Statistical Properties and Petrography of the Misri Banda Quartzite, Nowshera Tehsil. N.W.F.P.

Abstract

This paper presents the statistical properties and petrography of the Devonian and Carboniferous Misri Banda Quartzite. It occurs interbedded and overlying the Nowshera Formation of Siluro-Devonian reef complex.

The statistical analysis shows that most of the quartzite samples fall in the well-sorted range and are unimodal in their size distribution. The size fequency curves show maximum sorting towards the coarse grades and skewness towards finer grades. Kurtosis values of size distribution range between 0.27 and 0.24.
Microscopic examination of several slides reveals that quartz grains, embedded in a carbonate matrix, are elongated with their longer axis being parallel to each other and to the longer dimensions of calcite/dolomite grains, Well-rounded grains of zircon, tourmaline, and orher heavy minerals are present in lesser amounts. The high degree of textural and mineralogical maturity of the Misri Banda Quartzite and its association with the rerf carbonates indicate o long history of trransporation, reworking and winnowing in shallow waters dominated by stable shelf environments, Statistical data, heavy mineral distribution, and fiels observations indicate that ihe Misri Banda Quartzite conformably overlying the Nowshera Formation, and beds and stringers of quartzite, occuring interbedded with the reef carbonates are one and the same derived from a common source.