University of Isfahan Journal of Stratigraphy and Sedimentology Researches 2008-7888 26 2 2010 06 22 Using palynological evidences in reconstruction of depositional settingsof the Shemshak Formation, northern Semnan Using palynological evidences in reconstruction of depositional settingsof the Shemshak Formation, northern Semnan 129 148 16721 FA F Sajjadi Assistant Professor, Department of Geology, University of Tehran, Tehran S.H Hashemi Assistant Professor, Department of Geology, Tarbiat Moallem University, Tehran Y Rezazade M.Sc. Department of Geology, University of Tehran F Hashemi Yazd M.Sc. Department of Geology, University of Tehran Journal Article 2016 06 14 Various palynological elements including miospores, transparent and opaque AOM, dark phytoclasts, acritarchs, algal and fungal spores, and wood debris occur in surface samples of the Shemshak Formation, Shahmirzad, east-Central Alborz. Interpretation of relative abundance of these elements denotes notable sedimentation rate in an oxygenated, turbulent, non-marine environment deposits of which contain poorly preserved organic matter. It must be emphasized, however, that occurrence of marine microphytoplankton cysts (sensu lato) at several intervals in the Shemshak Formation section studied suggest intermittent marine incursions. Based on the spore-plant relationships, ferns and fern-allies, gymnosperms, and bryophytes, in descending order of importance, constituted the contemporaneous coastal vegetation. Presence of such fern spores as Cyathidites, Todisporites, Gleicheniidites, Dictyophyllidites, Klukisporites, Stiatella, and Deltoidospora implies sedimentation under moist warm-temperate climate. Co-occurrence in the material studied of fungal spores is also believed to corroborate the miospore-based palaeoclimate reconstruction presented herein. <strong> </strong> Various palynological elements including miospores, transparent and opaque AOM, dark phytoclasts, acritarchs, algal and fungal spores, and wood debris occur in surface samples of the Shemshak Formation, Shahmirzad, east-Central Alborz. Interpretation of relative abundance of these elements denotes notable sedimentation rate in an oxygenated, turbulent, non-marine environment deposits of which contain poorly preserved organic matter. It must be emphasized, however, that occurrence of marine microphytoplankton cysts (sensu lato) at several intervals in the Shemshak Formation section studied suggest intermittent marine incursions. Based on the spore-plant relationships, ferns and fern-allies, gymnosperms, and bryophytes, in descending order of importance, constituted the contemporaneous coastal vegetation. Presence of such fern spores as Cyathidites, Todisporites, Gleicheniidites, Dictyophyllidites, Klukisporites, Stiatella, and Deltoidospora implies sedimentation under moist warm-temperate climate. Co-occurrence in the material studied of fungal spores is also believed to corroborate the miospore-based palaeoclimate reconstruction presented herein. <strong> </strong> https://jssr.ui.ac.ir/article_16721_c35cce30d0e06c18d9a60eb25d547be2.pdf