43 research outputs found

    Paleogene dinoflagellate cysts and thermal maturity from Pabdeh Formation ( Zagros basin, west of Iran)

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    Palynological investigation on 132 samples from the 428m thick outcrop section of Late Paleocene to Early  Oligocene of the Pabdeh Formation in southwestern Iran yielded 55 species of dinoflagellate cysts and allowed  establishment of seven biozones. Quantity of marine palynomorph elements indicate an open marine  environment at that time interval but, a slight increase in number of spore and pollen grains in some samples  indicate suitable conditions for forest development as a consequence of increase in climate humidity. The  species are common in various latitudes and most of them are cosmopolitan. Thermal maturity index  measurement indicates oil prone nature for majority of the samples.Keyword: Pabdeh Formation, Dinoflagellate cysts, Paleogene, Palynostratigraphy, Thermal maturit

    An early Little Ice Age brackish water invasion along the south coast of the Caspian Sea (sediment of Langarud wetland) and its wider impacts on environment and people

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    Caspian Sea level has undergone significant changes through time with major impacts not only on the surrounding coasts, but also offshore. This study reports a brackish water invasion on the southern coast of the Caspian Sea constructed from a multi-proxy analysis of sediment retrieved from the Langarud wetland. The ground surface level of wetland is >6 m higher than the current Caspian Sea level (at -27.41 m in 2014) and located >11 km far from the coast. A sequence covering the last millennium was dated by three radiocarbon dates. The results from this new study suggest that Caspian Sea level rose up to at least -21.44 m (i.e. >6 m above the present water level) during the early Little Ice Age. Although previous studies in the southern coast of the Caspian Sea have detected a high-stand during the Little Ice Age period, this study presents the first evidence that this high-stand reached so far inland and at such a high altitude. Moreover, it confirms one of the very few earlier estimates of a high-stand at -21 m for the second half of the 14th century. The effects of this large-scale brackish water invasion on soil properties would have caused severe disruption to regional agriculture, thereby destabilizing local dynasties and facilitating a rapid Turko-Mongol expansion of Tamerlane’s armies from the east.N Ghasemi (INIOAS), V Jahani (Gilan Province Cultural Heritage and Tourism Organisation) and A Naqinezhad (University of Mazandaran), INQUA QuickLakeH project (no. 1227) and to the European project Marie Curie, CLIMSEAS-PIRSES-GA-2009-24751
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