表层岩 meaning in English

mantle rock
regolith

Ffatures of epikarst zone in south china and formation mechanism
中国南方表层岩溶带的特征及形成机理
A study of superficial structure of karst zone and exploitation of karst water at the valley of daxiaojing underground river
贵州大小井地下河流域表层岩溶带结构及岩溶水开发
( 4 ) water - soil curing and using techniques of large opencast coal mine within loess area in our country have been divided into three types : water - soil safety techniques , water - soil conservation and water - soil recycling use techniques
( 4 )明确将我国黄土区大型露天谋矿水土整治和利用技术划分为水土安全调控、表层岩土水土保持和水土资源化利用三个阶段