Paleoecology investigations of Lower Eocene sediments, West Tafresh,using large benthic foraminifera distribution


H. Noroozpour, M. Yousefi-Rad

Regarding the consequential role of large benthic foraminifera associations in detecting undersea conditions, we have attempt to study these faunas in the 27 samples derived from Paleocene-Eocene sediments with a thickness of nearly 110 meters belonging to the Naghusan section located in the west Tafresh. The studied interval lithologically made up of sandy-marly limestone and tuff with a low percentage of sedimentary rocks such as sandstone. In this study, 17 species belonging to 9 genera of benthic foraminifera were identified and based on environmental index fossils, as various species of Assilina, Discocyclina and Nummulites genera, a carbonate semi-deep open marine environment has been suggested for these sediments. Indeed, an oligotrophic condition with relatively high lightening and normal salinity in a limy-sandy floor has been reported for the studied succession.

Keywords: Paleoecology; lower eocene; west tafresh

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