East-trending structural lineaments in central Nevada

Abstract

Several east-trendi:gg topographic and structural lineaments in central Nevada coincide locally with lithologic boundaries, range and valley termini, caldera boundaries, and strong magnetic interruptions. Most of the observed magnetic anomalies or interruptions along the lineaments can reasonably be attributed to the deposition of volcanic rocks against easterly trending topographic highs, to the juxtaposition by faulting of rocks having different magnetic properties, or. to plutonic rocks intruded into structures within the lineament trend. The tangential association of volcanic centers and cauldrons with the lineaments implies a deep-seated crustal control. Two of the lineaments can be traced from central Nevada in to easternmost California; another extends into western Utah. Two lineaments appear to cross the Walker Lane without offset and bound a block of ground that is not greatly displaced by strike-slip faults of theW alker Lane system. Whether the lineaments are partly a result of conjugate faults developed at the inception of the Walker Lane and other major northwesttrending faults in the southwestern Great Basin, or whether they owe their origin to an even more regional or even continentwide fracture system is an unresolved question.