Stratigraphic Analysis of the Navajo Sandstone
1975; Society for Sedimentary Geology; Volume: Vol. 45; Linguagem: Inglês
10.1306/212f6e06-2b24-11d7-8648000102c1865d
ISSN1938-3681
AutoresWilliam E. Freeman, Glenn S. Visher,
Tópico(s)Clay minerals and soil interactions
ResumoABSTRACT The Navajo Sandstone (Upper Triassic(?)-Lower Jurassic) has beeninterpreted as desert-eolian in origin principally based upon type cross-bedding; well-rounded, well-sorted, and frosted grains; and lack of fossil evidence. Reevaluation of these criteria reveals that they are ambiguous, non-diagnostic, and insufficient tosubstantiate an eolian interpretation. It was found that comparisons of log-probability curve shapes of samples from Navajo and modern tidal-current environments show they were deposited by similar processes. The Navajo possesses sedimentary structures, such as current lineation, bioturbation, andlarge-scale contorted bedding characteristic of subaqueous conditions of deposition. Pelletal glauconite occurs in a correlate of the Navajo, the Nugget Formation of the Wind River basin, indicative of a marine environment. Vertical sequence and facies patterns of the Glen Canyon Group and Carmel Formation suggest a transgression of Navajo and Carmel marine deposits eastward from the Cordilleran geosyncline onto continental deposits of the Kayenta, Moenave, Wingate, and Chinle Formations.
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