Montmorillonite forms when basic rocks such as volcanic ash in Marine basins are altered.
海相盆地中的基性岩石(如火山灰)经蚀变后形成蒙脱石。
2
It is known that the volcanicrocks of the Yingcheng Formation were altered into bentonite in the Songliao Basin, and the major bentonite deposits in the area are located in Jiutai City.