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, evolving fluvial systems, 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. Localized growth faulting also generated seismites (earthquake-induced features in soft sediment) during deposition of the Cretaceous Wahweap Formation (shown on the left). We have mapped the locations, styles and intensities of seismites in specific stratigraphic horizons in and around the Kaiparowits basin. The emerging pattern shows strong local earthquakes superimposed on a broader regional background of Cretaceous earthquake activity. The pattern of seismites supports our hypothesis that faulting occurred during Wahweap deposition, and that faulting is limited to the western margin of the basin, probably signaling an early stage of Laramide uplift along the East Kaibab monocline.