Document Type : Original Paper

Author

کار گر شمالی- پردیس فنی- انیستیتو مهندسی نفت

Abstract

The excellent preservation of the acritarchs, their great abundance, diversity and good stratigraphic control permit establishment of a detailed Middle and Late Cambrian acritarch biozonation. A total of 56 palynomorph species form the basis of 10 local acritarch assemblage zones. Assemblage zones I-II occur in the lower and middle parts of the Member C of the Mila Formation and suggest Early-mid Middle Cambrian; assemblages zones III-IV appears in the upper part of the Member C of the Mila Formation and the lower part of Ilebeyk Formation and encompass latest Middle and earliest Late Cambrian; acritarch assemblage zones V-IX occur in the middle and upper parts of the Ilebeyk Formation and characterize Late Cambrian; finally, acritarch assemblage zone X appears in the basal part of the Zardkuh Formation and proves to have an early Tremadocian age. Amongst the Late Cambrian acritarch assemblages of Laurentia only the two cosmopolitan species of Timofeevia phosphoritica and Vulcanisphaera turbata are shared with coeval strata in the High Zagros Mountains.Iranian acritarch assemblages show a marked Gondwanan paleobiogeographical affinity, share a high proportion of taxa with typical Baltican and North Africa–Gondwanan assemblages, and are different from known Laurentian microphytoplankton suites. These results are in general agreement with paleogeographical models that place Avalonia, Baltica, and the North African part of Gondwana, at relatively high southern paleolatitudes, whereas Laurentia occupies a sub-equatorial position. Four new acritarch species, namely Leiosphaeridia iranense, Navifusa reticulata, Ooidium zagrosensis, and Veryhachium ilebeykensis are described.

