Petrography and Diagenetic processes of the Asmari Formation, Tange –Nayab area, SW Iran.

The Asmari formation is a thick carbonate succession of the Oligo_Miocene in Zagros Mountains.Petrographical study of the Asmari Formation in this area, have allowed the recognition of thirteen facies.According to microfacies analysis, six major depositional environments were identified: supratidal, tidalflat, lagoon (restricted lagoon and shelf lagoon), shoal, slope and outer slope. Miocene carbonate of the Asmari formation was deposited in a carbonate ramp. Asmari carbonate rocks have been affected byvarious diagenetic processes. These processes include: micritization, cementation, fracturing,dolomitization, dissolution, mechanical and chemical compaction. Diagenetic environments were identified based on petrographic study and diagenetic events. Based on petrographic study and diagenetic events, three main diagenetic environments can be determined: marine, meteoric and burial diagenetic environments. Finally, during uplift, fracturing and dissolution is also occurred in carbonaterocks

Keywords:

Asmari , carbonate diagenesis , microfacies , Sedimentary environment