Foraminiferal biostratigraphy of the Bolorian deposits in east-central Iran and its paleobiogeographic implications

The most important events in the early Permian history of Tethys were the post –Sakmarian regression and subsequent late Yakhtashian –Bolorian transgression. Approximately at the same time climate warmed suddenly.The same events led to profound biotic changes affecting various faunal grops. After the Sakmarian, Lower Permian marine deposits are sparsely developed in southern Asia through the Middle East to Iran, Afghanistan and India. Two sections with these deposits, Bagh-e Vang and SheshAngosht, located in east-central Iran, are revised. Acording to the study, four local fusulinid biozones are distinguished: latest YakhtashianPamirinadarvasica and Sakmarella spp. Zone, earlyBolorianMisellina(Brevaxina)dyrhenfurthi Zone, middle BolorianCuniculinella Zone and late BolorianMisellina(Misellina) cf. termieri Zone (probably equivalent to the traditional Misellina(Brevaxina)parvicostata Zone). These results could confirm the association of the study areas with other areas of Paleotethyan and Panthalassan bioprovinces, therefor the distribution of the Cuniculinellagenus can be considered as a result of climate warming and moving this warm water along the Paleotethys Ocean

Keywords:

Early Permian , Yakhtashian , Bolorian , fusulinid biozone.