The Tirgan Formation (Barremian – Aptian) is exposed in the Kopet Dagh in northeast Iran. One stratigraphic section in Zavin was measured with a thickness of 110 meters. This Formation in section consists of three parts (including lower carbonate, limy shale – marl and upper carbonate rocks). Based on the study of 94 thin sections, 10 carbonate and 2 siliciclastic lithofacies have been identifi...

Isotope data from bulk carbonates, micrite, marine calcite cements, non-skeletal grains and brachiopods indicate deposition of a wide spectrum of warm to cold water carbonates during the Ordovician and the Jurassic. This isotopic interpretation is supported by warm to cold climatic models proposed for the Ordovician and the Jurassic. These carbonates formed during the Greenhouse mode (condition...

The geographic distribution of Astragalus (Fabaceae) in Iran was analyzed using a database of 7606 georeferencedobservations. Astragalus occurs in all provinces of Iran, but 88% ofthe observations are in five provinces including Tehran, West-Azerbaijan, Esfahan, Kordestan, and Khorasan-e Razavi.Most species are rare and narrowly endemic: Thelargest distance between two observations of the same ...

The aim of this study is to analyze the assemblage of trilobites in the Silurian sequences of Iran by exploring stratigraphic section of the Silurian Niur Formation (Asadli section).  Based on comprehensive field studies and laboratory investigations three Trilobite genera were identified in the study area including Calymene blumenbachii, Gravicalymene convolva, Dalmanites brevigladiolus </...

Paleoclimatic investigation of loess-paleosol sequences from northern Iran is important for understanding past changes in a region highly sensitive to shifts precipitation, and along potential routes human migration. Here, we present carbon oxygen isotopic compositions bulk carbonate (? 13 C bc ? 18 O , respectively) coupled with particle size distributions samples the Mobarakabad section, Iran...

the sanganeh formation crops out throughout the kopeh-dagh basin and is mainly composed of shale and marl with interbeds of siltstone and limestone. in this study, the sanganeh formation, with 550 meter thickness, has been studied at north of the sanganeh village in eastern parts of the basin. according to distribution of organic matter content, four palynofacies types are identified. the main ...

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...

the granites south of mashhad are located in the north-east of iran and occur in the suture zone between the binalud and kopeh dagh areas. these s-type granites are peraluminous with an upper triassic age and include intersecting pegmatites. these pegmatites are homogenous and show simple mineralogical combinations which include k-feldspars (microcline and orthoclase), plagioclase, quartz, mica...

isotope data from bulk carbonates, micrite, marine calcite cements, non-skeletal grains and brachiopods indicate deposition of a wide spectrum of warm to cold water carbonates during the ordovician and the jurassic. this isotopic interpretation is supported by warm to cold climatic models proposed for the ordovician and the jurassic. these carbonates formed during the greenhouse mode (condition...