■ 'r -

-

-

Digitized by the Internet Archive
in 2019 with funding from
Brigham Young University

https://archive.org/details/rockformationsinOOIong

Please do not destroy or throw away this publication. If you have no further use
for it, write to the Geological Survey at Washington and ask for a frank to return it

DEPARTMENT OF THE INTERIOR

Hubert Work, Secretary

United States Geological Survey

George Otis Smith, Director

Professional Paper 132 — A

ROCK FORMATIONS IN THE COLORADO PLATEAU OF
SOUTHEASTERN UTAH AND NORTHERN ARIZONA

C. R. LONGWELL, H. D. MISER, R. C. MOORE,
KIRK BRYAN, and SIDNEY PAIGE

Published July 27, 1923

Shorter contributions to general geology, 1923

(Pages 1-23)

WASHINGTON

GOVERNMENT PRINTING OFFICE

1923

CONTENTS.

Nature and purpose of investigation

Previous work .

Topography .

Sedimentary rocks .

General features .

Carboniferous system .

Goodridge formation .

Supai (?) formation .

Coconino sandstone .

Ivaibab limestone .

Erosion interval .

Triassic system .

Moenkopi formation .

Shinai’ump conglomerate...

Chinle formation .

Jurassic system .

General features .

Wingate sandstone .

Page.

1

1

2

2

2

7

7

7

8
8
9
9
9

10

11

11

11

12

Sedimentary rocks — Continued.

Jurassic system — Continued.

Todilto (?) formation .

Navajo sandstone .

Gypsiferous shales and sandstones
Varicolored sandstones and shales.

McElmo formation (Cretaceous?) .

Cretaceous system .

Dakota (?) sandstone .

“Tununk shale” .

Tununk sandstone.... .

“Blue Gate shale” .

Blue Gate sandstone .

“Masuk shale” .

Masuk sandstone .

Tertiary system .

Local sections .

Page.

13

13

14
14
14

14

15
15
15
15

15

16
16
16
16

ILLUSTRATIONS.

Plate I. Generalized columnar sections of the Paleozoic and Mesozoic rocks of northern Arizona and south¬
eastern Utah .

II. Generalized columnar sections of the Paleozoic and Mesozoic rocks of southeastern Utah .

III. A, View looking down San Juan Canyon, Utah, at a point 9 miles by stream above Honaker trail;

B, View looking down Green River toward its junction with Colorado River, Utah; C, View
in Cataract Canyon of the Colorado, Utah .

IV. A, View lpoking down San Juan Canyon, Utah, at a point between Clay Hill Crossing and the

mouth of Moonlight Creek; B, View near Colorado River 2 miles below mouth of Trachyte
Creek, Utah; C, View looking down San Juan Canyon at the mouth of Slickhorn Gulch,

Utah . . .

V. A, View looking southwest down head of Marble Canyon from point near Lees Ferry, Ariz.;
B, View looking up Colorado River from a high point near the mouth of Crescent Creek,
Utah; C, Erosion remnants standing on platform of Coconino sandstone near mouth of Fre¬
mont River, Utah .

VI. A, View looking up San Juan Canyon from point near mouth of Clay Gulch, Utah; B, View look¬
ing west toward high mesa at Clay Hill Crossing on San Juan River, Utah .

VII. A, Castle Butte, near mouth of Red Canyon, Utah; B, View looking north across Colorado River

at Lees Ferry, Ariz .

VIII. A, View looking northwest up Colorado River toward proposed dam site near Lees Ferry, Ariz.;

B, View from point half a mile south of Spencer Camp looking south down San Juan

Canyon toward Navajo Mountain, Utah . . .

IX. A, View looking northeast toward Wilson Mesa from point on Wilson Creek near San Juan Canyon,
Utah; B, View looking across Colorado River opposite Smith’s Fork, Utah; C, Sheer cliff

of Navajo sandstone at Warm Spring Creek on Colorado River, Utah .

X. A, View of Waterpocket Fold and Cretaceous plateaus between the Circle Cliffs and the Henry
Mountains, Utah; B, Sketch of the country between the Circle Cliffs and the Henry Moun¬
tains, Utah, showing the surface distribution of the rock formations .

Figure 1. Index map of parts of Utah and Arizona showing location of columnar sections given in Plates
land II .

Pag®.

6

6

6

6

6

7

12

12

12

13

6

ii

SHORTER CONTRIRUTIONS TO GENERAL GEOLOGY, 1923.

ROCK FORMATIONS IN THE COLORADO PLATEAU OF SOUTHEASTERN

UTAH AND NORTHERN ARIZONA.

By C. R. Longwell, H. D. Miser, R. C. Moore, Kirk Bryan, and Sidney Paige.

NATURE AND PURPOSE OF THE INVESTIGATION.

The field work of which this report is a record
was done in the summer and fall of 1921 by
members of the United States Geological Sur¬
vey. A project to build a large storage dam
at Lees Ferry, on Colorado River in northern
Arizona, called for a detailed topographic sur¬
vey of the area covered by the project, for the
purpose of determining the capacity of the res¬
ervoir. This work was undertaken by the
United States Geological Survey in coopera¬
tion with the Southern California Edison Co.
Three surveying parties were sent to the field,
each accompanied by a geologist, whose specific
duty was to study and report on the rock for¬
mations within the area to be flooded.

One topographic party, under A. T. Fowler,
which started at Lees Ferry and worked up¬
stream in Arizona, was accompanied by Kirk
Bryan. Another party, under K. W. Trimble,
which started near Bluff and worked down the
San Juan and thence down the Colorado, was
accompanied by H. D. Miser. The third party,
under W. R. Chenoweth, worked from Fremont
River to the Waterpocket Fold and then re¬
turned to Green River, Utah, and traversed
Cataract Canyon during the period of low water.
C. R. Longwell was with this party until Sep¬
tember, when his place was taken by Sidney
Paige. Mr. Paige, in company with the Kolb
brothers, E. C. La Rue, and Henry Rauch, left
the Chenoweth party after Cataract Canyon
had been surveyed and rowed down the Colo¬
rado to the mouth of the San Juan, where they
were joined by Mr. Miser. Then they took a
hurried trip by boat down the Colorado to Lees
Ferry, making a few short stops and visiting
the famous Rainbow Bridge.

Thus the geology of the canyons of Colorado
and San Juan rivers and of the lower parts of
tributary canyons was examined continuously,
and reconnaissance work was done in the coun¬
try back from the rivers. At the same time a
fourth party, under R. C. Moore, was mapping
parts of Kane, Garfield, and Wayne counties,
Utah, to determine whether oil might be found
there.

The present paper includes brief descriptions
of the rocks of the regions traversed, detailed
geologic sections, and columnar sections meas¬
ured not only by the geologists who accom¬
panied these parties but by other geologists
who have worked in the same regions or in
adjoining regions. The positions of the colum¬
nar sections measured and many of the other
sections are shown on Figure 1.

PREVIOUS WORK.

The first geologic work done in the area here
considered was that recorded in the report of
the Macomb expedition of 1859 by J. S. New¬
berry,1 who examined the Mesozoic formations
near Bluff. Next followed J. W. Powell’s his¬
toric explorations in 1869 to 1872, which con¬
tributed some geologic information, although
their most valuable results were geographic.2
G. K. Gilbert’s work in 1875 and 1876 was
necessarily of a reconnaissance nature, but it
showed powers of observation and interpreta¬
tion that have aroused the admiration of later
workers who have used his report 3 as a guide.

1 Newberry, J. S., Geological report, in Report of the exploring expe¬
dition from Santa Fe, N. Mex., to the junction of the Grand and Green
rivers of the Great Colorado of the West, in 1859, under the command
of Capt. J. N. Macomb, pp. 101-109, 1876.

2 Powell, J. W., Exploration of the Colorado River of the West, 1875.

3 Gilbert, G. K., Report on the geology of the Henry Mountains, U. S.
Geog. and Geol. Survey Rocky Mtn. Region, 1880.

1

2

4

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

W. H. Holmes contributed information on the
San Juan district,4 in a report on field work
that was in part contemporaneous with that
done by Gilbert farther north and west. The
classic reports of Gilbert and Holmes served
all practical needs for a knowledge of this
sparsely settled region until oil was discovered
at Goodridge in 1908. H. E. Gregory 5 and
E. G. Woodruff 6 made reports on the geology
of the oil field, and Gregory later, in his reports
on the Navajo country,7 described the geology
of the region on the south side of the San Juan.
The most recent papers of direct interest in
the present connection are those by W. B.
Emery,8 C. L. Dake,9 Dorsey Hager,10 C. T.
Lupton,11 and R. C. Moore.12 Numerous papers
on adjacent areas, herein referred to, have been
of great assistance in making correlations.

TOPOGRAPHY.

The area considered in this report is part of
a large arid region that is sparsely settled and
difficult of access. It is a typical portion of
the Colorado Plateau, characterized by can¬
yons, cliffs, mesas, and buttes. The general
plateau surface, averaging between 5,000 and
6,000 feet in altitude, appears fairly regular
and continuous in a panoramic view; but Colo¬
rado River and its tributaries have cut hun¬
dreds of feet below the general level, and Navajo
Mountain and the Henry Mountains project
conspicuously above it, attaining maximum
altitudes of about 11,000 feet. The Henry
Mountains are classic as the type locality of
the igneous intrusive masses known as lacco¬
liths. Northwest of these mountains are the
so-called High Plateaus, lofty forest-clad table¬
lands with gently irregular surface topography

4 Holmes, W. H., Geological report on the San Juan district: U. S.
Geog. and Geol. Survey Terr. Ninth Ann. Rept., for 1875, pp. 237-276,
1877.

5 Gregory, H. E., The San Juan oil field, Utah: U. S. Geol. Survey
Bull. 431, pp. 11-25, 1911.

6 Woodruff, E. G., Geology of the San Juan oil field, Utah: U. S.
Geol. Survey Bull. 471, pp. 76-104, 1912.

7 Gregory, H. E., The Navajo country: U. S. Geol. Survey Water-
Supply Paper 380, 1916; Geology of the Navajo country: U. S. Geol.
Survey Prof. Paper 93, 1917.

s Emery, W. B., The Green River Desert section, Utah: Am. Jour.
Sci., 4th ser., vol. 46, pp. 551-577, 1918.

s Dake, C. L., The pre-Moenkopi unconformity of the Colorado Pla¬
teau: Jour. Geology, vol. 27, pp. 61-74, 1920: Horizon of the marine
Jurassic of Utah: Jour. Geology, vol. 27, pp. 634-646, 1919.

10 Hager, Dorsey, Oil possibilities of the Holbrook area in northeast
Arizona, 1921. A private publication.

11 Lupton, C. T., Geology and coal resources of Castle Valley, Utah:
U. S. Geol. Survey Bull. 628, 1916.

Moore, R. C., On the stratigraphy of northeastern Arizona: Am.
Assoc. Petroleum Geologists Bull., vol. 6, No. 1, pp. 47-49, 1922. Dis¬
cusses paper by Hager cited above.

and precipitous borders, which have an average
altitude of more than 9,000 feet.

Alternating sedimentary formations of vary¬
ing resistance exert a strong topographic con¬
trol. Heavy sandstone and limestone units
form vertical cliffs or level mesa tops; shales
produce slopes or local areas of badlands.
Stream courses cut into sandstone or limestone
are confined in narrow, steep-walled canyons;
but at horizons of thick shales the valleys are
wide, with vertical outer walls made by the
overlying sandstones. Typical cross sections
of the larger streams show prominent struc¬
tural terraces or benches, which mark abrupt
changes in the character of the rocks.

SEDIMENTARY ROCKS.

GENERAL FEATURES.

The nakedness of the surface rocks and their
deep dissection give an excellent opportunity
for detailed study, and when the entire region
has been systematically surveyed there should
be few important problems of correlation left
unsolved. But in spite of the apparent sim¬
plicity of the geology it is not safe to attempt
correlation of widely separated sections without
knowledge of the intervening areas, however
thorough the study of the sections may have
been. Errors have already resulted from such
attempts, and a certain degree of confusion
now exists as to the exact stratigraphic succes¬
sion and the proper terminology. Many of the
formations are of continental origin, and some
have yielded no determinable fossils. Certain
of these formations have lithologic characteris¬
tics that are remarkably persistent over wide
areas ; but in many sections two or more forma¬
tions are strikingly similar in general appear¬
ance, and members that are of only local dis¬
tribution may be confused with formations that
are considered the most trustworthy as guides
to correlation. In correlating these deceptive
formations, therefore, it is desirable to measure
sections as close together as possible, and con¬
tinuous tracing in the field is the most satisfac¬
tory method. The rocks are essentially hori¬
zontal or dip gently, except for local strong
flexures, and the present writers found it pos¬
sible to follow certain guide horizons essentially
without interruption.

The rocks range in age from Pennsylvanian
to Tertiary, but the Tertiary formations were
not studied in detail. Triassic and Jurassic
rocks are the most widely distributed forma-

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

3

tions on the surface, and they are largely of
continental origin. Bright colors prevail, mak¬
ing the region a “ painted desert” of great scenic
interest. In Utah the older formations are
revealed in a few broad anticlines, notably in
Cataract Canyon and in the San Juan oil field;
and in the adjoining part of Arizona they appear
in Marble Canyon.

Besides the laccoliths of igneous rocks in the
Henry Mountains there are a few igneous dikes
and volcanic necks at other places in the part
of the Colorado Plateau under discussion. In
the High Plateaus, west of the Henry Moun¬
tains, there are large areas of extrusive igneous
rocks. None of these igneous rocks are here
described.