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  1. Albani R., Bagnoli G., Bernárdez E., Gutiérrez-Marco J.C., Ribecai C. Late Cambrian acritarchs from the “Túnel Ordovícico del Fabar”, Cantabrian Zone, N Spain. Review of Palaeobotany and Palynology. 139: 41-52 (2006).
  2. Albani R., Bagnoli G., Ribecai C., Raevskaya E. Late Cambrian acritarch Lusatia: Taxonomy, palaeogeography, and biostratigraphic implications. Acta Palaeontologica Polonica 52 (4): 809-818 (2007).
  3. Bergström S.M. Relations between conodont provincialism and changing palaeogeography during the Early Palaeozoic. In: McKerrow, W.S., Scotese, C.R. [Eds.], Palaeozoic Palaeogeography and Biogeography. Geol. Soc. Lond. Mem. 12: 115-125 (1990).
  4. Burmann G., Weitere organische Mikrofossilien aus dem unteren Ordovizium. Paläontologische Abhandlungen, Abteilung B. 3: 289-332 (1970).
  5. Clark D.L., Hartleberg E.W. Paleoenvironmental factors and distribution of conodonts in Lower Triassic of Svalbard and Nepal. Fossils Strata. 15: 171–175 (1983).
  6. Cocks L.R.M., Torsvik T.H. Baltica from the late Precambrian to mid Palaeozoic times: the gain and loss of a terrane's identity. Earth-Science Reviews. 72: 39–66 (2005).
  7. Di Milia A. Upper Cambrian acritarchs from the Solanas Sandstone Formation, Central Sardinia, Italy. Bollettino della Società Palaeontologica Italiana. 30: 127-152 (1991).
  8. Di Milia A., Tongiorgi M., Albani R. Acritarch finding in Early Paleozoic, low-grade metasediments of Sardinia (Italy): a review. Revista española de Palaeontología. 8 (2): 170-176 (1993).
  9. Downie C. Acritarchs in British stratigraphy. Geological Society of London, Special paper 17: p 26 (1984).
  10. Erkmen U., Bozdogan N. Cambrian acritarchs from the Sosink Formation in southeast Turkey. Revista Espaбola de Micropalaeontología. 13: 47- 60 (1981).
  11. Ghavidel-Syooki M. Palynological study of Paleozoic sediments of the Chal-i Sheh Area, Southwestern Iran. J. Sci.I.R. Iran. 4: 32–46 (1993).
  12. Ghavidel-Syooki M. Palynostratigraphy and palaeobiogeography of the Lower Palaeozoic sequence in the north-eastern Alborz Range (Kopeh-Dagh region) of Iran. In Goodman, D. K. and Clarke, R.T., editors, Proceedings of the IX International Palynological Congress Houston, Texas, U.S.A., 1996. American Association of Stratigraphic Palynologists Foundation. 17-35 (2001).
  13. Ghavidel-Syooki M. Palynostratigraphy and palaeogeography of the Cambro-Ordovician strata in southwest of Shahrud City (Kuh-e-Kharbash, near Deh-Molla), Central Alborz Range, Northern Iran. Review of Palaeobotany and Palynology. 139: 81–95 (2006).
  14. Ghavidel-Syooki M., Vecoli M. Palynostratigraphy of Middle Cambrian to lowermost Ordovician stratal sequences in the High Zagros Mountains, southern Iran: Regional stratigraphic implications and palaeobiogeographic significance. Review of Palaeobotany and Palynology. 150: 97-114 (2008).
  15. Jachowicz-Zdanowska M. Cambrian organic microfossils at the border area of the East- and West-European platforms (SE Poland and western Ukraine). Annales In Annales Societatis Geologorum Poloniae. 81: 241–267 (2011).
  16. King W.B.R. Note on the Cambrian fauna of Persia. Geological Magazine. 67: 316–327 (1930).
  17. Liñán E., Gozalo R., Palacios T., Gámez Vintaned J.A., Ugidos J.M., Mayoral E. Cambrian. In: Gibbson, Web, Moreno, Teresa [Eds.], the geology of Spain. Geological Society, London. 3: 17–29 (2002).
  18. Loeblich Jr A.R., Tappan H. Some middle and late Ordovician microphytoplankton from central North America. Journal of Palaeontology. 52: 1233-1287 (1978).
  19. Loeblich Jr A.R. Morphology, ultrastructure and distribution of Paleozoic acritarchs. In Proceedings of the North American Palaeontological Convention, Chicago, 1969, part G. 705-788 (1970).
  20. Martin F., Dean W. T. Middle and Upper Cambrian and Lower Ordovician acritarchs from Random Island, eastern Newfoundland. Bulletin of the Geological Survey of Canada. 343. 1–43 (1981).
  21. Martin F., Dean W.T. Middle and Upper Cambrian acritarch and trilobite zonation at Manuels Rivers and Random Island, eastern Newfoundland. Bulletin of the Geological Survey of Canada. 381: 1–91 (1988).
  22. Mette W. Acritarchs from Lower Paleozoic rocks of the western Sierra Morena, SW-Spain and biostratigraphic results. Geol. Palaeontol. 23: 1–19 (1989).
  23. Moczydłowska M., Stockfors M. Acritarchs from the Cambrian–Ordovician boundary interval on Kolguev Island, Arctic Russia. Palynology. 28: 15-73 (2004).
  24. Moczydlowska M. Cambrian acritarchs from Upper Silesia, Poland— biochronology and tectonic implications. Fossils and Strata. 46: 1–121 (1998).
  25. Moczydłowska M. The Ediacaran microbiota and the survival of Snowball Earth conditions. Precambrian Research. 167: 1–15 (2008).
  26. Molyneux S., Osterloff P., Penney R., Spaak P. Biostratigraphy of the Lower Palaeozoic Haima Supergroup, Oman; its application in sequence stratigraphy and hydrocarbon exploration. GeoArabia-Middle East Petroleum Geosciences. 11 (2): 17-48 (2006).
  27. Molyneux S.G., Le Hérissé A., Wicander R. Palaeozoic phytoplankton In: Jansonius, J., McGregor, D.C. [Eds.], Palynology: Principles and Applications. American Association of Stratigraphic Palynologists Foundation. 2: 493–530 (1996).
  28. Palacios T. Acritarch assemblages from the Oville and Barrios Formations, northern Spain: a pilot proposal of a middle Cambrian [Series 3] acritarch biozonation in northwestern Gondwana. Review of Palaeobotany and Palynology. 219: 71-105 (2015).
  29. Palacios T., Jensen S., Barr S.M., White C.E. Acritarchs from the MacLean Brook Formation, southeastern Cape Breton Island, Nova Scotia, Canada: New data on Middle Cambrian–Lower Furongian acritarch zonation. Palaeogeography, Palaeoclimatology, Palaeoecology. 273: 123-141 (2009).
  30. Paris F., Le Hérissé A., Monod O., Kozlu H., Ghienne J.F., Dean W.T., Vecoli M., Gunay Y. Ordovician chitinozoans and acritarchs from southern and southeastern Turkey. Rev. Micropaleontol. 50: 81–107 (2007).
  31. Parsons M.G., Anderson M.M. Acritarch microfloral succession from the Late Cambrian and Ordovician [Early Tremadoc] of Random Island, eastern Newfoundland, and its comparison to coeval micro−floras, particularly those of the East−European Platform. American Association of Stratigraphic Palynology Contribution Series. 38: 1–123 (2000).
  32. Peng S.C., Babcock L.E., Cooper R. The Cambrian Period. In: Gradstein, F. M., Ogg, J. G., Schmitz, M. D., Ogg, G. J. [Eds.]. The Geologic Time Scale. Elsevier, Boston, 437–488 (2012).
  33. Potter T.L., Pedder B.E., Feist-Burkhardt S. Cambrian Furongian Series acritarchs from the Comley area, Shropshire, England. Journal of Micropalaeontology 31: 1-28 (2012).
  34. Raevskaya E.G., Servais T. Ninadiacrodium: A new Late Cambrian acritarch genus and index fossil. Palynology. 33: 219-239 (2009).
  35. Rasul S.M. The Lower Palaeozoic acritarchs Priscogalea and Cymatiogalea. Palaeontology. 17: 41–63 (1974).
  36. Rasul S.M. New species of the genus Vulcanisphaera (Acritarcha) from the Tremadocian of England. Micropalaeontology. 22: 479–484 (1976).
  37. Ribecai C., Tongiorgi M. Lusatia dramatica, a distinctive new species from the Upper Cambrian of Öland (Sweden). Review of Palaeobotany and Palynology. 98: 27-32 (1997).
  38. Ribecai C., Vanguestaine M. Latest Middle-Late Cambrian acritarchs from Belgium and northern France. Special Paper of Palaeontology. 48: 45-55 (1993).
  39. Scotese C.R., McKerrow W.S. Revised world maps and introduction. Geological Society, London, Memoirs. 12: 1-21 (1990).
  40. Setudehnia A., The Palaeozoic sequence at Kuh-e Dinar and ZardKuh. Iranian Petroleum Institute, Bulletin. 60: 16-33 (1975).
  41. Tongiorgi M., Ribecai C. Late Cambrian and Tremadocian phytoplankton (acritarchs) communities from Öland (Sweden). Bollettino della Societá Palaeontologica Italiana. 29: 77-88 (1990).
  42. Vanguestaine M., Brück P.M. A Middle and Late Cambrian age for the Booley Bay Formation, County Wexford, Ireland: New acritarch data and its implications. Revue de micropaléontologie. 51: 67-95 (2008).
  43. Vanguestaine M., Van Looy J. Acritarches du Cambrien moyen de la vallée de Tacheddirt [Haut-Atlas, Maroc] dans le cadre d'une nouvelle zonation du Cambrien. Annales de la Société géologique de Belgique. 106: 69-85 (1983).
  44. Vanguestaine M. New acritarchs from the Upper Cambrian of Belgium. In Proceedings of the Third International Palynological Conference, (Novosibirsk 1971). 28-31 (1973).
  45. Vecoli M. Stratigraphic significance of acritarchs in Cambro-Ordovician strata, Hassi-R’Mel area, Algerian Sahara. Bollettino della Società Palaeontologica Italiana. 35: 3-58 (1996).
  46. Vecoli M., Playford G. Stratigraphically significant acritarchs in Uppermost Cambrian to basal Ordovician strata of northwestern Algeria. Grana. 36: 17-28 (1997).
  47. Vecoli M. Cambro-Ordovician palynostratigraphy (acritarchs and prasinophytes) of the Hassi-R'Mel area and northern Rhadames Basin, North Africa. Palaeontographia italica. 86: 1-112 (1999).
  48. Vecoli M. Palaeoenvironmental interpretation of microphytoplankton diversity trends in the Cambrian-Ordovician of the northern Sahara Platform. Palaeogeography, Palaeoclimatology, Palaeoecology. 160: 329-346 (2000).
  49.  

