Metamorphic evolution of mafic granulites from Tiyara area, Makrohar granulite belt, Singrauli district, Madhya Pradesh, India

Abstract

The mafic granulite rocks from the Makrohar Granulite Belt of the Chotanagpur Granite Gneissic complex (CGGC) have been studied with reference to their petro-graphy, mineral chemistry and pressure–temperature (P–T) conditions of metamorphism. The common mine-ral assemblage observed within different thin sections is orthopyroxene–clinopyroxene–hornblende–plagioclase–biotite–quartz. The average P–T condition of the mafic granulites in the study area suggests a peak of meta-morphism at 799° ± 40°C/6.3 ± 0.9 kbar. However, the peak P–T estimate obtained from the conventional two-pyroxene thermobarometer is 5.83–6.47 kbar and 887° ± 62°C at a fixed pressure of 6 kbar, followed by post-peak P–T conditions of metamorphism at 590°–693°C/ 2.1–2.4 kbar.