The section exposed in the walls of the Grand
Canyon, which adjoins Marble Canyon, is prob¬
ably better known than any other in the Colo¬
rado Plateau, and it is taken as a standard in
correlating Paleozoic formations in the region.
This section has been studied in great detail by
L. F. Noble, and he has recently proposed some
changes in the stratigraphic subdivision and the
terminology to be used.13 (See Fig. 1 and PI. I.)

w Noble, L. F., in Schuchert, Charles, On the Carboniferous of the
Grand Canyon of Arizona: Am. Jour. Sci., 4th ser., vol. 45, pp. 347-362,
1918. Noble, L. F., Paleozoic formations of the Grand Canyon at the
Bass trail: U. S. Geol. Survey Prof. Paper 131, pp. 23-73, 1922.

His usage is indicated below, in comparison with
the older usage, with a view to making clearer
the discussion of Paleozoic formations here
presented.

Older usage.

Kaibab limestone .

Coconino sandstone .

Supai forma- [Upper-
tion |

[Lower . .

[Upper . .

Redwall lime¬

stone

[Lower. . .

Unconformity.
Pre-Carboniferous forma¬
tions.

Noble’s usage.

.Kaibab limestone 1
. Coconino sandstone ((Permian ) .
.Hermit shale J
Unconformity.

. 1 Supai formation (Pennsylva-
/ nian and Permian?).
Unconformity (?).

. Redwall limestone (Mississip-
pian).

Unconformity.

Pre-Carboniferous formations.

In thus redefining the Supai and Redwall for¬
mations Noble has definitely referred the Her¬
mit shale to the Permian on the basis of plant
remains first discovered by Schuchert and
identified by David White. No fossils have
been found in the thick red sandstone at the
top of the Supai formation as redefined, and
this member may therefore belong either in the
Permian or in the Pennsylvanian.

The rock formations studied in southeastern
Utah and the adjoining part of Arizona are in¬
dicated in the following table:

Bock formations in southeastern Utah and the adjoining part of Arizona.

Age.

|

Formation. 1 Character.

'

Thickness

(feet).

Remarks.

Tertiary (Eo¬
cene).

Wasatch ( ?) formation .

Calcareous sandstone, shale, and
limestone; pink, white, and vari¬
colored, evenly stratified, soft;
composes highest plateaus; crops
out in cliffs and forms slopes.

2, 000

Upper

Cretaceous.

Masuk sandstone.

Yellowish-gray massive sandstone
with some sandy shale; grades
without break into formation be¬
low ; a prominent cliff-forming
division.

300-500

“Masuk shale.”

Gray to drab sandy shale containing
some thin beds of yellow sand¬
stone.

500-1, 000+

Blue Gate sandstone.

Yellow to brown irregularly bedded
medium to massive sandstone;
contains lignite beds up to 4 feet in
thickness; forms prominent es¬
carpments.

230-1, 000

4

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

Rock formations in southeastern Utah and the adjoining part of Arizona — Continued.

Ag0.

Formation.

Character.

Thickness

(feet).

Remarks.

Upper

Cretaceous.

“Blue Gate shale.”

Bluish-drab argillaceous to sandy
shale; very uniform in color and
texture ; forms slopes and badlands ;
thickness, 1,100-1,200 feet.

2, 115-2, 250

Tununk sandstone.

Yellowish medium to massive irreg¬
ularly bedded sandstone ; contains
lignite; forms escarpments and
hogbacks; thickness, 60-100 feet.

“ Tununk shale.”

Bluish-drab sandy shale grading to
fossiliferous sandstone at base;
shale contains abundant Gryphaea
newberryi and other fossils; thick¬
ness, 900-1,000 feet.

Dakota (?) sandstone.

Yellow to nearly white sandstone;
conglomeratic in part; irregularly
bedded; contains lignite locally.

0-100

Cretaceous (?)
(Lower Cre¬
taceous ?).

McElmo formation.

Maroon to light bluish-gray sandy
banded shale; conglomerate; and
coarse gritty maroon, yellow, and
gray irregularly bedded sandstone ;
forms escarpments.

125-565

Varicolored sandstones
and shales.

Very massive soft light creamy-
white, tan, and orange-brown cross-
bedded sandstone; grades into very
sandy shale; weathers readily in
rounded slopes and forms abundant
dune sand.

Jurassic.

170-1, 430

Navajo sandstone of
Emery. Included
by Lupton in Mc¬
Elmo formation.

Gypsiferous shales and
sandstones.

Pink to red and bluish sandy shale,
gypsum in beds up to 5 feet thick,
and massive white sandstone;
forms badlands; 50-300 feet.

Shale, sandstone, and siliceous
dark-maroon and light bluish-green
limestone; forms distinct escarp¬
ment; 30-55 feet.

45-450

Todilto (?) formation
of Emery. Hori¬
zon of marine Ju¬
rassic. Included
in McElmo forma¬
tion by Lupton.

Navajo sandstone.

Light creamy-yellow, white, pinkish,
and buff, highly cross-bedded,
very massive calcareous sandstone ;
weathers in high cliffs and innu¬
merable cones, towers, and domes ;
forms caves, alcoves, and natural
bridges. '

500-1, 800

Gregory’s usage. In¬
cluded in Wingate
sandstone by Em¬
ery.

Todilto (?) formation.

Maroon coarse-grained cross-bedded
sandstone ; conglomerate ; blue-gray
hard dense limestone; maroon and
brown shale. All in thin irregular
beds.

125-249

Gregory's usage. In-
■ eluded in Wingate
sandstone by Em¬
ery.

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

5

Rock formations in southeastern Utah and the adjoining part of Arizona — Continued.

Age.

Formation.

Character.

Thickness

(feet).

Remarks.

Jurassic.

Wingate sandstone.

Reddish-brown very massive sand¬
stone; prominently jointed; out¬
cropping commonly in a single ver¬
tical cliff resembling a palisade.
Cross-bedded but not so promi¬
nently as Navajo sandstone.

250-500

Gregory ’s usage . I n-
cluded in Wingate
sandstone by Em¬
ery.

Upper Triassic.

Chinle formation.

Thick variegated calcareous shales or
“marls,” fine-grained sandstones,
cherty limestones, and conglom¬
eratic limestone. Sandstone most
abundant near top of formation.

300-1, 000

Upper (?) Tri¬
assic.

Shinarump conglomer¬
ate.

Light-gray to yellow coarse-grained
to conglomeratic sandstone, very
irregularly bedded and variable in
thickness ; grades locally into blu¬
ish sandy shale ; contains silicified
wood; forms prominent bench in
topography.

0-220

Lower Triassic.

Moenkopi formation.

Chocolate-brown to yellowish shale
and sandstone, containing locally
in upper portion very thin hard
limestones. The shale very sandy
and grading into shaly sandstones ;
the sandstone ranging from thin-
bedded platy to thick massive
beds. Ripple-marked. Contains
DeChelly (?) sandstone lentil in
middle portion; thickness, 0-200
feet.

304-920

Directly overlies

Coconino sand¬

stone where Kai¬
bab limestone is
absent.

Permian.

Kaibab limestone.

White to yellowish massive more or
less dolomitic limestone; in part
cherty; lower part increasingly
sandy and grading into subjacent
sandstone without sharp change.
Fossiliferous in part.

0-250

Not continuous.

Coconino sandstone.

White to tan massive calcareous sac-
charoidal hard to friable sandstone.
In Circle Cliffs not differentiated
from Supai (?) formation.

300-1, 000

Supai (?) formation.

Red to light-yellow shale and sand¬
stone.

380

Possibly Hermit

shale.

Pennsylvanian.

Goodridge formation.

Bluish fine-grained dense, medium to
massively bedded limestone; red
and grayish-white sandstone, in
part petroliferous; red and dark-
gray sandy shales . Limestone pre¬
dominates in lower part of section,
sandstone and shale in upper part.

1,582

6

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

Figure 1.— Index map of parts of Utah and Arizona showing location of columnar sections (numbered dots) given in Plates I and II. Nos. 1

to 10 are given in Plate I; Nos. 11 to 14 in Plate II.

. s. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 132 PLATE I

Generalized section in
theShinumo quadrangle
in the Kaibab division of
the Grand Canyon

By L. F. Noble.
U.S. Geol. Survey
Bulletin 649, Plate IX.

Composite section at
Bass Trail and on
Cedar Mountain in the
Grand Canyon region
By L. F Noble.

U. S. Geol Survey
Professional Paper 131-B

Generalized section at
and near Lees Ferry.
Arizona
By Kirk Bryan

Castle Butte. 5 miles
east of "The Crossing
of the Fathers"

East end of
Wilson Mesa
in San Juan River
By H. D. Miser

Composite section
between Clay Gulch
and Zahns Camp
on San Juan River
By H. D. Miser

Composite section at
Clay Hill Crossing,
Piute Farms,
and mouth of
Moonlight Creek
By H. D Miser

Composite section
at mouth of
Slickhom Gulch and
Honaker trail
By H. D. Miser

Composite section
from Bluff down
San Juan River to
mouth of Chinle Creek
Compiled from measure¬
ments by H. D. Miser
and from reports, by
Woodruff and Gregory

10

Generalized section
showing strata in
San Juan oil field
By E. G. Woodruff.

U. S. GeoL Survey
Bulletin 471. Plate VIII.

Generalized section
of rocks of the
Navajo country
By H. E. Gregory.
U. S- Geol. Survey
Professional Paper 23,

g

MC Elmo
Formation

200 feet 1

Red

300 foot* \
Sandstone end
s hate 100 feet

Navajo

sandstone

300 feet
„ —

1. Thickness estimated

1. Estimated thickness at
mouth of Slickhom Gulch

2. Measured at mouth
of Slickhom Gulch

3. Measured at Honaker trai

sandstone and McEnno
1 1 formation in much of the

I i Colorado Plateau arere
not considered distinct
formations by Gregory
along Glen and San'j jin
canyons. He there in¬
cluded them in his Me-
Elmo formation

GENERALIZED COLUMNAR SECTIONS OF TIIE PALEOZOIC AND MESOZOIC ROCKS OF NORTHERN ARIZONA AND SOUTHEASTERN UTAH

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 132 PLATE II

14

Generalized section
of rocks in the
Circle Cliffs
By R. C. Moore

13

Generalized section
of sedimentary
rocks in the
Henry Mountains
ByG. K. Gilbert, Report
on the geology of the
Henry Mountains, 1877

12

Generalized section
of rocks in the
Green River Desert
By W. B. Emery, The
Green River Desert
section, Utah:
American Journal of
Science, 4th ser.,
vol. 46, 1918

11

Composite section
along Colorado
River from mouth
of Green River
to WaterpocketFold
By C. R. Longwell
and Sidney Paige

8

Composite section
at mouth of
Slickhom Gulch and
Honaker trail
By H. D. Miser

Generalized section
of rocks of the
Navajo country
By H. E. Gregory,
U. S. Geol. Survey
Professional Paper 93,
1917

1. The lower part of the
section beginning 70 feet
below the top of the Kai-
bab limestone is compil¬
ed from the log of Circle
Cliffs well of the Ohio
Oil Company

1. Measured by Longwell
near Warm Springs
Canyon

2. Measured by Longwell
2 miles below mouth

of Trachyte Creek

3. Generalized section
measured by Longwell
between Cataract Can¬
yon and Trachyte Creek

4. Measured by Paige
in Cataract Canyon

1. Estimated thickness
at mouth of Slickhorn
Gulch

2. Measured at mouth
of Slickhorn Gulch

3. Measured at Honaker
trail

1. The beds that are equiv¬
alent to the Navajo and
Todilto formations of Em¬
ery were not considered
distinct formations by
Gregory along Glen and
San Juan canyons. He
there included them in
his McElmo formation

GENERALIZED COLUMNAR SECTIONS OF THE PALEOZOIC AND MESOZOIC ROCKS OF SOUTHEASTERN UTAH

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 132 PLATE III

A. VIEW LOOKING DOWN SAN JUAN CANYON, UTAH, AT A POINT 9 MILES BY STREAM

ABOVE HONAKER TRAIL.

Canyon has been cut in Goodridge formation. Photograph by Robert N. Allen.

B. VIEW LOOKING DOWN GREEN RIVER TOWARD
ITS JUNCTION WITH COLORADO RIVER, UTAH.

Canyon cut in Goodridge formation. Photograph by Sidney Paige.

C. VIEW IN CATARACT CANYON OF THE COLORADO,
UTAH.

Goodridge formation forms lower part of canyon walls and
Coconino sandstone the upper part. These two formations
are probably separated by beds that are equivalent to the
Supai (?) formation of the San Juan Canyon. Photograph by
Sidney Paige.

XT. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 132 PLATE IV

A. VIEW LOOKING DOWN SAN JUAN CANYON, UTAH, AT A POINT BETWEEN CLAY HILL
CROSSING AND THE MOUTH OF MOONLIGHT CREEK.

Coconino sandstone forms canyon walls. Photograph by H. D. Miser.

B. VIEW NEAR COLORADO RIVER 2 MILES BELOW
MOUTH OF TRACHYTE CREEK, UTAH.

Showing Chinl e formation, about 320 feet thick, capped by
Wingate sandstone. Part of wide bench in foreground is on
Shinarump conglomerate. Photograph by C. R. Longwell.

C. VIEW LOOKING DOWN SAN JUAN CANYON AT
THE MOUTH OF SLICKHORN GULCH, UTAH.

1, Coconino sandstone; 2, Supai (?) formation; 3, Goodridge
formation. The rapid is produced by a boulder bar at the
mouth of Slick horn Culch. Photograph by Robert N. Allen.

XJ. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 132 PLATE V

A. VIEW LOOKING SOUTHWEST DOWN HEAD OF MARBLE CANYON FROM POINT NEAR LEES

FERRY, ARIZ.

