Facies

, Volume 58, Issue 3, pp 339–365

Biodiversity and community structure of Late Pleistocene foraminifera from Kish Island, Persian Gulf (Iran)

  • Zahra Karimi Mossadegh
  • Justin Parker
  • Eberhard Gischler
Original Article

Abstract

The raised coral reef sequences at Kish Island provide a rare window into the depositional setting and paleoenvironment of a high-latitude, shallow-water coral reef that developed under turbid conditions in the Persian Gulf during Marine Isotope Stage 7 (~200 to 250 ka). Six sedimentary facies and eight foraminiferal assemblages can be identified throughout the sequence. A ninth assemblage can be defined for the modern subtidal realm. At the base of the sequence is a marl rich in hyaline foraminifera (Elphidium, Ammonia, Asterorotalia, Bulimina, Nonion, and Quinqueloculina) and ostracods, which was deposited in about 30–40 m water depth in a turbid deltaic setting. Shallowing resulted in the marl becoming sandy, and changing to a mollusc-rich facies with rare foraminifera (mostly smaller miliolid taxa) that formed the substrate for coral recruitment. The coral marl layer contains many large corals embedded in situ in an aggregate and coralline algae-rich marl. Two abundance peaks in the foraminifera occur at the base and mid-way through this layer, which also correspond to a change from Murrayinella-dominated to Placopsilina-dominated assemblages, indicating deepening and more open-marine conditions, but elevated turbidity. Towards the top of the layer, abundance of foraminifera decreases and miliolid foraminifera become dominant. The top-most layer is dominated by coral and mollusc fragments and has an Amphistegina-rich reef-related assemblage. Of the Late Pleistocene foraminiferal assemblages, the Murrayinella-, Pararotalia-, and Placopsilina-dominated assemblages are no longer present in the modern gulf for unknown reasons. Of the other five assemblages, only the Amphistegina assemblage is found within proximity to the modern Kish Island. The Elphidium and Asterorotalia-Bulimina assemblages are from deeper areas of the gulf. The Ammonia and Quinqueloculina assemblages occur in lagoonal sediments on the Arabian side of the gulf. Like the modern Persian Gulf, the diversity of foraminifera was low (~80 common species) during the Pleistocene and does not correlate with foraminiferal abundance.

Keywords

Late Pleistocene Persian Gulf Coral reef Foraminifera Marine Isotope Stage 7 Biodiversity 

Supplementary material

10347_2011_286_MOESM1_ESM.doc (84 kb)
Appendix 1 Systematic list of foraminifera from the Pleistocene of Kish Island (DOC 84 kb)
10347_2011_286_MOESM2_ESM.xls (34 kb)
Appendix 2 Counts of benthic foraminifera (XLS 34 kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Zahra Karimi Mossadegh
    • 1
    • 3
  • Justin Parker
    • 1
    • 3
  • Eberhard Gischler
    • 2
  1. 1.Biodiversity and Climate Research CentreFrankfurt am MainGermany
  2. 2.Institut für GeowissenschaftenGoethe UniversitätFrankfurt am MainGermany
  3. 3.School of Earth and Environmental Sciences - M004University of Western AustraliaPerthAustralia

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