对喷发层和撞击坑的详尽研究是了解巨大陨石撞击地球引起的复杂的物理、化学现象的关键，然而，地球表层往往被掩埋、剥蚀，以致撞击坑和喷发物消失．陆地上保存完好的撞击坑和喷发层极其少见，因此，撞击所引起的许多现象难以确定，尤其是大洋撞击事件．迄今为止，已识别的陆 Detailed study of eruptions and craters is the key to understanding the complex physical and chemical phenomena caused by huge meteorites striking the Earth. However, the earth’s surface is often buried and denuded so that craters and eruptions disappear. It is extremely rare for craters and eruptions to remain intact on land so that many of the phenomena caused by the impact are difficult to determine, especially in the case of an oceanic impact. So far, the identified land