Petrological and structural charateristics of the peddavura schist belt and adjacent rocks in eastern Dharwar craton in parts of Nalgonda district, Telangana state

The NW-SE trending Peddavura Greenstone belt extending over 25 kms with a width of 0.5 to 2 km is flanked by granitoid rocks. The rocks are classified as Basalt, Basaltic Andesite, Andesite, Dacite and Rhyolite. Pillow structures with cherty layers along the margin of the pillows of basaltic rocks were observed in the field. Quartz veins intrude along the fractures of the felsic rocks. South of river Krishna, banded iron formations (BIF) occur interlayered with the volcanic rocks. Basaltic rocks are fine grained and made up of hornblende and calc-plagioclase feldspar. Felsic volcanic rocks show porphyritic texture with quartz occurring as phenocrysts set in a fine-grained matrix of quartz and feldspar. In the study area, sulfide and oxide ore minerals are concentrated within quartz veins that traverse the metavolcanics.