Platform in foreground is underlain by Kaibab limestone; next higher platform reveals l lie Moenkopi formation and
is capped by Shinarump conglomerate; the high Vermilion Cliffs, to the righL, are formed by Wingate and Navajo
sandstones. Chinle formalion is exposed on steep slope below Vermilion Cliffs. Photograph by Kirk Bryan.

B. VIEW LOOKING UP COLORADO RIVER FROM A HIGH POINT NEAR THE MOUTH OF

CRESCENT CREEK, UTAH.

Crescent Creek in foreground. The Colorado is deeply incised in the Coconino sandstone, which forms the light-
colored platform. Moenkopi formation in the foreground is stripped from this platform. Photograph by C. R.
Longwell.

C. EROSION REMNANTS STANDING ON PLATFORM OF COCONINO SANDSTONE NEAR MOUTH

OF FREMONT RIVER, UTAH.

1, Coconino sandstone; 2, lower member of Moenkopi formation; 3, De Chelly (?) sandstone lentil of Moenkopi
formation; 4, conglomerate at base of upper member of Moenkopi formation. Photograph by C. R. Longwell.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 132 PLATE VI

- V T'-

A. VIEW LOOKING UP SAN JUAN CANYON FROM POINT NEAR MOUTH OF CLAY GULCH,

UTAH.

Platform is underlain by Shinarump conglomerate, but in foreground terrace gravels and landslide material rest on
Shinarump. Moenkopi formation is exposed in lower part of canyon walls. Photograph by Robert N. Allen.

D. VIEW LOOKING WEST TOWARD HIGH MESA AT CLAY HILL CROSSING ON SAN JUAN

RIVER, UTAH.

Coconino sandstone underlies level foreground; Moenkopi formation, next above, weathers with fluted edges;
De Clielly (?) sandstone lentil of Moenkopi is absent; Chinle forms steep badland slope with dark and light
bands; Wingate, Todilto (?), and Navajo formations form cliffs at top of mesa. Shinarump conglomerate
is absent. Photograph by Robert N. Allen.

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA

7

CARBONIFEROUS SYSTEM.

Goodridge formation. — The Goodridge forma¬
tion, which has been described by Woodruff,14
is best exposed at the type locality on the
Honaker trail in San Juan Canyon near Good¬
ridge, where the canyon has been carved into
it to a depth of 1,338 feet without revealing
the base. It is of marine origin and consists
of sandstone, sandy shale, and cherty lime¬
stone, with gray limestone predominating in
the lower 500 feet and sandstone and shale in
the upper portion. (See Pis. Ill, A, and IV, G.)
Red is the most common color of the beds in
the upper 700 feet. The base of the formation
is nowhere exposed, and therefore its relation
to older rocks is not known. A less complete
section of the formation — about 1,000 feet — is
exposed in another anticline east of Goodridge.
About 1,500 feet of it is exposed in Cataract
Canyon on the Colorado. (See Pis. II, III, B
and C.) A deep well drilled in the Circle Cliffs
by the Ohio Oil Co. penetrated in its lower part
1,582 feet of white sandstone and limestone
that may represent the Goodridge formation.

Fossils are abundant and are distributed
throughout the type section from a horizon near
the base to the top. G. H. Girty, who has
studied the faunas, makes the following state¬
ment:

The Goodridge formation, as described by Woodruff,14
comprises two widely different faunas. The lower fauna,
which contains almost no true Mollusca, changes abruptly,
at bed No. 55 of his published section, to one that contains
almost nothing else. The base of the bed as measured by
Miser is 314 to 324 feet below the top of the formation.
The character of the change suggests that it may not be
as significant as the degree of the change might indicate.

The two sections that naturally invite comparison with
the Goodridge are the San Juan section, Colorado, to the
east, and the Grand Canyon section, to the west. [See
PI. I.] As I suggested in 1912, the general faunal resem¬
blances would tend to correlate the upper part of the
Goodridge with the Rico formation in the San Juan region
and with the upper part of the Redwall limestone [old
usage of Redwall] in the Grand Canyon region. On the
same grounds the lower part of the Goodridge would be
correlated with the Hermosa formation of the San Juan,
which underlies the Rico. In the Grand Canyon section,
however, the lower part of the Goodridge has no equivalent
that can at present be recognized, but it is closely related
faunally to the Magdalena limestone of New Mexico.

Developments of the last ten years have brought about
an assignment of the Rico formation to the Permian (?),
while the upper part of the old Redwall limestone is
referred to the Pennsylvanian and now included in the
Supai formation. It is evident that the upper part of the

14 Woodruff, E. G., op. cit., pp. 80-85.

33371°— 23 - 2

Goodridge can not be correlated with both these forma¬
tions and yet these assignments be correct. An error evi¬
dently exists, but it can not at present be located. The
correlations here adopted seem the natural ones, and it is
thought better to continue them for the present and to
leave adjustments of age determinations to a future day
and more satisfactory evidence.

At present, therefore, the upper part of the
Goodridge can not be assigned with assurance
to any epoch, but the greater part of the forma¬
tion is certainly Pennsylvanian. It is evident
from Mr. Girty’s remarks that any attempt to
match the Goodridge with a part of the stand¬
ard Grand Canyon section must be considered
as tentative only. This fact should be borne
in mind in connection with the columnar sec¬
tions (Pis. I, II) offered in this paper.

Sandstone and limestone beds of the Good¬
ridge formation supply the oil in the San Juan
field, as noted by Gregory and Woodruff.
Some of these oil-bearing beds are near the top
of the formation, but others are much deeper,
the lowest being 1,300 feet below the top. Oil
seeps occur at several places along the bottom
of the San Juan Canyon. The largest extends
for If miles above the mouth of Slickhorn
Gulch, and the oil at this locality comes from
westward-dipping beds along and near a fault
about 520 feet below the top of the Goodridge.

Supai ( ?) formation. — The Goodridge forma¬
tion in the San Juan region and in Cataract
Canyon is overlain by red sandy shale and shaly
sandstone. (See PL III, C.) Gregory notes
that no definite unconformity is recognized at
the top of the Goodridge,16 but there appears
to be a transition to the red beds above through
limestone conglomerate that may represent a
gradual change from marine to continental con¬
ditions. At the mouth of Slickhorn Gulch, on
the west side of the San Juan oil field, these
higher red beds are 380 feet thick. (See PI.
IV, C.) In view of their lithologic character
and their position immediately beneath the
Coconino sandstone, a possible correlation with
Noble’s Hermit shale is suggested; but in the
absence of fossils the beds are correlated doubt¬
fully with the upper part of Noble’s Supai
formation, which has a much wider known dis¬
tribution than the Hermit shale. Woodruff
and Gregory referred these red beds to the lower
part of the Moenkopi formation, which is now
recognized as Triassic. (See Pis. I and II.)

16 Gregory, H. E., Geology of the Navajo country: U. S. Geol. Survey
Prof. Paper 93, p. 21, 1917.

8

SHORTER CONTRIBUTION'S TO GENERAL GEOLOGY, 1923.

In the head of Marble Canyon about 500 feet
of red shale and sandstone containing beds of
blue limestone in their lower part were observed
beneath the Coconino sandstone. The highest
of these beds may be equivalent to Noble’s
Hermit shale, but the lowest are probably
equivalent to his Supai formation.

Coconino sandstone. — The Coconino sand¬
stone has yielded no determinable fossils, but
it is recognized in southern Utah by criteria
other than its peculiar lithologic character.
In Marble Canyon, southwest of Lees Ferry,
Ariz., the sandstone is present in its normal
position beneath the Kaibab limestone, which
in turn is unconformably overlain by the Lower
Triassic Moenkopi beds. In Circle Cliffs the
same relations are seen but the Kaibab is
much thinner than at Lees Ferry and localities
farther west. In and about Cataract Canyon
and on the San Juan the Kaibab is absent and
the Moenkopi rests unconformably on a thick
sandstone that has all the characteristics of
the Coconino. Gilbert recognized this rela¬
tion n'ear Cataract Canyon and referred to the
sandstone as the “ Upper Aubrey sandstone,”
the name used at that time for the Coconino
in the Grand Canyon. (See Pis. I, II, IV, C,
and V, B and C.)

The sandstone here called Coconino has been
traced by B. S. Butler,17 F. L. Hess,18 H. E.
Gregory,18 C. R. Long well, and H. D. Miser
practically the entire distance from Cataract
Canyon to the San Juan oil field by way of
White Canyon. The three large natural bridges
in White Canyon are stated by Hess and
Gregory to have been formed in this sand¬
stone. On the San Juan the Coconino is ex¬
posed in a small area on the crest of an
anticline at Zahns Camp, but farther upstream
it is exposed over large areas, being the surface
formation in the part of Moonlight Valley in
which Train and Organ rocks are situated and
also in the broad dissected plateau between
the Clay Hills and the San Juan oil field.
(See PI. IV, A and C.) The eastern part of
the plateau is known as Cedar Mesa. Wood¬
ruff19 states that eastward from Cedar Mesa
the sandstone grades completely into red sandy
shale on the southeast side of the oil field.
This shale and the equivalent sandstone were

17 Butler, B. S., The ore deposits of Utah: U. S. Geol. Survey Prof.
Paper 111, pp 619-620, 1920.

18 Oral communication.

19 Woodruff, E. G., op. cit., p. 86.

included by Woodruff20 and Gregory21 in their
Moenkopi formation. (See Pis. I and II.)

The sandstone is massive and highly cross-
bedded, and its color is creamy white, though
on Cedar Mesa much of it is tan. The grains
are fine to medium in size, and as a rule the
cement of calcium carbonate is sufficient to
make the rock fairly firm, although in places
it is friable. The greatest thickness observed
is in Cataract Canyon, where it measures
nearly 1,000 feet. In the Circle Cliffs only
the top of the formation can be seen, but the
deep well mentioned above penetrates white
sandstone hundreds of feet thick immediately
beneath the Kaibab and then passes through
beds that are probably the equivalent of the
Supai ( ?) formation. The Coconino, as well
as most of the supposed Supai there, consists
of white sandstone, so that these two forma¬
tions can not be separated in the well log.
Their combined thickness is 1,550 feet. Near
the mouth of Moonlight Creek on the San
Juan the thickness of the Coconino is about
600 feet; at the mouth of Slickhorn Gulch,
also on the San Juan, it is about 400 feet;
at Lees Ferry it is 300 feet; in the Grand
Canyon it ranges from 250 to 350 feet; and
to the west it gradually decreases,22 the for¬
mation losing its identity in southern Nevada.23
Thus it is evident that the sandstone thickens
consistently toward the northeast in the area
of its known distribution.

Kaibab limestone. — Typical Kaibab lime¬
stone consisting of white and yellow dolomite
and limestone with numerous chert nodules is
present in the Circle Cliffs, but its thickness is
only 150 feet, as compared with 250 feet at Lees
Ferry, 400 to 600 feet in the Grand Canyon,24 and

I, 000 feet in northwestern Arizona and south¬
western Utah.25 (See PL V, A.) It is not
found in Cataract Canyon, in the Henry Mount¬
ains,26 or along San Juan River. (See Pis. I and

II. ) Thus it appears to thin progressively
toward the northeast, with the thickening

29 Woodruff, E. G., op. cit., pp. 86-87.

21 Gregory, H. E., Geology of the Navajo country: U. S. Geol. Survey
Prof. Paper 93, pp. 29-30, 1917.

22 Reeside, J. B., and Bassler, Harvey, Stratigraphic sections in south¬
western Utah and northwestern Arizona: U. S. Geol. Survey Prof.
Paper 129, pp. 57-58, 1922.

23Longwell, C. R., Geology of the Muddy Mountains, Nev., with a
section to the Grand Wash Cliffs in western Arizona: Am. Jour. Sci.,
5th ser., vol. 1, p. 47, 1921.

24 Noble, L. F., The Shinumo quadrangle, Grand Canyon district,
Ariz.: U. S. Geol. Survey Bull. 549, p. 70, 1914.

25 Reeside, J. B., and Bassler, Harvey, op. cit., pp. 69-76.

26 Gilbert, G. K., Geology of the Henry Mountains, p. 4, U. S. Geog.
and Geol. Survey Rocky Mtn. Region, 1880.

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

9

of the Coconino sandstone in this direction,
suggesting lateral gradation of the limestone
into the sandstone at the top of the Coconino.
It is probable, however, that a large part of
the thinning is due to beveling during the
erosion interval recorded by the unconformity
at the base of the Triassic. This problem is of
•considerable interest, especially to the paleo-
geographer, for under the first interpretation
the Kaibab shore line certainly lay at no great
distance east of the Circle Cliffs, whereas the
alternate explanation permits a much greater
extension of the Kaibab sea eastward. Study
of the Kaibab faunas gives weight to the sug¬
gestion that pre-Triassic erosion beveled pro¬
gressively eastward, for the fauna found in the
Circle Cliffs is of the “ normal Kaibab” type27
and not the upper “ Bellerophon limestone”
fauna. Therefore it is probable that the Kaibab
present in the Circle Cliffs is lower stratigraphi-
cally than the top of the Kaibab in the Grand
Canyon and the “Bellerophon bed” in the Park
City formation of the Uinta country.

EROSION INTERVAL.

A significant unconformity separates the
Paleozoic and Mesozoic sections. There is no
perceptible divergence between beds, but an
unmistakable surface of erosion lies beneath
the Moenkopi formation wherever it has been
studied in Arizona, Utah, and Nevada. The
unconformity is particularly well shown near
Cataract Canyon and about the mouth of
Fremont River, where the top of the Coconino
sandstone forms wide structural platforms.
Recent erosion has stripped away the soft
Triassic sediments, and the more resistant
Coconino preserves large areas of the pre-
Triassic erosion surface almost unchanged,
with patches of the basal conglomerate of the
Moenkopi still adherering to it here and there
in the shallow valleys and rounded divides.
Farther back from the main streams recent
canyons are cut through the contact, revealing
it as a distinct wavy line, overlain by conglome¬
rate in which all the pebbles are of sandstone.

