Biotite is a subordinate constituent of the mafic and ultramafic rocks generally.黑云母一般是镁铁质及超镁铁质岩石中的次要成分.Late Precambrian mafic dyke swarms are extensively developed in the central North China Craton.华北克拉通中部广泛发育晚前寒武纪镁铁质岩墙...

mafic的音标：mafic的英式发音音标为：['mæfɪk]mafic的美式发音音标为：['mæfɪk]...

adj.铁镁质的...