WSP02732

• File Number: 8276.852
• Description: Moapa Valley Unit - Colorado River Salinity Control Program
• State: NV
• Basin: Colorado Mainstem
• Date: 2/1/1981
• Title: Salinity Control and Environmental Assessment
• Water Supply Pro - Doc Type: EIS

Chinle Formation: Characteristic of arid climate deposition in water
with basin or lagoon conditions indicated by gypsum layers.

Shinarump Conglomerate: May represent deposition by slope wash and
temporary streams in areas with moderate relief and arid or semiarid climate.

Moenkapi Formation: Lower part of formation deposited in shallow
marine waters. Gypsum near the top indicates partial or complete isolation
from the open sea, perhaps in a hot, dry climate. The top of the formation
has ripple marked sandstone, gypsum and indications of lagoon and deltaic
conditions in a dry climate along the margin of a slowly withdrawing sea.

Kaibab Limestone: Formed in a shallow sea in a generally arid climate
as indicated by gypsum layers.

Supai Formation: Continental and probably nearshore conditions with
effective dry seasons as evidenced by the red sandstone and gypsiferous
shale. These are massive beds of gypsum up to 15 feet in thickness southwest
of Overton.

Callville Limestone, Bluepoint Limestone, Rogers Spring Limestone,
and Muddy Peak Limestone: Probably all shallow inland sea formations.

~dl ~l
Cah!on.id Tee; Ck Tnn Mu<lrly
-i?G~ (T'C~T~ _

Mormon
Ma..
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K

t

_ ..:.tl~.

,1 :! Mll~~
,

LEGEND

Qll1 All uvf II 1 depos its
Tn: Muddy Creek formation
Ths tlorse Spring formation
Tof Overton famglomerate
J Red and gray sandstone
Tre Chinle formatiun
Trm Moenkopi formation
Ck KII1bilb l1mestone
Cs Suoal fOnll<ltfon
(c Callville limestone

Reference: l.on9well. C. R.. 192R

0'1')
(...G89

Fi gure 4-A

GEO.LOGIC CROSS SECTION

Moapa Valley Subevaluation Unit. Nevada

USDA-SCS

9

of the Virgin River Unit
Colorado River Basin Salinity Control Program