New findings on Stratigraphy of the Paleocene–early Eocene successions in Lorestan Zone, Iran

The foraminiferal contents of the Paleocene-Eocene successions were examined in two sections; at the southern and northern flanks of Chenareh anticline, Lorestan Zone. The Paleocene-Eocene in northern flank was subdivided into three formations from older to younger: Taleh Zang, Kashkan, and Shahbazan formations. During this time, sedimentation of the Paleocene-Eocene Pabdeh and Shahbazan formations took place in the southern flank of Chenareh anticline. Four biostratigraphical zones were defined in Pabdeh Formation as a result of summarizing available data on the taxonomy, stratigraphical range and occurrence of planktic foraminifera, ranging in age from Late Danian to Early Ypresian. The zones are: Praemurica uncinata Interval Zone (P2); Morozovella angulata-Igorina pussila Interval Zone (P3); Globanomalina pseudomenardii Total Range Zone (P4); Morozovella velascoensis Interval Zone (P5). The Taleh Zang Formation and upper part of the Pabdeh Formation contain a rich and diverse assemblage of alveolinids, and nummulitids (Nummulites, Assilina). Their assemblages, referred to SBZ 6, 7 and SBZ 8 (Early Ypresian). The Shahbazan Formation has no index fossils, and it was attributed to Lutetian in age, based on stratigraphic position.