And what we see is extremely regular thin beds that extend for kilometers and exceptional preservation of soft-bodied material in what's called lithographic siltstone.

我们是极其规则薄层，绵延数公里，并且在所谓平版粉砂岩中保了特殊软体材料。

You're searching for fossils in the Harrison Formation -- a big swath of siltstone, sandstone, and volcanic ash dating back to the Miocene Epoch some 22 million years ago.

你在哈里森层中寻找化石——层由泥岩、砂岩和火山灰组成，可以追溯约2200万年前中新世。