Kinematics of late Mesozoic thrusting,Pilot Mountains,west-central Nevada,U.S.A.

The northern Pilot Mountains of west-central Nevada, consist of a complexly deformed terrane of imbricate thrust nappes composed of rocks of Permian(?), Triassic through Jurassic, and possible Cretaceous ages. Three episodes of fold and thrust generation are recognized on the basis of folded thrusts and thrusted folds, and deformation and emplacement of the nappes is constrained as having occurred during the late Mesozoic. Folds are apparently coeval with thrust faults, and fold geometry is used in determining approximate directions of thrust displacement. The history of thrust displacement is complex and involves three directions of motion on a regionally extensive detachment surface, the Luning thrust. The first motion, from NW to SE, results in displacements of the order of several tens of kilometres and is the probable result of NW-SE regional compression. The final two episodes of motion are NE-SW followed by E-W; they result in small displacements and are possibly the product of gravity sliding of the thrust sheet into depressions in the autochthon. Sites of downwarp in the autochthon may have been formed either by load induced subsidence or regional compression.