نتایج جستجو برای: permian
تعداد نتایج: 3143 فیلتر نتایج به سال:
A suite of Permian sylvite samples from Boulby potash mine, Yorkshire, UK, consistently yield traces of hydrogen upon analysis by a cold crush technique for liberating volatiles from entrapped fluid inclusions. In contrast, accompanying halite samples do not yield hydrogen. These data suggest the formation of hydrogen by radiolysis of water due to irradiation from potassium in the sylvite. The ...
The end-Permian mass extinction was the most severe biodiversity crisis in Earth history. To better constrain the timing, and ultimately the causes of this event, we collected a suite of geochronologic, isotopic, and biostratigraphic data on several well-preserved sedimentary sections in South China. High-precision U-Pb dating reveals that the extinction peak occurred just before 252.28 ± 0.08 ...
Globally, Late Permian to Early Triassic carbonate rocks record several pronounced positive and negative C-isotope excursions, indicating a dramatic reorganization of the global carbon cycle. These C-isotopic anomalies provide important constraints on environmental changes that occurred during end-Permian extinction subsequent delayed biotic recovery. In this study, we present high-resolution d...
The Middle Permian Tapinocephalus Assemblage Zone in South Africa has produced a rich record of tetrapods domi− nated by dinocephalian therapsids and pareiasaurid para− reptiles. In this study we reassess the affinities of a specimen from this horizon previously identified as a procolophonoid and provide evidence that it is instead referable to a nyctero− leter parareptile, an identification th...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید