Tectonic events since early Paleozoic in the Carlin-Pinon Range area, Nevada

Abstract

Following a long tranquil interval in early Paleozoic time, rocks of the area were subjected to at least seven distinct deformational episodes as follows: (1) multiple subparallel thrusts of great displacement in late Late Devonian to early Early Mississippian; (2) deep subsidence in the area coupled with strong uplift close to the west edge of the area beginning in middle Early Mississippian; (3) regional uplift and local folding and eastward-directed thrusting in late Middle to early Late Pennsylvanian; {4) renewed uplift and permanent end of marine conditions in early Mesozoic; (5) igneous intrustion followed by intense folding, some of very large scale, and westward-directed thrusting climaxing in Late Jurassic to Early Cretaceous; (6) igneous intrusion and local folding in early Oligocene; and (7) normal faulting climaxing in Miocene. Evidence from this area suggests that the displacement on the Roberts thrust at this latitude was at least 110 km (68 mi) and probably much more. The leading edge of the upper plate of that thrust probably lay diagonally or irregularly across the area after movement ceased. Sedimentation was scarcely interrupted near this leading edge of the upper plate, but other areas nearby to the west were emergent and were deeply eroded immediately after emplacement. Mesozoic tectonism involving prolonged uplift, injection of large igneous bodies, volcanism, intense folding, and thrusting constitutes a complex orogenic event of major importance and is a principal orogenic event in the history of the area.