Depositional Environment of Sohnari Member Sandstone of Laki Formation from Southern Indus Basin, Pakistan

Abstract

The Sohnari member, a clastic unit of generally carbonate Laki Formation is exposed in Lakhra anticline, northwest of Jamshoro town. Seven sandstone samples from Sohnari member at Lakhra anticline were collected for the investigation of its depositional environment. Grain size analysis was carried out through sieving. The sieved data was used for plotting of cumulative curves and measurement of statistical parameters (mean, median, sorting, skewness and kurtosis). Present study shows that the studied sandstone samples are medium to fine grained, moderate to poorly sorted, ranging in skewness from near symmetrical, positive to negative with very Leptokurtic, Leptokurtic and Mesocratic kurtosis. The analysis of grain size parameters indicated fluvial depositional environment of Sohnari member of Laki Formation