Red Ant Schist
Red Ant Schist
Jurassic or older
Chiefly blueschist facies metasedimentary and metavolcanic rocks. Disharmonically folded quartz schist, black schist, and phyllite plus schistose and brecciated greenstone. Blueschist facies minerals crossite, glaucophane, and lawsonite are preserved locally. Protolith age unknown. Schweickert and others (1980) report muscovite K-Ar ages of ~157, ~173, and ~175 Ma, and whole-rock K-Ar ages of ~176 and ~190 Ma for this unit.