Nisai Fm
Type Locality and Naming
Holotype section: 12 km north of Nisai railway station. Hypo: Kasria Jhur, a tributary of River Hub. Author: Hunting Survey Corporation, 1960.
Lithology and Thickness
Clayey limestone. The formation consists of limestone, marl and shale with minor sandstone and conglomerate. At the type locality, the formation is divided into three parts. Lower part is dominantly a limestone with minor shale; Middle part is dominantly shale; Upper part is again a limestone with minor sandstone. The limestone at places is massive and brecciated.
Reference section: Lithology not reported but likely to be same as in the type section. A residual conglomerate of deeply weathered lateritic bed marks its lower unconformable contact.
Thickness: 240-1,200 m. (much reduced thickness at Ghazaband Pass). The formation is about 1,200 m thick at the type section, 240-455 m at the reference section, 300-750 m in the Khud Range, about 600 m at Wad and only 3-10 m at Ghazaband Pass.
Relationships and Distribution
Lower contact
Unconformably underlain by Cretaceous and older strata, as well as the Muslimbagh Fm intrusions.
Regional extent
The main area for the development of the Nisai Fm is the Axial Belt, and it is also reported from the Kakar-Khorasan Province (K-KP) of Balochistan Basin. Some occurrences are reported from near the Iranian border.
GeoJSON
Fossils
Richly fossiliferous, and forams of Eocene and Oligocene age are found abundantly.
Age
Depositional setting
Additional Information