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1
Manuscript received, November 1, 1960. Published by permission of the Shell Oil Company.
2
The Shell Oil Company. The writer is grateful to J. A. Peterson, who encouraged the initiation of this paper, and offered many helpful suggestions.

Abstract

Three widely distributed sandstone bodies—the Cedar Mesa, De Chelly, and Coconino-Glorieta sandstones—are conspicuous components of the Permian System of the Colorado Plateau. All are light colored, highly cross-stratified, quartzose sandstones, but they differ radically in geometric configuration, geographic distribution, source area, primary bedding features, and depositional environment.

The Cedar Mesa sandstone is present in the western part of the plateau as a thick sequence of light colored, nearshore-marine to littoral deposits that occur in a linear north-south trend. The unit grades eastward through abrupt facies changes into lagoonal red beds of the Cutler group that were derived from a different source.

The De Chelly sandstone is considerably more widespread, and is present over most of the province, except southwestern Colorado. The red sands were derived from Cutler sediments and distributed by northeasterly winds, forming an eolian desert in the greater Four Corners area, that graded southward into horizontally bedded marine deposits along the southern margin of the plateau. The sea encroached upon the vast dune area from the south and reworked the eolian deposits in its path, but did not reach the northern desert.

The Coconino-Glorieta sandstone was deposited as a fan-shaped wedge in northern Arizona, by eolian processes. The central Arizona source also supplied sands to a relatively stable marine area in central New Mexico, where they were deposited in shallow-marine to littoral environments. The marine deposits were widely and uniformly distributed—in marked contrast to their eolian counterparts in Arizona that were physically separated by the slightly positive Defiance uplift near the Arizona-New Mexico State line. The geometric configuration of the dual-environment formation is very distinctive.

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