Mesozoic • Cretaceous complex Literature

Kamila Amphibolite Belt

Early to mid-Cretaceous (transition from oceanic to arc magmatism inferred); hornblende Ar-Ar cooling ages c. 80-83 Ma record suturing-related deformation

Kohistan Arc · Kohistan Batholith

Cretaceous in the time scale →

Cited in 4 sources Last reviewed Aug 20, 2026

Unit summary

Rank: complex
Status: Published
Age: Mesozoic · CretaceousEarly to mid-Cretaceous (transition from oceanic to arc magmatism inferred); hornblende Ar-Ar cooling ages c. 80-83 Ma record suturing-related deformation
Named by: Treloar et al. (1989, 1996)
Type locality: Kamila area, Indus valley, Kohistan; forms the southern part of the arc (Kamila Shear Zone).
Thickness: Not recorded
Lithology: Amphibolite-facies basic lavas (some pillowed), hyaloclastite and breccias intruded by gabbros and diorites; two suites — a Ti-rich, HFSE/HREE-enriched high-Ti oceanic-type MORB suite and a Ti-poor, calc-alkaline low-Ti arc suite with a negative Nb anomaly.
Synonyms: Not recorded

The Kamila Amphibolite Belt is the oldest part of the Kohistan island arc — a variably sheared, amphibolite-facies mixture of basic lavas (some pillowed), hyaloclastite and intrusive gabbros/diorites. It comprises two geochemical suites: an older high-Ti suite of transitional oceanic-type basalts (MORB-like, interpreted as magmatically thickened, possibly ocean-plateau, pre-arc crust) forming the basement, intruded by a low-Ti calc-alkaline suite marking the earliest true arc magmatism. Its southern part is the c. 20 km-wide, SW-vergent Kamila Shear Zone.

Fossils

Not recorded

Contacts

Lower contact — not recorded; upper contact — intrusive.

In the Kohistan Arc column

MetamorphicIgneousConglomerateFossils recordedConformableIntrusive

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

Kohistan Arc

Basin: Kohistan Arc
Region: Kohistan Batholith
Depositional environment: volcanic-arc, oceanic, marine
Coordinates: Not recorded

Correlation

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

Economic significance

Not recorded

Remarks

Demonstrates that the earliest part of Kohistan is oceanic basement, not subduction-related — the high-Ti basalts are pre-arc oceanic crust intruded by the first arc-type magmas. Amphibolitised Chilas Complex gabbronorites occur in its northern part.

Sources (5)

Treloar, P.J., Petterson, M.G., Jan, M.Q. & Sullivan, M.A. (1996). A re-evaluation of the stratigraphy and evolution of the Kohistan arc sequence, Pakistan Himalaya. Journal of the Geological Society, London, 153, 681-693.
Treloar, P.J., Petterson, M.G., Jan, M.Q. & Sullivan, M.A. (1996). A re-evaluation of the stratigraphy and evolution of the Kohistan arc sequence, Pakistan Himalaya: implications for magmatic and tectonic arc-building processes. Journal of the Geological Society, London, 153, 681-693.
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.
Anczkiewicz, R., Burg, J.-P., Hussain, S.S., Dawood, H., Ghazanfar, M. & Chaudhry, M.N. (1998). Stratigraphy and structure of the Indus Suture in the Lower Swat, Pakistan, NW Himalaya. Journal of Asian Earth Sciences, 16(2-3), 225-238.
Coward, M.P., Jan, M.Q., Rex, D., Tarney, J., Thirlwall, M. & Windley, B.F. (1984). Geology of the South Central Karakoram and Kohistan. In: Miller, K.J. (ed.), The International Karakoram Project, Vol. 2, 71-84. Cambridge University Press.

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: Defined in journal or other literature; not found in a GSP memoir. There is no body currently ratifying unit status, so provenance is shown in place of a formal ruling.

Cite this unit

APA

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

BibTeX

@misc{stratigraphypk_kamilaamphibolitebelt,
  author    = {Qudsi, Lareb},
  title     = {{Kamila Amphibolite Belt} --- 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/kamila-amphibolite-belt (accessed August 30, 2026).

To cite the unit's original definition instead, see: Treloar et al. (1989, 1996).

Above · younger

Jaglot Group

Jurassic–Cretaceous