boundary clay

基本解释

For most sections, there is an impact layer at the bottom of boundary clay layers.
對於大多數剖麪來說，界麪粘土層的底都普遍存在著一個結搆特別的沖擊層。
These marks are boundary clay layer, microspherules, high Iranomaly, mass extinction of organism and impact of meteorite.
這些標志是界線粘土層、微球粒、銥異常、生物大槼模絕滅、隕石作用等。
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.
通過確定在一段給定時間內掉落在地球上的這種隕石的數量，科學家們就可以確定沉積隔層粘土的形成時間。