Kussak Fm
Type Locality and Naming
Holotype section: Fort Kussak, Eastern Salt Range (northern Indus Basin). Hypo: Saiyiduwali section, Khisor Range. Author: F. Noetling, 1894. Reference section: Being suggested by Nusrat K. Siddiqui; lithology same as in the type section.
Lithology and Thickness
Sandy claystone. In the type section, it mainly consists of grey, silty and sandy glauconitic shales with some sandstone intercalations and few black shales; the formation exhibits a uniform lithology throughout. At the base, there is a very regular and characteristic grit and conglomerate, no more than a foot thick.
Thickness: 55-525 m. The thickness of the formation in the type section is 75 m, and 55 m in the suggested reference section. In southern Punjab plains a thickness of 200 m was drilled, and farther south, a well Marvi-1 drilled 525 m of this formation.
Relationships and Distribution
Lower contact
Disconformably underlain by Khewra Sandstone Fm , across a typical thin well-marked conglomeratic bed with well-sorted and rounded granule to sand-size clasts, which are poorly cemented
Upper contact
Conformably overlain by Jutana Fm
Regional extent
The formation is well exposed in the Salt Range escarpment from Jogi Tilla in the east to Chhidru Nallah in the west, as well as in the Khisor Range. It has also been encountered in wells drilled in eastern Potwar and those in the Punjab plains, and farther south, in the Badin area (Marvi-1 well). The formation is thickening from Potwar in the north to Badin area in the south.
GeoJSON
Fossils
Fossils are reported from two horizons, one near the base and the other near the top.
Upper part- Hyolithes wynnei sp., Ptychoparia warthi sp., Redlichia noetlingi var angulata sp., Redlichia noetlingi var lata sp., Linguella wanniecki sp., Linguella fuchsia sp.
Lower part- Hyolithes kussakensis sp., Hylothes sp., Neobolus warthi Waag sp., Discinolepis vaporate Waag sp., Chizophollis rugosa Waag sp., Linguelella khurensis Waag sp.
Age
Depositional setting
Marine depositional environment.
Additional Information