| 释义 |
plagiogranite, n. Petrogr.|ˌpleɪdʒɪəʊˈgrænɪt|
[a. Russ. plagiogranitȳ (N. Khruschov 1931, in Trans. Geol. & Prospecting Service U.S.S.R. XC. 16), shortened f. G. Plagioklasgranit (A. G. Högbom 1905, in Bull. Geol. Inst. Univ. Upsala VI. 232): see plagioclase, n., granite n.]
Any of a range of granitic rocks which occur esp. in ophiolites and are rich in sodic plagioclase feldspar.
[1932A. Johannsen Descriptive Petrogr. Igneous Rocks II. 382 ‘Plagioclase-granite’. Long Bay, Virgin Gorda, West Indies.] 1959Bull. Volcanologique XX. 177 The development of folding processes, accompanied by deep fractures, brought about the formation of a complicated intrusive magmatic complex consisting of gabbro-amphibolites, ultrabasites, plagiogranites, spessartites and acid Na granitoids. 1979Nature 7 June 491/1 A single arcuate (folded?) and fault-bounded block of plagiogranite is present in the much-faulted northern part of the mapped area. 1985Thorpe & Brown Field Descr. Igneous Rocks x. 133/2 The white ‘anorthositic’ rocks of ophiolites are usually rich in sodium-rich plagioclase feldspar and some of them contain substantial amounts of quartz (up to 30{pcnt}), so that the term plagiogranite is more appropriate. |