mafic, a. Min.
(ˈmæfɪk)
[f. magnesium + L. f-errum iron + -ic.]
Pertaining to, containing, or designating the dark-coloured minerals of igneous rocks, which are predominantly ferromagnesian in character. Opp. felsic a.
| 1912 W. Cross et al. in Jrnl. Geol. XX. 561 We suggest the term..mafic for the group of modal ferromagnesian minerals of all kinds. 1920 [see femic a.]. 1926 [see ankaramite]. 1969 Nature 20 Dec. 1153/1 The lavas are intruded by ultramafic and mafic bodies and dyke swarms. 1970 Ibid. 31 Oct. 413/1 The African rifts are sites of under-saturated, predominantly mafic volcanics erupted in comparatively small volume from single vents. 1971 I. G. Gass et al. Understanding Earth v. 83/1 The oceans, with their thin (about 5 km) mafic crust. |