Paleozoic • Ordovician formation In GSP lexicon

Vidiakot Formation

Ordovician

Karakoram-Hindukush Basin · Central Karakoram Batholith

Part of Baroghil Group

Ordovician in the time scale →

Cited in 6 sources Last reviewed Jul 31, 2026

Unit summary

Rank: formation
Status: Published
Age: Paleozoic · Ordovician · Early OrdovicianOrdovician
Named by: Quintavalle et al. (2000)
Type locality: Type section along the Vidiakot ridge (Baroghil side), Axial Unit; named after the Vidiakot ridge, crops out between the Paur Gol and Chilmarabad.
Thickness: 400–500 m
Lithology: Fine-grained slate and siltstone with fine sandstone intercalations.
Synonyms: Not recorded

Early Ordovician slates and siltstones of the western Karakoram.

Vidiakot formation consists of fine grained slates and siltstone with fine sandstone intercalations. Its age Lower Ordovician.

Fossils

Not recorded

Contacts

In the Karakoram column

MixedLimestoneMetamorphicFossils recordedUnconformityContact not recorded

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, outer shelf
Coordinates: Not recorded

Correlation

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

Economic significance

Not recorded

Remarks

A Lower Ordovician fine-clastic unit of the lower Paleozoic succession of the western Karakoram-Hindukush.

Research notes (5)

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)

CONFIRMED against Zanchi & Gaetani (2011, full text, Fig. 19): the Vidiakot Formation (~500 m in the Axial sheet) is Ordovician (above the Yarkhun Fm, Baroghil Group), black splintery shales/siltstones with recrystallized dolostone. Corroborates the Ordovician age.

Gaetani, M., Le Fort, P., Tanoli, S., Angiolini, L., Nicora, A., Sciunnach, D. & Khan, A. (1996)
Zanchi & Gaetani (2011): the Vidiakot Formation (upper Baroghil Group) begins near the Arenig–Llanvirn boundary (acritarch assemblage VK3) and is supposed to span the rest of the Ordovician and at least part of the Silurian — poorly preserved orthoceratid cephalopods in upper carbonate lenses tentatively suggest a Silurian age (evidence poor). At least 400–500 m of black splintery slates with dolostone lenses; an outer-shelf mud with reappearing carbonate toward the top.

Zanchi, A. & Gaetani, M. (2011)
Talent et al. (1999): the Vidiakot Formation is INTRODUCED here for the upper, finer-grained part of the former Yarkhun Formation (Gaetani et al. 1996) — shales, siltstones and arkosic sandstones of the Vidiakot section yielding Early Ordovician (Arenig) acritarchs (nitidus/gibberulus to hirundo Graptolite Zone; Amerise et al. 1998). It sits between the restricted (lower, coarser) Yarkhun Formation and the Chilmarabad Formation, the three together = Tahirkheli's Baroghil Formation/Group. Corroborates the curated Ordovician age and adds the definitional source.

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

Thickness (1)

Thickness surfaced from the age note: the Vidiakot Formation is ~500 m in the Axial sheet — at least 400–500 m of black splintery slates with dolostone lenses (Zanchi & Gaetani 2011).

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

Sources (7)

Malkani, M.S. & Mahmood, Z. (2017). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 24.
Gaetani, M. and others (1996). Reconnaissance geology in Upper Chitral, Baroghil and Karambar districts (northern Karakorum, Pakistan). Geologische Rundschau, 85, 683-704.
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.
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.
Gaetani, M., Le Fort, P., Tanoli, S., Angiolini, L., Nicora, A., Sciunnach, D. & Khan, A. (1996). Reconnaissance geology in Upper Chitral, Baroghil and Karambar districts (northern Karakorum, Pakistan). Geologische Rundschau, 85, 683-704.
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: 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). Vidiakot Formation. In Pakistan Stratigraphy Dataset [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21363991

BibTeX

@misc{stratigraphypk_vidiakotformation,
  author    = {Qudsi, Lareb},
  title     = {{Vidiakot 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/vidiakot-formation (accessed October 29, 2026).

To cite the unit's original definition instead, see: Quintavalle et al. (2000).

Below · older

Yarkhun Formation

Ordovician

Above · younger

Chilmarabad Formation

Devonian

Referenced in other successions

Overlain by Vandanil Formation