Quaternary stratigraphy and paleoenvironments of the Texas Rolling Plains

Abstract

The Lingos Formation (new) comprises a thick sequence of Quaternary alluvial-fan, lacustrine, fluvial, and eolian deposits. These strata cover 9,250 km 2 of the western Rolling Plains of Texas. The Lingos Formation is part of the newly designated Paducah Group, which includes three previously recognized middle to upper Pleistocene formations in addition to the Lingos Formation and several unnamed or uncorrelated stratigraphic units. The origin of these formations is closely associated with westward retreat of the Caprock Escarpment and with subsidence resulting from regional intrastratal dissolution of Permian evaporites. Dissolution produced subsidence basins, which gradually filled with sediment derived from the retreating escarpment. Lakes occupied at least some of the subsidence basins and were sustained by emergent ground water rather than by surficial inflow. Stratigraphic relations and paleofaunas document significant Quaternary environmental change linked to subsidence, stream incision, and climatic variation. Chronologic control is afforded by diagnostic vertebrate faunas (Rancholabrean and Holocene), Paleoindian through historic archeological remains, and more than 50 radiocarbon ages. On the basis of these data, deposition of the Lingos Formation spanned the period from less than 300 ka ago to the present. The depositional history of the Lingos Formation provides a model for the origin of the Paducah Group as a whole, and for Quaternary landscape evolution throughout the Rolling Plains.