Paleozoic • Devonian formation In GSP lexicon

Chilmarabad Formation

Devonian

Karakoram-Hindukush Basin · Central Karakoram Batholith

Cited in 7 sources Last reviewed Jul 31, 2026

Unit summary

Rank: formation
Status: Published
Age: Paleozoic · DevonianDevonian
Named by: Gaetani et al. (1996)
Type locality: Type section measured north of Chilmarabad village, Yarkhun Valley; also exposed on the plateau NW of Lashkargaz.
Thickness: max ~145 m (Axial) to ~300 m (Karambar); ~230 m in the Lashkargaz/Baroghil sheet
Lithology: Slate, dolomitic limestone and dolomite.
Synonyms: Not recorded

A Devonian slate-and-dolomite unit above the Baroghil Group and below the Shogram Formation.

Chilmarabad formation consists of Devonian slates, dolomitic limestone and dolomites unconformably overlies the Baroghil group in the Baroghil pass region (LeFort et al., 1994). It is overlain by Late Devonian Shogram formation (Gaetani et al. 1995).

Fossils

Tabulate corals (Thamnopora, Pachycanalicula)Calcareous alga (Pseudopalaeoporella)Stromatoporoids

Contacts

In the Karakoram column

Shale / mudLimestoneMetamorphicMixedFossils recordedContact not recordedUnconformity

Band colour = period; texture = dominant rock type. Lines between bands mark the contact type (wavy = unconformity inferred from a missing period); dotted = no contact recorded in the sources (not a claim of conformity). 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

A Devonian carbonate–slate unit that rests with angular unconformity on the Baroghil Group in the Baroghil Pass region and passes up into the Late Devonian Shogram Formation.

Research notes (6)

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 (3)

Zanchi & Gaetani (2011): the Chilmarabad Formation is Eifelian to ?Givetian — the upper dolostone member yields algae and tabulate corals (Pseudopalaeoporella, Thamnopora, Pachycanalicula; Hubmann & Gaetani 2007). Two members: a lower doloarenitic member (~125 m) with terrigenous input and an upper monotonous light-grey stromatolitic dolostone member (~110 m); deposited on a wide peritidal flat. In the Karambar Unit it overlies the Vandanil Formation and is covered upward by the Shogram Formation.

Zanchi, A. & Gaetani, M. (2011)
Gaetani et al. (2008): the Chilmarabad Formation (Gaetani et al. 1996) is divided into two members — a lower mixed siliciclastic–carbonate package (present in most southern/western thrust sheets) and a ubiquitous upper member of often-stromatolitic dolostones (the calcareous part of the Tash Kupruk Zone is similar facies). Its carbonate flats show a trend towards emersion at the top and are overlain, across a regional unconformity, by the basal Shogrâm Formation. Devonian; corroborates the curated age and adds the primary source.

Gaetani, M., Mawson, R., Sciunnach, D. & Talent, J.A. (2008)
Talent et al. (1999): the Chilmarabad Formation (Gaetani et al. 1996) had no previously known fossils; a horizon with poorly-preserved stromatoporoids 'not younger than Middle Devonian' occurs above Lashkargaz, and a coral horizon further supports a Devonian age. It may be, in a general way, a lateral equivalent of the Charun Quartzite, and forms part of the Yarkhun-Vidiakot-Chilmarabad (Baroghil) assemblage. Corroborates the curated Devonian age.

Talent, J.A., Gaetani, M., Mawson, R., Molloy, P.D. & Conaghan, P.J. (1999)

Thickness (1)

CONFIRMED against Zanchi & Gaetani (2011, Fig. 19): the Chilmarabad Formation sits at the Silurian-Devonian level, max ~145 m (Axial) to ~300 m (Karambar). Corroborates the Devonian age; thickness gap-filled.

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

Fossils & biostratigraphy (1)

Surfaced from the age notes into fossils[]: the upper dolostone member yields algae and tabulate corals — Pseudopalaeoporella, Thamnopora, Pachycanalicula (Hubmann & Gaetani 2007, in Zanchi & Gaetani 2011). Talent et al. (1999) add poorly-preserved stromatoporoids 'not younger than Middle Devonian' and a coral horizon above Lashkargaz — the first fossils reported from a formation previously without any.

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

Sources (7)

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.
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.
Gaetani, M., Mawson, R., Sciunnach, D. & Talent, J.A. (2008). The Devonian of Western Karakorum (Pakistan). Acta Geologica Polonica, 58(3), 261-285.
Talent, J.A., Gaetani, M., Mawson, R., Molloy, P.D. & Conaghan, P.J. (1999). Early Ordovician and Devonian conodonts from the Western Karakoram and Hindu Kush, northernmost Pakistan. Rivista Italiana di Paleontologia e Stratigrafia, 105(2), 201-226.
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: 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.

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Cite this unit

APA

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

BibTeX

@misc{stratigraphypk_chilmarabadformation,
  author    = {Qudsi, Lareb},
  title     = {{Chilmarabad 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/chilmarabad-formation (accessed October 29, 2026).

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

Below · older

Baroghil Group

Ordovician–Silurian

Above · younger

Shogram Formation