The terraces are made of travertine, a sedimentary rock deposited by water with a very high mineral content from the hot springs.

梯田由钙华构成，是一种由温泉中矿物质含量很高的水沉积而成的沉积岩。

And so the state consequently had a massive, massive amount of petroleum-rich shale rock deposits beneath its surface, ripe for the new fracking technique to exploit.

因此，该州地表下蕴藏着大量富含石油的页岩矿床，为新的水力压裂技术提供了成熟的开采条件。