Basalt cinder cone

OLIVINE BASALT--Same as Tb in adjacent Powell Mountain quadrangle to
north (Stewart and others, 1981)

BASALT CINDER CONE

TUFFACEOUS SILT, SAND, GRAVEL, AND DIATOMITE--Intercalated rhyolitic
and basaltic tuffs. See Gilbert and others (1968, p. 289-291) for
further description

GRAVEL--Mostly granitic clasts

LATITE IGNIMBRITE OF GILBERT AND OTHERS (1968, p. 285-287)--Consists
of sanidine-beating tuff and an overlying andesine- and
biotite-bearing tuff

ANDESITE FLOWS AND BRECCTAS (LAHAR)

SEDIMENTARY ROCKS AND BRECCIA--Includes sandstone, coarse boulder
conglomerate, and sedimentary breccia

CANDELARIA JUNCTION TUFF OF SPEED AND COGBILL (1979)--See Speed and
Cogbill (1979) and Stewart (1979) for description. Figure 1 shows
correlation with units in quadrangles to east

ANDESITE BRECCIA (LAHAR)

ASH-FLOW TUFFS--Consists of several different ash-flow units
including a moderately crystal-rich tuff containing sanidine,
biotite, and quartz which may be the Metallic City Tuff of Speed
and Cogbill (1979). Other tuffs include biotite-poor sanidine-
and quartz-bearing types. Gravel containing basalt(?) boulders
locally occurs between different ash-flow units

BRECCIA PIPE OF GILBERT AND OTHERS (1968)
pLuToNrc Rocks!

GRANODIORITE OF HUNTOON VALLRY--Light- to medium-gray medium- to
coarse-grained equigranular to porphyritic hornblende biotite
granodiorite. Average mineral composition, in percent: quartz
(19), potassium feldspar (17), plagioclase feldspar (49), mafic
minerals (15). Distinguished from adjacent plutonic rocks by a
gray topsoil and biotite flakes as large as 8 mm across. Sodic
andesine (Anz,) crystals are subhedral to euhedral, as long as
4.5 mm, and show normal zoning; cores of some of crystals are
sericitized. Myrmekite is uncommon. Microcline and microcline
perthite are subhedral and as long as 1 cm. Quartz is as large as
3 mm in diameter. Brown biotite, as much as 8 percent of rock,
occurs in cores of hornblende crystals and as individual flakes as
large as 8 mm. Green hornblende, as much as 6 percent of rock,
and averaging 3 percent, is subhedral and euhedral and as long as
3.5 mm. Small amounts of green chlorite occur as distinct flakes
or alteration products of biotite. Other minerals observed in
small amounts of | percent or less include magnetite, sphene, and
apatite. K-Ar ages of 86 m.y. (biotite) and 100 and 101 my.
(hornblende) were obtained from samples collected in Rattlesnake
Flat and Huntoon Valley quadrangles (Rvernden and Kistler, 1970,
loc. nos. 238, 239)

GRANITE OF WHISKY FLAT--Light-gray to pinkish-gray medium to
coarse-grained porphyritic biotite granite. Average mineral
composition, in percent: quartz (26), potassium feldspar (31),
plagioclase feldspar (37), and mafic minerals (6). Rock weathers
readily to coarse sandy grus- Oligoclase (An),) forms subhedral
crystals as long as 4 mm that exhibit weak zoning and uncommon
myrmekite intergrowths. Some twin lamellae are noticeably bent.
Orthoclase(?)=perthite forms subhedral phenocrysts as long as
15 mm. Quartz crystals are anhedral and as much as 3.5 mm in
diameter. Mafic minerals, constituting from 2 to 10 percent of
rock, include chiefly biotite (as much as 8 percent of rock but
averaging 3 percent) and lesser amounts of hornblende. Biotite
forms light-brown to brown subhedral crystals as long as 4 mm and
is chloritized in some parts of pluton. Muscovite and sericite
range in amount from a trace to as much as 8 percent of rock, and
their concentration in altered zones indicates a probable

secondary origin related to hydrothermal alteration. Opaque
minerals constitute as much as 2 percent of rock and include
magnetite and hematite. Other minerals, present from trace

amounts up to as much as 1 percent of rock, include hornblende,
sphene, apatite, and zircon

ALASKITE

SEDIMENTARY AND VOLCANIC ROCKS

DUNLAP FOKMATION--Interbedded red siliciclastic and carbonate

rocks: sandstone, mudstone, conglomerate, sedimentary breccia,
metalimestone, and calcarenite. Siliciclastic sandstone is fine
to coarse grained, thin to thick bedded, consists of chert grains,
quartz, and feldspar and a lithic and (or) clayey matrix, and is
locally plane or cross laminated and normally or inversely graded;
beds are commonly tabular but coarser sandstones have scoured
bases. Conglomerate and sedimentary breccia consist of chert,
quartzite, andesite porphyry, and rarely, black slate in clasts as
coarse as 14 cm; such rocks occur in tabular or lobate beds. Red
mudstone is interlayered with other rocks but also occurs in
discrete intervals up to 30 m thick. Carbonate rocks are chiefly
calcarenite and chert-quartz calcarenite; strongly recrystallized
pure carbonate rocks also occur and are called metalimestone-
Local tabular bodies of poorly sorted carbonate breccia may be
evaporite solution breccias. Age in the Huntoon Valley quadrangle
is Early Jurassic, probably Sinemurian, as indicated by Arietitid
ammonites and Weyla sp. in collections by S. W. Muller and R. C.
Speed, identified by N. J. Silberling- Mudstone and wacke are
commonly well cleaved and beds throughout the unit are strongly
folded; deformation occurred in at least two phases of which the
second was cleavage forming. Base not exposed; all contacts with
pre-Tertiary units are faults

1

Plutonic rock named based on IUGS modal classification (Streckeisen, 1973).

GEOLOGIC MAP OF THE HUNTOON VALLEY QUADRANGLE, MINERAL COUNTY, NEVADA
AND MONO COUNTY, CALIFORNIA

by

John H. Stewart, Frank J. Kleinhampl, Dann C. Johannesen,

Robert C. Speed and John C. Dohrenwend

1981

OPEN-FILE REPORT
81-274

/

MePzv VOLCANOGENIC ROCKS OF INTERMEDIATE COMPOSITION--Fault-bounded unit
of tectonized sedimentary rocks, tuff, and igneous protrusions of
intermediate composition that are locally metamorphosed by nearby
granitic rocks of Late Cretaceous age but are otherwise undated.
Rocks are characteristically well foliated and lineated, poorly
bedded, dark green, strongly feldspathic and chloritic, and
nonquartzose. Lithotypes are chlorite phyllite with augen and
foliae of feldspar and volcanic lithic fragments, foliated
sandstone comprising grains of feldspar and feldspar porphyry in
chlorite-rich matrix, sparing thin-bedded graded volcanic
turbidites, volcanic conglomerate containing exclusively volcanic
clasts; micro- and coarse-grained porphyries, scoria, massive
aphanite, and flow-foliated rocks, volcanic breccia of feldspar
porphyry fragments, tuff breccia, and massive feldspar porphyry
that occurs in irregular bodies that grade to breccia and engulf
sedimentary masses; the massive porphyries are thought to be
syndepositional protrusions. Coarse particles in the layered
rocks are alined in the foliation plane and have preferred long
axis orientation which parallels a stretching lineation.
Foliation may locally be relict compaction foliation

MzPzp MAFIC PORPHYRY--Massive rocks and breccia of mafic porphyry
characterized by abundant exceptionally coarse phenocrysts.
Plagioclase is ubiquitous and as coarse as 1 cm; clinopyroxene and
(or) hornblende are locally absent but commonly form between 5 and
20 percent of the rock. The matrix is chloritic. Massive bodies
are as thick as >100 m and are probably protrusions; they grade
laterally to or cut breccia that comprises unsorted fragments of
porphyry as coarse as 10 cm. Mafic porphyries are older than
nearby Late Cretaceous granitic intrusions but are otherwise
undated. Their contacts with the Mina Formation are not
exposed. The mafic porphyries are conceivably contemporaneous
with Permian(?) protrusions and breccia of like composition 10 km
east in the Little Huntoon Valley quadrangle

