Mesozoic • Triassic formation In GSP lexicon

Gwal Formation

Triassic

Kirthar Basin · Western Kirthar (Balochistan)

Part of Khanozai Group

Triassic in the time scale →

Cited in 5 sources Last reviewed Jul 18, 2026

Unit summary

Rank: formation
Status: Published
Age: Mesozoic · Triassic · TriassicTriassic
Named by: Anwar et al. (1991)
Type locality: Trakai-Gwal section, Axial Belt
Thickness: 350 m
Lithology: It consists of variegated shale and thin bedded limestone and marl with rare mafic intrusion and diabase flow.
Synonyms: Not recorded

A Triassic unit of the Zhob area, found near exotic older Permian limestone blocks.

Gwal Formation Gwal named by Anwar et al. (1991) after Gwal village. It consists of variegated shale and thin bedded limestone and marl with rare mafic intrusion and diabase flow. On the basis of ammonites including Meekoceras, Owenites, Anakashmirites, Anasibirites, Durgaites, Hemiprionites, etc the age is Early Triassic (Late-Middle Scythian). It is exposed in Khanozai, Zhob, Quetta, Shirinab (Mastung, Kalat), etc, areas. It is 350 m thick in the Trakai-Gwal section. It contains exotic blocks of Permian limestone containing brachiopods, corals etc. Its lower contact is not exposed and upper contact with Wulgai is sharp and conforable with fossiliferous conglomeratic and dense limestone.

Fossils

Not recorded

Contacts

In the Kirthar Range column

LimestoneSandstoneShale / 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

Kirthar Range

Basin: Kirthar Basin
Region: Western Kirthar (Balochistan)
Depositional environment: marine
Coordinates: Not recorded

Correlation

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

Economic significance

Not recorded

Remarks

A Triassic unit of the Zhob/Muslimbagh area of the Balochistan ophiolite belt, associated with exotic Permian limestone blocks bearing brachiopods, fusulinids and corals.

Sources (4)

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.
Indian Plate Lexicon (indplex.geolex.org), Geological Society of India and international compilation.
Shah, S.M.I. (2009). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 22.

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: Name attested in the Shah (1977/2009) Geological Survey of Pakistan compilation — the national stratigraphic lexicon. This records where the name is documented; it is not an endorsement of the unit’s definition, age or figures.

Cite this unit

APA

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

BibTeX

@misc{stratigraphypk_gwalformation,
  author    = {Qudsi, Lareb},
  title     = {{Gwal 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/gwal-formation (accessed September 5, 2026).

To cite the unit's original definition instead, see: Anwar et al. (1991).

Above · younger

Wulgai Formation