Journal of Stratigraphy and Sedimentology Researches (Feb 2015)
Plant Macrofossils from the Takht Coal Mine, Minoodasht and its Dating, Relative abundance and Sørensen index in comparison with the other Florizones in Iran and Eurasia
Abstract
Takht mine, SE Minoodasht contains well-preserved plant macrofossils belonging to 27 species allocated to 22 genera of various orders viz., Equisetales, Osmundales, Filicales, Peltaspermales, Bennettitales, Ginkgoales and Coniferales. The plant macrofossils in this area are studied for the first time. Based on the occurrence of Equisetites muensteri, Clathropteris meniscoides, Dictyophyllum exile, Anthrophyopsis crassinervis, Scytophyllum persicum, Pterophyllum bavieri, and Baiera muensteriana a Rhaetian age is suggested for this assemblage. Since, there was no differentiation between formations in geological map these flora emphasized spreading the Kalariz Formation in this area. The Minoodasht flora is correlated to the plant macrofossil assemblages of Zirab, Tazareh, Narges-Chal, Hiv, Jajarm (Alborz), Parvadeh mines (Tabas), and Darbid-Khun (Kerman Basin). Therefore, there were close floristic relationships between North and Central-East Iran (i.e. Kerman Basin and Tabas Block) and two areas were palaeogeographically closely related, probably forming a uniform paleoenvironment. On the basis of relative abundances of taxa, Filicales, Bennettitales, Ginkgoales and Pinales were 42.02%, 38.11%, 7.17% and 6.51%, respectively. It is noteworthy that variety and relative abundance of the species of Filicophyta and Bennetittales were high within Iran during the Late Triassic epoch. Therefore, a warm wet climatic regime dominated. In addition, a more uniform climate in continental scale is suggested. On the basis of similarity indices and relative abundance of taxa, Iran located within Eurasia climatic belt, Euro-Sinian Region, and the Middle Asia Province of Vakhrameev’s subdivisions and south-western region of Dubroskina’s subdivisions during this epoch.
