Tectonic style and regional relations of the central Nevada thrust belt

Abstract

The Mesozoic( ) Central Nevada thrust belt (CNTB) lies in a geographically and structurally central position in the Great Basin. Understanding the structural geometries and timing of deformation in this belt is critical to reconstructing pre-thrusting sedimentary basins, post-thrusting sediment source locations and the syn- to post-thrusting Cretaceous Newark Canyon basins. The authors recent detailed studies in the thrust belt better constrain the structural geometries, associated sedimentary basins and timing of deformation in the CNTB. They suggest that contractile structures in the CNTB east and south of Railroad Valley are part of the same orogen as the Eureka belt which north and west of that valley. Therefore, the CNTB is an essentially continuous orogen for 250 km along strike, from Alamo to Eureka, Nevada. The structural style effects paleogeographic reconstructions. The CNTB is made up of a stack of at least six separate thrusts. Many thrusts have long ramps that cut from the Mississippian into the Cambrian ([approximately] 2,200 m of section) suggesting large vertical uplifts. Shortening in the CNTB is bracketed between Late Permian and Cretaceous, but regional correlations indicate it may be Jurassic to Cretaceous. The youngest contraction is no younger than Early Cretaceous as indicated by (1)more » folding and thrusting of parts of the Albian-Aptian Newark Canyon Formation, (2) intrusion of an anticline by the 84.6 Ma (new date) Troy stocked, and (3) intrusion of another anticline by the [approximately]100 Ma (new date) Lincoln stock. The onset of shortening is more difficult to ascertain because Triassic and Jurassic rocks are not present. Rocks as young as Pennsylvanian in the south and Permian in central region are deformed. A Jurassic age is based on regional correlations with the Jurassic Elko orogenic belt.« less