Science and Mathematics Faculty Publications

Document Type

Abstract

Publication Date

2019

Journal Title

Journal of Creation Theology and Science, Series C: Earth Sciences

Volume

8

Issue

2

Abstract

The purpose of this study was to correlate Upper Paleozoic sandstone bodies of Pennsylvanian and Permian ages across the western United States. The cross-bedded Coconino Sandstone (Arizona) is perhaps one of the best-known formations in this collection of sandstones, many of which contain large cross-beds and thus are often interpreted as eolian in origin (McKee and Bigarella 1979). The Coconino Sandstone (Leonardian) is found in northern Arizona in places like Sedona and Grand Canyon.

Stratigraphic columns were obtained from multiple sources including the AAPG’s COSUNA charts and data, the RMAG’s Geological Atlas of the Rocky Mountain Region, and published papers from a variety of books and journals (Adler 1986; Ballard et al. 1983; Bergstrom and Morey 1984; Hintze 1985, 1988; Hills and Kottlowski 1983; Kent et al. 1988; Mankin 1986; Mallory 1972a, 1972b). About 60 generalized stratigraphic columns were collected, drawn and then correlated across the western United States. North American Chronostratigraphic Units were used for this study since virtually all the Permian and Pennsylvanian literature for the western United States uses this nomenclature. Columns were “hung” on the Pennsylvanian/Permian boundary. Four sections were correlated from southern to northern states. Some of the better-known sandstones and formations included in this study were the Casper (WY), Cedar Mesa (UT), Coconino (AZ), Cutler (UT), De Chelly (AZ), Esplanade (AZ), Glorieta (NM, OK, TX), Lyons (CO), Minnelusa (MT, WY), Quadrant (MT), Queantoweap (UT), Tensleep (MT, WY), Weber (UT) and White Rim (UT). These sandstones often do not contain fossils, so many of the correlations were based on lithology, presumed age and distinctive units above and/or below the sand bodies of interest (such as limestone, salt, gypsum and phosphorite deposits). It was found equivalent sandstones can be correlated on both the eastern and western sides of the Rocky Mountains along transects from California-Arizona-Utah-Idaho-Montana-Dakotas and from California-Arizona-New Mexico-Texas-OklahomaColorado-Wyoming-Nebraska-Dakotas. The sandstone body is diachronous, meaning the northern sandstones were found to be slightly older than the southern ones. When the correlations are examined, it is clear there are large lenses of mud and siltstone within the sandstone bodies (like the Hermit Formation of Grand Canyon). It is estimated that the total area covered by the nearly continuous sand body consisting of all these named sandstones is about 2.0-2.5 million km2. The conventional interpretation of the Coconino is that it is an eolian deposit, its cross-beds forming as the result of large migrating desert sand dunes. The outcome of this study is significant because it demonstrates the lithostratigraphic equivalence of the Coconino with other sandstones, some of which are recognized as being marine, which is consistent with other findings indicating a marine origin for the Coconino (Whitmore and Garner 2018). Additionally, it would be hard to conceive of an eolian sand body being continuous around the area of the Ancestral Rocky Mountains (roughly in central and western Colorado); a continuous marine body would be much more plausible.

Keywords

Coconino sandstone

Included in

Geology Commons

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