TRIASSIC SYSTEM.

Moenkopi formation. — The Moenkopi forma¬
tion, of Lower Triassic age, comprises thick beds
of shale and sandstone that lieunconformablyon

27 See Reeside, J. B., and Bassler, Harvey, op. cit., pp. 66-67.

the Permian rocks and are at most places uncon-
formably overlain by the distinctive Shinarump
conglomerate. As thus defined the Moenkopi
consists of several members, which vary consid¬
erably in character and thickness from one lo¬
cality to another. The total thickness ranges
from 304 feet in the Circle Cliffs to 920 feet south
of the Henry Mountains and along San Juan
River. No marine fossils have been reported
from the formation in southern Utah, but the
lower beds exhibit a regularity and a uniformity
of texture that suggest deposition in a large
body of water. Farther west and southwest,
in Arizona, southern Nevada, and southwestern
Utah, the lower part of the formation is clearly
of marine origin but the upper part is un¬
mistakably of continental origin.

Along the San Juan the Moenkopi consists
principally of red sandy shale and earthy sand¬
stone, with a little gypsum. (See PL VI, B.)
South and southwest of Piute Farms, on the
river, a thin bed of cream-colored sandstone is
found near the middle of the formation, and
this layer thickens gradually toward the south,
developing into a massive cross-bedded mem¬
ber which in Train Rock has an estimated
thickness of about 200 feet. This sandstone is
apparently the same as the sandstone in south¬
eastern Utah called De Chelly by Gregory.
He treated the De Chelly as a separate forma¬
tion, because in most of the region he studied
south of the San Juan he found it above
Moenkopi shales and immediately underneath
the Shinarump conglomerate. He also found
that the “Oljato sandstone” of Woodruff is
made up of the De Chelly and the Shinarump.
(See PI. I.) The De Chelly sandstone, accord¬
ing to Gregory, is present on the east side of
the San Juan oil field, where it is red and thins
out toward the north. He also states that the
Shinarump conglomerate, wherever it is present
on the east side of the oil field, rests on the
De Chelly sandstone. It appears probable,
therefore, that the upper shales of the Moenkopi
were entirely removed in part of the Navajo
country by pre-Shinarump erosion. An alter¬
nate hypothesis might be that these upper
shales are replaced toward the south by the
thickening of the De Chelly sandstone.

The sandstone that is here tentatively corre¬
lated with the typical De Chelly sandstone of
northeastern Arizona disappears entirely near

10

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

Piute Farms and Clay Hill Crossing on the San
Juan, and it was not recognized in sections for
25 miles north of Clay Hill Crossing.

Along Colorado River below Cataract Canyon
the Moenkopi again shows three distinct divi¬
sions. The lower division, about 400 feet
thick, consists of red and maroon sandstone
and sandy shale in regular beds, with a gray
conglomerate layer at the base. Shaly beds
predominate near the bottom of the section,
forming a slope that steepens upward and
merges into a cliff made of the more resistant
red sandstone. In most sections this cliff is
capped with a layer of cross-bedded gray or
cream-colored sandstone, ranging in thickness
from a few inches to 60 feet. On account of
its persistence and its striking contrast with
the underlying red beds this member forms an
excellent horizon marker. Its stratigraphic
position and lithologic character suggest its
correlation with the De Chelly ( ?) lentil on the
San Juan.

The upper division of the Moenkopi along
this portion of the Colorado consists chiefly of
chocolate-colored, red, and gray shale and
sandstone ranging in thickness from 350 to
nearly 400 feet. Thin-bedded sandstone pre¬
dominates in the lower part, and the proportion
of sandy shale increases upward. The division
as a whole has a weak topographic expression,
forming a concave slope below the Shinarump
cliff. Thin flaggy sandstone layers with strong
ripple marks and current marks recur at short
intervals in the section. Lenticular layers of
cross-bedded sandstone 15 feet in maximum
thickness are also common and form the roofs
of many old cliff dwellings that are built in
reentrants at horizons of shale. All the sand¬
stone beds show evidence of strong fluviatile
action, and the shales were probably deposited
on flood plains or in shallow temporary lakes.
A persistent layer of conglomerate, from a few
inches to 25 feet thick, forms the base of the
upper division and fills erosion channels in the
De Chelly ( ?) sandstone. This distinct ero-
sional unconformity within the Moenkopi is
seen in all sections along Colorado River and
its tributaries from Cataract Canyon to Red
Canyon, where the gradual westward dip car¬
ries the formation below the surface. (See
Pis. V and VII, A.)

Near Lees Ferry, Ariz., the Moenkopi con¬
sists of about 500 feet of red sandy shale and

thin-bedded sandstone with seams of gypsum,
but 50 miles to the south it has numerous
thick beds of red and buff sandstone. Near
Jacobs Pools, 25 miles west of Lees Ferry, 12
feet of greenish-yellow sandy shale and 12 feet
of yellow sandy and gypseous limestone occur
at the top of the formation.

In the Circle Cliffs the Moenkopi consists of
475 feet of chocolate-colored and yellow shale
and sandstone with a few thin beds of hard
limestone near the top. No gypsum was seen
in the formation in this area or along the Colo¬
rado, but secondary veins of gypsum traverse
the Moenkopi shales near Fruita, in Wayne
County, Utah. Only a little gypsum occurs in
the Moenkopi of the San Juan region and near
Lees Ferry, and the general scarcity of the
mineral in the entire region under discussion
is noteworthy in view of the high content of
primary and secondary gypsum found in both
the marine and continental phases of the Lower
Triassic in Arizona, southern Nevada, and
southwestern Utah.

From the foregoing account and from the
columnar sections (Nos. 6 to 9 on PL I) it is
apparent that the Moenkopi of Woodruff and
Gregory in the San Juan region includes not
only the typical or true Moenkopi but also the
Coconino sandstone and the Supai ( ?) for¬
mation.

Shinarump conglomerate. — The remarkable
persistence of the Shinarump conglomerate has
excited the wonder of geologists who have
studied Triassic sections in different parts of
the Colorado Plateau. Within the area under
discussion it is generally present at the base
of the Upper Triassic, lying on the eroded upper
surface of the Moenkopi formation. It is a
massive unit of coarse cross-bedded sandstone,
in which are interspersed lenses of conglom¬
erate that contain small rounded pebbles of
chert, quartzite, and silicified wood. Silicified
logs are abundant, and many plant impressions
were seen on bedding surfaces. The average
thickness of the unit is probably less than 50
feet, but it fills depressions in the underlying
beds and at some localities attains a thickness
of more than 200 feet. Near the mouth of
Nokai Creek on the San Juan the thickness is
220 feet.

The position of the Shinarump conglomerate
between two thick shaly formations gives it a
strong topographic expression on the sides of

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

11

valleys, the edge forming a prominent cliff in
front of a stripped bench and above a pro¬
nounced slope. (See Pis. IV, B\ V, A; VI,
A; and VII.) The formation is made still
more conspicuous in many sections by its dark
color on exposed edges; for although the fresh
sandstone is ordinarily gray, it appears to ac¬
quire an especially dark coat of desert varnish
with long exposure. This characteristic is so
pronounced that the Shinarump is often re¬
ferred to as “the black layer” by prospectors
and others along the Colorado. Deposits of
carnotite in the formation have been mined
at several localities.

The exact conditions under which the Shina¬
rump was deposited have been the subject of
much discussion, and no conclusion appears to
be generally accepted. Whatever the condi¬
tions were, it is evident that they must have
been almost uniform over a very wide region,
for in its essential characteristics the formation
differs little in all the sections studied in Utah, ’
Arizona, and Nevada. The uniformity ex¬
tends even to its thickness, for the total sec¬
tion rarely exceeds 200 feet, and this maximum
applies to very small areas. The lenticular and
cross-bedded structure indicates the action of
shifting streams with fluctuating volume, and
the uniformly small thickness evidently indi¬
cates a nearly even surface with slight eleva¬
tion. It is not probable that the region was a
desert, for the abundance of silicified wood
found in all sections testifies to a climate suit¬
able for the growth of large trees.

Chinle formation. — The Shinarump is be¬
lieved to be the “basal conglomerate” of the
Upper Triassic, for the finer sediments of the
Chinle formation in this region follow without
any apparent break. Thick beds of marly
shale, gray, pink, lavender, yellow, and varie¬
gated, form the most conspicuous part of the
Chinle. Fine-grained sandstone, cherty lime¬
stone, and a few conglomeratic beds are inter¬
calated with the shale. Large silicified logs
are found in sandstone layers at several hori¬
zons, and there are other indications that the
entire deposit is of continental origin. Along
the San Juan the thickness ranges from 800 to
1,000 feet, and at Lees Ferry it is about 1,000
feet thick, but it is much thinner to the north,
averaging 300 feet along the Colorado above
the Waterpocket Fold and 450 feet west of the
Waterpocket Fold. This thinning may be due
33371°— 23 - 3

in part to pre-Jurassic erosion, for an erosional
unconformity at the top of the Chinle is gener¬
ally recognized, especially in the northern lo¬
calities, although it does not appear to be
profound.

Wherever the Chinle is exposed over areas
of considerable size it gives rise to badland
topography. Along the sides of valleys it
forms long slopes, broken by low steps at
horizons of sandstone or limestone layers.
(See Pis. IV, B; V, A; VI, B; VII; and VIII, B.)

Limestone is found in the upper part of the
formation in beds that range from a few inches
to 2 feet in thickness, intercalated with limy
shales. The limestone is dense and hard and
contains an abundance of chert in nodules or
lenses. Layers of intraformational limestone
conglomerate are not uncommon. In most
places the limestone beds are thin and are
limited to a section not exceeding 30 feet in
thickness, but at a few localities the individual
layers average nearly 2 feet in thickness and
make up fully half of a section 50 or 60 feet
thick. Sandstone increases in amount toward
the top of the formation.

JURASSIC SYSTEM.

General features. — Red, brown, tan, and gray
sandstones of Jurassic age form the most
prominent outcrops in the area under consider¬
ation. The units were traced almost contin¬
uously, and their relations for this portion of
the plateau were determined without question.
There still exists some degree of doubt as to
the proper terminology to be applied in the
Jurassic section, however, and the reasons for
this uncertainty will be discussed briefly.

In the eastern part of the Navajo country
Gregory recognized three Jurassic formations,28
which he thought were equivalent to the La
Plata sandstone of southwestern Colorado.
For the lowest unit he adopted Dutton’s term
Wingate sandstone, considering it identical
with the section in the Zuni Plateau,29 to which
this name had been applied, and he called
the upper formation the Navajo sandstone.
In western New Mexico and eastern Arizona
these two thick, cross-bedded formations
are separated by beds of hard limestone
and limy shale, at no place aggregating a

28 Gregory, H. E., Geology of the Navajo country: U. S. Geol. Survey
Prof. Paper 93, pp. 52-59, 1917.

29 Dutton, C. E., Mount Taylor and the Zuni Plateau: U. S. Geol.
Survey Sixth Ann. Rept., pp. 136-137, 1885.

12

SHORTER CONTRIBUTIONS TO GENERAL. GEOLOGY, 1923.

thickness of more than a few feet, but so per¬
sistent that they were recognized as a distinct
unit and named the Todilto formation, from
Todilto Park, N. Mex. In his reconnaissance
survey Gregory was not able to trace the
Todilto continuously to the west, but along
the San Juan and in the vicinity of Navajo
Mountain he recognized a distinct threefold
division that appeared to correspond to the
three formations observed farther east. The
middle unit along the San Juan contains more
sandstone than the typical Todilto, but lime¬
stone and limy shale are present at numerous
places, and the sandstone formations above
and below appear to be identical with the
Navajo and Wingate of western New Mexico.
Accordingly, Gregory applied the name Todilto
to the middle unit tentatively, realizing that
the correlation was not certain but only very
probable.30 His Wingate and Navajo of the
western Navajo country correspond respec¬
tively to Powell’s Vermilion Cliff and White
Cliff sandstones in the region north of the
Grand Canyon and Marble Canyon, but no
intervening formation is recognized in that
region.

Emery worked with Gregory in the eastern
part of the Navajo country and later made a
survey of the Green River Desert, east of the
San Rafael Swell, where he recognized three
distinct Jurassic formations and applied to
them Gregory’s names Wingate, Todilto (?),
and Navajo.31 The Todilto (?) of Emery con¬
tains fossils and is known to be at the horizon
of the marine Jurassic. He noted an apparent
threefold division of his Wingate in different
sections, the middle member consisting of thin-
bedded sandstone and shale; but the height of
these thin beds above the base of the Wingate
varies at different localities, and therefore he
believed that the beds were lenticular and did
not represent a constant horizon. Later work,
however, indicates that the beds occur at a
definite horizon and that the variation in
height above the base of the Wingate merely
represents a variation in thickness of that
formation, perhaps due in part to the uncon¬
formity at the top of the Chinle. The thin-
bedded unit was traced by Mr. Moore along the
San Rafael Swell and the Waterpocket Fold,

30 Gregory, H. E., op. cit., pp. 55-56.

,l Emery, W. B., The Green River Desert section, Utah: Am. Jour.
Sci., 4th ser., vol. 46, pp. 551-577, 1918.

and other contributors to this report followed
the beds continuously in other parts of the
region, tracing them to the San Juan and to
Rainbow Bridge and other localities where the
beds form the unit correlated with the Todilto
by Gregory. (See PI. II.) It appears, there¬
fore, that Gregory’s usage has priority and
should be retained for the present. It remains
for future field work to determine the exact
horizon of the Todilto at the type locality. If
Gregory’s tentative correlation along the San
Juan should prove to be correct, then his
terminology should be kept permanently and
new names should be given to the formations
designated Todilto (?) and Navajo by Emery.
If the type Todilto is found to be at the hori¬
zon of the marine Jurassic, then Emery’s tenta¬
tive usage of the name will be established; but
in that case his use of the names Wingate and
Navajo should be reconsidered, for it appears
that the name Navajo might well be retained
for the sandstone that is typically exposed in
Navajo Canyon and at Navajo Mountain, and
the series of thin beds beneath it (Gregory’s
Todilto of the San Juan) deserves a new
formation name.

