Warcha Sandstone Fm

Nilawahan Gr – third formation. Holotype section: Warchha Gorge, Western Salt Range. Hypo: Saiyiduwali section. Author: B.R. Hussain, 1967.

Synonym: Warcha Sandstone, Warcha Fm

Sandstone. The formation consists of medium to coarse-grained sandstone, conglomeratic in places with interbeds of shale. The sandstone is generally thick bedded to massive, reddish brown, cross bedded, medium to coarse grained and arkosic, the sand grains are angular to sub-angular in the lower part. The higher horizons are very coarse grained and conglomeratic with angular or sub-angular pebbles of quartzite, red felsite, and of the underlying Jutana Fm. Purple to dark-grey shale layers are interbedded with sandstones and reach a thickness of several meters each. In WSR, reddish brown to dark brown sandy shale with white or reddish sandstone layers prevail. In Burikhel (Western Salt Range) thin shaly coal beds are developed at the base, which are mined. This, however, is the only Permian coal in Pakistan.

Reference section: Typical lithology as in the type section, with less coal beds.

Thickness: It is 150-165 m in Salt Range and 120 m in Khisor Range. In Potwar area, the thickness generally increases from the southeast to the northwest.

Unfossiliferous. Only some plant remains have been reported.

Variable thicknesses together with the strong cross bedding suggest that the formation was a fluviatile deposit, and was laid down in extended alluvial flats.

EMW: Coal (poor quality and low production). This, however, is the only Permian coal in Pakistan.