| 释义 |
diabase Min.|ˈdaɪəbeɪs|
[a. F. diabase, erroneously formed, since (according to Littré) it was meant to signify ‘rock with two bases’ (for which dibase would have been a proper form), and subsequently abandoned by its author, Brongniart, for Haüy's name diorite; but in 1842 re-introduced by Hausmann, perhaps with an intended affiliation to Gr. διάβασις a crossing over, transition.]
The name originally given by A. Brongniart to the rock afterwards called diorite; now applied to a fine-grained, compact, crystalline granular rock, consisting essentially of augite and a triclinic feldspar, with chloritic matter in varying amount; a variety of the class of rocks called greenstone and trap, being an altered form of basalt.
[1816Cleaveland Min. 609 Greenstone (note), Diabase of some French mineralogists.] 1836Macgillivray tr. Humboldt's Trav. xiv. 166 They observed two large veins of gneiss in the slate, containing balls of granular diabase or green⁓stone. 1862Dana Man. Geol. ix. 79 Diabase, a massive hornblende rock..It is like diorite in composition, except that the feldspar is less abundant, and is either labradorite or oligoclase. 1882Geikie Text-bk. Geol. 145 The main difference between diabase and basalt appears to be that the rocks included under the former name have undergone more internal alteration, in particular acquiring the ‘viridite’ so characteristic of them.
b. attrib., as in diabase-aphanite, a very fine-grained variety of quartz-diabase in which the separate constituents are not distinguishable by the naked eye; diabase-porphyrite, -porphyry, the dark-green antique porphyry, containing hornblende in its compact diabase-like mass; diabase-schist, a schistose form of diabase-aphanite.
1868Dana Min. 343 If the diabase contains distinct crystals of porphyry, it is a diabase porphyry, the green porphyry or oriental verd-antique of Greece..being of this nature. 1879Rutley Stud. Rocks 247 Diabase aphanite..Diabase schist. |
