Chichali Fm

Surghar Gr - lower formation: Holotype section: Chichali Pass, SuR. Author: W. Danilchik, 1961. Reference section: None.

Sandstone. It consists of dark green, greenish grey weathering rusty brown glauconitic sandstone, with dark grey, bluish grey, sandy, silty, glauconitic shale in the lower part. In Trans Indus Range (TrIR), Western Salt Range and Samana Range the formation is divisible into three members. The lower member is sandy, silty, glauconitic shale with some phosphatic nodules passing upward into dark green glauconitic sandstone with abundant belemnites. The middle member is greenish to rusty brown, fine to medium grained calcareous sandstone, which stands out in topography. The upper member is glauconitic, chamositic, generally unfossiliferous sandstone; this upper member in type section and adjoining areas is sufficiently rich in iron to form a low-grade iron ore.

Thickness: 12-70 m. In the type section, the thickness varies from 55- 70 m and at Shaikh Budin Hill, it is 48 m thick. In west of Kohat (Samana Range) the thickness ranges from 15-20 m. In eastern Kohat, Nizampur and KcR it varies from 12-27 m. In Hazara region, it attains a thickness of 64 m, northwest of Kalapani.

In the basal part late Oxfordian fauna like Perisphincte ( Kranaosphinctes ), P. (Dichotomosphinctes), Mayaites, Belemnopsis gerardi and Hibolithes are common. These are followed by Kimmeridgian ammonoids including Aspidoceras, A (pseudowaggenia), Physodoceras (Simaspidoceras) sp., Katrliceras cf. pottingeri , Pachysphinctea robustus, Hibolithes and Belemnopsis gerardi. Early Tithonian fossils include Aulacosphinctoides sp., Virgatosphinctes, Hildoglochioceras, Proniceras indicum, and Provalanginites. Vertebrate remains of Plesiosaur, a dinosaur of Cretaceous age were collected from Makarwal coal mine. The Jurassic/Cretaceous contact is lithologically gradational and the boundary is marked by the first appearance of ammonoid Subthurmannia (abundant), Neocomoceras, Neocomites, and Killianella etc.

EMW: Low grade iron ore. Possible source rock for hydrocarbons.