1. Ancient Seismites and Syntectonic Sediments in the Kaiparowits Basin, Utah
P.I.s – Sarah E. Tindall and Edward L. Simpson, Kutztown University, Kutztown, PA
Earthquakes and surface topography generated by Cretaceous (~80 Ma) normal faults affected local depositional environment, sediment supply, and stratigraphic thickness on the western margin of the Kaiparowits coal basin. Cretaceous growth faulting has the potential to influence thickness and distribution of coal resources as well as oil and natural gas traps in this and other basins in the Cordilleran foreland of the western U.S.
The response of sediment to the growth faulting was examined. Specific fault blocks were identified in which movement generated seismites (earthquake-induced features in soft sediment). The northern-most footwall sediments experienced less intense seismic shaking than hanging wall sediments to the south. In addition the preservation of fluvial systems varies from footwall to hanging wall. The fluvial systems preserved in the hanging wall are predominantly low sinuosity. Crossing the normal faults, high sinuosity fluvial systems are preserved interbedded with the low sinuosity systems. Therefore, these local faults are exhibiting an important control on the style of fluvial preservation and the modification of primary sedimentary structures.