Mesozoic • Jurassic formation GSP memoir

Dark Limestone

Jurassic

Karakoram-Hindukush Basin · Central Karakoram Batholith

Cited in 2 sources Last reviewed Jul 31, 2026

Unit summary

Rank: formation
Status: Published
Age: Mesozoic · Jurassic · Early Jurassic (Pliensbachian)Jurassic
Named by: Gaetani et al. (1996a)
Type locality: Not recorded
Thickness: about 150 m
Lithology: About 150 m of dark limestone.
Synonyms: Not recorded

An Early Jurassic dark limestone unit, about 150 m thick.

Dark limestone is named by Gaetani et al. (1996a) and consists of 150m thick limestone and its age is Liassic (Pliensbachian).

Fossils

Not recorded

Contacts

In the Karakoram column

MarlLimestoneSandstoneShale / 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

Karakoram

Basin: Karakoram-Hindukush Basin
Region: Central Karakoram Batholith
Depositional environment: marine
Coordinates: Not recorded

Correlation

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

Economic significance

Not recorded

Remarks

An Early Jurassic (Liassic, Pliensbachian) limestone of the Karakoram Mesozoic succession.

Research notes (2)

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 (1)

Kazmi & Abbasi (2008) CORROBORATES the flag: the book treats the Chitral/Karakoram 'dark limestone' informally (consistently in quotation marks) — a ~150 m sequence of dark grey massive-to-thin-bedded limestone (Gaetani et al. 1996a) overlying the Ailak Formation, of Liassic (Pliensbachian) age. Confirms this is an informal descriptor, effectively the same body later formalised as the Darwaz An Formation; not a stand-alone formal unit.

Kazmi, A.H. & Abbasi, I.A. (2008)

Geological significance (1)

Data-quality flag (reviewer, 2026-07-30): "Dark Limestone" is an informal lithological descriptor (attributed by the GSP lexicon to Gaetani et al. 1996a), NOT a formally named formation, and it is not carried as a formal unit in Kazmi & Jan (1997). Its Early Jurassic (Pliensbachian) age, ~150 m thickness and Karakoram setting overlap the now-formal Darwaz An Formation (Zanchi & Gaetani 2011) and related Baroghil-Darwaz platform limestones. Candidate for merger into a formal unit or removal; downgraded to under-review pending a decision.

Malkani, M.S. & Mahmood, Z. (2017)

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: 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: 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.

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Cite this unit

APA

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

BibTeX

@misc{stratigraphypk_darklimestone,
  author    = {Qudsi, Lareb},
  title     = {{Dark 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/dark-limestone (accessed October 7, 2026).

To cite the unit's original definition instead, see: Gaetani et al. (1996a).