boundary clay

基本解释

For most sections, there is an impact layer at the bottom of boundary clay layers.
对于大多数剖面来说，界面粘土层的底都普遍存在着一个结构特别的冲击层。
These marks are boundary clay layer, microspherules, high Iranomaly, mass extinction of organism and impact of meteorite.
这些标志是界线粘土层、微球粒、铱异常、生物大规模绝灭、陨石作用等。
By measuring how many of these meteorites fall to Earth over a given period of time, scientists can estimate how long it might have taken to deposit the observed amount of Ir in the boundary clay.
通过确定在一段给定时间内掉落在地球上的这种陨石的数量，科学家们就可以确定沉积隔层粘土的形成时间。