زیست چینه نگاری ، ریز رخساره ها و دیرینه بوم شناسی سازند آسماری در برش مخملکوه، ناحیه لرستان، باختر ایران

نویسندگان

1 دانشجوی دکترا چینه‌شناسی و فسیل‌شناسی، دانشگاه آزاد واحد علوم و تحقیقات، تهران

2 دانشیار گروه مهندسی معدن، دانشگاه بین‌المللی امام خمینی (ره)، قزوین

3 دانشیار گروه زمین‌شناسی، دانشگاه پیام‌نور، تهران

4 استادیار سازمان زمین‌شناسی و اکشافات معدنی کشور، دفتر نظارت و ارزیابی، تهران

چکیده

سازند آسماری توالی ضخیم کربناته­ای در حوضه فورلند زاگرس است که در زمان الیگومیوسن نهشته شده است. به منظور انجام مطالعات زیست­چینه­نگاری، ریزرخساره­ها و تفسیر محیط­رسوبی، برش مخملکوه از پهنه لرستان واقع در باختر زاگرس مورد بررسی قرار گرفت. برش مخملکوه دارای 85 متر ضخامت است که از تناوبی از سنگ­آهک­های ضخیم لایه با میان لایه­هایی از سنگ­آهک نازک­لایه تشکیل شده است. بر اساس مطالعات زیست­چینه­نگاری­، 12 جنس وابسته به 7 خانواده از روزنبران کف­زی و پلانکتونیک در برش مورد مطالعه شناسایی شد. در این برش، دو تجمع فسیلی و 12 ریزرخساره بر اساس الگوهای پراکندگی روزن­داران با سن روپلین- آکیتانین تشخیص داده شد. تجمعات فونی با زون­های استاندارد جهانی تطابق داده شده است. مطالعه ریزرخساره­ها­ی موجود نشان­دهنده دو کمربند رسوبی شامل لاگون و دریای باز در برش مورد مطالعه است. زیرمحیط­های رسوبی سازند آسماری قابل تطابق با بخش­های رمپ داخلی، میانی و خارجی هستند که تحت شرایط مزوفوتیک، الیگوفوتیک و آفوتیک در یک رمپ هموکلینال نهشته شده­اند. 

کلیدواژه‌ها


عنوان مقاله [English]

Biostratigraphy, Microfacies and palaeoecology of the Asmari Formation in Makhmal Kuh section, Lurestan Province, western Iran

نویسندگان [English]

  • M. Rajabi 1
  • S. Senemari 2
  • M. Parvaneh Nejad Shirazi 3
  • M. Bahrammaneshtehrani 4
چکیده [English]

The Asmari Formation is a thick carbonate sequence in the Zagros Foreland Basin that was deposited during the Oligo–Miocene. In order to conduct biostratigraphic studies, microfacies and to interpret the depositional environment, the Makhmal Kuh section in the Lurestan province located in west of Zagros was investigated. The section is 85 m thick, consisting of alternating layers of thick limestone interbedded with thin-layer limestone. Based on biostratigraphic studies, 12 genera belonging to 7 families of foraminifera were identified in the studied section. In this section, two fossil assemblages and 12 microfacies were identified based on the Rupelian-Aquitanian foraminifera distribution patterns. The fauna assemblages conform to the world standard zones. The study of microfacies indicates two different sedimentary sub-environments including lagoon and open sea in the studied section. These depositional sub­-environments of the Asmari Formation are compatible with the inner, middle and outer ramp parts, formed under a Mesophotic, Oligophotic and Aphotic conditions in a homoclinal ramp.

کلیدواژه‌ها [English]

