Document Type : Original Research Paper


1 Ph.D. Student, Department of Geology, Faculty of Basic Science, Islamic Azad university, Science and Research Branch, Tehran, Iran

2 Assosiate Professor, Payame Noor university, Tehran, Iran

3 Assistant Professor, Department of Petroleum Engineering, Islamic Azad University, Masjed-Soleiman Branch Masjed-Soleiman, Iran

4 Assosiate Professor, Department of Geology, Faculty of Basic Science, Islamic Azad university, Science and Research Branch,Tehran, Iran


The Asmari Formation was measured and sampeled in Ghar-e Agha Seyyed at Farsan area in order to determine sedimentary environment based on facies analysis. In the study area, the Asmari Formation has a thickness of 183 m and conformably underlained the Pabdeh Formation. Based on microfacies studies, 8 microfacies were recognized such as:1) Porcelanouse foraminifera – bioclastic – red algal wackestone / packstone, 2) Rotalia grainstone, 3) Bioclastic –red algal grainstone, 4) Red algal – coral boundstone, 5) Red algal wackestone (Floatstone), 6) Red algal –large hyaline foraminifera – intraclast packstone, 7) Red algal – bioclastic  - large hyaline foraminifera  wackestone / packstone, 8) Large hyaline foraminifera packstone. These microfacies represent three facies belts including Inner ramp, Middle ramp and Outer ramp. On the other hand, based on the presence of benthic foraminifera, the age of the Asmari Formation is related to Oligocene (Rupelian – Chatian).


Amirshahkarami, M., 2010- Biostratigraphy characterization of the Rupelian- Burdigalian carbonate succession at the Chaman- Bolbol area in the Zagros baisin. Stratigraphy and sedimentary researches, Vol. 40, no. 3, p. 119- 136.
Babazadeh, S. A. & Hamidzadeh S. M. (2017)-Biostratigraphy of Asmari Formation in Ghar-e Agha seyed of Farsan region, Chaharmahale Bakhtiari Province, Iran. Global geology, 20 (3), 144-152.
Bassi, D., Hottinger, L.  and  Nebelsick, H., 2007- Larger Foraminifera from the Upper Oligocene of the Venetian area, northeast Italy: Palaentology, V. 50(4), p. 845-868.
Burchett, T. P. and Wright, V. P., 1992- Carbonate ramp depositional systems. Sedimentary Geology, Vol. 79, no. 1-4, p. 3-57.
Busk, H. G. and Mayo, H. T., 1918- Some notes on the geology of the Persian oil field: J. Nst. Petrol. Tech. no.5, p.5-26.
Buxton, M. W. N and Pedley, H. M., 1989- Short Paper, A Standardized model for Tethyan Tertiary Carbonate ramps: Journal of the Geological Society, London, Vol. 146, p. 746-748.
Dunham, R. J., 1962- Classiiiiiification of Carbonate rocks according to depositional texture, in: Classification of Carbonate Rocks: a Symosium ed. W. Ham. AAPG. Mem. 1, p. 108-121.
Embry, A. F. and Klovan, J. E., 1971- A Late Devonian reef tract on northeastern Banks Island. N.W.T.: Bulletion of Canadian Petroleum Geology, Vol. 19, pp. 730-781.
Flugel, E., 2010- Microfacies of Carbonate rocks, analysis interpretation and application: Springer- Vergal Berlin, Heidelberg, 976 p.
Geel, T., 2000- Recognation of Stratigraphic Sequences in Carbonate platform and slope deposits: empirical models based on microfacies analysis of palaeogene deposits in southeastern Spain, Palaeogeography, Palaeoclimatology, Palaeoecology, V. 155, p.211-238.
Hakimzadeh, S. and Seyrafian, A., 2008- Late Oligocene – Early Miocene benthic foraminifera and biostratigraphy of the Asmari Formation, South Yasuj, North central Zagros basin, Iran. Carbonate and Evaporites, Vol. 23, no. 1, p. 1-10.
James, G. A. and Wynd, J. G., 1965- Stratigraphic nomenclature of Iranian oil consortium agreement area: Am. ASSOC. Petrol. Geol. Bull., V49, p. 2182- 2245.
Lees, G. M., 1933- The reservoir rocks of Persian oil fields, American Association Petroleum Geology Bulletin, V. 17, no.3, p. 299- 240. Ology, Paleoecology, Vol. 175, p. 249 – 272.
Pomar, L., 2001- Ecological control of sedimentary accommodation: evolution from a carbonate ramp rimmed helf, Vpper Micene, Baleric Islands: Palaeography palaeoclimatology palaeoecology, p. 249- 272.
Richardsons, R. K., 1924- The geology and oil measures of southwest, Persia: J. Inst. Petrol. Tech. 10 (43), p. 256- 283.
Romero, J., Caus, E., Rossel, J., 2002- A model for the paleoenvironmental distribution of larger foraminifera based on late middle Eocene deposits on the margin of the South Pyrenean basin: Palaeogeograph, Palaeoclimatology, Palaeoecology, no. 179, p. 43-56.
Seyrafian, A. and Hamedani, A., 1998- Microfacies and depositional environment of the upper Asmari Formation (Burdigalian), north central Zagros basin, Neues Jahrbuch fur Geologie und Palaontologie, no. 210, p. 129- 141.
Seyrafian, A., 2000- Microfacies and depositional environment of the Asmari Formation at the Dehdez area. Carbonate and evaporates. Vol. 15. P. 121- 130.
Vaziri – Moghaddam, H., Seyrafian A., Taheri, A., and Motiei, H., 2010- Oligocene – Miocene ramp system (Asmari Formation) in the NW of the Zagros baisin, Iran: Microfacies, paleoenvironmental and depositional sequence. Revista Mexicana de Ciencias Geologicas, Vol. 27, no. 1, p. 56- 71.
Wilson, J. L., 1975- Carbonate Facies in Geological History, 471p