The plateau sloped down, to the south, toward outcroppings of rock that gave the landscape a chaotic look.高原缓缓地倾斜下去，南边为一片露出地面的岩层，呈现出一种乱石嶙峋的地貌。The rocks are dated by examining the fossils found in the same layer.通过查看在同一岩层里发现的化石来鉴定岩石的年代。They tunnelled through the rock.他们穿过岩层挖出一条地道。