    Volkova N.A., Kirjanov V.V. Regionalnaya strati-graficheskaya skhema sredne-verhnekembrijskikh otlozhenij vostochno-evropejskoj platformy. Stratigr. Geol. Correlation. 3: 66-74 (1995).
  1. Volkova N.A. Elenia, a new genus of acritarchs from the Cambrian-Ordovician deposits of the Russian platform. Journal of Micropalaeontology. 3: 7-10 (1984).
  2. Volkova N.A. Middle and Upper Cambrian acritarchs in the East-European Platform. Academy of Sciences of the USSR, Transactions. 454: p 116 (1990).
  3. Welsch M. Die Acritarchen der hoheren Digermul-Gruppe, Mittelkambrium bis Tremadoc, Ost-Finnmark, Nord Norwegen. Palaeontogr. B. 201: 1–109 (1986).
  4. Williams K.E. Early Paleozoic paleogeography of Laurentia and Western Gondwana: evidence from tectonic subsidence analysis. Geology. 25: 747–750 (1997).
  5. Wood G.D., Stephenson J.T. Cambrian palynomorphs from the warm water provincial realm, Bonneterre and Davis formations of Missouri and Arkansas (Reelfoot rift area): biostratigraphy, paleoecology and thermal maturity. In: Gregg, J.M., Palmer, J.R., Kurtz, V.E. [Eds.], Field Guide to the Upper Cambrian of South Eastern Missouri: Stratigraphy, Sedimentology and Economic Geology. Department of Geology and Geophysics, University of Missouri (Rolla), Geological Society of America Field Trip (Annual Meeting). 84–102 (1989).
  6. Young T., Martin F., Dean W.T., Rushton A.W.A. Cambrian stratigraphy of St. Tudwal's Peninsula, Gwynedd, Northwest Wales. Geological Magazine. 131(3): 335- 360 (1994).