In the following descriptions the three names
are used in Gregory’s sense, with the reserva¬
tion suggested above regarding the Todilto.
Emery’s Todilto ( ?) will be referred to as
“ gypsiferous shales and sandstones” and his
Navajo will be designated “varicolored sand¬
stones and shales.” Gregory, during field
work since the publication of his reports on the
Navajo country, has recognized these two units
but has applied only temporary field names to
them.

Wingate sandstone. — The Wingate sandstone
is the most conspicuous cliff-maker in the
region. (See Pis. IV, B; V, A; VI, B ; VII, A ;
and VIII.) It is from 250 to 500 feet thick,
and commonly the greater part of the total
thickness appears as a single massive unit,
which is cut by vertical joints and presents an
impassable wall at the top of Chinle slopes.
In some sections the lowermost beds are len¬
ticular, in part conglomeratic, and apparently
fill slight depressions in Chinle shale. These
lower beds are obviously waterlaid. The mas¬
sive, cliff-making portion, which averages about
300 feet in thickness, has indistinct and dis¬
continuous bedding and is cross-bedded on a
large scale. These structural characteristics,

U. S. GEOLOGICAL SUliVEY

PROFESSIONAL PAPER 132 PLATE VII

A. CASTLE BUTTE, NEAR MOUTH OF RED CANYON, UTAH.

1, Shale of upper member of Moenkopi formation; 2, Shinarump conglomerate; 3, Chinle formation; -I, Wingate

sandstone. Photograph by C. R. Longwell.

■ --■'s

B. VIEW LOOKING NORTH ACROSS COLORADO RIVER AT LEES FERRY, ARIZ.

Small rounded knoll to loft stands on Shinarump conglomerate, which dips east. All the higher beds to the right
form entire thickness of Chinle formation. Vermilion Cliffs in left background. Photograph by Robert N.
Allen.

U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE VIII

A. VIEW LOOKING NORTHWEST UP COLORADO RIVER TOWARD PROPOSED DAM SITE NEAR

LEES FERRY, ARIZ.

Cauyou walls are formed by Wingate and Navajo sandstones. Todilto (?) formation is apparently absent. Photograph

by Kirk Rryan.

B. VIEW FROM POINT HALF A MILE SOUTH OF SPENCER CAMP, LOOKING SOUTH DOWN
SAN JUAN CANYON TOWARD NAVAJO MOUNTAIN, UTAH.

Canyon has been cut in Navajo, Todilto (?), Wingate, and Chinle formations. Photograph by Robert N. Allen.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 132 PLATE IX

A. VIEW LOOKING NORTHEAST TOWARD WILSON MESA FROM POINT ON WILSON CREEK

NEAR SAN JUAN CANYON, UTAH.

Showing bare domes and “mosques” of Navajo sandstone. Todilto (?) formation underlies platform in foreground.

Photograph by Robert N. Allen.

B. VIEW LOOKING ACROSS COLORADO RIVER OPPOSITE SMITHS FORK, UTAH.
Showing colossal domes of Navajo sandstone. Photograph by Sidney Paige.

C. SHEER CLIFF OF NAVAJO SANDSTONE AT WARM SPRING CREEK ON COLORADO RIVER,

UTAH.

Photograph by Sidney Paige.

GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE

VIEW OF WATERPOCKET FOLD AND CRETACEOUS PLATEAUS BETWEEN THE CIRCLE CLIFFS AND THE HENRY MOUNTAINS, UTAH, AND SKETCH

SHOWING THE SURFACE DISTRIBUTION OF THE ROCK FORMATIONS.

ROCK FORMATION'S IF THE COLORADO PLATEAU OF UTAH AFD ARIZONA.

13

as well* as the universal fineness and roundness
of grain, suggest an eolian origin for this prin¬
cipal member. The only fossils reported from
the formation are a few dinosaur tracks
observed by Mr. Miser on surfaces of the lower
lenticular beds at a locality several miles above
the mouth of San Juan River.

The color of the sandstone on exposed sur¬
faces gives the cliffs a striking appearance even
in a “painted desert”; but the color is reddish
brown rather than vermilion as suggested by
the old formation name. On unweathered sur¬
faces the rock is typically buff-colored, the
darker shade ordinarily seen on cliffs resulting
from weathering.

This sandstone forms the Vermilion Cliffs in
western Kane County, Utah. Together with
the overlying Todilto ( ?) formation it corre¬
sponds in age to Gilbert’s Vermilion Cliff group
in the Henry Mountains.32 But the massive
sandstones of the Vermilion Cliffs near Lees
Ferry, Ariz., and of the Echo Cliffs are made up
not only of the Wingate sandstone but of the
Navajo sandstone; the Todilto (?) formation
has not been recognized and is apparently
absent there.

Todilto ( ?) formation— The character of de¬
posits in the formation tentatively correlated
with the Todilto varies considerably both ver¬
tically and horizontally; but the formation is
sharply distinguished from the underlying and
overlying sandstones by comparative thinness
of beds and by undoubted evidence of deposi¬
tion in water. Measured sections of the forma¬
tion in the region under discussion range from
125 to 249 feet in thickness. Layers of flinty
limestone and of calcareous shale are present in
most localities, except perhaps to the north and
west, but everywhere sandstone makes up the
greater part of the thickness. The lower part is
commonly very lenticular and contains consider¬
able conglomerate with small sandstone pebbles.
These beds, as well as others higher in the forma¬
tion, were probably deposited by streams with
rapid, shifting currents. The layers of shale
and limestone are found for the most part in
the middle and upper portions. The shale
forms a zone of weakness that commonly causes
the overlying Navajo sandstone to retreat be¬
hind the Wingate cliffs, leaving benches floored
by the lower resistant sandstone of the

Todilto (?). (See Pis. VIII, B, and IX, A.)
The limestone beds are lenticular and range from
a few inches to 2 feet in thickness. The material
is dense, hard, and cherty and is probably of
fresh-water origin.

In some sections the transition from the
massive Wingate to the thinner beds above ap¬
pears to be gradual, but at many localities along
the Colorado a distinct erosional unconformity
separates the two formations, lenticular fluvia-
tile beds filling valleys on the surface of the
Wingate. In a cliff the lower sandstones of
the Todilto ( ?) are readily distinguished from
the light-colored Wingate by their dark-maroon
or reddish-brown color. At higher horizons
the Todilto (?) beds vary in color through
shades of brown, tan, and lavender. The lime¬
stone layers are usually gray.

Navajo sandstone. — Many of the picturesque
and grotesque erosion forms common in south¬
ern Utah and northern Arizona are carved in
the Navajo sandstone of Gregory, which is es¬
sentially equivalent to Gilbert’s “Gray Cliff
group” and to Powell’s White Cliffs sandstone.
It is exposed over large areas along the Colo¬
rado and the San Juan, in the Waterpocket
Fold and the Circle Cliffs, and farther west in
south-central Utah and forms great tracts of
almost impassable badlands, in which domes,
“mosques,” and “minarets” are common fea¬
tures. (See Pis. VI, B; VIII, and IX.)
Caves, alcoves, and arches are conspicuous in
cliffs of this sandstone, and it forms a number of
natural bridges, notably the Rainbow and Owl
bridges, near Navajo Mountain.

The thickness varies between wide limits,
reaching a reported maximum of 1,800 feet in
western Kane County, Utah, and a minimum of
about 500 feet south of the Henry Mountains.
Along the Colorado and the San Juan the thick¬
ness is commonly from 600 to 800 feet, but a few
sections measure 1,000 feet. From the Water-
pocket Fold westward the thickness is generally
above 1,000 feet. There is also a marked
change in color from east to west. From the
Waterpocket Fold westward a large part of the
formation is commonly gray or creamy white,
whereas in the region south of the Henry
Mountains, around Navajo Mountain, at Lees
Ferry, and in Comb Ridge the sandstone is
typically tan or buff.

This sandstone is frequently cited as a
typical eolian deposit. Cross-bedding of the

32 Gilbert, G. K., Report on the geology of the Henry Mountains,
pp. 5-7, U. S. Geog. and Geol. Survey Rocky Mtn. Region, 1880.

0

14

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

“ tangential” type and on a very large scale
characterizes the greater part of the formation,
and the laminae of the cross-bedded structure
show the abrupt and repeated truncation so
commonly seen in “ living” sand dunes. True
bedding planes are present but not distinct,
so that the entire formation stands in some
cliffs with the appearance of a single massive
layer. Beds of compact limestone from 2 to 5
feet thick lie at several horizons but chiefly in
the upper half of the formation. These beds
extend laterally from a few hundred feet to
half a mile and probably represent deposition
in shallow pans or basins. In view of the
general high porosity of the sandstone, it
would seem that these deposits required a
high ground-water level, at least locally.

Gypsiferous shales and sandstones. — The series
of beds here designated gypsiferous shales and
sandstones is exposed at Bluff, in the Henry
Mountains, and farther north, between Kaipa-
rowits Plateau and Escalante River and along
the Colorado below the mouth of the San
Juan almost to Lees Ferry. (See PI. X,A.)
It is also found west of the Kaiparowits Plateau
at several localities, notably in western Kane
County, Utah, where it is apparently repre¬
sented by about 100 feet of bluish-gray marl
with considerable gypsum. In typical sections
the beds consist of gypsiferous shale inter¬
calated with layers of sandstone and .some
limestone, with an average total thickness of
about 75 feet. In 1918 W. B. Emery 33
studied these beds in the Green River Desert and
reported the occurrence of marine Jurassic
fossils in some of the limestone layers. This
fossiliferous series had been noted previously by
Gilbert 34 and by Lupton.35 In some sections
there are indications of an unconformity be¬
tween these beds and the underlying Navajo
sandstone.

The beds deserve a formation name, but it
appears best to postpone assigning a definite
name until the Todilto problem, discussed
above, has been finally solved by further field
work.

Varicolored sandstones and shales. — The thick
series of beds here termed varicolored sand¬
stones and shales includes the greater portion
of the rocks in Gilbert’s “ Flaming Gorge

33 Op. cit., pp. 568-569.

31 Gilbert, G. K., Geology of the Henry Mountains, p. 6, 1880.

33 Lupton, C. T., U. S. Geol. Survey Bull. 628, p. 24, 1916.

group.” These beds reach a maximum thick¬
ness of approximately 1,430 feet in the Water-
pocket Fold. (See PL X, A.) Along Colorado
River between the mouth of the San Juan and
the Crossing of the Fathers the series appears
to have a thickness as great as 500 feet, and
near Bluff it is from 170 to 270 feet thick.
Complete and partial sections are exposed at
many localities south and west of the Henry
Mountains and northeast of the Kaiparowits
Plateau. The series contains a massive cross-
bedded sandstone member, tan, red, and gray,
which has some resemblance to the typical
Navajo sandstone. Other parts of the section
consist of thin-bedded sandstone, much of it
shaly. East of the Waterpocket Fold the
predominant colors are red and tan, but in
western Kane County, where the stratigraphic
position of the series is occupied chiefly by
sandy shale, many of the beds are gray and
bluish gray.

Emery considers that this series of beds, as
well as those at the horizon of the marine
Jurassic, corresponds to the La Plata sandstone
of Cross. Gregory limits the La Plata group
to his Wingate, Todilto, and Navajo forma¬
tions.

McELMO FORMATION (CRETACEOUS?).

The McElmo formation, of Cretaceous (?)
age, is exposed near Bluff, where it consists of
gray, red, and green shale and thin beds of
sandstone with two heavy conglomeratic layers,
making an incomplete section several hundred
feet thick. At places these conglomerates con¬
tain carnotite deposits. Along the Colorado
below the San Juan partial sections of the for¬
mation are made up chiefly of a massive cliff¬
making greenisli-gray sandstone, in part con¬
glomeratic. In western Kane County the Mc¬
Elmo appears to be represented by a coarse
conglomerate of undetermined thickness.

CRETACEOUS SYSTEM.

Rocks of known Cretaceous age, all probably
belonging to the Upper Cretaceous series, are
represented in southern Utah by exposures in
the vicinity of the Henry Mountains, along the
southern border of the High Plateaus in west¬
ern Garfield and Kane counties, and in a
southeastward projection, of which Kaiparo¬
wits Plateau is the chief part, extending into
eastern Kane County. (See PI. X, A and B.)

