Early Cretaceous benthic foraminiferal biozonation of the Fahliyan and Gadvan Formations in the Assaluyeh and Halegan stratigraphic sections, Zagros Basin, Southwest of Iran

• Borzu Asgari Pirbalouti ^[1] ; Ahmad Abyat ^[1]
  1. [1] Islamic Azad University

     Islamic Azad University

     Irán

     
• Localización: Carbonates and Evaporites, ISSN 0891-2556, Vol. 34, Nº. 2, 2019, págs. 249-260
• Idioma: inglés
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• Resumen

  • Early cretaceous sediments (Fahliyan and Gadvan Formations) in the Coastal Fars (namely Assaluyeh and Halegan), Zagros fold-thrust belt, SW Iran, were measured and sampled for micropaleontological investigations. In this research, Fahliyan Formation lies unconformably on the Hith/Surmeh formations and the Gadvan Formation overlies the Fahliyan Formation with conformable contact. The Gadvan Formation overlies by Dariyan Formation; this contact is sharp and conformable. The Fahliyan Formation in these stratigraphic sections can be divided into two informal members: Lower Fahliyan member and Upper Fahliyan member; and the Gadvan Formation was divided into three informal members: Lower Shale member, Khalij member and Lower Shale member. The Fahliyan Formation and Gadvan Formation in the Zagros include a diversified assemblage of benthic foraminifera and dasycladalean algae. In Assaluyeh and Halegan sections based on foraminifers, three biozones and one subzone are recognized that in ascending order are: (1) Pseudochrysalidina (Dukhania) zone (Berriasian), (2) Pseudocyclammina lituus zone (Valanginian–Hauterivian), (3) Orbitolina–Choffatella–Salpingoporella dinarica assemblage zone (Barremian), and (4) Montseciella arabica subzone (Barremian).