First report of the SardinellaSardinites (Heckel, 1850) in the Kond formation in the Saran area, Central Alborz in Iran

Investigating the fossil-bearing horizons of the kond formation in the saran area resulted in the identification of sardinellasardinites (heckel 1850) belonging to the family of clupeidae bonaparte (1831) for the first time the east of tehran province. furthermore, biostratigraphic analyses based on the presence of benthic and planktonic foraminifera in this area demonstrate that the sedimentary sequence including strata of conglomerate, tuff, shale, gypsum, limestone, and marl with a thickness of 376 m in the saran area belongs to the priabonian, which is discontinuously located on middle eocene green tuffaceousshales. in the present study, 18 species belonging to 9 genera from the benthic foraminifera were identified. in the late middle eocene, the performance of the orogenic pyrenean phase led to the rising of the sedimentary strata and subsequent retreat of the sea and then the sea re-advanced during the priabonian stage. the presence of a conglomerate at the base of the formation reveals the next activity of the tectonic phase. in this study, the rock unit of the lower red formation belonging to the oligo-miocene is located on the deposits of the kond formation.