MzPans METASEDIMENTARY ROCKS, UNDIVIDED

Pm MINA FORMATION--Interbedded metamorphosed volcanogenic sandstone,
pelite, and thick-bedded chert. Sandstones are medium to coarse
grained and locally pebbly and plane laminated where they occur in
thick homogeneous tabular layers. Thinner and finer grained
sandstones are typical turbidites that grade up to pelitic tops.
Sand grains are feldspar, pyroxene, porphyry, hornblende, and
quartz in order of decreasing abundance. Pebbles are exclusively
composed of mafic porhpyry- Pelite occurs in both turbiditic and
apparently nonturbiditic beds; it is strongly metamoprhosed to
hornfels and variably silicified to chertlike rocks. Chert is
thick bedded, white to black, and commonly interbedded with thick
sandstone. These rocks are undated but are correlated
lithologically with Permian beds of the Mina Formation whose type
area is 40 km east at Douglas Canyon, Garfield Hills, Nev. (Speed,
1977)

SANDSTONE, PELITE, AND CHERT--Comprised of two lithic associations
(Rs and (p), one predominantly of thick-hedded sandstone and the
other of pelite and chert. The two lithic associations are
probably, but not certainly, in stratigraphic continuity. Age of
thin-bedded chert is early to medial Pennsylvanian in two
collections and Pennsylvanian or Permian in a third collection
according to D. L. Jones (writtten commun-, 1980). Sandstone
sequences are compositionally similar to those of Mina Formation
but differ by lack of abundant thick chert interbeds that are
typical of Mina Formation. Sandstone, pelite, and chert sequence
differs from volcanogenic rocks of intermediate composition (unit
Nef v) by prevalence of well~defined bedding, by presence of mafic
grains in sandstone, and by presence of bedded chert

Ps Sandstone--Volcanogenic: fine to very coarse grained, locally
pebbly; composed of feldspar grains, mafic mineral grains,
mafic volcanic rock fragments, and mudclasts; thin to very thick
bedded. Coarse sandstones are typically thick bedded and
massive or plane laminated whereas finer grained sandstones are
classic turbidites that grade up to pelitic tops which are
commonly chertified- Thick-bedded chert occurs, but sparingly,
in sandstone-rich associations

Bp Pelite and chert--Red and black pelite with planar-spaced
cleavage, locally slaty; pelite is commonly homogeneous but also
includes thin sandy turbidites- Thin-bedded green radiolarian
chert occurs in clustered beds throughout sequence; and coarse
volcanogenic sandstone occur locally

—~—?~ Contact--Queried where approximately located

b-—--+Fault--Dashed where inferred or approximately located, dotted where
concealed. Bar and ball on downthrown side.

AeA Thrust or low-angle fault--Dashed where approximately located.
Sawteeth on upper plate

Strike and dip of stratified rock
Vertical bedding

Overturned bedding

Strike and dip of foliation

Vertical foliation

bet he + bs

Strike and dip where foliation parallels bedding

REFERENCES CITED

Gilbert, C. M., Christiansen, M. N., Al-Rawi, Y-, and Lajoie, K- R., 1968,
Structural and volcanic history of Mono Basin, California-Nevada, in
Coats, R. R-, Hay, R. ©., and Anderson, C. A., eds-, Studies in
voleanology: Geological Society of America Memoir 116, p- 275-329.

Speed, R. C., 1977, Excelsior Formation, west-central Nevada: Stratigraphic
appraisal, new divisions, and paleogeographic interpretations in Stewart,
J. He, Stevens, C. H., and Fritsche, A. E+, eds-, Paleozoic
paleogeography of the western United States: Society of Economic
Paleontologists and Mineralogists, Pacific Section, Pacific Coast
Paleogeography Symposium 1, p. 325-336.

Speed, R. C-, and Cogbill, A. H-, 1979, Cenozoic volcanism of the Candelaria
region, Nevada: Geological Society of America Bulletin, pt- 2, v- 90,
p- 456-493.

Stewart, J+ H+, 1979, Geologic map of the Miller Mountain and Columbus
quadrangles, Mineral and Esmeralda Counties, Nevada: U.S. Geological
Survey Open-File Report 79-1145.

Streckeisen, A. L-, 1973, Plutonic rocks--classification and nomenclature:
Geotimes, v. 18, no. 19,. p. 26-39.

This map is preliminary and has

not been reviewed for conformity

with U.S. Geological Survey editorial
standards and stratigraphic nomenclature.