Major Elements of Nari Formation Sandstone from Jungshahi Area of Southern Indus Basin, Pakistan
Geochmical Investigation of Nari Formation from Jungshahi
This study is carried out for geochemical investigation of the Nari formation from Jungshahi area southern Indus basin, Pakistan. Six rock samples of Nari formation were analyzed for the information of classification, paleo-weathering conditions, provenance and tectonic setting of Oligocene (33.9-23.03 Ma) geological time. The study of major elements (Si, Ti, Al, Na, Ca, K, Mn, Mg, Fe+3, P and S) and their ratios indicate that the Nari formation is dominantly composed of intermediate quartz. The silica has originated as either bio-genically precipitated or in detrital modes. Most of the sediments are detritus from the study area and Oligocene formation is composed of sandstone with subordinate shale. Field observation reveals that most of the sandstone is consolidated, calcareous and ferruginous. This sandstone is variegated in colour, light grey to dark grey, camel and red in colour at some places. The geochemical classification of Nari sandstone classified as the Subarkose and sub-litharenite and quartz-arenite. The CIA, PIA and CIW values indicate that, the Nari formation is deposited under low weathering conditions in the southern Indus basin during Oligocene time in an arid climate. Major elements indicate the sediments of Nari formation were supplied from the Mafic to Intermediate igneous source. The provenance and tectonic setting demonstrate that oligocence sediments of Nari formation sediments were deposited in tectonically in an active continental margin.