Paradox Diapir Inclusions as a Window Into Diapiric Processes in Proximity to the Uncompahgre Uplift and the Early History of the Paradox Basin, Utah and Colorado
Layered evaporite sequences, cyclic, kilometer-thick deposits of salt, are among the most unusual and fascinating lithologies that geologists encounter. There is no recent analogue to their formation, and their ability to flow when subject to differential pressure makes them unique. Salt structures serve as sources for halite, bittern salts, metals, and hydrocarbons and can be used for storage of materials, including hydrocarbons, carbon dioxide, hydrogen, and nuclear waste. Basins in which layered evaporite sequences are deposited receive detrital input sporadically from adjacent areas, depositing inclusions of non-evaporite lithologies that are entrained when salt flows. These inclusions are exposed in a series of breached salt walls in the Paradox Basin and provide a window into the paleogeography and earliest stages of basin formation, for example if it was born as a uniform depression or as a series of indentations separated by steps. Integrating field, microscopic, and geochemical observations, I have reconstructed the depositional setting of inclusions from three different sites: the Gypsum Valley, Salt Valley, and Sinbad Valley diapirs. I have used this information to elucidate the early history of detrital input into the Paradox Basin, and thereby gained insight into its paleogeography. Known non-evaporite lithologies in the Paradox Formation identified in this study include black shale, limestone, and sandstone. These lithologies are exposed in breached salt walls today as diapiric inclusions derived from the Paradox Formation layered evaporite sequence that were carried to the surface during diapirism. Conglomerate inclusions found in Paradox Basin diapirs, on the other hand, are not a known or recorded lithology of the Paradox Formation. This study reveals that they were part of the Paradox Formation and that the most likely detrital source was basement steps within the basin that were active during its deposition and contributed as a significant source of detritus in the Paradox layered evaporite sequence.
Woelfel, Madison Clare, "Paradox Diapir Inclusions as a Window Into Diapiric Processes in Proximity to the Uncompahgre Uplift and the Early History of the Paradox Basin, Utah and Colorado" (2023). ETD Collection for University of Texas, El Paso. AAI30634994.