Chemical and Mineralogic Variations in an Arkosic Quartzite During Progressive Regional Metamorphism

Seven samples of biotite-bearing arkosic quartzite were collected along a traverse essentially normal to isograds in a series of regionally metamorphosed sedimentary rocks in the Peninsular Ranges, California. X-ray fluorescence, rapid chemical, and emission spectrographic analyses have been made of total rock, biotite, ilmenite, and K feldspar. Going from lower to upper hornblende-hornfels facies, the following changes are observed: bulk …