UNITED STATES DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY BULLETIN 1021 PLATE 47

AGE FORMATION UAE GENERAL DESCRIPTION AND REMARKS

0-304

Pediment gravels, terrace deposits, Gravel veneer on pediment surfaces; gravel, sand, and silt as terraces; and coarse gravel and

Recent and Pleistocene aaailrivenaashh each type sand in stream channels. All deposits unconsolidated except where locally cemented by
Ou deposit caliche
SS UNCONFORMITY
SS

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eth
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ih
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QTp, coarse to fine gravel, sand and silt intercalated with basalt flows. Clastic sediments are in

== part water-laid and contain some fresh-water limestone; QTv, coarse gravel, sand, and silt
é : i formation
ait ee QTp Qtv Qtp | QW Basalt flows intercalated within this sequence of deposits. Although the mutual relationship

Pleistocene(?) to Plocene(?) of the Perkinsville formation with the Verde formation is not demonstrated in the quadrangle,

|
|

Perkinsville
|
| they are tentatively correlated with each other
|

|
[/- \--~_ UNCONFORMITY

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|
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Verde formation 0-500 to coc marginal to and interfingering with lakebeds which consist of limestone, siltstone, and clay.
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Tinie
at
tL

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iif
Aig “a ‘aig Intermediate basalt 50-150
Dt eae

Locally extruded olivine basalt in flows about 50 feet thick

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a AN

A
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ie Be Ay na |_~_—~ unconrormiry
cto OSE AM HN ns Chiefly olivine basalt as massive flows and flow breccias which are in part scoriaceous. Locally
iH ea Tan tH AST includes biotite- and hornblende-bearing andesites. Minor amounts of tuffaceous and basaltic
i AIM Volcanic rocks 0-1400 sediments intercalated between flows. Basait dikes are associated with the thick lava
tH Lun MS iy i Hickey Thy sequence and contributed flow material by fissure activity
i Pliocene(?) formation
ETT HAs 5
ME nh i
iMag gael HA Coarse to fine gravel, which consists chiefly of Precambrian and Paleozoic rock types and minor
ae i Sedimentary rocks 0-200 amounts of basaltic fragments, is relic of former stream deposits confined to channels
Teese ea ai beneath the thick sequence of overlying lava
oth

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me ST
= 1“ UNCONFORMITY

White to gray rather thin-bedded crystalline but sandy limestone that alternates with sandstone;

Tr 0 contains bedded chert. Basal part contains buff to yellow sandstone unit which grades

Gert Wetec GEIES upward into the white arenaceous limestone and sandstone. Formation becomes less arena.
ceous upward. Forms series of cliffs and ledges

[~~ UNCONFORMITY =

Lower part is reworked Coconino sandstone which grades upward into a ledge-forming massive

calcareous sandstone or arenaceous limestone about 50 feet thick. A sequence of redbeds,
Toroweap formation 150-165 which consists of sandstone, siltstone, and shale, is intercalated with clean white sandstone,
Permian Pt > and comprises the upper half of the formation. The formation forms a slope except for above
mentioned unit

: Massive pale-orange to grayish orange sandstone of fine and even grain, which is characterized
Coconino sandstone 500-650 by crossbedding on a large scale. The formation nearly everywhere forms a sheer cliff
Pe

Chiefly strongly crossbedded medium- to coarse-grained reddish-orange sandstone units sepa-
rated by horizontally bedded but very thinly laminated fine-grained pale-reddish-brown sand-
stone and siltstone. Member as a whole forms cliffs, buttresses, and pinacles

Upper member

Permian Psu CED

‘Supai

formation

Chiefly pale-red to grayish-red siltstone, somewhat calcareous and interbedded with conglom-
. Middle member 250-300 erate and orange cross-laminated sandstone. Member is very irregularly and thinly bedded.
Pennsylvanian Psm Siltstone weathers to thin irregular slabs and chips which form a subdued topography

(Carboniferous) -

Lower third of member is particularly thin bedded and consists of shale, siltstone, and’sand-
stone of various shades of red; generally 2 or 3 gray limestone beds are intercalated near the”
Lower member 580-625 base. Member becomes thicker bedded upward with less shale content. Top of member
PPs! contains pale-red to pink crossbedded sandstone unit 70-90 feet thick. Member forms a
moderate steplike slope which becomes increasing steeper upward

> UNCONFORMITY

Lower part consists of thin-bedded reworked Devonian materials and a bluish-gray oolitic lime-
stone 25-55 feet thick, above which is a fine-grained cherty limestone 55-80 feet thick that

Lower Mississippian Redwall limestone 235-285 passes upward into a coarsely crystalline noncherty limestone unit 100 feet thick. At top
(Carboniferous) Ir of formation is a dense bluish-gray micro-oolitic limestone unit that averages 40 feet thick
UNCONFORMITY

The lower unit of the formation is a 20-50 foot crossbedded impure clastic dolomitic limestone
overlain by 80-110 feet of light-gray thin-bedded lithographic limestone. Above this is 65-80
feet of thicker bedded mottled dark-gray dolomitic limestone. The upper 247-289 feet of the

Upper and Middle@) Devonian Martin limestone 440-480 formation consist of alternating coarsely crystalline dolomitic limestone, lithographic lime-

Dm stone, siltstone, and some shale and sandstone. The formation is characteristically thin
bedded and has a general overall dark-gray appearance. It weathers with a moderate to
steep slope of receding ledges

UNCONFORMITY-
Comprises two units: a lower unit of dark-reddish-brown crossbedded sandstone that averages
Cambrian) Tapeats(?) sandstone 0-60+ 50 feet thick; an upper unit of reddish- to yellowish-gray shaly siltstone and mudstone that
er?) is 10-15 feet thick

|_-~_-UNCONFORMITY

p€q, quartz porphyry; p€gg, Grapevine Gulch formation, largely fine-grained
tuffaceous sediments; p€d, Deception rhyolite, largely bedded sedimentary rocks of rhyolitic
Older Precambrian rocks A composition; p€s, Spud Mountain volcanics, includes andesitic breccia, and tuffaceous sedi-
Older Precambrian rocks p€g; p€a; pCgg: pCd: pes mentary rocks of rhyolitic and andesitic composition. The Spud Mountain volcanics are in

7 7 7 b fault contact with the Grapevine Gulch formation and the Deception rhyolite. Their age rela-
tion is not known

INTERIOR GEOLOGICAL SURVEY, WASHINGTON, D. C. MR S526

STRATIGRAPHIC SECTION OF THE ROCKS IN THE CLARKDALE QUADRANGLE, ARIZONA