Permian and Triassic Palegeography of the Eastern Klamath Arc and Eastern Hayfork Subduction Complex, Klamath Mountains, California

Abstract

Middle Permian and Middle Triassic volcanic-hypabyssal intrusive complexes form ensimatic arc deposits in the eastern Klamath terrane, northern California. Sedimentary matrix melange with blocks of sand stone, chert, and Tethyan fauna-bearing limestone compose the westward- lying eastern Hayfork terrane. Limestone olistoliths were derived from seamounts and incorporated into a subduction complex that was active during the Late Triassic and probably as early as the Permian. Geologic and biogeographic relations imply a genetic relationship between the ensimatic arc and subduction complex, constraining Permo (?)-Triassic subduction as eastward-dipping.