groundmass

/ground-mas/US // ˈgraʊndˌmæs //UK // (ˈɡraʊndˌmæs) //

地面物质,地盘,地表水,地表水层

Definitions

n.名词 noun

1
- : the crystalline, granular, or glassy base or matrix of a porphyritic or other igneous rock, in which the more prominent crystals are embedded.

The felted or hyalopilitic texture is the most common, and plagioclase is the principal groundmass constituent.
In a basal flow in Moraine Park, the slaggy and compact phases show differences in phenocrysts as well as in groundmass.
These lavas have groundmass textures that vary from almost holo-crystalline to glassy.
Pyroxene, quartz and augite form the groundmass, as seen in section.