滇黔地区陆相二叠系—三叠系界线附近粘土岩中发现微球粒

Discovery of Microspherules in Claystone near the Terrestrial Permian——Triassic Boundary

在滇东黔西地区的几条陆相二叠系—三叠系界线地层剖面研究中,二叠系—三叠系界线附近普遍存在1～2层非正常事件成因的粘土岩,并在粘土岩中发现了大量微球粒。依据化学成分,这些微球粒可分为硅质和钡质两类。笔者认为这种含微球粒的粘土岩成因很可能是,陨石撞击地球诱发大规模火山爆发,其产物又经历正常沉积作用并有非火山和撞击的正常沉积物混入。这些奇异的球粒,可能就是撞击的产物之一。

Study of several terrestral Permian-Triassic bounday sections in the eastern Yunnan-western Guizhou area shows that ther commonly occur 1~2 horizons of claystones of non-normal event origin near the Permian-Triassic boundary. Many microspherules have been first found in the claystones. According to their chemical compositions, the microspherules can be divided into two types: siliceous and baritic. Writers considered that this claystone with the microspherules must be formed by co-sedimentation of normal sediments and the volcanic clast. The volcaism was coused by collision of meterorite and the earth. The microspherules is one of the products formed in collision.