| 释义 |
theralite Petrogr.|ˈθɪərəlaɪt|
[ad. G. theralith (H. Rosenbusch Mikrosk. Physiogr. (ed. 2, 1887) II. 248), f. Gr. θηρᾶν to hunt, pursue: see -lite, -lith.]
Any of a group of mafic, intrusive, igneous rocks that contain nepheline and calcic plagioclase.
1898Bull. U.S. Geol. Survey No. 150. 197 This feldspar was determined as in part ordinary sanidine, in part a soda-lime feldspar, and the rocks were therefore made the types of a plutonic rock characterized by the mineral combination nephelite, soda-lime feldspar, and named theralite by Professor Rosenbusch. 1938A. Johannsen Descr. Petrogr. Igneous Rocks IV. 222 Among rocks difficult to place are the shonkinites, theralites, and teschenites. On the basis of their limited extent and mode of occurrence as sills, small intruded masses, and border facies, the rocks are hypabyssal; on the character of their usual textures, they are plutonic. 1978S. R. Nockolds in S. R. Nockolds et al. Petrol. for Students xvi. 177 Theralites appear to be rather rare but occur, for instance, as dykes cutting nepheline syenite in the Khibina complex, Kola Peninsula, U.S.S.R... Theralites are found also in the Lugar sill, Ayrshire. |