At many archaeological sites, soil stratigraphy is everything: it gives context to artifacts, showing when and how they were deposited and what the environmental conditions were at the time.

• 在很多考古场地，地层的岩石组成意味着一切：它解释物品的环境，显示它们是什么时候、如何被埋起来的，当时的环境条件如何。