| 释义 |
sima/ˈsaimə/n. Geol. 【地质】 1 the lower layer of the earth's crust, underlying both the oceans and continental masses 硅镁圈，硅镁带，硅镁层(地壳中较低的一层，海底和大陆板块底部主要为此成分) 2 the material of this, relatively heavy basic rock rich in silica and magnesia 硅镁材料 [SILICA + MAGNESIA] |