Paleozoic • Cambrian formation In GSP lexicon

Ambar Formation

Cambrian

Northern Indus Suture

Cited in 7 sources Last reviewed Aug 10, 2026

Unit summary

Rank: formation
Status: Published
Age: Paleozoic · CambrianCambrian
Named by: Pogue and Hussain (1986)
Type locality: Ambar village, Swabi-Jehangira road (Nowshera-Swabi area)
Thickness: more than 425 m
Lithology: Brownish-grey dolomite with chert lenses and shale layers; the upper part is more massive with stromatolitic laminations.
Synonyms: Amber Formation; Amber dolomite

A Cambrian dolomite — the oldest Paleozoic unit near Nowshera — matched with the Abbottabad Formation.

The Ambar Formation is named after Ambar village along the Swabi–Jehangira road by Pogue and Hussain (1986) for dolomite, dolomitic limestone, quartzite and argillite.

Fossils

Not recorded

Contacts

In the Khyber–Nowshera Belt column

MetamorphicLimestoneFossils recordedContact not recorded

Band colour = period; texture = dominant rock type. Lines between bands mark the contact type; 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

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

The oldest unit of the Nowshera Paleozoic complex (the 'Amber dolomite'), correlated on lithology with the Cambrian Abbottabad Formation of Hazara; it is overlain unconformably by the Ordovician Misri Banda Quartzite (dataset Jobra Formation).

Research notes (4)

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)

Lithology (1)

Room et al. (2023): the massive Cambrian dolomite of the Ambar Formation (Peshawar Basin) records multiphase dolomitisation — a replacive matrix-dolomite phase (MD-I to MD-III), a pore-filling saddle-dolomite and calcite-cement phase with brecciation and stylolitisation (characteristic of burial dolomitisation), and a final white-calcite calcitisation phase. MD-I δ18O values of −7.64 to −8.13‰ PDB retain a Cambrian marine signature, implying dolomitisation during the Mid–Late Cambrian by thermal-convection burial fluids channelled along fractures and faults.

Room, S.A., Kashif, M., Ullah, H., Rehman, A.U., Ahmad, W. & Akhtar, S. (2023)

Geological significance (2)

Pogue, Harris & Hussain (1992; unit named by Pogue & Hussain 1986): the Ambar Formation is ~500 m of massive sandy dolomite with characteristic 'butcher-block' weathering and basal pisolitic beds. No conodonts were recovered, but microscopic shell debris in the pisoliths argues against a Late Proterozoic age and it is correlated on lithology with the Lower Cambrian Sirban Formation (upper Abbottabad Group) - hence a Cambrian(?) age. It unconformably overlies the Tanawal Formation and is overlain by the Misri Banda Quartzite.

Pogue, K.R., Harris, A.G. & Hussain, A. (1992)
Hussain, DiPietro & Pogue (1998): the Ambar Formation (dolomite, dolomitic limestone and calcareous quartzite with algal laminations and poorly developed stromatolites) has its type section at Ambar village (34 deg 03' N, 72 deg 25' E) on the Swabi-Jehangira road. It rests unconformably on the Precambrian Tanawal Formation (locally a ~10 m cobble-pebble conglomerate at Chingalai) and is unconformably overlain by the Ordovician Misri Banda Quartzite across 5-10 m of maroon shale; correlated with the Abbottabad Formation of Hazara. Its Cambrian(?) age rests only on stratigraphic position.

Hussain, A., DiPietro, J.A. & Pogue, K.R. (1998)

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.
Shah, S.M.I. (2009). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 22.
Room, S.A., Kashif, M., Ullah, H., Rehman, A.U., Ahmad, W. & Akhtar, S. (2023). Characterization of Dolomite in Ambar Formation (Cambrian), Peshawar Basin, Khyber Pakhtunkhwa, Pakistan. Petroleum and Coal, 65(3), 875-885.
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.
Pogue, K.R., Harris, A.G. & Hussain, A. (1992). Paleozoic and Mesozoic stratigraphy of the Peshawar basin, Pakistan: Correlations and implications. Geological Society of America Bulletin, 104(8), 915-927.
Hussain, A., DiPietro, J.A. & Pogue, K.R. (1998). Stratigraphy and structure of the Peshawar basin, Pakistan. Journal of Nepal Geological Society, 18, 25-35.

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). Ambar Formation. In Pakistan Stratigraphy Dataset [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21363991

BibTeX

@misc{stratigraphypk_ambarformation,
  author    = {Qudsi, Lareb},
  title     = {{Ambar 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/ambar-formation (accessed October 29, 2026).

To cite the unit's original definition instead, see: Pogue and Hussain (1986).

Above · younger

Jobra Formation

Ordovician

Referenced in other successions

Overlain by Misri Banda Quartzite