  • Aquitanian
  • Rupelian
  • sedimentary environment
  • Zagros
  • Asmari Formation
  • Lurestan
آقانباتی، ع (1383) زمین­شناسی ایران، انتشارات سازمان زمین­شناسی و اکتشافات معدنی کشور، 586 ص.
درویش­زاده، ع (1382) زمین­شناسی ایران، انتشارات امیرکبیر، 902 ص.
زارع، م.، وحـیدی­نیا، م.، قرائی­مــحمودی، م. ح (1389) چینه­نگاری زیستی، ریزرخساره­ها، محیط­رسوبی و دیرینه بوم­شناختی سازند آسماری در جنوب­باختری ایران. دوفصلنامه رسوب­شناسی کاربردی، دوره 7، شماره 13، ص 130102.
مطیعی، ه (1372) زمین­شناسی ایران، چینه­شناسی زاگرس، انتشارات سازمان زمین­شناسی و اکتشافات معدنی کشور، 536 ص.
Alavi, M (2007) Structures of the Zagros fold–thrust belt in Iran. American Journal of Science, 307: 1064–1095.
Ahmadhadi, F., Lacombe, O., Daniel, J. M (2007) Early Reactivation of Basement Faults in Central Zagros (SW Iran): Evidence from Pre-folding Fracture Populations in Asmari Formation and Lower Tertiary Paleogeography. In: Lacombe, O. (ed.), Thrust belts and foreland basins: from fold kinematics to hydrocarbon systems. Springer Verlag, Berlin, 11: 205­–­208.
Adams, T. D., Bourgeois, F (1967) Asmari biostratigrapy Geological and Exploration Div­. IOOC Report, No 1074 (Unpubished).
Allahkarampour Dill, M., Seyrafian, A., Vaziri-Moghaddam, H (2010) The Asmari Formation, north of the Gachsaran (Dill anticline), southwest Iran: facies analysis, depositional environments and sequence stratigraphy. Carbonates & evaporates, 25: 145–160.
Amirshahkarami, M., Vaziri-Moghaddam, H., Taheri, A (2007) paleoenviornmental model and sequence stratigraphy of the Asmari Formation in Southwest Iran. Historical Biology, 19: 173–183.
Cahuzac, B., Poignant, A (1997) An attempt of biozonation of the Oligo-Miocene in the European basins, by means of larger neritic foraminifera. Bulletin de la Societe Geologique de France, 168 (2): 155–169.
Dorobek, S. L (1995) Synorogenic carbonate platforms and reefs in foreland basins: controls on stratigraphic evolution and platform/reef morphology. SEPM Special Publication, 52: 127–147.
Dunham, R. J (1962) Classification of carbonate rocks according to depositional texture, In: Ham, W., E., (ed.), Classification of carbonate rocks. American Association of Petroleum, Geologists Memoir, 1: 108–121.
Ehrenberg, S. N., Pickard, N. A. H., Laursen, G. V., Monibi, S., Mossadegh, Z. K., Svana, 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 Petroleum Geology, 30: 107–128.
Einsele, G (2000) Sedimentary basin evolution, facies and sediment Buolget. Spirnger, Berline, 792 p.
Geel, T (2000) Recognition of stratigraphic sequences hn carbonate platform and slop deposits: empirical models based on microfacies analysis of Paleogene deposits in Southeastern Spain. Paleogeography, Paleoclimatology, Paleoecology, 155: 211–238.
Hottinger, L (2007) Revision of the foraminiferal genus Glo-boreticulina RAHAGHI, 1978, and of its associated fauna of larger foraminifera from the late Middle Eocene of Iran. Carnets de Geologie, CG2007 (A06): 1-51.
James, G. A., Wynd, J. G (1965) Stratigraphic nomenclature of Iranian oil consortium agreement area. AAPG Bulletin, 49: 2182–2245.
Laursen, G. V., Monibi, S., Allan, T. L., Pickard, N. A. H., Hosseiney, A., Vincent, B., Hamon, Y., van Buchem, F. S. H., Moallemi, A., Driullion, G (2009) The Asmari Formation revisited: Changed stratigraphic allocation and new biozonation. First international petroleum conference & exhibition, Shiraz, Iran. 1-6. http://dx.doi.org/10.3997/2214-4609.20145919
Loeblich, A. R., Tappan, H (1987) Foraminiferal Genera and Their Classification. Van Nostrand Reinhold Company, New York, 970 p.
Maghfouri-Moghaddam, I., Samiei, S (2015) Microbiostratigraphy of Asmari Formation in Robat Namaki section, Zagros Basin. Journal of Tethys, 3 (2): 142–151.
Pomar, L (2001) Ecological control of sedmentary accommodation: evolution from a carbonate ramp to rimed shelf, Upper Miocene, Balearic Islands. Journal of Palaeogeology, Palaeoclimatology, Palaeoecology, 175: 249-272.
Pomar, L., Brandano, M., Westphal, H (2004) Environmental factors influencing skeletal grain sediment association: A critical review of Miocene examples from western Mediterranean. Sedimentology, 51: 627–651.
