Mahnaz AMIRSHAHKARAMI

Microfacies correlation analysis of the Oligocene-Miocene Asmari Formation, in the central part of the Rag-e-Safid anticlinal oil field, Zagros Basin, south-west Iran

The Oligocene-Miocene Asmari Formation was deposited in a carbonate ramp setting at the margin of the Zagros Basin in south-western Iran. The subsurface sedimentary successions of the Asmari Formation have been studied using cores from the Rag-e-Safid oil field, in order to determinate their microfacies and sedimentary palaeoenvironments. Based on texture analysis and faunal assemblages, 10 microfacies types have been recognised and interpreted. They indicate different depositional settings: open marine, oolitic and bioclastic shoal, lagoon, tidal flat and beach. The microfacies have been interpreted as indicative of the inner and middle ramp. In accordance with the temporal and spatial correlation model for the Asmari Formation across the south-western part of the Zagros basin, deposition of the Asmari Formation in the south-west had started in a deeper environment and continued in a shallower high energy environment.

Anahtar Kelimeler:

Asmari Formation, Oligocene-Miocene, microfacies correlation, carbonate platform ramp, larger benthic foraminifera, Zagros Basin, Iran.

Microfacies correlation analysis of the Oligocene-Miocene Asmari Formation, in the central part of the Rag-e-Safid anticlinal oil field, Zagros Basin, south-west Iran

Keywords:

Asmari Formation, Oligocene-Miocene, microfacies correlation, carbonate platform ramp, larger benthic foraminifera, Zagros Basin, Iran.,