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

15

The total thickness of the Cretaceous section
in this region is about 3,500 feet. The rocks
consist of alternating divisions of bluish-drab
shale and yellowish-brown sandstone, the
former appearing in slopes and badlands, the
latter in more or less prominent escarpments
and hogback ridges. They are divisible into
seven distinct units, the basal one of which is
doubtfully correlated with the Dakota sand¬
stone. To the rocks above this basal sand¬
stone Gilbert applied the following local names,
in ascending order: Tununk shale, Tununk
sandstone, Blue Gate shale, Blue Gate sand¬
stone, Masuk shale, and Masuk sandstone.
These names were derived from geographic
features in the Henry Mountains. As duplica¬
tion of names is contrary to the practice of
the United States Geological Survey, only
Gilbert’s names for the sandstones have been
adopted, and in this report his names for the
shales will be used in quotation marks, be¬
cause of the doubt regarding the relations of
this whole succession of sandstone and shale
to named units to the north and east. In the
present state of knowledge Mr. Moore tenta¬
tively correlates the “ Tununk shale,” Tununk
sandstone, and "Blue Gate shale” with the
Mancos shale of southwestern Colorado and
east-central Utah. The Blue Gate sandstone
he tentatively correlates with the Mesaverde
formation, the “ Masuk shale” with the Lewis
shale, and the Masuk sandstone with the so-
called “ Laramie” sandstone of southwestern
Colorado. Some geologists, however, believe
that the whole succession corresponds to the
Mancos shale.

Dakota ( ?) sandstone. — As in most of the
Cretaceous sections of the Rocky Mountain
and Plateau region, there is present in southern
Utah a basal sandstone and conglomerate
which appears to be homotaxially equivalent
to the Dakota sandstone. This sandstone
attains a thickness of 100 feet in the escarp¬
ment of Kaiparowits Plateau, but in the Henry
Mountains district it is much thinner and in
places is absent. It evidently overlies the
beds beneath it unconformably, for the upper
surface of the McElmo is somewhat uneven, the
thickness of the upper division of the McElmo
is variable, and at one place a slight fold in the
McElmo strata was found to have been trun¬
cated before the deposition of the sandstone.

To these evidences may be added the conglom¬
eratic character of the formation. The color
of the Dakota ( ?) sandstone is yellowish brown
to white. The bedding is irregular. Locally
thin beds of lignite are present.

“ Tununk shale. ” — The formation above the
Dakota (?) sandstone consists of bluish-drab
argillaceous and in part sandy shale, called
“Tununk shale” by Gilbert. The shale is
900 to 1,000 feet thick in exposures east of the
Waterpocket Fold. It is very sandy and
grades at the base into extremely fossiliferous
brown sandstone. The shale is also fossilifer¬
ous, containing especially large numbers of
Gry'phaea newberryi.

Tununk sandstone. — The sandstone over-
lying the shale just described was called
Tununk sandstone by Gilbert. It has a
maximum observed thickness of about 100
feet. It is well developed in the vicinity of the
Henry Mountains and appears to be present
in the Kaiparowits Plateau but was not found
southwest of Table Cliff Plateau in western
Garfield County. It is light yellowish brown,
is irregularly bedded, and locally contains
some lignite.

“Blue Gate shale .” — Overlying the Tununk
sandstone is a shale formation 1,100 to 1,200
feet thick, which resembles the “Tununk
shale” in texture and color but lacks the
numerous fossils that are characteristic of the
“Tununk.” To this shale Gilbert applied
the name “Blue Gate shale.”

Blue Gate sandstone. — A prominent creamy-
yellow to light-brown massive and irregularly
bedded sandstone succeeds conformably the
shale just described. Its thickness in the
Henry Mountains, where it was named the
Blue Gate sandstone by Gilbert,36 is 250 to 500
feet, but in the Kaiparowits Plateau and west
of Escalante the thickness of this formation
is at least 1,000 feet. The sandstone contains
lignite, which locally is of very good grade and
reaches a thickness of 4 feet west of Mount
Ellen. No fossils were obtained from this
sandstone, but Lee 37 has suggested that it is
comparable with the Mesaverde. It is ex¬
tremely improbable that this sandstone could
represent the Ferron sandstone of Castle

s6 Gilbert, G. K., op. cit., p. 4.

37 Lee, W. T., Relation ,of the Cretaceous formations to the Rocky
Mountains in Colorado and New Mexico: U. S. Geol. Survey Prof. Paper
95, p. 50, 1915.

16

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

Valley, as suggested by Lupton.38 The Ferron
occurs about 600 feet above the base of the
Mancos as there identified and is overlain by
3,000 feet of Mancos shale, whereas this sand¬
stone is 2,200 feet above the base of the Mancos
and, as seen in the Henry Mountains, is suc¬
ceeded by only a few hundred feet of shale.
The Cretaceous section of southern Utah
appears to be intermediate in character between
those of southwestern Colorado, northwestern
New Mexico, and northern Arizona and those
of central and northern Utah.

“ Masuk shale.” — Above the Blue Gate
sandstone is a light-drab, very sandy shale,
which in the Henry Mountains area has a
thickness of 500 to 700 feet and to which
Gilbert applied the name “Masuk shale.”
Below Table Cliff Plateau, in western Garfield
County, the thickness of this shale is un¬
determined but is probably more than 1,000
feet. The upper part of the shale contains
thin beds and lenses of brown sandstone and
appears to grade without break into the over-
lying formation, the Masuk sandstone.

Masuk sandstone. — The uppermost Creta¬
ceous formation in the region is a massive
yellowish-gray sandstone, which east of the
Circle Cliffs appears in a prominent table-land
bounded by high, sheer cliffs. Its thickness
is about 300 feet according to measurements
made at its west margin, but Gilbert 39 reports
a thickness of 500 feet.

TERTIARY SYSTEM.

In the High Plateaus are found exposures of
the youngest stratified rocks of the region,
comprising pink, lavender, white, and vari¬
colored limestones, sandstones, and shales of
Eocene age. These rocks, which in Garfield
and Kane counties have been referred to the
Wasatch formation, appear in vertical cliffs
and in the fantastically carved, brilliantly
tinted walls of canyons that head along the
margins of the plateaus. The thickness of the
Tertiary sequence in this region is about 2,000
feet. Much of it, especially toward the north,
is buried beneath a great accumulation of
extrusive igneous rocks.

The Tertiary beds rest with very great
unconformity on the Mesozoic rocks, the
unconformity being angular as well as erosional.
The base of the Tertiary is found in contact

38 Lupton, C. T., Geology and coal resources of the Castle Valley, Utah:
U. S. Geol. Survey Bull. 628, p. 32, 1916.

39 Gilbert, G. K., op. cit., p. 4.

successively with all the formations from the
highest Cretaceous to the Navajo sandstone,
and much of the Navajo was in places removed
before Eocene sedimentation. It therefore
appears that an important deformative move¬
ment, in which such structural features as the
Waterpocket Fold, the Circle Cliffs dome, and
the gentle flexures south of Table Cliff Plateau
were formed, followed Cretaceous deposition,
and that before the deposition of the Tertiary
strata began this deformed rock series had
been planed off by erosion to a nearly level
surface, a denudation involving the removal
in places of rock strata some thousands of feet
in thickness.

LOCAL SECTIONS.

General section of rocks near Lees Ferry, Ariz.

Feet.

(?)

[Measured by Kirk Bryan.]

Brown thin-bedded sandstone and shale,
which are probably the equivalent of the

beds of marine Jurassic farther north .

Navajo and Wingate sandstones: Massive tan¬
gentially cross-bedded red to buff sand¬
stone. No parting visible at the center,
but upper half has lenses of dense gray
limestone 6 inches to 3 feet thick at inter¬
vals, and near the top nodules of limonite
the size of peas are common. In the Ver¬
milion Cliffs the upper half is distinctly
lighter in color. The Todilto (?) formation

is apparently absent . 1, 100-1, 200

Chinle formation: Blue, green , and red shale;
white, gray, purple, and red sandstone;
and cherty limestone. Upper part con¬
sists of heavy-bedded sandstone and red

shale; lower part contains fossil wood .

Shinarump conglomerate : Gray conglomerate
with lenses of sandstone and shale; much

fossil wood .

Unconformity.

Moenkopi formation: Red sandy shale and
thin-bedded sandstone with seams of gyp¬
sum. In places has beds of red and gray
sandstone 2 to 6 feet thick, and in one local¬
ity 12 feet of gypsiferous limestone at the
top. Base, generally, 1 to 10 feet of chert

conglomerate .

Unconformity.

Kaibab limestone: Yellow limestone with
numerous more or less rounded nodules of

chert .

Coconino sandstone: Gray cross-bedded mas¬
sive sandstone .

Unconformity (?).

Hermit (?) shale: Red shale

and sandstone .

Unconformity (?) (not ob¬
served).

Supai formation: Red shale
with beds of blue limestone.

1, 000 ±

0-40

(observed) . .

500 ±

250

300

500 ±

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

17

Section about 8 miles southeast of Piute Farms on San

Juan River.

[Measured by H. D. Miser.]

Wingate sandstone : Feet.

Massive cross-bedded tan sandstone forming
sheer cliff; cut by numerous vertical joints;

face of cliff is stained dark brown . 270

t Coarse brown sandstone with pebbles of shale

and sandstone up to 2 inches in diameter .... 4

Chinle formation: Green and pink marly clay with
beds of mottled pink and gray compact limestone
as much as 4 feet thick in upper part. Some of
the limestone is conglomerate. Pebbles in con¬
glomerate are limestone. Pink and gray flint
on slope may have been derived from weathering
of limestone. Some parts of clay contain irreg¬
ular concretions of calcareous earthy material. . . 830

Shinarump conglomerate: Massive gray sandstone. . 10

Moenkopi formation :

Chocolate-colored shale with some green shale
in upper half; light chocolate-colored shale
with some thick beds of brown fine-grained

sandstone in lower half . ' . . . 340

Brick-red sandy shale and earthy sandstone in
beds of uniform thickness. The De Chelly (?)
sandstone is absent at this place but wedges
in farther south near the top of this part of

the formation . 500

Moenkopi or Coconino: “Transition beds” like
those described in section at Zahns Camp.
Coconino sandstone.

Section at Zahns Camp on San Juan River.

[Measured by H. D. Miser.]

Chinle formation : Variegated marly shale. Feet.

Shinarump conglomerate: Massive gray pebbly
sandstone; forms cliff . 50

Coconino sandstone: Massive cross-bedded cream- Feet,
colored sandstone. Two beds of brown sandy
shale aggregating 3 feet near the top. Exposure of
sandstone extends down to San Juan River . 55

Section on San Juan River north of Spencer Camp.

[Measured by H. D. Miser.)

Navajo sandstone: Cream-colored to yellow massive
cross-bedded sandstone .

Feet.
200 +

Todilto (?) formation:

Brown fine-grained shaly sandstone with

lavender cast . 170

Lenses of conglomerate as much as several feet
thick; conglomerate composed of sandstone

pebbles in sandy matrix .

Lavender, brown, and buff fine-grained sand¬

stone in comparatively thin layers . 50

Total thickness of Todilto (?) formation. 220
Wingate sandstone: Buff fine-grained cross-bedded

sandstone; no conglomerate at base . 330

Chinle formation: Variegated marly shale; con¬
cealed almost everywhere by landslides. Forma¬
tion extends to river, and base is not exposed .... 510

Section on north side of San Juan River just above its junc¬

tion with the Colorado.

[Measured by H. D. Miser.]

Navajo sandstone: Feet.

Gray thin-bedded very fine grained limestone;

forms flat top of small mesa . 4^

Buff massive cross-bedded sandstone . 310

Todilto (?) formation: Dark and light brown sand¬
stone in comparatively thin beds . 200

Wingate sandstone: Buff sandstone to water’s edge
of San Juan River . 10+

Moenkopi formation:

Chocolate-brown sandy shale with a smaller
amount of brown shaly and platy sandstone;

forms steep slope . 325

Brick-red sandy shale and earthy sandstone in

even-bedded layers. . . . 55

Cream-colored cross-bedded massive sandstone;

De Chelly (?) sandstone lentil . 90

Brick-red sandy shale and a smaller amount
of red earthy sandstone in even-bedded
layers . 450

Total thickness of Moenkopi formation .... 920

Moenkopi or Coconino (“transition beds”):

Heavy gray sandstone . . 5

Brown sandy shale and brown shaly sandstone.

A bed of gray limestone 1 foot or more thick

near top . 45

Massive gray sandstone . 6

Brown sandy shale . 5

Massive gray sandstone . 4

Brown sandy shale and brown earthy sandstone.
Contains one or two thin beds of gray lime¬
stone . 24

89

Section on Colorado River near the mouth of Fremont River.

[Measured by C. R. Longwell. The canyons of Colorado and Fremont
rivers are cut in the Coconino sandstone. Above the canyons there
is a wide stripped bench on the Coconino, with scattered buttes of
the Moenkopi formation.]

Moenkopi formation : Feet.

Conglomerate at base of upper member of for¬
mation. Contains angular pebbles of chert,
with maximum length of 2 inches, also a few
fragments of silicified wood. Firmly ce¬
mented by calcium carbonate . 15

Unconformity.

Gray sandstone, medium to coarse, strongly
cross-bedded throughout. Conspicuous by
contrast with red sandstone below. De

Chelly (?) lentil . 40

Regular beds (a few with cross laminae) of red to
maroon sandstone, averaging several feet in
thickness, of fine, uniform grain. A ’few
shaly layers, forming narrow benches in cliff. 158
Heavy bed of cross-bedded pink to tan sand¬
stone; persistent, good horizon marker; fine

uniform grain . 28

Heavy bed of reddish-brown sandstone, grad¬
ing into gray at the base . 6

Total thickness of “transition beds”

18

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

Moenkopi formation — Continued. Feet.

Fine-grained maroon and red sandstone and
sandy shale in regular beds from 6 to 30 inches

thick; form steep interrupted slope . 115

Red sandy shale, with some layers of cross-
bedded fine-grained sandstone; forms slope;

muscovite abundant . 45

Massive white to gray sandstone, with medium

grain . 2

Gritty shale and fine-grained sandstone, red to
light brown . 22

Incomplete thickness of Moenkopi forma¬
tion . 431

Unconformity.

