天文事件与二叠纪末联合古陆解体

Astronomical events and its bearings on the breakup of Pangea during the latest Permian

二叠纪末发生了全球规模的剧烈变化 ,这种变化表现为古地磁逆转、古气候改变、显生宙规模最大的海退、缺氧事件、火山活动、地球化学异常及地史上规模最大的生物集群灭绝。全球二叠纪 /三叠纪界线附近陆续发现了陨星撞击抛射物 (微球粒 )和不同程度的Ir等地球化学异常 ,表明二叠纪末发生了陨星撞击地球的天文事件。联合古陆从三叠纪开始解体 ,联合古陆解体的过程实际上就是特提斯洋缩小直至消亡的过程 ,也就是特提斯洋周缘板块聚合的过程。陨星撞击点可能位于二叠纪末特提斯洋北部 ,最终导致了特提斯洋消亡及联合古陆解体。

The spectacular changes on a global scale once took place during the latest Permian. These events include palaeomagnetic reversal,palaeoclimatic changes,large-scale regression,anoxic events,volcanism,geochemical anomaly,and mass extinction during the periods of the Phanerozoic. The discovery of the meteorite falls (micropellets) and Ir anomaly at the Permian/Triassic boundary on a global scale show that the astronomical events such as meteorite impacts also occurred during the latest Permian,followed by the breakup of Pangea from the earliest Triassic (250 Ma). The breakup in reality marked the waning and waxing of the Tethys Sea,or the plate convergence around the Tethys Sea. The meteorite impact sites may be delineated in the northern par of the latest Permian Tethys Sea. The meteorite impacts eventually resulted in the termination of the Tethys Sea and the breakup of Pangea.