| 释义 |
femic, a. Petrogr.|ˈfɛmɪk|
[See quot. 1902.]
Of or pertaining to one of the two primary categories erected by Cross, Iddings, Pirsson, and Washington to classify the igneous rocks, and broadly including the non-aluminous ferromagnesian rocks (see also quots.).
1902W. Cross et al. in Jrnl. Geol. X. 573 To express concisely the two groups of standard minerals and their chemical characters in part, the words sal and fem have been adopted... Fem indicates Group II, since its minerals are dominantly ferromagnesian. As adjectives to express these ideas the words salic and femic will be used. 1912Ibid. XX. 560 Some petrographers have fancied the terms salic and femic as short words, which they wish to apply to modal quartz, feldspar, and felspathoid minerals in one case, and to all modal ferromagnesian minerals in the other. These terms have also been applied to major rock groups. Such applications are not proper uses of these terms. 1920A. H. Fay Gloss. Mining & Mineral Ind. 264/2 Femic... Often but incorrectly used in place of Mafic or Subsilicic. 1932F. F. Grout Petrography ii. 46 The terms ‘salic’ and ‘femic’ refer to calculated molecules, not actual minerals, and should be used only in connection with chemical composition. 1939A. Johannsen Descr. Petrogr. (ed. 2) I. viii. 86 Femic does not mean ‘ferromagnesian’. 1966Mineral. Abstr. XVII. 704 The problems of the determination of the amounts of femic minerals are discussed. |
