Paleozoic • Permian formation In GSP lexicon

Gum Formation

Permian–Cretaceous

Karakoram-Hindukush Basin · Southern Metamorphic Belt

Cited in 4 sources Last reviewed Jul 30, 2026

Unit summary

Rank: formation
Status: Published
Age: Paleozoic · PermianPermian–Cretaceous
Named by: Le Fort & Gaetani (1998)
Type locality: Qalandar Gum glacier, upper Yasin/Darkot region
Thickness: about 1000 m
Lithology: About 1000 m of limestone and slate.
Synonyms: Not recorded

A thick (about 1000 m) Permian limestone-and-slate unit of the Darkot Group.

Gum formation (1000m) is named after Qalandar Gum glacier and consists of limestone and slates. Gaetani (2004) mentioned the Permian to Triassic or up to Cretaceous.

Fossils

Not recorded

Contacts

In the Karakoram column

LimestoneSandstoneMixedShale / 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: Southern Metamorphic Belt
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 thick limestone-and-slate unit of the Darkot Group (its Southern Stack); assigned a Permian age, though Gaetani (2004) suggested it may range up into the Triassic or even the Cretaceous.

Research notes (3)

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

Name & nomenclature (1)

Attested in Shah (2009), Geological Survey of Pakistan Memoir 22 - the Stratigraphic Committee of Pakistan's compiled lexicon (listed in the memoir's contents). Adds the definitional GSP/SCP lexicon citation.

Shah, S.M.I. (2009)

Age & correlation (1)

Zanchi & Gaetani (2011): the Gum Formation (Le Fort & Gaetani 1998; Darkot Group) is Permian to Triassic — Member 1 carries a Permian-aspect bryozoan/brachiopod fauna, Member 2 Late Triassic megalodontids. Well-bedded recrystallized limestones and dolostones (Mb 2 >700 m; Mb 1 ≥300 m). NB: the curated top age 'Cretaceous' is not supported by this paper (Triassic top) — flagged for reconciliation.

Zanchi, A. & Gaetani, M. (2011)

Lithology (1)

CONFIRMED against Zanchi & Gaetani (2011, full text): massive light limestone/dolostone (named after the Qalandar Gum Glacier) with a Permian-aspect bryozoan-brachiopod fauna. Supports a Permian age; the Cretaceous extension in the dataset is NOT confirmed by this map.

Zanchi, A. & Gaetani, M. (2011)

Sources (3)

Malkani, M.S. & Mahmood, Z. (2017). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 24.
Zanchi, A. & Gaetani, M. (2011). The geology of the Karakoram range, Pakistan: the new 1:100,000 geological map of Central-Western Karakoram. Italian Journal of Geosciences, 130(2), 161-262.
Shah, S.M.I. (2009). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 22.

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: 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.

Spotted an error? Suggest a sourced correction →

Cite this unit

APA

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

BibTeX

@misc{stratigraphypk_gumformation,
  author    = {Qudsi, Lareb},
  title     = {{Gum 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/gum-formation (accessed October 7, 2026).

To cite the unit's original definition instead, see: Le Fort & Gaetani (1998).