the upper cretaceous carbonate sequence of ab-deraz formation is well exposed in the kopet- dagh basin. this formation comprises marly limestone and three chalky limestone units. chalky limestone of ab-deraz formation is mainly composed of calcareous dinoflagellate (pithonellid calcispher), cocolithofore and planktonic foraminifera. carbon and oxygen stable isotopes analysis of the third chalky...

The distribution patterns of taxa belonging to the section Hypoglottidei DC. were investigated using DIVA-GIS software. Based on Zohary classification, five global patterns, with the exception of widely distributed species, include 1. Centro-Asiatic province, 2. Irano-Anatolian province, 3. Pontic province, 4. East Mediterranean subregion and 5. West Mediterranean subregion, were identified. In...

Irán es el principal centro de especiación y endemismo Astragalus (Fabaceae), mayor género angiospermas en viejo mundo. Las áreas los hotspots del no son bien conocidos necesaria una evaluación detallada utilizando aproximaciones SIG. En este artículo, se estudian patrones distribución espacial endemismos la riqueza especies, análisis parsimonioso endemicidad (PAE por sus siglas inglés) interpo...

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...

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 ...

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...

clay minerals are considered the most important components of clastic reservoir rock evaluation studies. the shurijeh gas reservoir formation, represented by shaly sandstones of the late jurassic-early cretaceous age, is the main reservoir rock in the eastern kopet-dagh sedimentary basin, ne iran. in this study, x-ray diffraction (xrd), x-ray fluorescence (xrf), scanning electron microscopic (s...