Palaeoecology and distribution of upper Oligocene–lower Miocene foraminifera in the Qom Formation, the Bagher-Abad section, NE Isfahan, Central Iran

• Maryam Nouradini ^[1] ; Ali Reza Ashouri ^[1] ; Mehdi Yazdi ^[2] ; Amir Hossein Rahiminejad ^[3]
  1. [1] Ferdowsi University of Mashhad

     Ferdowsi University of Mashhad

     Irán

     
  2. [2] University of Isfahan

     University of Isfahan

     Irán

     
  3. [3] Graduate University of Advanced Technology, Kerman

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• Localización: Carbonates and Evaporites, ISSN 0891-2556, Vol. 34, Nº. 3, 2019, págs. 563-579
• Idioma: inglés
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  • These palaeoecological investigations were carried out on foraminiferal assemblages from the Qom Formation in the Bagher-Abad section, northeast of Isfahan, Central Iran. Foraminiferal analysis of the lower limestone part of the succession revealed correlation with the Chattian zone SBZ (Shallow Benthic Zone) 23, and the overlaying marly strata revealed planktonic foraminifera of the Aquitanian Zone M1 (“Paragloborotalia” kugleri Taxon-range Zone). Finally, the topmost, barren zone, and benthic foraminifera assemblage were correlated with the Burdigalian, based on the regional stratigraphic scheme. Palaeoecological interpretations based on microfaunal composition and abundance of benthic foraminifera revealed that late Oligocene microfossils were dominated by larger foraminifera (Rotaliids), whereas early Miocene assemblage was dominated by miliolids. The foraminiferal associations generally reflect well-oxygenated shallow warm tropical waters within the photic zone (<50 m depth) during the Chattian–Burdigalian. These Oligocene/Miocene foraminiferal assemblages indicated middle shelf and inner shelf with normal marine salinity and oligotrophic-to-mesotrophic conditions.