Sachse Monument Pendant, central Sierra Nevada, California: Eugeoclinal metasedimentary rocks near the axis of the Sierra Nevada batholith

Abstract

Sachse Monument pendant, located near the axis of the Sierra Nevada batholith in the central Sierra Nevada, exposes an assemblage of eugeoclinal metasedimentary rocks that consists of tightly to isoclinally folded siltstone, sandstone, argillite, chert, limestone, lime-stone-clast conglomerate, and quartzite. The eugeoclinal rocks lie structurally above the miogeoclinal rocks of Snow Lake pendant along a structural break which is intruded by a 148 Ma igneous complex. Structural and stratigraphic studies at Sachse Monument pendant provide new supporting evidence for large displacement on the Mojave-Snow Lake fault, a proposed intra-arc, right-lateral strike-slip fault that may have displaced miogeoclinal rocks in the central part of the Sierra Nevada from an original position in the Mojave Desert. Geologic features of Sachse Monument pendant, including eugeoclinal rocks that rest structurally upon miogeoclinal rocks, and a 148 Ma igneous complex, together with other features, are characteristic of the western Mojave Desert region.