White Pine news. [volume] (East Ely, Nev.) 1920-1923, 1921-04-24
REPORT OF NOTED GEOLOG|ST
NEvADA'S FOREMOST O|LF|ELD
THE ILLPAH OIIFIELD.

to Illipah basin during the days of
March 30 and 81 and April I, year
l9z1. As far as the writer's labors
are concerned the field Investigation
was concentrated upon the question
whether geologic structural condi-
tions favorable to the accumulation
OF Oil and gas existed in the region
under consideration in this report.
All previous accessible reports upon
the region and Nevada In general
were consulted with a view toward
presenting comprehensive interpre-
tation OF the existing geologic struct-
ure In the Illipah basin area.
The writer was accompanied By
Bessrs. CRAIG and Caperton. vhose
efforts and knowledge of the feld
facilitated the writer in covering the
eround- Mr.. Moorman, . landowner
=. IL ..se S1t:s:.c. .c., accompanied the party
during the second day and acknowl-
edgments are hereby made to the
gentlemen, who pointed out several
open cuts and shafts and designated
some fossiliferous areas, which ac-
commodation materially aided In ex-
pediting the investigation.
Topography The topographic
features of eastern Nevada as q whole
are somewhat striking on account of
the persistent northward-southwar
striking axes of the parallel noun
tains and valleys. The Illipah basin
region may be considered as typical
example of the eastern part of Ne
vada.
The ranges or ridges In the Illipah
basin area are long and narrow and
are broken by narrow passes and low
ridges. each Of which have been given
different names. No attempt will be
made here to discuss the mountains
and ridges in detail.
Geology-In eastern Nevada geoI-
ogic studies have revealed that the
main formations range from Cam
brian to and inclusive OF the Permian
rocks. The Jura-Triassic rocks are
missing, as well as tho important cre-
taceous system, which series of for
nations have yielded most of the oil
developed In the state of Wyoming.
In discussing the geology of eastern
Nevada attention is invited to the
latest important government publica-
tion by the department OF the inte-
rior, United States geological survey,
professional paper No. 96, entitled
THE Geology and Ore Deposits Of
Fly, Nevada" by Arthur c. Spencer,
Washington, 1917, In which Mr..
Spencer Ii quoted as follows from
page Is.
THE rocks which enter into the
architecture OF the basin ranges in
western Utah and central Nevada are
mainly limestones, shales and sand
stones and range In age from Cam
brian to late carboniferous. LOCALLY
ana grantees. LaveB of the Tertiary
age are abundant In the mountainous
belts and cover considerable areas In
some OF the lower country. Meaozoic
rocks. which occupy extensive areae
east of the Great Basin and which
are likewise prominently developed
In central and western Nevada, are
not present In western Utah or east
ern Nevada. This part OF the Great
fasin seems, the1 efore. to have con-
stituted a land area throughout the
have been subject to erosion during
long period"
The sedimentary rocks In eastern
Nevada have been greatly disturbed
by earth movements and the profound
faulting hiss resulted in the series Of
parallel northward-trending breaks of
great magnitude. Resides the major
series of northward faults there Is
also evidences of some east-west fault
ing, which latter condition is proba-
bly, apparent In Il1ipah basin. In II
lipah basin only the Devonian and
lower carboniferous rocks were stud
fed. since only these formations were
present and because the question un-
der consideration In this paper is con.
fined solely to those rocks. The age
Of these formations was established
years ago by the first geoloyists Of
the government. as may be inferred
from the following by Arnold Hague
which appeared in the "United States
Exploration OF the Fcrtfeth Parallel"
Vol. IT., 1877. Washington, d. c.:
In the narrow longitudinal mp
lifts lying between the Sierra Ne
vada and the Wahsatch ranges. the
greater number OF which, In general
terms. consist of single snticlinal or
monocllnal folds. made up of quartz
tie and limestone formations of great
thickness, IT Is exceptional to find ex-
posed In any one region q wide geo.
logical horizon. But here at White
Pine the mountains, which have Al
average width OF twelve miles from
valley 10 valley. are formed OF three
distinct north and south ridges. two
OF which are Inonoclinal folds. with
a sharp anticlinal lying between
them. exposing from the base of Pog-
onip mountain on the western side to
the top of Mokomoke ridge on the
eastern side, strata from the Primor-
dial shales Of the coal measure limo
stones.
| Granite crops out In several small
bodies along the base OF Pogonip
ridge, bat In only one locality was II
observed In any large mess, where II
occurs In somewhat isolated hill a.
a coarse-grained hornblendic rock
with friable texture. At the north
ern end OF the ridge, apparently un-
conformable with the granite, are OBJ
scure outcrops of mica states and
black arenaceous and argillaceous
states and shales. In turn overlaid by
an undetermined thickness of com.
nact xiire0ns steal=1rax mart zife