the sarcheshmeh formation is a shaly sequence of lower cretaceous age (aptian) which is deposited in koppeh-dagh sedimentary basin and conformably overlies and underlies the tirgan and sanghaneh formations respectively in the toos well # 1. lithologically, this formation has a thickness of 177m and consists mainly of marl, shale and shaly limestone. palynological studies resulted in identificat...

in this study, depositional environment and provenance of sandstones of the surijeh formation (lower cretaceous) in the abgarm section in the kopet-dagh basin are investigated. analysis of sedimentary facies in this section shows that there are two clastic (continental and coastal plain) and two carbonate (coastal plain) facies associations are present. the results of modal analysis and geochem...

the kalat formation is one of units in the kopet dagh sedimentary basin and so far have been studied by other fossils (case study) (palynomorphs, calcareous nanoplankton and foraminifera). according to the important ostracoda in diagnosis paleoecology and paleoenvironment, in this study, investigated ostracoda in shale units of the kalat formation in chahchaheh section have been studied for the...

A stratigraphic section from the Tirgan Formation was selected in Arkan village nearby Bojnourd city in order to study echinoderm fauna systematically. Many specimens of echinoderms, especially toxasteridae which is associated with brachiopods were collected and studied systematically in this paper. Microscopie slides were also prepared and studied. All slides contain benthic foraminifers and c...

We investigate the evolutionary history of the wide-ranging Nearctic treefrog Hyla arenicolor through the integration of extensive range-wide sampling, phylogenetic analyses of multilocus genetic data, and divergence dating. Previous phylogeographic studies of this frog documented a potential signature of introgressive hybridization from an ecologically and morphologically divergent sister spec...