The diatreme breccia pipes belong to volcanic crater phase and volcanic conduit phase, and consist of breccias and binding material.
A flat - bottomed, roughly circular volcanic crater of explosive origin that is often filled with water.
"Crater Lake:a lake of southwest Oregon in a volcanic crater of the Cascade Range. at 589.3 m (1,932 ft) deep, it is the second-deepest lake in North america. The lake and surrounding parkland are popular tourist attractions."
Deep in the Mt. Lingwu, a huge volcanic crater is like a monster, holding its head high in the sky, as if telling about its great achievements.
There are many noticeable and well-developed joints in the volcanic crater group in the Changle area, and they are unique in shape.
The small public toilet against the wall was open, and the dung pit was like a volcanic crater surrounded by yellow ice like Mount Fuji.
