نتایج جستجو برای: late neoproterozoic
تعداد نتایج: 196368 فیلتر نتایج به سال:
Discovery of fossils of the Ediacara biota near the top of the Spitzkopf Member at farm Swanpunt extends the known range of these remains in Namibia more than 600 m to near the sub-Cambrian unconformity. The fossiliferous beds occur approximately 100 m above a volcanic ash dated at 543 +/- 1 Ma, and thus may be the youngest Proterozoic Ediacara-type fossils reported anywhere in the world. Fossi...
Abstract The Longshou Shan of western China is the northern backstop Cenozoic Himalayan-Tibetan orogen and occupies a key linkage between Tarim continent North craton which separate pre-Cenozoic Tethyan orogenic system Central Asian system. Therefore, Paleoproterozoic–Paleozoic evolution this region critical to understanding extent overprinting deformation, construction Eurasian continent, rela...
The Neoproterozoic glacial intervals represent one of the most curious expressions of Earth’s climate. Despite the popularity of the hard “Snowball” hypothesis in the popular press, the scientific community remains divided over the extent of the Neoproterozoic glaciations, the age of the glaciations, the number of glacial events and the triggering mechanism for the glaciations. A major, and yet...
Age and Provenance of the Beardmore Group, Antarctica: Constraints on Rodinia Supercontinent Breakup
New U-Pb ages for detrital and igneous zircons constrain the depositional age and sedimentary provenance of the Beardmore Group, a siliciclastic succession that records transformation of the East Antarctic margin during Rodinia breakup and subsequent Gondwana amalgamation. We divide rocks previously mapped as the Beardmore Group into (1) an inboard late Neoproterozoic assemblage (probably ≤670 ...
In orogenic belts, a basal décollement zone often develops at depth to accommodate the shortening due to folding and thrusting of the sedimentary cover. In the Early Mesozoic intracontinental Xuefengshan Belt of South China, such a décollement zone is exposed in the core of anticlines formed by the emplacement of the late-orogenic granitic plutons. The detailed, multi-scale structural analysis ...
The Sturtian and Marinoan snowball Earth episodes initiated 720 and 650 million years ago, respectively, are among the most dramatic events in Earth’s history. The ultimate causes of these events remain obscure, however, and there is still uncertainty about the critical levels of greenhouse gas concentrations at which the snowball transition occurs. Furthermore, earlier modelling results (with ...
Abstract The Proterozoic–Phanerozoic tectonic evolution of the Qilian Shan, Qaidam Basin, and Eastern Kunlun Range was key to construction Asian continent, understanding paleogeography these regions is critical reconstructing ancient oceanic domains central Asia. This issue particularly important regarding North China-Tarim continent South China craton, which have experienced significant late N...
South China has been considered as part of the Rodinian supercontinent during Neoproterozoic time, although its paleogeographic position within this supercontinent is still a matter of debate. The Wangjiangshan and Bijigou complexes along the northern margin of South China are among the largest mafic intrusions in China. New SHRIMP zircon U-Pb results indicate that these two intrusions have cry...
The South China Block is situated in the Eastern Asian margin. Since Neoproterozoic, its tectonic evolution was constrained by successive consumption-closure processes of Paleo-South China, Proto-Tethys, Paleo-Tethys, and Paleo-Pacific oceans. Studies suggest that this block initially formed Neoproterozoic assembly Yangtze Cathaysia blocks following subduction-accretion Ocean. Then after, it ex...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید