Little is known of the depositional histories or tectonic settings of Cretaceous-early Tertiary sedimentary basins which formed in the hinterland of the Sevier orogenic belt. Numerous structural studies suggest that the hinterland was influenced by Mesozoic-early Tertiary compression and thrust faulting. Others suggest periods of extension and normal fault development. In addition, preserved hinterland basin sedimentary sequences are extremely rare. Very little detailed stratigraphic, sedimentologic, or provenance analysis has been conducted on hinterland basin deposits. The goal of this research is to better the understanding of the sedimentary- tectonic history of these hinterland basins. For this project, Cretaceous-early Tertiary hinterland basin-fill in east-central Nevada will be subjected to detailed lithostratigraphic, biostratigraphic, and petrographic analysis. Classical field methods involving detailed section measurement, description, and facies mapping, biostratigraphic and lithologic sample collection, paleocurrent measurement, and conglomerate clast counts will be combined with standard laboratory petrographic procedures. Synthesis of the data collected will be used to discern as completely as possible the following parameters concerning such basins: 1) types of depositional environments and their geographic and temporal distributions, 2) location and composition of sediment source areas as inferred from provenance of terrigeneous clastic units, 3) age relationships within the basin-fill, 4) possible changes in rates of basin subsidence as indicated by changes in fluvial style and architecture, 5) styles of tectonism in the source areas as reflected by vertical and lateral changes in sediment composition and depositional environments, and 6) geographic extent and temporal duration of individual basins.
