Goldstein Peak Formation
Goldstein Peak Formation
Early Cretaceous, ~129-140 Ma MDA
Consists of metaconglomerate, sillimanite-biotite-quartz schist, hornblende-rich amphibolite, and local carbonate and calc-schist. Crops out in the southwestern Sierra Nevada foothills northwest of the Kaweah River in a pendant within the Stokes Mountain intrusive suite (unit Gsm). Protoliths are conglomerates and sandstones from fluvial and alluvial fan environments, mud-rich sediments and air-fall tuffs deposited in a lacustrine(?) environment, and subaqueous to subaerial basalt to dacite volcanic rocks. Approximate stratigraphic thickness of 1,250 m. Unit stratigraphically overlies metasedimentary rocks of the Merced River terrane (unit MRCS) to the east and northeast. This unit has yielded detrital zircon MDAs of ~129-140 Ma (Martin and Clemens-Knott, 2015). This unit is cut by a granitic dike that has evidence of wet-sediment intrusion with a U-Pb age of ~139 Ma (Clemens-Knott and others, 2013). Unit coeval with forearc deposits of the Great Valley sequence in the Diablo and Temblor Ranges and the subsurface of San Joaquin Valley to the west of the map area. Unit is one of the youngest sedimentary deposits (excluding volcaniclastic sedimentary rocks in the dominantly volcanic unit SHKOV) preserved within the metamorphic framework of the exhumed batholith.