Source provenance

Ahmad, S., Kroon, D., Rigby, S. & Khan, S. (2016). Paleogene Nummulitid biostratigraphy of the Kohat and Potwar Basins in north-western Pakistan with implications for the timing of the closure of eastern Tethys and uplift of the western Himalayas. Stratigraphy, 13(4), 277-301.

Cited by 3 units (3 published) · 2 field-level citations · 4 revision notes.

Primary larger-benthic-foraminifera (LBF) biostratigraphy of the Paleogene Kohat and Potwar basins. Erects six nummulitid Benthic Foraminiferal Zones (BFZ 1-6) tied to Serra-Kiel et al. (1998) SBZ zones and to Schaub (1981): BFZ 1 (LO Miscellanea miscella), BFZ 2 (FO Assilina dandotica; late Thanetian-early Ilerdian boundary), BFZ 3 (FO Nummulites atacicus/N. globulus and Orbitolites complanatus; early Eocene, SBZ 8-11), BFZ 4 (FO Assilina exponens; middle Lutetian 1, SBZ 14), BFZ 5 (FO Nummulites beaumonti; middle Lutetian 2), BFZ 6 (range of Assilina cancellata; Upper Lutetian, ~ A. gigantea Zone / SBZ 16). Records cessation of marine sedimentation in the Kohat and Potwar basins in early Eocene (Middle Cuisian ~ BFZ 3, ~50-49.5 Ma), a Middle Lutetian marine return in the Kohat Basin (eustatic), and final closure of the eastern Tethys seaway in the Kohat Basin in Upper Lutetian (~BFZ 6, ~41.2 Ma). Sections: Sheikhan/Panoba/Tarkhobi Nala (Kohat) and Kalabagh/Chahali Nala (Potwar-TIR).

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Units citing this source

• Cenozoic Kohat Formation Paleogene
  Fossils
  • Fossils: Ahmad, Kroon, Rigby & Khan (2016, Stratigraphy 13(4)) document the Kohat Formation in the Sheikhan Nala section (Kohat Basin) as hosting their upper three nummulitid Benthic Foraminiferal Zones - BFZ 4 (FO Assilina exponens; 32 m), BFZ 5 (FO Nummulites beaumonti; 9 m) and BFZ 6 (range of Assilina cancellata; 28 m) - with a figured LBF assemblage of Assilina exponens, A. laminosa, A. papillata, A. cancellata, Nummulites beaumonti, N. acutus, Alveolina elliptica and A. spinosa. This constrains the formation to the Middle-Upper Lutetian (middle Eocene), consistent with the curated age.
  • Age: In the Kohat Basin the top of the Kohat Formation (BFZ 6, Upper Lutetian ~ SBZ 16 / Assilina gigantea Zone of Schaub 1981) records the final cessation of marine sedimentation and closure of the eastern Tethys seaway at ~41.2 Ma, per Ahmad et al. (2016).
• Cenozoic Panoba Formation Paleogene
  Fossils
  • Age: Ahmad, Kroon, Rigby & Khan (2016, Stratigraphy 13(4)) place the Panoba Formation in the Panoba Nala section within their BFZ 3 Zone (FO Nummulites atacicus/N. globulus and Orbitolites complanatus; ~40 m thick), correlated to SBZ 8-11 of Serra-Kiel et al. (1998) and the Laki Stage - i.e. early Eocene (Middle Ilerdian 2-Middle Cuisian). The associated LBF include O. complanatus, R. sahini, N. pinfoldi, A. spinosa, A. laminosa, Alveolina elliptica, Lockhartia conica and Operculina sp. They date the regional cessation of marine sedimentation at this level to ~50-49.5 Ma. Corroborates the curated Early Eocene age.
• Cenozoic Shekhan Formation Paleogene
  • Age: Ahmad, Kroon, Rigby & Khan (2016, Stratigraphy 13(4)) record the Sheikhan Formation (Sheikhan Nala, Kohat Basin) within their BFZ 3 Zone (~22 m thick), with figured Orbitolites complanatus and flosculinized Alveolina pasticillata - an early Eocene (Middle Ilerdian 2-Middle Cuisian, SBZ 8-11) assemblage that conformably overlies the Panoba Shale. Corroborates the curated Early Eocene age.