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.

们看到的是极其规则的薄层，绵延数公里，并且在所谓的平版粉砂中保了特殊的软体材料。

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.

你在哈里森地层中寻找化石——这片地层、砂和火山灰组成，可以追溯到约2200万年前的中新世。