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 .

要加大对轮胎禁止土法炼油厂宣传，环保局邀请县有线电视仙游跟踪报道，起到了“打击那边威慑，教育和”的作用。

A discussion on formation process of tufa landscape as tour resources -- a case study of the tufa in jiuzhaigou , sichuan and huangguoshu , guizhou etc.

论旅游资源中石灰华景观的形态建成过程--以四川九寨沟和贵州黄果树等地石灰华群为例。