Microbiostratigraphy of Asmari formation at Derak section (Shiraz)

This study concentrates on biostratigraphy Asmari Formation on Derak section that is located at Shiraz city with 333.5 meter thickness. Asmari Formation in this section comprises of limestone with marlyinterbedded.Asmari Formation trasitionally overlies the Jahrum Formation and underlies the Razak Formation. 3 lithologic units identified within the Asmari Formation in this section. In the Micropaleontological study, Asmari Formation at Derak section led to identify 31 genera and 38 species benthic foraminifera. Therfore, in this study the base of biostratigraphy is on benthic foraminifera. In biostratigraphy study, Wynd s report (1965) and Adams and Bourgeois (1967) report are such as pattern. The first appearance of Archaiasasmaricus and Meandropsinaanahensisand Peneroplisthomasi show the boundary between Oligocene (chattian)-Miocene (Aquetanian). Biozone no. 1 is comparable to biozone no. 2 Adams and Bourgeois(1967) and biozone no. 59 Wynd(1965) and middelASmari in Thomas (1949) report.Biozone no. 2 identified with appearance of Nummulitesfichteli,N.intermediusalso in this zone there is Archaiasoperculiniformis. Biozone no.2 is synonymous with biozone no. 3 Adams and Bourgeois (1967) and biozone no. 57, 58 Wynd (1965). Finally,the biozone no. 2 show Oligocene and synonymeous with lower Asmari of Thomas (1949).