Jobra formation

This unit (highlighted) within its province column; faded ends continue above and below. Line style marks the contact type.

The Ordovician Misri Banda Quartzite near Nowshera, with Cruziana trace fossils, above the Ambar dolomite.

Nowshera formation is named by Stauffer (1968a) for the fossiliferous limestone and dolomite. Its synonym Jobra formation is named by DiPietro (1990) in the Swat area, 5km SE of Ilam for calcsilicate marble and he now suggested to be a synonym of Nowshehra formation. It occurs in between the Swat granite gneiss and Alpurai indicate a Paleozoic age Early Devonian. Its lower contact with Kandar phylite and upper contact with Misri Banda quartzite are conformable revealing Late Silurian to early Devonian. Misri Banda quartzite is named after Misri Banda village by Satuffer (1968a) for quartzite, limestone and argillite exposed in the Nowshera hills in the northern fault block of Attock-Cherat range and in Swabi area. Early to middle Ordovician (Pogue et al. 1992). It rests unconformably on the Cambrian? Amber formation. It rests on Nowshera formation in the Khyber area and aged as Middle Devonian to Carboniferous (Khan, M.A. 1970).

Significance. The Misri Banda Quartzite of the Nowshera area — a cross-bedded feldspathic quartzite carrying the trace fossil Cruziana rugosa (Early–Middle Ordovician) — resting unconformably on the Cambrian Ambar Formation and overlain unconformably by the Panjpir Formation.

Fossils

Provinces

• Malkani, M.S. & Mahmood, Z. (2017). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 24.
• Kazmi, A.H. & Jan, M.Q. (1997). Geology and Tectonics of Pakistan. Graphic Publishers, Karachi.

Reviewer confidence: medium