GILBERT, JOSEPH J., University of Nevada, Las Vegas, Dept. of Geoscience, Las Vegas, NV

ABSTRACT: Structures Exposed in the Pancake Range, Central Nevada: Tectonic Implications for the Central Nevada Thrust Belt

The temporal and spatial extent of the Mesozoic thrusts in central Nevada is difficult to delineate due to the overprinting by multiple sets of both high- and low-angle Cenozoic normal faults. However, Mesozoic contractional structures are part of the central Nevada thrust belt, a belt suggested to be hinterland structures related to the Sevier orogenic belt. Mesozoic folds and thrusts are exposed in the Pancake Range, central Nevada, but their location and geometry is the object of published debate.The Pancake Range, central Nevada, lies next to one of the largest oil producing areas in the Basin and Range province, Railroad Valley. The major source rock for Railroad Valley, the Mississippian Chainman Shale, is deformed by the Mesozoic structures and later by Cenozoic normal faults. Hydrocarbon generation within the Chainman Shale depends upon either thrust burial or burial by basin fill sediments. Within the Pancake Range, Chainman Shale is exposed, and therefore, structures in the range may serve as potential hydrocarbon traps.

The purpose of this study is to delineate Mesozoic contractional structures through the Pancake Range and correlate them regionally. This goal will be accomplished by detailed field mapping and construction of deformed state and retrodeformed cross sections. Retrodeformed cross sections will allow a step-wise reconstruction of Cenozoic normal faults which may constrain timing of Cenozoic deformation, burial and maturation of source rock, and allow the delineation of the geometries of central Nevada thrust belt structures.

AAPG Search and Discovery Article #90909©2000 AAPG Foundation Grants-in-Aid