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Adams, C.G. & Bourgeois, E. 1967. Asmari biostratigraphy. Iranian Oil Offshore Company, Geological and Exploration Division, Report 1074 [Unpublished].
Alavi, M. 2004. Regional stratigraphy of the Zagros fold-thrust belt of Iran and its proforeland evolution. American Journal of Science 304, 1–20.
Amirshahkarami, M., Vaziri-Moghaddam, H. & Taheri, A. 2007a. Sedimentary facies and sequence stratigraphy of the Asmari Formation at Chaman-Bolbol, Zagros Basin, Iran. Journal of Asian Earth Science 29, 947–959.
Amirshahkarami, M., Vaziri Moghaddam, H. & Taheri, A. 2007b. Paleoenvironmental model and sequence stratigraphy of the Asmari Formation in southwest Iran. Historical Biology 19(2), 173–183.
Amirshahkarami, M., Ghabishavi, A. & Rahmani, A. 2010. Biostratigraphy and paleoenvironment of the larger benthic foraminifera in wells sections of the Asmari Formation from the Rag-e-Safid oil field, Zagros Basin, southwest Iran. Stratigraphy and Sedimentology Research 40(3), 63–84.
Berberian, M. & King, G.C.P. 1981. Towards a paleogeography and tectonic evolution of Iran. Canadian Journal of Earth Science 18, 210–265.
Boeckh, H. de, Lees, G.M. & Richardson, F.D.S. 1929. Contribution to the stratigraphy and tectonics of the Iranian ranges. In: Gregory JW (ed), The Structure of Asia, 58–177.
Burchette, T.P. & Wright, V.P. 1992. Carbonate ramp depositional systems. Sedimentary Geology 79, 3–57.
Busk, H.G. & Mayo, H.T. 1918. Some notes on the geology of the Persian oilfields. Journal Institute Petroleum Technology 5, 5–26.
De Jong K.A. 1982. Tectonics of the Persian Gulf, Gulf of Oman and southern Pakistan region. In: Narin, A.E.M. & Stehli, F.G. (eds), The ocean basins and margins: The Indian Ocean. Elsevier, Amesterdam 6, 315–351.
Dunham, R.J. 1962. Classification of carbonate rocks according to their depositional texture. In: Ham, W.E. (ed), Classification of Carbonate Rocks. A Symposium: American Association of Petrology Geologists Bulletin, 108–121.
Ehrenberg S.N., Pickard, N.A.H., Laursen, G.V., Monibi, S., Mossadegh Z.K., Svånå, T.A., Aqrawi, A.A.M., McArthur J.M. & Thirlwall M.F. 2007. Strontium isotope stratigraphy of the Asmari Formation (Oligocene–Lower Miocene), SW Iran. Journal of Petrolium Geology 30(2), 107–128.
Embry A.F. & Klovan, J.E. 1971. A Late Devonian reef tract on Northeastern Banks Island, NWT. Canadian Petroleum Geology Bulletin 19, 730–781.
Flügel, E. 2004. Microfacies of carbonat rocks. Springer, BerlinHeidelberg, New York, p. 976.
Geel, T. 2000. Recognition of stratigraphic sequences in carbonate platform and slope deposits: empirical models based on microfacies analysis of paleogene deposits in southeastern Spain. Palaeogeography, Palaeoclimatology, Palaeoecology 155, 211–238.
Hallock, P. & Glenn, E.C. 1986. Larger foraminifera: A Tool for Paleoenvironmental Analysis of Cenozoic carbonates depositional facies. Palaios 1, 55–64.
Hohenegger, J. 1996. Remarks on the distribution of larger foraminifera (Protozoa) from Palau (western Carolines). In: Aoyama, T. (ed), The Progress Report of the 1995 Survey of the Research Project, Man and the environment in Micronesia. Kagoshima University Research Center for the Pacific Islands, Occasional Papers 32, 19–45.
Hohenegger, J., Yordanova, E. & Tatzreiter, Y. 1999. Habitats of larger foraminifera on the upper reef slope of Sesko Island, Okinawa. Marine Micropaleontology 36, 109–168.
Hosseinibarzi, M., Jafarzadeh, M. & Adabi, M.H. 2008. Geochemistry of the Ahvaz member sandstone from the Asmari Formation in the Ahvaz oil Field: A tools for recognization of the tectonically setting and primary weathering of parent rock. Science Journal of Shahid Chamran University of Ahvaz 19, 34-45 (In Persian).
Hottinger, L. 1983. Processes determining the distribution of larger foraminifera in space and time. Utrecht Micropaleont Bulletin 30, 239–253.
Hottinger, L. 1997. Shallow benthic foraminiferal assemblages as signals for depth of their deposition and their limitations. Bulletin of Society of Geology of France 168(4), 491–505.
James, G.A. & Wynd, J.G. 1965. Stratigraphic nomenclature of Iranian oil consortium agreement area. American Association Petroleum Geology Bulletin 49, 2182–2245.
Jones, B. & Desrochers, A. 1992. Shallow platform carbonates. In: Walker, R.G. & James N.P. (eds), Facies models response to sea level changes. Geological Association, Canada, St. Jones, Newfoundland, 277–303.
