An architectural analysis and depositional interpretation of the Dockum Group in the West Texas High Plains

Abstract

The Triassic Dockum Group of the west Texas high plains represents the PermianTriassic boundary. This group has been extensively studied paleontologically but lacks a detailed sedimentological overview. Six lithofacies assemblages were identified across three formations: upperflow regime channels, upperflow regime sheets, perennial channel belts and bars, floodplain, paleosol and lacustrine deposits. The assemblages consist of unique lithofacies bedforms. These bedforms were previously unidentified in the Dockum Group. Fluvial architectural analysis was conducted on three channel assemblages in order to understand the fill patterns. The depositional patterns of each assemblage were driven by a megamonsoon climate that perpetuated throughout the Triassic. This study aims to clarify the previous lithofacies interpretations and discuss the climatic implications that ultimately controlled the Dockum Group depositional environments.