Precambrian • Neoproterozoic Literature

Tanaki Boulder Bed

Late Neoproterozoic (Marinoan, ~605–595 Ma)

Cited in 2 sources Last reviewed Aug 20, 2026

Unit summary

Rank: Not recorded
Status: Published
Age: Precambrian · NeoproterozoicLate Neoproterozoic (Marinoan, ~605–595 Ma)
Named by: Latif (1970)
Type locality: Southeastern Hazara, Hazara Fold-and-Thrust Belt, northern Pakistan (named by Latif 1970).
Thickness: Not recorded
Lithology: Very poorly sorted, matrix-supported conglomerate (diamictite) with angular to sub-rounded clasts 3–50 cm across — dark-grey siltstone, slate and shale and light-grey to brown quartzite reworked from the Hazara and Tanawal formations — in a matrix of fine pebbles, sand, silt and argillite.
Synonyms: Tanakki Boulder Bed; Tanakki Conglomerate

A jumbled glacial boulder bed in the Hazara hills marking a global ice age at the end of the Precambrian — the local record of the Marinoan 'snowball Earth' glaciation.

The Tanaki Boulder Bed is a glaciogenic diamictite of the Hazara Basin (Lesser Himalaya, northern Pakistan), named by Latif (1970), that overlies the Tanawal Formation and underlies the Cambrian Abbottabad Formation. As documented by Umar et al. (2015), its angular clasts, lack of fluvial features and preserved striations indicate a glacial origin, and it is interpreted as part of the terminal-Neoproterozoic Marinoan glaciation (~605–595 Ma). It forms an excellent regional marker horizon.

Fossils

Not recorded

Contacts

In the Hazara Basin column

MetamorphicConglomerateLimestoneFossils 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

Hazara Basin

Basin: Not recorded
Region: Not recorded
Depositional environment: glaciogenic, glaciomarine
Coordinates: Not recorded

See it in the field

Geoheritage site where this unit is exposed at outcrop.

Tanaki Boulder Bed — Marinoan glaciation

Hazara Basin

Correlation

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

Economic significance

Not recorded

Remarks

A glaciogenic marker horizon recording the terminal-Proterozoic Marinoan glaciation in the Lesser Himalaya; correlated with the Blaini Formation of the Indian Lesser Himalaya and the Sinian diamictites (Changan/Fulu/Silikou formations) of South China, part of the globally correlative Neoproterozoic 'snowball Earth' glaciation (Umar et al. 2015).

Research notes (1)

Field-by-field findings drawn from the cited literature. Every statement is traced to a registered source — follow a citation for the full reference.

Age & correlation (1)

Qasim et al. (2018): U-Pb detrital-zircon dating of the Tanaki conglomeratic bed (sample 2015A3) yields grains clustering ~750-950 Ma with an age peak at ~830 Ma, confirming a Precambrian (Neoproterozoic) age; the matrix-supported, lithic-rich bed marks the angular unconformity between the underlying Hazara/Tanawal succession and the Cambrian Abbottabad Formation. Independent corroboration of the Late Neoproterozoic assignment — lifts the unit to two sources.

Qasim, M., Ding, L., Khan, M.A., Jadoon, I.A.K., Haneef, M., Baral, U., Umar, M., Cai, F., Shah, A. & Yao, W. (2018)

Sources (1)

Umar, M., Betts, P., Khan, M.M.S., Sabir, M.A., Farooq, M., Zeb, A., Jadoon, U.K. & Ali, S. (2015). Signatures of Late Neoproterozoic Gondwana assembly and Marinoan glaciation in Lesser Himalaya: a palaeogeographical and stratigraphical approach. Acta Geologica Polonica, 65(1), 1-19.

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: 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.

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Cite this unit

APA

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

BibTeX

@misc{stratigraphypk_tanakiboulderbed,
  author    = {Qudsi, Lareb},
  title     = {{Tanaki Boulder Bed} --- 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/tanaki-boulder-bed (accessed October 29, 2026).

To cite the unit's original definition instead, see: Latif (1970).

Below · older

Tanawal Formation

Neoproterozoic

Above · younger

Abbottabad Formation

Cambrian