Kimiagari, M. 2006. Biostratigraphy, microfacies and sequence stratigraphy of the Asmari Formation in the Gurpi Anticline (Lali area) to Khaviz Mountain (Behbahan area. PhD Thesis, Isfahan University, p. 220, [In Persian with English abstract].
Laursen, G.V., Monibi, S., Allan, T.L., Pickard, N.A.H., Hosseiney, A., Vincent, B., Hamon, Y., Buchem, F.S.P. van, Moallemi, A. & Druillion, G. 2009. The Asmari Formation Revisited: Changed Stratigraphic Allocation and New Biozonation. First International Petroleum Conference and Exhibition Shiraz, Iran B
Lees, G.M. 1933. Reservoir rocks of Persian oil Wells. American Association Petroleum Geology Bulletin 17, 224–240.
Leutenegger, S. 1984. Symbiosis in benthic foraminifera, specificity and host adaptations. Journal of Foraminifera Research 14, 16–
Motiei, H. 1993. Stratigraphy of Zagros. Geological Survey of Iran, p. 5
Rahmani, A., Vaziri-Moghaddam, H., Taheri, A. & Ghabeishavi, A. 200 A model for the paleoenvironmental distribution of larger foraminifera of Oligocene–Miocene carbonates rocks at Khaviz Anticline, Zagros Basin, SW Iran. Historical Biology 21, 215–227. Read, J. 1985. Carbonate platform facies models. American Association Petroleum Geology Bulletin 69(1), 1–21.
Reiss, Z. & Hottinger, L. 1984. The Gulf of Aqaba: Ecological Micropaleontology. Berlin, Springer, p. 354.
Richardson, R.K. 1924. The geology and oil measures of southwest Persia. Journal Institute Petroleum Technology 10, 256–283.
Romero, J., Caus, E. & Rossel, J. 2002. A model for the palaeoenvironmental distribution of larger foraminifera based on Late Middle Eocene deposits on the margin of the south Pyrenean basin. Palaeogeography, Palaeoclimatology, Palaeoecology 179, 43–56.
Seyrafian, A. 2000. Microfacies and depositional environments of the Asmari Formation, at Dehdes area (a correlation across Central Zagros Basin). Carbonates and Evaporites 15, 22–48.
Seyrafian, A. & Hamedani, A. 1998. Microfacies and depositional environment of the Upper Asmari Formation (Burdigalian), north-central Zagros Basin, Iran. Neues Jahrbuch für Geologie und Paläontology, Abhandlungen 21, 129–141.
Seyrafian, A. & Hamedani, A. 2003. Microfacies and palaeoenvironmental interpretation of the lower Asmari Formation (Oligocene), North-Central Zagros Basin, Iran. Neues Jahrbuch für Geologie und Paläontology, Montashefte 3, 164–174.
Seyrafian, A., Vaziri-Moghaddam, H., Arzani, N. & Taheri, A. 20 Facies Analysis of the Asmari Formation in central and north-central Zagros basin, southwest of Iran: Biostratigraphy, paleoecology and diagenesis. Revista Mexicana de Ciencias Geolόgicas 28(3), 439-458. Shirmohammadi, N., Verstfelt, P. & Wiley, J. 1974. Geology study of Asmari Reservoir in Rage-Safid oil field. Report p- 2451, National Iranian South Oil Company (Nisoc), Ahwaz p. 90.
Stöcklin, J. 1968. Structural history and tectonics of Iran: A review. American Association Petroleum Geologists Bulletin 52, 1229– 12
Thomas, A.N. 1948. The Asmari Limestone of southwest Iran. National Iranian Oil Company, Report 706 [unpublished].
Tucker, M.E. 1985. Shallow marine carbonate facies and facies models, in: Brenchley P.J. & Williams B.P.J. (eds), Sedimentology, recent development and applied aspects. Geological Society of London, Special Publication 18, 139–161.
Vaziri-Moghaddam, H., Kimiagari, M. & Taheri, A. 2006. Depositional environment and sequence stratigraphy of the Oligocene-Miocene Asmari Formation in SW Iran, Lali Area. Facies 52(1), 41–51.
Vaziri-Moghaddam, H., Seyrafian A., Taheri, A. & Motiei, H. 2010. Oligocene-Miocene ramp system (Asmari Formation) in the NW of the Zagros basin, Iran: Microfacies, paleoenvironmental and depositional sequence. Revista Mexicana de Ciencias Geolόgicas 27(1), 56–71.
Wells, A.J. 1967. Lithofacies and geological History of Lower Tertiary sediments in southwest Iran. Iranian Oil Offshore Company Report 1108 [Unpublished].
Wiley, J. & Habibi, F. 1978. Geology study of Asmari Reservoir in Rage-Safid field. National Iranian South Oil Company (NISCO), Report P-3543 [Unpublished].
Wilson, J.L. 1975. Carbonate facies in geological history. Springer, Berlin–Heidelberg, New York p. 471.
Wynd, J. 1965. Biofacies of Iranian Oil Consortium Agreement Area. Iranian Oil Offshore Company, Report 1082 [Unpublished].
Yazdani, R. 2006. Subsurface stratigraphy of the Asmari Formation in the Aghajari oil field, southeast Ahvaz. M.Sc. Thesis, Isfahan University, p. 153 [In Persian with English abstract].
Zahrabzadeh, M. 2007. Geology studying of the Asmari Reservoir in the Rag-e-Safid oil field. National Iranian South Oil Company (Nisco), Ahvaz, Report 5954, [Unpublished, In Persian].