felsic, a. Min.
(ˈfɛlsɪk)
[f. feldspar + lenad (= feldspathoid) + silica + -ic.]
Of or pertaining to such light-coloured minerals as the feldspars, the feldspathoids, quartz, and muscovite, or to rocks containing a high proportion of these or similar minerals.
| 1912 W. Cross et al. in Jrnl. Geol. XX. 561 We suggest the term felsic for the group of modal feldspars, feldspathoids, and quartz. 1965 G. J. Williams Econ. Geol. N.Z. iv. 38/1 The host-rock is a splintery siliceous bluish-grey slate with some micaceous, talcose and felsic facies. |