Importance of microfacies and Paleoecological of calcareous alge and larger benthic foraminifera of Esfandiar Formation in central Tethys

The central Tethys realm in Iran is one of the most complex geodynamic settings within the Alpine-Himalayan belt. Evolution and Geological Significance of calcareous alge and larger Benthic Foraminifera is incredibly clear for carbonate basin analysis. High evolutionary rates make larger foraminifera and calcareous alge useful biostratigraphic tools for datation of sediments deposited in shallow marine platforms. Some shallow larger benthic foraminfera and calcareous algae are defined in the time span ranging from the base of Esfandiar Limestone Foramtion to the top of this formation. Seven distinct microfacies are recognized in the Esfandiar Limestone Formation south of the Shotori Mountains, east-central Iran. The most important larger agglutinated Foraminiferal and calcareous algae are Alveosepta jaccardi, HOTTINGER and Diversocallis moesicus respectively. All those taxa were adapted to special paleoecological conditions, such as a continuous terrigenous input. The stratigraphic distribution of the larger benthic Foraminifera allow us to propose a Oxfordian to Lower Kimmeridgian age for the studied sequence. The data provided by the larger Foraminifera, the Algae, and the lithology may suggest an internal platform environment of warm shallow water. The low-energy environment of the platform interior was episodically subjected to storms as is evidenced by chaotic and poorly bioconglomeratic layers indicating in situ reworking of the platform sediments. These calcareous algae and foraminiferal association are constituted by cosmopolitan species which are frequent in the Tethyan Realm.