The Coconino Sandstone: Implications for Flood Geology

The Coconino Sandstone is a well-known rock layer of the Grand Canyon and surrounding regions. Researchers have long considered it to be an example of an ancient eolian, or wind-blown, sandstone. However, literature review and prior research (in lab and field) show that we should interpret this as a marine sandstone instead. Surrounding formations such as the Lyons, Tensleep, and Glorietta Sandstones show remarkably similar features to that of the Coconino. Geologist Dr. John Whitmore attempts to correlate their emplacement during approximately the same geologic time period, analogous to a large “blanket” over much of the western U.S. states.

This study is significant in our understanding of Flood geology. The similarities across these widespread Permian sandstones imply that they likely deposited in a marine environment like the Coconino.

The following article is a summary of “Lithostratigraphic Correlation of the Coconino Sandstone and a Global Survey of Permian “Eolian” Sandstones: Implications for Flood Geology.“ by John H. Whitmore, and of the surrounding discussion and research pertaining to it. The views expressed do not necessarily reflect those of New Creation.

Dr. Whitmore’s Study

Whitmore’s research concludes that we can correlate the Coconino sandstone as a diachronous sand body that ranges all the way from North Dakota to southern California with a total area of approximately 2.4 million km². Interestingly, provenance studies of the Coconino and its equivalents show that the origin of the sand likely came from across the entire continent–from eastern North America! This demonstrates that a massive amount of sand was eroded and transported across the country and deposited as a “blanket” over a large portion of the west. Paleocurrent data also supports this; consistent currents over such a big area favor a marine deposition model. 

Additionally, other data collected from these sandstones strongly indicate subaqueous deposition. Cross-beds found in Coconino and its equivalents average an angle of about 20°, while in modern deserts the average is a much steeper 34°. The gentle slopes indicate that these sand waves formed underwater. Interestingly, other data at the microscopic level also point to marine deposition. In a modern sand dune, the wind typically sorts and rounds sand grains, and only the more resistant minerals such as quartz remain. In the Coconino, though, the grains are poorly sorted, consisting of various sizes, and sub-rounded to sub-angular. Researchers have even found soft minerals such as micas! Micas like muscovite and biotite rarely last in wind-blown settings. It is significant that researchers have found them in the Coconino and other Permian sandstones.

Conclusion

These findings, along with other collected data and studies, have led Whitmore and others to conclude that these sandstones are not only correlated as one diachronous body, but that they have been deposited in a marine environment. This is consistent within a Flood model. The Coconino likely formed as Flood waters surged over the supercontinent of Pangea. 

Footnotes:

• Whitmore, John H. 2019. “Lithostratigraphic Correlation of the Coconino Sandstone and a Global Survey of Permian “Eolian” Sandstones: Implications for Flood Geology,” Answers Research Journal 12, 275–328.