stratigraphy of the upper jurassic shallow marine carbonates of the moghan area (nw iran), with paleobiogeography implication on alveosepta jaccardi (schrodt, 1894)

a micropaleontological study has been carried out on the samples collected from the sarv abad section, the oldest and only known jurassic sedimentary rocks cropping out in the moghan area. studied sequence consists of carbonates bounded at both base and top by clastic deposits. studied carbonate deposits provide an assemblage of benthic foraminifera as well as calcareous algae. the stratigraphic distribution of the larger benthic foraminifera, particularly, almost consistent present of alveosepta jaccardi allowed us to propose an age of late oxfordian to early kimmeridgian for the studied succession. at this time, paratethys basin was at very beginning of its opening. larger benthic foraminifera and inhabited fauna at this basin are in close similarity with tethyan realm association. data provided by larger foraminifera, calcareous algae, and microfacies analysis may suggest an environment of warm shallow water with low to medium energy regime