Lava and white ash mixed with floodwaters to form a hard , sun baked layer known as tufa .
火山岩浆和白色火山灰与洪水融合，被阳光烤干，形成坚硬的地层凝灰岩。
Formation process of tufa landscape as tour resources .
旅游资源中石灰华景观的形成过程。
To intensify propaganda and refineries in the banning of tires tufa , the epa invited the county 's cable tv xianyou tracking reports , played a " crack down on that side deterrence , education and a " role .
A discussion on formation process of tufa landscape as tour resources -- a case study of the tufa in jiuzhaigou , sichuan and huangguoshu , guizhou etc.
