نتایج جستجو برای: albian
تعداد نتایج: 541 فیلتر نتایج به سال:
The Lower Cretaceous Carbonate deposits of the Dariyan Formation of the HighZagros Belt are mainly composed of thick to medium bedded limestone. These depositscontain abundant and diversified benthic foraminifera which have been recovered fromcarbonate rocks. A rich assemblage of microfossils with characteristic: Palorbitolinalenticularis (Blumenbach), Mesorbitolina subconcava (Leymerie), Mesor...
A new genus and species of ibis fly is described from an isolated wing in amber from the Late Albian-Early Cenomanian of Charentes, southwestern France. Galloatherix incompletus gen. et sp. n., is the first Athericidae fossilized in Cretaceous amber, and only the eighth Mesozoic species. It adds to the diverse aquatic and semiaquatic paleobiota already identified from Charentese amber.
Abstract. The Early Cretaceous is characterized by warm background temperatures (i.e., greenhouse climate) and carbon cycle perturbations that are often marked ocean anoxic events (OAEs) associated shifts in the hydrologic cycle. Higher-resolution records of terrestrial marine δ13C δ18O (both carbonates organics) suggest climate during Aptian–Albian, including a period with OAE 1a early Aptian ...
Coal seams preserve continuous and high-resolution records of paleoenvironments wildfire events during peat accumulation. In order to elucidate characteristics terrestrial climate changes the time accumulation, petrographic coals in Lower Cretaceous Yimin Formation (Albian) Jiuqiao Sag, Hailar Basin, NE China were studied. petrology analysis shows that studied coal are characterized by dominant...
The mid-Cretaceous (Albian and Cenomanian, 113–93.9 Myr) marked a transformative interval of shark evolution during which lamniforms (mackerel sharks) diversified as dominant marine predators. Yet, their radiation dynamics relative to major biotic turnovers delimiting the Albian–Cenomanian Cenomanian–Turonian boundaries are incompletely understood. Here, we use high-resolution dental fossil rec...
Detailed organic petrography analysis were conducted on drill core and cutting samples from the Nahr Umr (Middle Albian), Burgan (Lower Albian) and Ratawi (Hauterivian) formations on the Soroosh and Nowrooz fields, NW part of the Iranian sector of the Persian Gulf. The thermal maturity of the Middle Albian Nahr Umr Formation appears to have reached the top of the oil window. The underlying Burg...
three well - known source rocks of the zagros basin and the persian gulf are mesozoic in age.the jurassic sargelu, albian kazhdumi and neocomian-coniacian garau formations have charged the cretaceous reservoirs of this area. the northwest part of the persian gulf is strongly influenced by two major n-s trending paleohighs (hendijan- bahregansar-regesafid-izeh and kharge- mish) and surrounding p...
Many key aspects of early angiosperms are poorly known, including their ecophysiology and associated habitats. Evidence for fast-growing, weedy angiosperms comes from the Early Cretaceous Potomac Group, where angiosperm fossils, some of them putative herbs, are found in riparian depositional settings. However, inferences of growth rate from sedimentology and growth habit are somewhat indirect; ...
BACKGROUND Australia's dinosaurian fossil record is exceptionally poor compared to that of other similar-sized continents. Most taxa are known from fragmentary isolated remains with uncertain taxonomic and phylogenetic placement. A better understanding of the Australian dinosaurian record is crucial to understanding the global palaeobiogeography of dinosaurian groups, including groups previousl...
Pedogenic carbonate samples collected from three Lower Cretaceous (Aptian–Albian) fossil localities in Texas and Oklahoma were analyzed to develop paleoatmospheric pCO2 estimates by measuring the stable carbon isotopes of pedogenic calcite their co-existing occluded organic matter. Calcite ?13C values ranged ?10.9‰ ?4.4‰ while matter ?27.3‰ ?21.1‰. These isotope measurements combined with tempe...
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