Abstract

Gneissic rocks exposed in and around the Arjungarh of Central Rajasthan exhibits various geological signatures that attract many geologist and researchers for detail investigation. The present paper focused on the petrography and geochemistry of gneiss rocks of Arjungarh, Rajsamand. As in other areas of the BGC, gneiss was the main rock exposure found in the reported area. They were coarse-grained, light colored rock exhibiting well augen gneissic characteristics. The rock is mainly composed of quartz, feldspar, hornblende, biotite, and other opaque minerals. The rock was alumina rich and also high in potash content. There was also a pronounced negative Eu anomaly which suggests both K-feldspar and plagioclase were not removed in the differentiation sequence. Based on the geochemical analyses and interpretation, augen gneiss was found to be originated from granite to granodioritic igneous parentage of calc-alkaline composition in the tectonic setting of within plate granite..

Keywords: Arjungarh; Augen gneiss; BGC; Geochemistry; Gneissic rock; Petrography; Petrogenesis