Paleozoic • Silurian formation GSP memoir

Owsi Nala Limestone

Middle to Late Silurian

Northern Indus Suture

Cited in 2 sources Last reviewed Jul 31, 2026

Unit summary

Rank: formation
Status: Published
Age: Paleozoic · SilurianMiddle to Late Silurian
Named by: Not recorded
Type locality: Owsi Nala, Khyber area
Thickness: ~30 m
Lithology: Limestone with shale intercalations.
Synonyms: Not recorded

A Silurian limestone-and-shale unit of the Khyber area at Owsi Nala.

Owsi Nala limestone consists of limestone and shale intercalations. Mafic intrusions produced soapstone lenses. On the basis of superposition age is Middle to upper Silurian age (Khan, M.A. 1970). Kandar phyllite consists of phyllite, phyllitic schists interbedded with limestone and mafic sills which have produced soapstone. Middle to upper Silurian (Khan, M.A. 1970).

Fossils

Not recorded

Contacts

In the Khyber–Nowshera Belt column

LimestoneMixedMetamorphicConformable

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

Khyber–Nowshera Belt

Basin: Northern Indus Suture
Region: Not recorded
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 Silurian limestone-and-shale unit of the Khyber area.

Sources (2)

Malkani, M.S. & Mahmood, Z. (2017). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 24.
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.

Reviewer confidence: medium

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: Appears in a single-author Geological Survey of Pakistan memoir (Malkani & Mahmood 2017), not cross-confirmed against the Shah lexicon. The Stratigraphic Committee of Pakistan is largely inactive, so documented provenance — not formal ratification — is the available signal.

Cite this unit

APA

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

BibTeX

@misc{stratigraphypk_owsinalalimestone,
  author    = {Qudsi, Lareb},
  title     = {{Owsi Nala Limestone} --- 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/owsi-nala-limestone (accessed August 30, 2026).