Biofacies of Conodonts in Boundary of Frasnian-Famennian, Central Iran

Category Paleontology and Stratigraphy
Group GSI.IR
Location 21th symposium on geosciences
Holding Date 24 May 2008

      Statistical investigations on the population of different conodonts genera which are collected from the beds just below and above the Frasnian ? Famennian boundary prove changes or fluctuations of sea level in Central Iran. For example, in Chahriseh section (Esfahan), polygnathid ? icriodid biofacies governs on the Late Frasnian horizons, but the percent of Icriodus elements increases just above the boundary and changes the biofacies to icriodid ? polygnathid that shows a shallower environment. Late Frasnian sequence in Kal-e-Sardar section (east of Tabas) contains fossiliferous beds and some of them at the top of section have a lot of conodonts. These beds have polygnathid biofacies and number of elements reduces toward the boundary that shows a shallowing phase. Conodonts fauna which are recovered from southern Shotori?s Range sections, are different. Late Frasnian beds in Ghale-Kalaghu and Howz-e-Dorah sections have polygnathid ? icriodid biofacies, but these beds are not continues, they overlain by non-marine Early Famennian sediments with an unconformity surface.

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