silicified tuff

• 硅化凝灰岩

silicified tuff的用法和样例：

例句

1. This kind of rock is called tuff.
   这里的岩质是凝灰岩。
2. Over the tuff, a thinner layer of harder volcanic rock, like basalt, formed from lava flows.
   在凝灰岩，更薄一层难以火山岩，如玄武岩，形成由熔岩流。