Petrography and geochemistry study of the Thirtal lamprophyre dyke left bank of Muneru River, in eastern margin of the Eastern Dharwar Craton, Khammam, Telangana, India

Abstract

Various types of lamprophyres are very common in different part of the Cudappah Igneous Provice (CIP)/Prakasham Alkaline Province (PAP) in Eastern Dharwar Craton (EDC), southern India. Present paper reports a lamprophyre dyke near the Thirtal lamprophyre left bank of Muneru River area, Khammam District, Telangana, India (80°08ʹ 12.9ʹʹ:17°19ʹ 10.13ʹʹ) at the northeastern margin of the EDC. In the present paper also discuss the detail petrography and geochemistry of the newly found lamprophyre. The study area mainly consists of granitoids of Peninsular Gneissic Complex (PGC) of the EDC. Regionally, the area is bounded by two Proterozoic sedimentary basins, i.e. in the east Pakhal basin and in the south Cuddapah basin. The lamprophyre of the study area has been intruded within granitoids of the EDC. This dyke is ~0.5 to 1 mt wide having ~50 mt exposed strike length on the bank of Pakhal River. Petrographically clinopyroxene and olivine are present as a phenocryst and biotite, plagioclase, kfeldspar, carbonate, amphibole, chlorite and epidote present in the groundmass. In some of the part carbonate replace the clinopyroxene and olivine. The mineral chemistry, whole rock, trace elements and REE geochemistry suggested that this lamprophyre belongs to calc-alkaline group (CAL)