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 recordedContact not recorded

Band colour = period; texture = dominant rock type. Lines between bands mark the contact type; dotted = no contact recorded in the sources (not a claim of conformity). 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.

Research notes (6)

Field-by-field findings drawn from the cited literature. Every statement is traced to a registered source — follow a citation for the full reference.

Age & correlation (2)

Kazmi & Jan (1997): the Bibai Formation ('Bibai Volcanics' of Kazmi 1955, 1979b) is Late Cretaceous — interlayered Parh Limestone in its lower part yields Globotruncana lapparenti and G. linnei (Campanian), while the upper part carries Omphalocyclus macropora and Baculites binodosus (Early–Middle Maastrichtian; Kazmi 1955); Sawada et al. (1994) report a 71.4 ± 3.4 Ma age for the lower volcanics.

Kazmi, A.H. & Jan, M.Q. (1997)
Umar et al. (2024, after Mahoney et al. 2002; Siddiqui et al. 1996): radiometric dating places the Bibai submarine volcanism in the Late Campanian–Early Maastrichtian (73.4±2.0, 72±2.1 and 71.4±3.4 Ma); geochemistry indicates a hotspot-related (Deccan-linked) origin.

Umar, M., Kassi, A.M., Jamil, M., Kasi, A.K. & Khan, A.S. (2024)

Lithology (1)

Kazmi & Jan (1997): the lower Bibai comprises basaltic lava flows (locally altered to laterite between Kach and Loralai) and tuffs, interlayered with thick volcanic boulder conglomerate (the Kahan Conglomerate Member of Williams 1959); the upper part is mudstone and ash beds with subordinate sandstone. Volcanism was initially submarine (pillow lavas) then subaerial (Kazmi 1984), and geochemistry indicates within-plate alkali basalt — possibly hot-spot magmatism linked to the break-up of Gondwana (Sawada et al. 1992; Siddiqui et al. 1994). The book quotes a thickness of ~30 to 610 m (cf. the curated ~3,000 m Ziarat figure).

Kazmi, A.H. & Jan, M.Q. (1997)

Constituent units (1)

Umar et al. (2024, after Kassi et al. 2009; Shah et al. 2021): the Bibai Formation of the Kach–Chinjun area (IESZ, western SFTB) is divided into four members — Chinjun Volcanics (>500 m in-situ mafic volcanics with pillow structures and dolerite dykes), Kahan Conglomerate (>1000 m), Ahmadun (volcanic breccia/conglomerate/sandstone/mudstone with basaltic flows) and Kach Mudstone (fossiliferous turbiditic mudstone). The in-situ basalts conformably overlie the Parh Limestone and underlie the Pab Formation.

Umar, M., Kassi, A.M., Jamil, M., Kasi, A.K. & Khan, A.S. (2024)

Geological significance (2)

Kazmi & Jan (1997): the Bibai Formation of the Zhob thrust belt lies unconformably on the eroded Parh Limestone (its basal part locally interlayered with Parh) and grades up into the Dungan Formation; it is carried over the autochthonous Sulaiman fold belt on the Bibai Thrust and is correlated with the Mughal Kot Formation (Ziarat) and the Moro Formation, with the Porali Agglomerates and Bela Volcanics as further equivalents.

Kazmi, A.H. & Jan, M.Q. (1997)
Maldonado et al. (2011, USGS): the Upper Cretaceous Bibai Formation of the Quetta-Muslim Bagh-Sibi region is mapped as divided into an upper and a lower zone.

Maldonado, F., Mengal, J.M., Khan, S.H. & Warwick, P.D. (2011)

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.

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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 October 29, 2026).

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

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