نتایج جستجو برای: early aptian
تعداد نتایج: 686306 فیلتر نتایج به سال:
در این مطالعه نانوفسیلهای آهکی برش نیمبلوک در شمال باختر قائن ارزیابی و بررسی شده است. برش نیمبلوک با ستبرای 164 متر شامل سنگآهک، مارن و شیل است. در برش مورد مطالعه 76 گونه نانوفسیلی متعلق به 30 جنس از 15 خانواده شناسایی شد. بر پایه نانوفسیلهای شناسایی شده، بخشی از زیرزون CC7b و زیستزون CC8 و بخشی از زیستزون CC9 از زیستزونبندی Sissingh (1977) و زیرزون NC7Cو زیستزونهای NC9, NC8 و بخش...
This paper discusses the lithostratigraphy of the Xinminbao Group in the Mazongshan area of Gansu Province, northwestern China, and the correlation of its biota. The Xinminbao Group was deposited in a fluviolacustrine setting in Mesozoic graben basins under a semi-arid, subtropical climate. The fossil sites concentrated in the lower part of the group have yielded dinosaurs, mammals and other ve...
Superplumes have been put forward as a driving mechanism for a variety of global phenomena, ranging from geomagnetic reversal anomalies to global climate warming via massive additions of volcanic CO2. Here I propose that rates of uplift caused by modern superplumes would result in the liberation of hundreds of Gt of carbon from methane clathrates on a timescale from tens to hundreds of millions...
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...
Cretaceous aeolian deposition is important for understanding variations of the tropical−subtropical atmospheric circulation under greenhouse background. Nevertheless, detailed records revealing response to rising CO2 are still lacking. To shed light on their linkage, we examined Early stratigraphic evolution Hekou Group in Baiyin-Jingyuan Basin, northern China, using multiple methods. The resul...
The Hauterivian–Aptian Isachsen Formation at Glacier Fiord, Axel Heiberg Island, in the Sverdrup Basin of Canadian Arctic Archipelago was deposited contemporaneous with initiation High Large Igneous Province (HALIP). New palynological biostratigraphy and paleoenvironmental reconstruction, coordination emerging geochronology HALIP igneous rocks, permits exploration effects volcanism on vegetatio...
High-amplitude changes in sedimentary δ 13 C characterize the Cretaceous system and have been proven useful for supra-regional chemostratigraphic correlation. In Cretaceous, these perturbations indicate large shifts between global carbon reservoirs that are usually caused by volcanic activity of igneous provinces, widespread deposition thick organic carbon-rich sequences and/or orbital paramete...
Aptian/Albian (Early Cretaceous) paleogeography of the South Atlantic: a paleontological perspective
The fossil record of the turtle clade Baenidae ranges from the Early Cretaceous (Aptian–Albian) to the Eocene. The group is present throughout North America during the Early Cretaceous, but is restricted to the western portions of the continents in the Late Cretaceous and Paleogene. No credible remains of the clade have been reported outside of North America to date. Baenids were warmadapted fr...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید