Spingwar Formation
Triassic–Jurassic
Kirthar Basin · Western Kirthar (Balochistan)
Part of Sulaiman Group, Shirinab Formation, Alozai Group
Triassic in the time scale →Cited in 6 sources Last reviewed Jul 17, 2026
- Rank
- formation
- Status
- Published
- Age
- Mesozoic · Triassic · Early Jurassic (Liassic)Triassic–Jurassic
- Named by
- Williams (1959)
- Type locality
- Spingwar, 35 km northwest of Loralai30.5478°N, 68.3211°E
- Thickness
- 600–1,800 m
- Lithology
- Interbedded grey to black crystalline limestone, oolitic and shelly in places, with calcareous shale and sandstone interbeds in the lower part.
- Synonyms
- Spingwar Member (basal Shirinab Formation, with the Loralai and Anjira members; Williams 1959)
The lowest part of the Jurassic Shirinab Formation — a thick crystalline limestone dated by ammonites to the Early Jurassic.
Named by Williams (1959) as the Spingwar Member of the Shirinab Formation (type section north of Zamari Tangi, northwest of Loralai) and raised to formation rank by Shah (2009), the Spingwar Formation is grey-to-greenish shale with marl and limestone and local igneous sills near the Western Indus Suture, ranging from about 140 to 665 m across measured sections. It rests conformably on the Triassic Wulgai Formation and passes up into the Anjira/Loralai limestone. Ammonites, brachiopods, bivalves and crinoids indicate a Late Triassic–Early Jurassic age (Fatmi, 1977).
Fossils
Contacts
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
- Basin
- Kirthar Basin
- Region
- Western Kirthar (Balochistan)
- Depositional environment
- shallow marine
- Coordinates
- 30.5478°N, 68.3211°E
Correlation
Not recorded. Compare this unit against other basins on the correlation panel →
Economic significance
Not recorded
Remarks
The basal member of the Jurassic Shirinab Formation; its ammonites indicate an Early Jurassic (Liassic) age.
Sources (5)
- 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.
- 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.
- 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
Qudsi, L. (2026). Spingwar Formation. In Pakistan Stratigraphy Dataset [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21363991
@misc{stratigraphypk_spingwarformation,
author = {Qudsi, Lareb},
title = {{Spingwar 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/spingwar-formation (accessed August 30, 2026).
To cite the unit's original definition instead, see: Williams (1959).
Related units
Referenced in other successions
Overlain by Anjira Formation
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