A bedded deposit of anthophyllite schist in the Precambrian belt of Nellore, South India

Abstract

SummaryA pure anthophyllite schist occurs as a bedded deposit conformable with garnet-bearing quartz—muscovite, and quartz—chlorite—biotite schists and diopside-bearing caic-silicate rocks in the north-central part of the Nellore Schist Belt. Field and petrochemical studies show that anthophyllite schist has formed from regional metamorphism of Fe-, Mg-rich aluminous sediments aided by metamorphic differentiation due to local kinematic action under amphibolite facies conditions which is the general grade of metamorphism of the Nellore Schist Belt. A pure anthophyllite schist of sedimentary origin reported here is the first of its kind described from any terrain.