Ribat Formation
Early Carboniferous
Karakoram-Hindukush Basin · Central Karakoram Batholith
Carboniferous in the time scale →Cited in 5 sources Last reviewed Jul 31, 2026
- Rank
- formation
- Status
- Published
- Age
- Paleozoic · Carboniferous · Early CarboniferousEarly Carboniferous
- Named by
- Gaetani et al. (2004)
- Type locality
- Ribat River, upper Karambar region
- Thickness
- >300 m in the Karambar Unit (Ribat Valley type section), reduced to <100 m in the Baroghil-Lashkargaz Unit (upper part eroded/non-deposited before the Gircha Fm.)
- Lithology
- Fossiliferous limestone and marl.
- Synonyms
- Not recorded
An Early Carboniferous limestone-and-marl unit above the Margach Formation.
Fossils
Contacts
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
- Basin
- Karakoram-Hindukush Basin
- Region
- Central Karakoram Batholith
- Depositional environment
- marine, shallow marine
- Coordinates
- Not recorded
Correlation
Not recorded. Compare this unit against other basins on the correlation panel →
Economic significance
Not recorded
Remarks
An Early Carboniferous fossiliferous-limestone unit overlying the Margach Formation.
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 (2)
-
Zanchi & Gaetani (2011): the Ribat Formation spans the late Tournaisian–Bashkirian in the Karambar type section (conodonts Gnathodus spp., Siphonodella lobata; a rich spiriferid–productoid brachiopod fauna), reduced to middle–late Tournaisian along the Yarkhun River. Grey crinoidal limestones and marls of a fully marine, high-productivity carbonate shelf; overlain with a gentle angular unconformity by the Gircha Formation.
-
Gaetani et al. (2004) — DEFINES the Ribat Formation (new name; type section on the south side of the Ribat valley): grey crinoidal limestones passing up to dark marly limestones and marls, at least ~300 m thick (reduced to <100 m in the Baroghil–Lashkargaz Unit), dated late Tournaisian to Bashkirian (i.e. into the Pennsylvanian) — a fully marine carbonate ramp/shelf phase. Refines the curated 'Early Carboniferous' (the unit's top reaches the Bashkirian); adds the definitional source.
Lithology (1)
-
CONFIRMED against Zanchi & Gaetani (2011, full text, Fig. 19): Lower Carboniferous crinoidal-to-marly limestones overlying the Margach Fm; thickness 70-120 m (Lashkargaz/Baroghil) to >350 m (Karambar). Corroborates the Early Carboniferous age.
Fossils & biostratigraphy (1)
-
Surfaced from the age/lithology notes into fossils[]: the Ribat Formation's grey crinoidal limestones carry conodonts (Gnathodus spp., Siphonodella lobata) and a rich spiriferid–productoid brachiopod fauna dating the late Tournaisian–Bashkirian span (Zanchi & Gaetani 2011; Gaetani et al. 2004). Crinoids are the rock-forming bioclasts of the crinoidal limestone.
Sources (7)
- Gaetani, M. et al. (2004). Northern Karakoram sedimentary belt.
- Malkani, M. S. & Mahmood, Z. (2017). Stratigraphy of Pakistan. Memoir of the Geological Survey of Pakistan, Vol. 24.
- 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.
- Gaetani, M., Zanchi, A., Angiolini, L., Olivini, G., Sciunnach, D., Brunton, H., Nicora, A. & Mawson, R. (2004). The Carboniferous of the Western Karakoram (Pakistan). Journal of Asian Earth Sciences, 23(2), 275-305.
- 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.
Cite this unit
Qudsi, L. (2026). Ribat Formation. In Pakistan Stratigraphy Dataset [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21363991
@misc{stratigraphypk_ribatformation,
author = {Qudsi, Lareb},
title = {{Ribat 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/ribat-formation (accessed October 29, 2026).
To cite the unit's original definition instead, see: Gaetani et al. (2004).
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