Textural Evaluation of Nari Formation, Laki Range, Southern Indus Basin, Pakistan

Abstract

Textural evaluation of Nari Formation based on the grain size analysis is carried out in order to identify its textual signatures and depositional environment. Nari Formation, potential hydrocarbon and water reservoir is exposed at Kari Buthi Section, Northern Laki Range, Southern Indus Basin. Twenty two (22) loose and friable sandstone samples of Nari Formation are selected for sieving. The cumulative curves are produced from sieved data and various statistical parameters (mean, median, sorting, skewness and kurtosis) are derived from the cumulative curves. The outcome of the textural evaluation shows that the studied sandstone samples are dominantly fine to medium grained, mainly poorly sorted but at places shows moderate to well sorting, the skewness ranges from near symmetrical, positive to negative with varying Leptokurtic, Platykurtic, Mesokurtic, and Very Leptokurtic. The textural evaluation of Nari Formation sediments indicate the deposition in fluvial-deltaic depositional environment