| dc.description.abstract | There are currently two different theories for the formation of Upheaval Dome, an enigmatic circular geological formation comprising a tilted rim structure that encloses a central uplifted region. The first theory is that Upheaval Dome, located in Canyonlands National Park, Utah, was formed as a result of uplift caused by the diapiric rising of the buoyant Paradox Salt through the overlaying strata. The second theory is that the formation was caused by a meteorite impact. The objective of this project is to develop geoelectrical models corresponding to each of the two suggested explanations of Upheaval Dome. Starting with analytic solutions of the governing Maxwell equations, as found in Ward & Hohmann [1987], Everett [1990], Kauahikaua [1978], Ryu et al. [1970], and Morrison et al. [1969], software is developed based on an impedance recursion equation that can accurately simulate the response of a layered geoelectrical model to transient controlled-source electromagnetic (CSEM) excitation. With this analytic equation it will be possible to further develop a 3-D finite element numerical code that will be used to test and evaluate geological models representing a variety of possible subsurface conditions beneath Upheaval Dome. The best-fitting models can be validated through geophysical field work with the intent of resolving subtle resistivity contrasts between deeper layers in the model. With this application, the range of possible uses for terrestrial CSEM will be expanded to geological structural mapping in rugged, highly resistive terrains, and it will be possible to provide some insight to which of the candidate geological process that resulted in the formation of Upheaval Dome. | en |