Coconino sandstone: Gray and tan sandstone, of fine
to medium grain, in massive beds and with cross¬
bedding on large scale. Forms walls of Narrow
Canyon and Dirty Devil Canyon. Base not ex¬
posed.

Section on Colorado River near mouth of Crescent Creek
(“North Wash”).

[Measured by C. R. Longwell.]

Feet.

Wingate sandstone forms a sheer cliff at least 300 feet
high, at top of the steep slope on which the

Chinle formation is exposed . 300+

Chinle formation :

Regular beds of pink sandstone, 6 inches to 2

feet thick . 12

Coarse sandstone, pink to tan, cross-bedded _ 25

Gritty shale and fine-grained sandstone, in

thin layers . . . 10

Gray calcareous sandstone . 1

Pink sandstone in thin beds . 27

Massive layer of gray to buff sandstone . 6

Calcareous shale in massive layers, containing
more or less grit, with a few intercalated

thin layers of fine-grained sandstone . 155

Heavy bed of dense gray limestone, with chert

lenses and nodules . 4

Pink calcareous shale . 24

Alternating layers of gray limestone and pink¬
ish shale. Limestone layers average 2 feet in
thickness and are dense, with abundance of

chert . 27

Gray, lavender, and yellow shale, banded,
with a few thin sandy layers . 102

Total thickness of Chinle formation . 393

Shinarump conglomerate: Massive coarse-grained,
cross-bedded sandstone, with lenses of conglom¬
erate ; contains abundance of silicified wood . 35

Unconformity.

Moenkopi formation :

Lavender, pink, and greenish shale, with a few
sandstone layers; green layers prominent

near top . 72

Gray and yellow sandy shale and fine-grained

sandstone . 6

Bright-red clay shale . 22

Gray, lavender, and yellow shale, with a few
bands of dense gray limestone . 60

Moenkopi formation— Continued. Feet_

, Red and pink sandy shale and fine-grained

sandstone . . . * . 70

Fine-grained cross-bedded red to pink sand¬
stone . 2

Alternating layers of gray sandstone and red
shale ; shale papery, sandstone ripple marked . 1 7

Alternating layers of red and brown sandstone
and sandy shale; sandstone layers have cur¬
rent and ripple marks, also a few rain prints;

partings of brown paper shale . 55

Single bed of massive cross-bedded' light-brown

sandstone . 22

Alternating layers of red and brown sandstone
and sandy shale; sandstone layers have cur¬
rent and ripple marks, also a few rain prints. 65
Alternating thin beds of gray sandstone, with

very thin partings of brown shale . 6

Light-brown conglomeratic sandstone . 2

Alternating thin beds of gray sandstone, with

very thin partings of brown shale . 2

Light-brown conglomeratic sandstone . 2

Alternating thin beds of gray sandstone, with

very thin partings of brown shale . 4

Light-brown conglomeratic sandstone . 3

Alternating thin beds of gray sandstone, with

very thin partings of brown shale . 9

Massive gray cross-bedded sandstone . 3

Alternating thin beds of sandstone and shale,

yellow, red, brown, and lavender . 9

Firmly cemented conglomerate with angular
pebbles of chert and hard sandstone: frag¬
ments of lustrous coal and of silicified wood

also occur as pebbles . 10

Total thickness of upper member of

Moenkopi formation . 441

Unconformity.

Massive gray sandstone, with marked cross¬
bedding, loosely cemented with calcium
carbonate. De Chelly (?) sandstone lentil.. 35
Typical red and maroon beds of lower member.

Section on Colorado River below mouth of Crescent Creek.

[Measured by C. R. Longwell.]

Navajo sandstone: Tan and buff sandstone, cross-
bedded on large scale. The sandstone of this
locality is an isolated remnant capping a high
point . ^ .

Feet.

300

Todilto (?) formation:

Alternating regular beds of calcareous sand¬
stone and gritty shale, wdth a few layers of
limestone conglomerate. Two of the sand¬
stone layers are cross-bedded and tan. Other

beds are pink, gray, and lavender. Form

long slope . 77

Thin layers of red and maroon sandstone, cross-

bedded . 60

Light-brown and gray cross-bedded sandstone;
friable, forming slope; contains hard, con¬
cretionary nodules . 22

Total thickness of Todilto (?) formation. . 159

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

19

Unconformity (?). Feet.

Wingate sandstone :

Tan and light-brown cross-bedded sandstone,

forming cliff . 85

Conglomerate, with pebbles and boulders of
sandstone as much as 2 feet in diameter, also

pebbles of red clay; calcareous cement . 0-4

Massive cross-bedded sandstone, forming al¬
most unbroken cliff. Tan on fresh surfaces,
reddish brown on weathered face . 280

Total thickness of Wingate sandstone. . . 369

Chinle formation : Forms a long slope below the cliff
of the Wingate sandstone.

Section on Colorado River near month of Trachyte Creelc.

[Measured by C. R. Longwell.J

Feet.

Shinarump conglomerate: Coarse-grained gray con¬
glomeratic sandstone, with abundance of silicified
wood. Forms low cliff, with shelf above . 5-15

Unconformity.

Moenkopi formation:

Alternating layers of gray sandstone and green¬
ish shale . 5

Lavender, gray, and pink calcareous shale. ... 25

Fine-grained brown sandstone . 3

Gray ‘ 1 marl , ’ ’ sandy near base . 55

Gray cross-bedded sandstone . 3

Greenish-gray and pink shale, paper-thin . 4

Bright-red clay shale . 5

Yellow, lavender, pink, and gray “marly”

shale, in thick beds . 60

Alternating chocolate-colored shale and gray
to brown sandstone, in thin layers. Ripple

marks abundant . 60

Massive brown sandstone with strong current

marks . 2

Alternating chocolate-colored shale and gray to

brown sandstone . 8

Massive sandstone . 2

Chocolate-colored sandy shale . 6

Massive cross-bedded sandstone . 2

Gray sandstone and chocolate-colored shale, in

alternating thin layers . 4

Massive gray to brown cross-bedded sandstone. . 8

Alternating chocolate-colored shale and gray to
brown sandstone, with strong ripple marks. . 22

Light-brown cross-bedded sandstone . 5

Chocolate-colored sandy shale . 10

Thick layers of sandstone, with thin partings

of chocolate-colored shale . 11

Alternating gray sandstone and chocolate-

colored shale . 18

Heavy layers of cross-bedded current-marked
sandstone, with thin shale partings; sand¬
stone gray to brown, shale dark chocolate-

colored . 12

Brown fine-grained sandstone, with thin lami¬
nation . 6

Heavy layers of pink cross-bedded sandstone,

with shale partings . 16

Alternating gray sandstone and brown shale;
abundant ripple and current marks . 22

Moenkopi formation — Continued. j-eeh

Fine-grained sandstone with shaly lamination. . 9

Firmly cemented conglomerate containing
angular pebbles of chert and hard sandstone . . 2

Total thickness of upper member of

Moenkopi formation . 385

Unconformity.

De Chelly (?) sandstone lentil (gray to pink

cross-bedded sandstone) . 20

Typical red beds of the lower member.

Section on north side of Twomile Canyon, directly east of
Mount Holmes , in the Henry Mountains.

[Measured by C. R. Longwell.]

Navajo sandstone: Massive tan sandstone, capping
a rounded hill .

Feet

250

Todilto (?) formation:

Massive fine-grained cross-bedded lavender

and gray sandstone . 18

Purple and gray shale; forms slope . 10

Massive cross-bedded brown sandstone, me¬
dium to coarse . 9

Red and brown sandy calcareous shale with
thin layers of dense gray limestone; forms

slope . 40

Brown and gray heavy-bedded sandstone with

calcareous cement . 27

Pink sandy shale; forms slope . 14

Gray sandstone and pink sandy shale in alter¬
nating beds . 11

Reddish-brown and gray medium to fine
grained sandstone in heavy layers, some
with cross-bedding. Calcareous cement.

Layers of unequal resistance, forming steep
slope. All beds lenticular; a few lenses
conglomeratic . 120

Total thickness of Todilto (?) formation. 249
Unconformity.

Wingate sandstone: Tan to reddish-brown sand¬
stone, chiefly in unbroken cliff. Large-scale
cross-bedding . 366

Unconformity (?).

Chinle formation:

Alternating layers of hard fine-grained sand¬

stone and pink sandy shale . 14

Pink shale , with a few layers of gray sandstone . 22

Gray conglomeratic sandstone, with small

pebbles of chert and hard sandstone . 2

Heavy bed of fine-grained pink sandstone,

loosely cemented . 8

Varicolored calcareous shale, with a few sand¬
stone layers . 40

Cross-bedded gray sandstone, conglomeratic at

base; contains silicified logs . 6

Pink and yellow calcareous shale, sandy near

top . 17

Hard gray limestone, containing chert nodules. 2

Lenticular layers of gray sandstone with part¬
ings of shaje . 10

Pink and yellow gritty shale . 20

20

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923.

Chinle formation — Continued. Feet.

Gray and lavender “marlL” beds, jointed . 34

Cross- bedded gray and lavender sandstone ... 15

Massive fine-grained sandstone, rich with cal¬
cium carbonate and containing cherty

nodules . 6

Brick-red gritty shale, with layers of gray

sandstone . 28

Pink and gray calcareous shale or “marl,” ap¬
pearing massive . 80

Gray and purplish sandy shale in thin beds. . . 16

Total thickness of Chinle formation .... 320

Shinarump conglomerate: Coarse conglomeratic
massive and cross-bedded sandstone with lenses
of conglomerate; abundance of silicified logs;
plain impressions of plants on bedding surfaces.

Forms vertical cliff . 60-120

Unconformity.

Moenkopi formation: Greenish shale immediately
below unconformity. Forms slope.

Section of Chinle formation at north end of prominent Win-
gate-capped outlier west of South Fork of Silver Falls
Creek, in the Circle Cliffs.

[Measured by R. C. Moore.]

Wingate sandstone: Reddish-brown fine-grained
cross-bedded, very massive sandstone, forming
single vertical wall; prominently jointed; basal
few feet horizontally bedded in thin layers, with
ripple marks measuring about 6 inches from crest
to crest; thickness estimated .

Feet.

250

Chinle formation:

Soft limestone, lavender mottled with light
greenish blue, weathering in very irregular
fragments; partly covered with debris; upper
part oxidized and stained to dark purple
beneath Wingate sandstone and along joints . 5

Light-bluish conglomerate, mostly rather fine¬
grained; pebbles consist almost entirely of
limestone like the associated limestones of
the Chinle formation, but there are some
flint, quartz, and ironstone pebbles as much
as 1 1 inches in diameter; upper part grades
into very coarse limestone grit, with lines
and lenses of fine conglomerate; very mas¬
sive ; crops out in prominent bench . 28

Soft shaly limestone, light greenish blue and
lavender, mottled; contains locally harder
limestone in beds 6 to 10 inches thick which
project; this division weathers in a slope. . . 70

Very hard dense fine-grained limestone, light
bluish in lower part with mottling of lavender,
massive and uniform ; locally contains cal cite
crystals ; except for lower part, which is some¬
what softer, this bed forms prominent cliff,

which in places overhangs . 5

Light-blue hard calcareous shale; forms land¬
slide slope . 15

Argillaceous limestone, impure, mottled light
greenish blue and lavender; weathers in small
angular fragments but forms at outcrop a mas¬
sive vertical ledge ; grades upward and down¬
ward into hard calcareous shale . 3

Chinle formation — Continued. Feet.

Light-blue hard calcareous shale ; forms slope . . 14$

Hard dense nodular limestone, mottled light
greenish blue and lavender; weathers in
small irregular-shaped fragments; grades im¬
perceptibly into shale above and below;

forms bench . 8

Hard calcareous light-blue shale, forming slope. 38
Light-bluish shaly soft, very micaceous sand¬
stone, grading into sandy shale . 59$

Light-bluish to brown limestone conglomerate,
containing pebbles of limestone and chert 3
inches or less in diameter; grades into coarse

limy sandstone . 2$

Yellowish-brown hard sandy shale grading to

ash-gray and lavender shale . 53

Grayish-blue to lavender calcareous, highly
micaceous sandstone, grading upward into
soft massive cross-bedded sandstone; lower

part weathers in thin platy fragments . 35$

Purple shale, grading upward into yellow and
blue shale; sandy, especially in lower part;
contains abundant mica; weathers in rounded

slopes . 13

Brownish-gray thinly laminated to platy sand¬

stone, weathering dark brown; lower part
locally conglomerate, containing pebbles of
ironstone and jasper as much as 1 inch in

diameter . ; . 5-6

Sandy shale; upper part weathers to shades of
lavender and purple; lower part darker; the
proportion of sand increases toward the top;
contains satin spar, crystals of gypsum, and
mammillary concretions of ironstone with
crystalline cal cite; weathers in rounded

slopes . 91$

Brown thin-bedded flaggy sandstone, grading

laterally to burnt sienna slaggy ironstone,
containing nodules of limonite; this bed
forms a bench that weathers irregularly in

crumbly fragments . 2

Hard calcareous sandy shale, light greenish
blue predominant in variegated coloring;
weathers in rounded badland slopes . 25

Total thickness of Chinle formation . 474

Shinarump conglomerate: Grayish-brown irregu¬
larly bedded massive sandstone, showing thin

cross lamination; some of the weathered surfaces
are dark brown or black on account of a surface
deposit of iron oxide; contains bluish sandy shale

in middle part . . . 85

Moenkopi formation.

Section of Kaibab limestone west of The Peaks, in the Circle,
Cliffs.

[Measured by R. C. Moore.]

Moenkopi formation.

Kaibab limestone: Feet.

