Document Type : Original Research Paper

Authors

1 Ph.D. Student, Department of Geology, Shiraz Branch, Islamic Azad University; Department of Geology, Fars Science and Research Branch, Islamic Azad University, Fars, Iran

2 Associated Professor, Department of Geology, Lorestan University, Khorramabad, Iran

3 Professor, Department of Geology, Damavand Branch, Islamic Azad University, Damavand, Iran

Abstract

The Shahbazan Formation deposited in the Lorestan foreland basin and northeastern part of Dezful embayment zone during the Middle-Late Eocene age. In order to study the stratigraphy of the Shahbazan Formation, four surface sections of this formation in northeastern flank of Langar anticline, southeastern flank of Chenareh anticline, northeastern flank of Maleh Kuh anticline and southwestern flank of Poshte-Jangal anticline, have been selected. The Shahbazan Formation in Langar and Chenareh sections is composed of limestone with intercalation of dolomite. In other parts of the Lorestan such as Maleh kuh and Poshte Jangel, it consists of dolomite and intercalations of limestons. In these areas, the Shahbazan and Asmari formations form a prominent topographic unit and separating their boundary is often difficult to place, thus making it necessary to map the two formations as one unit. In this case, the two names are hyphenated as Shahbazan- Asmari Formation. According to study of benthic foraminifera in Chenareh and Langar sections, two biozone have been distinguished. The age of the Shahbazan Formation in these areas is determined as Middle- Late Eocene (Bartonian- Priabonian). In the Maleh Kuh section, the lower part of the Shahbazan- Asmari Formations is dolomitic but in the upper part it contains limestone beds with foraminifera that belong to two assemblage zones, in Aquitanian- Burdigalian age. In the Poshte Jangal section, the lower and middle parts of Shahbazan- Asmari formations are dolomitic but the upper part contains limestone beds with rare foraminifera which have been reported at the Chattian- Burdigalian beds of the Asmari Formation.

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BouDagher-Fadel, M, K., 2012- Biostratigraphy and Geological Significent of planktonic foraminifera,Ovper Ucl , 287.
Boukhary, M., Abdelghany, O., Bahr, S. and Hussein-Kamel, Y., 2005- Upper Eocene larger foraminifera from the Dammam Formation in the border region of United Arab Emirates and Oman. Micropaleontology, (51), 6: 487-504.James, G.A., and Wynd, J.G., 1965. Nomenclature of Iranian oil consortium agreement area, A. A.P.G. Bulletin 49, (12), 2182-2245.
Cuvillier, J., 1930- Revision du Nummulitique tgyptien. Memoire deI'Institute Egypte, (16), l-371.
Douville, H., 1919- l'hcene inferieur en Aquitaine et dans le Pyrenes. Memoires pour servir a I'Explication de la Carte Gtologique dttaillee de la France, Paris, 1-84.
Hottinger, L., 2007- Revision of the foraminiferal genus Globoreticulina Rahaghi, 1978, and of its associated fauna of larger foraminifera from the late Middle Eocene of Iran. Carnets de Géologie / Notebooks on Geology,( 6), 1-51.
James, G. A. and Wynd , J. G., 1965, Stratigraphic Nomenclature of Iranian Oil Consortium Agreement Area, A.A.p.G. Bulletin,vol.49, No.12. pp 2218-2232.
Kalantari, A., 1976- Microbiostratigraphy of the Sarvestan area, southwestern Iran, National Iranian Oil Company, 5, 129.
Kalantari, A., 1986- Microfacies of carbonate rocks of Iran:National Iranian Oil Company, Geologica LaboratoryPublication, no. 11, p. 250Liewellyn,v P., G., 1974, Geological map of Ilam-  Kuh Dast, 1:250 000.
Laursen, G. V., Monibi, S, Allan, T. L., Pickard, N. A. H., Hosseiney, A., Vincent, B., Hamon, Y., Van Buchem, F. S. P., Moallemi, A. and Druillion, G., 2009- The Asmari Formation revisited: changed stratigraphic allocation and new biozonation. In: First international peteroleum conference and exhibition, Shiraz, Iran
Liewellyn, V. P. G., 1974- Geological map of Liam-  Kuh Dast, 1:250 000.
Lobelich, A. R. and Tappan, J. H., 1988- Foraminiferal - genera and their classification. New York, Van Nostrand Reinhold Company., 2 Vol, plates. 847- 869.
Maghfouri-Moghaddam, I. and Samiei, S., 2015- Microbiostratigraphy of Asmari Formation in Robat Namaki section, Zagros Basin, Journal of Tethys: 3 (2) 142–151.
Racey, A., 1995- Lithostratigraphy and larger foraminiferal (nummulitid) biostratigraphy of the Tertiary of northern Oman. Micropaleontology, (41), 1–123
Rahaghi, A., 1973- Etude de quelques grands foraminiferes de la Formation de Qum (Iran Central). Rev. Micropaleont.16: 1. 23-28.
Rahaghi, A., 1976- Contribution a l’etude de quelques grands foraminiferes de l’Iran, Publ. Soc. )at. Iran. Petrol., Lab.Micropaleont., Tehran. 6:1-79.
Rahaghi, A., 1980- Tertiary faunal Assemblage of Qum, Kashan, Sabzewar and Jahrum area, ).I.O.C., Geol. Lab. Public. 8.
Rahaghi, A., 1983- Stratigraphy and faunal assemblage of PaleoceneEocene in Iran, ,N. I. O. C. pub., No.7, 161 p.
Serra-Kiel, J., Hottinger, L., Caus, E., Drobne, K., Ferràndez, C., Jauhri, A. K., Less, G., Pavlovec, R., Pignatti, J., Samsó, J. M., Schaub, H., Sirel, E., Strougo, A., Tambareau, Y., Tosquella, J. and Zakrevskaya, E., 1998- Larger foraminiferal biostratigraphy of the Tethyan Palaeocene and Eocene. Bulletin de la Société Géologique de France, 169( 2), 281–299.
Sherkaty, S. and Letouzey, J.,2004- Variation of structural style and basin evolution in the central Zagros (Izeh zone and Dezful beltl Iran): Marine and petroleum geology, 21(5): 35554.
Vaziri Moghaddam, H., Seyrafian, A., Taheri, A. And Motiei, M., 2010- Oligocene-Miocene ramp system (Asmari Formation) in the NW of the Zagros basin, Iran: Microfacies, paleoenvironment and depositional sequence , Revista Mexicana de Ciencias Geológicas,  27( 1), 56-71.
Wynd, I. G., 1965- Biofacies of the Iranian oil Agreement area;N.I .O. C. report, No 1089 (unpublished).