Lower Permian Dry Mountain Trough: Case Study for Recogni- tion of Widespread Post-Antler Continental Margin Tectonism

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This proposal is part of a broader effort to assess the magnitude, timing, and style of Late Paleozoic crustal uplifts and subsidence in eastern Nevada. These basins and associated uplifts are part of a recently recognized phase of Late Pennsylvanian-Permian tectonic instability along the continental margin of the Western U.S. The tectonic drive for these events is unknown and can be assessed only through basin analysis based on integrated and detailed biostratigraphic and lithostratigraphic studies. Previous work has concentrated on the history of one of these basins,the Dry Mountain Trough. Building on the work of Stevens PIs have documented the general tectonic origin of the Dry Mountain Trough, and recognized three distinct east-west divisions of the basin: Eastern Shelf Facies, Central Basinal Facies, and Western Margin Facies. This award is for a two-year intensive study of the Western Margin Facies. The conglomeratic, fluvial to deltaic to shallow marine Western Margin Facies records the tectonism that created the Dry Mountain Trough. PIs will study this record by: (1) tracking the position of the strandline to help document the subsidence history, (2) determining the age and facies progression of the basal units to define structural blocks and document possible differential subsidence, and (3) delineating the sequence stratigraphy and thus assess the timing and style of continued tectonism.