WSP05382

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications-Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/1/1975
• Title: The Natural Salinity of the Colorado River
• Water Supply Pro - Doc Type: Publication

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other areas, however, where the shale has been broken by faulting, or
where large masses have been loosened by mass movements, there may
be enough permeability to produce a significant underflow, and the
underflow, being in contact with the shale for a much longer time than
the overland runoff, would carry to the river a much higher
concentration of saIto

The Mancos shale and its enclosed sandstone tongues, dip gently in
a northwesterly direction off the San Rafael Swell and beneath the Price
area (Fig. 17). As a result the groundwater in these tongues is confined,
and wells drilled into them should be artesian. More importantly for our
interest the water should be of very poor quality. Some of this low grade
artesian water may escape into the Price River where it crosses any fault
or shear zone that would permit the confined water to rise to the surface.

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CLIFFS

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STAR POINT 55
EMERY 55

GARLEY CANYON 55

PRICE CITY a
PRICE RIVER

FARNHAr.l ANTICLINE
(North .nd 81m Rgloel S....II)

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Figure 17. Diagram showing sandstone tongues In Mancos shale dip-
ping WNW beneath and near PrIce, Utah.

Similarly. there is a gentle dip of the basal sandstone of the Upper
Cretaceous Series, the Dakota Sandstone, or its equivalents, and any
sandstone tongues in the Mancos shale, back toward the cliffs,
throughout the area' shown in Figure 10, ,and hence the conditions
described for the Price area, and diagrammed in Figure 17, are
'essentially repeated from GranclJunctiOli, Colorado, to the south end of
Castle Valley, Utah.

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The Mancos badlands have been lowered 'by the process of
pedimentaticin, the shale being removed be small streams and sheet
wash, originating on the sandstone cliffs above (Fig. 18). The traction
load of sandstone pebbles and cobbles, picked up at or on the cliff face,
and carried down across the shale, grade the pediment surfaces.

Lowering of base level at the major stream, or significant changes in
the amount of runoff, dissect old pediment surfaces and create new ones

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