Three deep canyons are located in the park, cut through the volcanic tuff of the Yellowstone Plateau by rivers over the last 640,000 years.
黄石公园里有三个幽深的峡谷。它们通过那些延续了64万年的河流斜着穿过黄石高原的火山凝灰巖。
The method takes the manganese slag as the lightweight aggregate to be mixed with the volcanic tuff stone powder, the fly ash and the cement, thus producing the wall block by pressing.