The Zang Trap Formation is a carbonate unit that is the result of the first transgression of the sea at the beginning of the Cenozoic on the northern and eastern margins of the Lorestan area. This unit is located on the Amiran turbidite Formation and below the clastic and continental deposits of the Kashkan Formation with a discontinuous boundary. The facies and age of the Taleh Zang Formation in different areas of Lorestan area show important differences. In order to study the facies and sedimentary environment of Taleh Zang Formation in the north of Lorestan area, two stratigraphic sections of Qableh and Darabi in the west and north of Kuh Dasht, respectively, were studied. Based on the recognized large foraminifera the age of the Taleh Zang Formation in the study stratigraphic sections is assigned to the Thaetian (late Paleocene). The petrographic analysis and fauna association of the Taleh Zang Formation led us to identify 6 microfacies that are belonged to to the tidal zone, inner and mid ramps.The absence of corals and the low abundance of calcareous algae and the high abundance of benthic foraminifer indicate that the bio assemblage of the Taleh Zang Formation was similar to that of the eastern Tethys.