Depositional Patterns and Stratigraphic Relationships in a Sag Basin: Middle Jurassic Gypsum Spring, Piper and Sundance Formations, NW Wyoming

Abstract

The Middle Jurassic Gypsum Spring, Piper and Sundance Formations of Wyoming are marine and evaporite deposits formed in a shallow epeiric sea east of an overthrust belt that existed near the western margin of North America. Lithofacies distribution was influenced by sag basin tectonics related to this continental collision. Resolving the stratigraphic relationships within these units provides insight into the interaction between global sea level change, regional tectonics, and local depositional facies distribution. Through the integration of lithostratigraphy, allostratigraphy and sequence stratigraphy, we seek to determine the origin and distribution of lithofacies and unconformities to better understand the timing of deposition as it relates to sea level change and tectonism.