| 释义 |
〔sinkhole〕A natural depression in a land surface communicating with a subterranean passage, generally occurring in limestone regions and formed by solution or by collapse of a cavern roof.灰岩坑:与某一地下通道相联的陆地表面的自然下沉地区,通常出现在灰岩地区并且由石灰岩溶解成溶洞顶部下沉形成〔chert〕A siliceous rock of chalcedonic or opaline silica occurring in limestone.硅石:出现在灰岩中的玉髓或蛋白色硅石〔coquina〕A soft, porous limestone, composed essentially of fragments of shells and coral, used as a building material.贝壳灰岩:一种质软、多孔的灰岩,基本上由贝壳及珊瑚的碎片构成,用作建筑材料 |