Mesozoic • Cretaceous formation Literature

Bibai Formation

Late Cretaceous

Sulaiman Basin

Cited in 5 sources Last reviewed Aug 9, 2026

Unit summary

Rank: formation
Status: Published
Age: Mesozoic · Cretaceous · Late CretaceousLate Cretaceous
Named by: Kazmi (1979)
Type locality: Bibai Peak, Gogai area, northeast of Quetta, Balochistan
Thickness: up to ~3,000 m (Ziarat region)
Lithology: Two zones. Upper zone: thick volcanic-boulder conglomerate interbedded with ash beds and tuff, interfingering with coarse sandstone, argillaceous tuff and mudstone. Lower zone: interbedded agglomerate, tuff and basalt lava flows; its basal part is interbedded with the Parh Limestone.
Synonyms: Not recorded

A thick pile of Late Cretaceous lavas, tuff and volcanic conglomerate around Bibai Peak northeast of Quetta — the volcanic component that locally forms the base of the Mughal Kot succession.

Upper Cretaceous volcanic unit of the Kach-Ziarat area northeast of Quetta, forming part of the Bibai and Gogai nappes. Named by Kazmi (1979) after Bibai Peak in the Gogai area. Mapped northeast of Quetta; in the eastern part of the USGS OFR 94-689 map area it is included in the lower part of the Mughal Kot Formation of the Mona Jhal Group. Records Late Cretaceous volcanism on the deforming northern margin of the Indo-Pakistan plate.

Fossils

bivalves brachiopods gastropods

Contacts

In the Sulaiman Fold Belt column

LimestoneIgneousShale / mudFossils recordedConformable

Band colour = period; texture = dominant rock type. Lines between bands mark the contact type. True scale makes height ∝ recorded thickness; hatched = thickness not recorded. Ages approximate, for ordering.

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

Distribution & setting

Sulaiman Fold Belt

Basin: Sulaiman Basin
Region: Not recorded
Depositional environment: marine, volcanic
Coordinates: Not recorded

Correlation

Not recorded. Compare this unit against other basins on the correlation panel →

Economic significance

Not recorded

Remarks

A thick Late Cretaceous volcanic succession (basalt lava flows, agglomerate, tuff and volcanic-boulder conglomerate) of the Kach-Ziarat region, part of the Bibai-Gogai nappes. Its basal lavas are interbedded with the pelagic Parh Limestone, dating submarine-to-subaerial volcanism along the Indian plate margin immediately before the Maastrichtian Mughal Kot clastic wedge.

Sources (5)

Maldonado, F., Khan, S.H. & Mengal, J.M. (1994). Preliminary Geologic Map of Parts of Loralai, Sibi, Quetta, and Khuzdar Divisions, Balochistan Province, West-Central Pakistan. U.S. Geological Survey Open-File Report 94-689, 20 p., 1 sheet.
Kazmi, A.H. & Jan, M.Q. (1997). Geology and Tectonics of Pakistan. Graphic Publishers, Karachi.
Kazmi, A.H. & Abbasi, I.A. (2008). Stratigraphy and Historical Geology of Pakistan. Department & National Centre of Excellence in Geology, University of Peshawar, Peshawar. 524 pp. ISBN 978-969-9119.
Umar, M., Kassi, A.M., Jamil, M., Kasi, A.K. & Khan, A.S. (2024). Cretaceous stratigraphic framework and sedimentary architecture, Pakistan: signatures of rift-drift tectonics and submarine volcanism along the western continental margin of the Indian Plate. In: Hart, M.B. et al. (eds) Cretaceous Project 200 Volume 2: Regional Studies. Geological Society, London, Special Publications, 545.
Maldonado, F., Mengal, J.M., Khan, S.H. & Warwick, P.D. (2011). Summary of the Stratigraphy and Structural Elements Related to Plate Convergence of the Quetta-Muslim Bagh-Sibi Region, Balochistan, West-Central Pakistan. U.S. Geological Survey Open-File Report 2011-1224.

Reviewer confidence: high

Every fact on this page is source-cited. This entry is part of the peer-archived Pakistan Stratigraphy Dataset (doi.org/10.5281/zenodo.21363991, CC‑BY‑4.0).

Lexicon status: Defined in journal or other literature; not found in a GSP memoir. There is no body currently ratifying unit status, so provenance is shown in place of a formal ruling.

Cite this unit

APA

Qudsi, L. (2026). Bibai Formation. In Pakistan Stratigraphy Dataset [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21363991

BibTeX

@misc{stratigraphypk_bibaiformation,
  author    = {Qudsi, Lareb},
  title     = {{Bibai Formation} --- Pakistan Stratigraphy Dataset},
  year      = {2026},
  publisher = {Zenodo},
  doi       = {10.5281/zenodo.21363991},
  url       = {https://doi.org/10.5281/zenodo.21363991}
}

Archived dataset: doi.org/10.5281/zenodo.21363991 (CC‑BY‑4.0) · Direct link to this entry: https://stratigraphy.pk/formation/bibai-formation (accessed August 30, 2026).

To cite the unit's original definition instead, see: Kazmi (1979).

Below · older

Parh Limestone

Cretaceous

Above · younger

Pab Sandstone