Rahmani, A., Vaziri-Moghaddam, H., Taheri, A., Ghabeishavi, A (2009) A model for the paleoenvironmental distribution of larger foraminifera of Oligocene–Miocene carbonate rocks at Khaviz Anticline, Zagros Basin, SW Iran. Historical Biology, 21 (3–4): 215–227.
Rahmani, A., Taheri, A., Vaziri-Moghaddam, H., Ghabeishavi, A (2012) Biostratigraphy of the Asmari formation at khaviz and bangestan anticlines, Zagros Basin, SW Iran. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, 263 (1): 1–16. DOI: 10.1127/0077-7749/2011/0189
Romero, J., Caus, E., Rossel, J (2002) A model for the Palaeoenviornmental distribution of larger foraminifera based on Late Middle Eocene deposits on the margine of the south Pyrenean Basin (SE Spain). Palaeogeography, Palaeoclimatology, Palaeoecology, 179 (1): 43–56.
Sadeghi, R., Vaziri-Moghaddam, H., Taheri, A (2011) Microfacies and sedimentary environment of the Oligocene sequence (Asmari formation) in Fars sub-basin, Zagros Mountains, southwest Iran. Facies, 57 (3): 431–446.
Saleh, Z., Seyrafian, A (2013) Facies and depositional sequences of the Asmari formation, Shajabil anticline, north of the Izeh zone, Zagros Basin, Iran. Acta Geologica Sinica, 87 (6): 1520–1532. https://doi.org/10.1111/1755-6724.12156
Seyrafian, A (2000) Microfacies and depositional environments of the Asmari formation, at dehdez area (a correlation across central Zagros Basin. Carbonates & Evaporites, 15 (2): 121–129.
Seyrafian, A., Arzani, N., Taheri, A., Vaziri-Moghaddam, H., Hashemi, M (2006) Facies Analysis of the Asmari Formation in the Central High Zagros (From Boldaji, Izeh, Shahr E Kord to South Yasuj­). National Iranian Oil Company (Unpublished).
Seyrafian, A., Vaziri-Moghaddam, H., Arzani, N., Taheri, A (2011) Facies analysis of the Asmari Formation in central and north-central Zagros basin, southwest Iran: biostratigraphy, paleoecology and diagenesis. Revista Mexicana de Ciencias Geológicas, 28: 439–458.
Shabafrooz, R., Mahboubi, A., Vaziri-Moghaddam, H., Ghabeishavi, A., Moussavi-Harami, R (2015a) Depositional architecture and sequence stratigraphy of the oligo–Miocene Asmari platform; Southeastern Izeh zone, Zagros Basin, Iran. Facies, 61 (1): 1–32.
Sherkati, S. H., Letouzey, J (2004) Variation of structural style and basin evolution in the Central Zagros (Izeh zone and Dezful Embayment), Iran. Marine and Petroleum Geology, 21: 535–554. https://doi.org/10.1016/j.marpetgeo.2004.01.007
Thomas, A. N (1948) The Asmari Limestone of southwest Iran. AIOC Report No. 703 (Unpublished).
van Buchem, F. S. P., Allen, T. L., Laursen, G. V., Lotfpour, M., Moallemi, A., Monibi, S., Motiei, H., Pickard, N. A. H., Tahmasbi, A. R., Vedrenne, V., Vincent, B (2010) Regional stratigraphic architecture and reservoir types of the Oligo-Miocene deposits in the Dezful Embayment (Asmari and Pabdeh formations), SW Iran. Geological Society, London, special publications, 329: 219–263.
Vaziri-Moghaddam, H., Torabi, H (2004) Biofacies and sequence stratigraphy of the Oligocene succession: Central basin, Iran. Neues Jahrbuch für Geologie und Paläontologie, 6: 321-344. DOI: 10.1127/njgpm/2004/2004/321
Vaziri-Moghaddam, H., Kimiagari, M., Taheri, A (2006) Depositional environment and sequence stratigraphy of the oligo-miocene Asmari formation in SW Iran. 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, paleoenvironment and depositional sequence. Revista Mexicana de Ciencias Geológicas, 27: 56–71.
Warren, J. K (2016) Evaporites: A geological compendium. Springer, 1829 p.
Wehrmann, A (1998) Modern cool-water carbonates on a coastal platform of Northern Brittany, France: Carbonate production in macrophytic systems and sedimentary dynamics of bioclastic facies. Senckenbergiana maritime­, 28: 151–166. https://doi.org/10.1007/BF03043146
Wilson, M. E. J., Evans, M. E. J (2002) Sedimentology and digenesis of Tertiary carbonates on the Mangkalihta Penninsula: Boreneo, hmplication for subsurface reservoir quality. Marine and Petroleum Geology, 19: 837–900.
Wynd, J (1965) Biofacies of Iranian oil consortium agreement area. Iranian Oil Offshore Company Report, no. 1082 (Unpublished).