Characterization and Evolution of the Professor Valley Pennsylvanian Salt Body (Paradox Basin, UT) Using Gravity and Magnetotellurics
Syndepositional halokinetic movement of the Pennsylvanian Paradox Formation in the Paradox Basin, UT & CO behaved as a control over the development of depositional systems during the Late Paleozoic and early Mesozoic periods (Trudgill, 2011). Understanding the controls on halokinetic evolution in the area serves as an invaluable outcrop analogue for similar subsurface salt bodies in petroleum-bearing basins and provides key insights for hydrocarbon exploration in salt basins world wide. Professor Valley, located 15 miles Northeast of Moab, UT is situated between the Fisher Valley (Onion Creek) and Cache/Salt Valley salt walls. It includes an anomalous, isolated 0.5 km² outcrop of the Pennsylvanian Paradox Formation 5 kilometers off the western flank of Onion Creek. Previous data collected in the area include only six gravity data points for the entirety of Professor Valley (Case & Joesting, 1972) with a decreased density of data towards both of the bounding salt walls. This lack of data or significant potential fields work in the area creates the opportunity for significant further geophysical investigations to better understand the area. An extensive new survey of 254 gravity points covering the region in 300-meter grid spacing was used in this study to identify subsurface features and guide an audio-magnetotelluric (AMT) survey. AMT allowed for collecting vertically unique resistivity data for the subsurface with a depth-resolution of up to 5km given longer residence times at lower frequencies. These methods, along with detailed surface geologic mapping of the area were used to determine the existence and subcircular geometry of the Professor Valley salt diapir, as well as the lack of apparent subsurface connection to the nearby & along strike Fisher Valley (Onion Creek) and Salt Valley salt walls. Diapiric rise most likely ceased shortly after deposition of the Wingate Formation. Outcrops of the Paradox Formation are primarily gypsic caprock, that locally surround unusual sandstone and conglomerate inclusions that are 10’s of meters across. The inclusions are thought to be derived from Paradox Formation depositional cycles and carried upward during diapirism.
Scott, Derek Travis, "Characterization and Evolution of the Professor Valley Pennsylvanian Salt Body (Paradox Basin, UT) Using Gravity and Magnetotellurics" (2022). ETD Collection for University of Texas, El Paso. AAI29211765.