Yellow dolomitic limestone in massive evenly
bedded ledges; weathers in large angular
blocks pitted by solution; part contains
numerous dendrites of manganese oxide and
concretions of a mineral resembling wad;
contains fossils; forms resistant cap of promi¬
nent bench . 37

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA.

21

Kiabab limestone: — Continued. Feet.

Light-yellow soft dolomitic massive limestone,
filled with angular fragments of chert;

weathers in smooth slope; exposed . 15

Soft light creamy-yellow thin to medium
bedded limestone; weathers in slope; partly

concealed . 37

White very sandy limestone, rounded sand
grains scattered rather evenly; more lime

than sand; weathers in thick ledges . 34

White medium to coarse grained massive sand¬
stone; rounded quartz grains in a lime

matrix . 19

White very sandy limestone, rounded sand
grains scattered rather evenly; more lime
than sand; weathers in thick ledges; forms
bench . 21

Total thickness of Kaibab limestone. . . . 163

Coconino (?) sandstone: White medium to coarse
grained moderately soft massive sandstone;
rounded quartz grains in a lime matrix; breaks
into irregular blocks on weathering ; exposed . 73

Section of lower beds in front of Kaiparovnts Plateau, south
of Tenmile Spring , about 15 miles southeast of Escalante,
in middle part of sec. 4, T. 37 S ., R. 4 E.

Section on Halls Creek about 8 miles above its mouth.

[Measured by R. C. Moore.]

McElmo formation: Reddish-brown and light green¬
ish-gray massive hard, irregularly bedded con¬
glomeratic sandstone; forms prominent escarp¬
ment; thickness reduced by erosion .

Feet.

76

“Varicolored shales and sandstones” :

Tliin-bedded red sandstone . 123

Tan-brown massive soft cross-bedded sandstone,
weathering in smooth rounded slopes, partly
covered . 850

Total thickness of “varicolored shales
and sandstones ” . 973

“Gypsiferous shales and sandstones” :

Light-red and greenish sandy shale; contains

beds of white sandstone and gypsum . 90

Maroon shale and hard fine-grained quartzitic
sandstone; forms escarpment . 50

Total thickness of “gypsiferous shales

and sandstones ” . 140

Navajo sandstone: White medium-grained very
massive cross-bedded sanstone; forms prominent
ridge . 600+

[Measured by R. C. Moore.]

Feet.

“Tununk shale Bluish sandy shale, grading

downward into soft fossiliferous sandstone . 400+

Dakota (?) sandstone: Conglomeratic buff to almost
white coarse to medium grained sandstone, con¬
taining lenses of conglomerate with pebbles as
much as 3 inches in diameter; irregularly cross-
bedded; forms cliff and prominent bench . 90

McElmo formation:

Red and light-brown sandy shale, interbedded
with sandstone of similar color; forms slope

r partly concealed . . 55

Light-brown and yellow fine-grained sandstone,
cross-bedded in part; occurs in massive layers
and forms bench . 70

Total thickness of McElmo formation. . . 125

“Varicolored shales and sandstones”:

Red and gray shale and sandstone, interbedded ;

mostly covered . 12

Red, gray, and drab sandstone and shale, in
thin alternating beds; considerable variation

in color and texture . 60

Yellow and buff soft, very massive sandstone;
weathers in smooth round slopes, locally with
caves and shallow depressions at outcrop _ 300+

Partial thickness of “varicolored shales
and sandstones ” . . 372

Section across Water pocket Fold near southwest corner of T.
32 S., R.8 E., at Bitter Creek divide , head of Halls Creek.

[Measured by R. C. Moore.]

Feet.

Masuk sandstone: Light-yellow massive sandstone,
weathering yellowish brown; forms very promi¬
nent escarpment; in lower part grades into

medium-bedded sandstone . 297

“Masuk shale”: Yellowish-brown to drab sandy
shale; upper part contains beds and lenses of soft
sandstone; forms slope beneath escarpment of

sandstone above . 700

Blue Gate sandstone: Yellow to light-brown me¬
dium to massively bedded sandstone forming pre¬
cipitous cliff; locally contains lignite . 230

“Blue Gate shale”: Bluish-drab sandy shale, very
uniform in color and texture; upper part grades

into soft shaly sandstone . 1,200

Tununk sandstone: Yellowish-brown medium to

massively bedded sandstone . 50-75

“Tununk shale”: Bluish-drab sandy shale, uniform
in color and texture; includes very fossiliferous

thin yellow sandstone at base . 975

Dakota (?) sandstone: Light-yellow soft irregularly
bedded sandstone, grading upward into sandy
shale; contains two thin beds of impure lignite
9 and 20 inches thick . 15

McElmo formation:

Grayish-blue, maroon, and purple banded soft
sandy shale, weathering in valleys and bad¬
lands .

415

22

SHORTER CONTRIBUTIONS TO GENERAL, GEOLOGY, 1923.

McElmo formation — Continued. Feet.

Grayish-white to light bluish-green conglomer¬
ate and sandstone; contains pebbles as much
as 2 inches in diameter; consists in part of
thick beds and lenses of coarse conglomerate
and in part of coarse gritty very irregularly

bedded sandstone . 150

Total thickness of McElmo formation . . . 563

“Varicolored shales and sandstones”:

Red and gray banded sandy shale grading to

soft thin-bedded sandstone . 90

Tan-brown massive soft cross-bedded sandstone,

weathering in smooth rounded surfaces . 260

Reddish-brown and bluish-gray very soft shaly
sandstone, weathering readily, forming val¬
ley; partly covered . 470

Tan-brown massive soft cross-bedded fine¬
grained sandstone, weathering in smooth
rounded surfaces . 340

Total thickness of “varicolored shales
and sandstones ” . ; . 1, 160

“Gypsiferous shales and sandstones:”

Light-red and bluish-gray shale and sand¬
stone; gray to white sandstone in alternat¬
ing beds; contains several beds of bluish to
white gypsum as much as 3 feet thick; the
gypsum occurs also in numerous thin veins. . 400

Dark to light red sandy shale, containing two
beds of very hard reddish and light green
mottled dense siliceous massive and flaggy

limestone that forms escarpments . 50

Total thickness of “gypsiferous shales

and sandstones ” . 450

Navajo sandstone: White to very light cream-
colored sandstone, locally stained light orange-
red in middle and lower parts; capped by bed of
coffee-brown sandstone, 10 feet, and light tan,
highly cross-bedded sandstone, 8 feet. Very

massive, highly cross-bedded on large scale; the
cross-beds are etched in relief by weathering;
crops out in high, prominent “reef” whose sur¬
face is marked by numerous conical tepees,

mosques, and rounded domes . 1, 400

Todilto (?) formation: Dark-red to maroon cross-
bedded sandstone, medium to coarse grained,
thin to medium bedded; some beds hard, others
soft; bedding very irregular; locally contains soft
maroon sandy shale; thickness in part estimated. 160
Wingate sandstone: Red very massive hard fine¬
grained sandstone, of uniform color and texture,
cross-bedded but bedding not prominent, much
jointed; crops out as single ledge making a ver¬
tical cliff or palisade . 340

Chinle formation:

Light-bluish hard calcareous shale, mottled
with lavender; upper part stained purple;
weathers in rough angular blocks; forms
slope . 48

Chinle formation — Continued. Feet.

Massive light greenish-blue limestone con¬
glomerate, composed of pebbles of lime¬
stone, quartz, jasper, and sand in a lime

matrix . . 2

Alternating beds of light bluish-green lime¬
stone and shale, mottled with lavender; the
shale is hard and calcareous, forms slopes,
and grades without demarcation into lime¬
stones that are nodular, hard, and massive

and form projecting ledges . 146

Sandy shale and sandstone, yellowish brown,
yellow, dark brown, blue, purple, and ash-
gray, dark tones predominating; sandstone in
part soft and massive, in part hard, dense,
cross-bedded, and forming projecting ledges,

locally conglomeratic . 304

Total thickness of Chinle formation . 500

Shinarump conglomerate: Hard very massive, ir¬
regularly bedded light bluish-gray to white
sandstone, weathering yellowish white locally;
forms prominent escarpment; at this place thick¬
ness ranges from 40 to 110 feet within a short

distance, average . 60

Moenkopi formation: Thin to medium-bedded
ripple-marked micaceous sandstone; weathers in
slopes and projecting ledges; base not exposed _ 250+

Section of Shinarump conglomerate and upper part of
Moenkopi formation on ivest side of Circle Cliffs between
Horse Creek and the Peaks.

[Measured by R. C. Moore.]

Shinarump conglomerate: Feet.

Light-gray coarse-grained very massive sand¬
stone, forming almost unbroken vertical¬
faced escarpment; weathers in large angular
blocks . 30-60

Massive cross-bedded light bluish-gray sand¬
stone, mottled and streaked along irregular
joints with purple; grades upward without
demarcation into sandy limestone; weathers
in single massive bed softer than overlying
sandstone and therefore forming a reentrant
in the cliff; upper surface uneven . 16

Moenkopi formation :

Chocolate-brown very sandy shale, grading

into shaly sandstone; more calcareous above. 7
Chocolate-brown thin-bedded ripple-marked

and cross-laminated sandstone . 3

Chocolate-brown very micaceous sandy shale,

grading into thin shaly sandstone . 5

Chocolate-brown hard shaly to platy sandstone;

forms slight projecting ledge . 1

Brown sandy shale, grading into thin shaly

sandstone; weathers as slope . 8

Chocolate-brown hard platy sandstone, forming

a ledge . 1

Chocolate-brown sandy shale, grading into
shaly sandstone . 22£

ROCK FORMATIONS IN THE COLORADO PLATEAU OF UTAH AND ARIZONA. 23

Moenkopi formation — Continued. Feet.

Chocolate-brown thin-bedded ripple-marked
laminated sandstone, locally weathering
massive and forming a prominent projecting

ledge . 5

Chocolate-brown sandy micaceous shale with
thin seams and beds of soft sandstone; in
upper part contains thin beds of shaly

sandstone . 46£

Light greenish-gray platy fine-grained mica¬
ceous sandstone, with large asymmetrical
ripple marks; produces a slight bench . §

Chocolate-brown sandy micaceous shale, con¬
taining abundant thin beds of shaly sandstone

which weathers in thin chips and platy slabs;

weathers in gentle rounded slope . 27

Brown very micaceous ripple-marked sand¬
stone, with thin light-gray bands, platy with
thin shale beds between harder layers; top

layer very hard and slabby . 2J

Chocolate-brown sandy shale, with thin yellow
and brown sandstone beds that make slight

benches . * . 56

Light-yellow very massive hard sandstone;

forms projecting wall . 50

Light-yellow massive sandstone, weathering in
thin plates; grades into shaly sandstone;

forms bench . . 12

Chocolate-brown sandy micaceous shale . 40

Light-yellow massive sandstone ; locally stained
red on outcrop; grades locally into shaly or
thin-bedded sandstone; forms prominent

bench . 160

Yellow very shaly sandstone, grading to sandy

shale . 5

Yellow calcareous micaceous sandstone, mas¬
sive but thinly laminated, with ripple bed¬
ding; grades to shaly sandstone . 4

Partial thickness of Moenkopi formation . 456

(Top of Kaibab limestone 25 to 40 feet below.)

Section of Moenkopi formation in canyon north of The Peaks,
northwest of Wagonbcx Mesa, in the Circle Cliffs.

[Measured by R. C. Moore.]

Feet.

Shmarump conglomerate: Gray medium to fine
grained massive sandstone, weathering yellowish

in part, locally conglomeratic; weathers in large
angular blocks; outcrop forms prominent cliff.. . 50-150
Moenkopi formation:

Maroon sandy shale grading into yellow shale
in upper 15 feet, with many paper-thin

sandstone layers . 50

Yellow fine-grained soft sandstone; weathers

rather shaly . 3

Maroon shale with thin shaly sandstone .... 39

Buff, brown, and gray fine-grained sandstone,

in layers 1 to 4 inches thick . , _ 8

Yellowish-brown sandy shale . 26

Pink to maroon sandstone, thin bedded, with
a few massive layers as thick as 16 inches at
intervals; interbedded with very sandy

shale ; upper part yellow-brown . 48

Fine-grained hard gray and light-pink sand¬
stone, weathering brown and light gray;
weathers in beds 2 to 12 inches thick, but

in fresh exposures beds appear very massive;
upper part more reddish than lower; ordi¬
narily well exposed . ; . 42

Red sandstone, with thin sandy shale inter¬
bedded, medium to massive bedding . 31

Very thin bedded platy light-brown and yel¬
low to pink sandstone, weathering reddish
brown; abundant ripple marks; grades lo¬
cally into shale; forms slopes . 36

Pink to red sandy shale, containing thin beds
of platy sandstone ; weathers in slopes . 21

Total thickness of Moenkopi formation . . 304

Kaibab limestone: Deep-yellow to buff very hard
fine-grained dense dolomitic limestone, in mas¬
sive beds 3 to 6 feet thick; weathers in large
angular blocks ; forms prominent bench ; exposed
thickness . 20

o

1 ''.‘Sol 9

Please do not destroy or throw away this publication. If you have no further use
for it, write to the Geological Survey at Washington and ask for a frank to return it

DEPARTMENT OF THE INTERIOR

Hubert Work, Secretary

United States Geological Survey

George Otis Smith, Director

Professional Paper 132 — C

NOTES ON THE GEOLOGY OF GREEN RIVER VALLEY BETWEEN
GREEN RIVER, WYOMING, AND GREEN RIVER, UTAH

JOHN B. REESIDE, Jr.

Published November 30, 1923

Shorter contributions to general geology, 1923
( Pages 35-50 )

WASHINGTON

GOVERNMENT PRINTING OFFICE

1923