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

Abstract

The mafic granulite rocks f rom the Makrohar Granulite Belt of the Chotanagpur Granite Gneissic complex (CGGC) have been studied with reference to their petrography, mineral chemistry and pressure–temperature ( P–T ) conditions of metamorphism. The common mineral 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 metamorphism 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.