Document Type : Original Research Paper


1 School of Earth Science, Damghan University, Damghan, Iran

2 Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran

3 Institute of Earth Sciences, Geological Survey of Iran, Tehran, Iran


During the Carboniferous time, Iran was a part of the northern margin of Gondwana. Carboniferous deposits of Iran are characterized by continental to shallow marine deposits. The studied section (Simeh- Kooh) is located in 5 Km Northwest of Damghan city in the east Alborz region. The lower Carboniferous Mobarak Formation consists of variable thickness of limestones interbeded with shale beds. The thickness of this section is about 115 m. The Mobarak Formation overlay the upper Devonian Jeirud Formation with a transitional contact and is unconformably underlain by lower Permian mixed siliciclastic-carbonate succession of Dorud Formation. This research is focused on the conodonts and facies. Conodont elements consist of 13 genus and 19 species. 5 Biozones is identified including, costatus zone (Latest Famennian), Sandbergi-L. crenulata zone,  isostaticha-U. crenulata zone (Middle Tournaisian), typicus-anchoralis-latus zone (Late Tournaisian) and G. bilineatus zone (Middle-Late Visean) correspond to global zonation. The Tournaisian succession consist of alternation of organic matter rich shales and dark thin-bedded limestones is supposed to have deposited in a deep marine environment with a low oxygen condition. The paleontological and facies characteristics of Devonian-Carboniferous transition definitely show a rapid sea level rise and flooding event in this time in Eastern Alborz which corresponds with the Hangenberg Bioevent known in other parts of the world.


Ashouri, A. R., 2006- Middle Devonian-Early Carboniferous Conodont Faunas from the Khoshyeilagh Formation, Alborz Mountains, North Iran. Journal of Sciences, Islamic Republic of Iran 17(1): 53-65, University of Tehran, ISSN 1016-1104
Assereto, E., 1963- the Paleozoic formations in Central Elborz (Iran), Riv. Ital., paleontol., V.69, N.4
Bozorgnia, F., 1973- Paleozoic foraminiferal biostratigraghy of central and east Alborz mountain, Iran, National Iranian Oil, geol. lab., publ. No.4
Hamdi, B. & Janvier, P., 1981- Ministry of industry and mines geological survey of Iran, Contribution of the paleontological researches in North and Central Iran, Geol. Surv. of Iran, R.N.49
   Kaiser, S. I., Steuber, T., Becker, R. T. & Joachimski, M. M., 2006- Geochemical evidence for major environmental change at the Devonian-Carboniferous boundary in the Carnic Alps and the Rhenish Massif, Palaeogeography, Palaeoclimatology, Palaeoecology 240 (2006) 146-160.
Lane, R., Sandberg, Ch. & Ziegler, W., 1980. Taxonomy and phylogeny of some Lower Carboniferous Conodonts and preliminary standard post-Siphonodella zonation. Geologica et Paleontologica, 14, p.117-164.
  Mawson, R. & Talent J. A., 1999- Early Carboniferous (mid-Tournaisian) conodonts from north-eastern Queensland(Ruxton and Teddy Mountain Formations): age-implications and stratigraphic alignments. Centre for Ecostratigraphy and Palaeobiology, Macquarie University, Boll. della Soc. Pal. Italiana, p. 407-425, 8 pls.
Mosaddegh, H., Rahimi, B.& Aharipour, R., 2006- Sequence Stratigraphy and Depositional Environments of the Lower to Middle Carboniferous Strata ( Mobarak and Ghesel-Ghal'eh Formations)in Central and Eastern Alborz, North of Iran, Absrtact Book,Germany, P.89-90
    Ruttner, A. & Stocklin, J., 1966- Foreword in contribution to the paleontology of east Iran. Geological Survey of Iran,6.
    Walliester, H. et al., 1966- Contribution to the Paleontology of east Iran, Geol. surv. Iran, Report No.6.