greensand
/ˈgriːnsænd/noun
mass noun
1- Geology a greenish kind of sandstone, often loosely consolidated【地质】海绿石砂岩。
1.1
- （一般作the Greensand）a stratum largely composed of such sandstone, deposited during the Cretaceous period and often underlying chalk海绿石砂岩地层。