摘要
辽西中生代粗面玄武岩的K-Ar同位素年龄为84.76±1.67Ma,其中含有丰富的超镁铁质岩和深部壳源捕虏体,主要有角闪尖晶二辉橄榄岩、尖晶石二辉橄榄岩、二辉橄榄岩、含斜长石的角闪二辉石岩、二辉麻粒岩和辉石斜长片麻岩等。包体的组构及矿物化学研究表明超镁质岩捕虏体来源于上地幔,麻粒岩和片麻岩则为深部壳源捕虏体。该类包体的发现对中国东部中生代上地幔和下地壳的研究具有重要意义。
The K-Ar isotopic age of Mesozoic trachybasalts in western Liaoning is 84. 76±1. 67 Ma. Abundant ultramafic and deep crust xenoliths are found in the trachybasalts. They consist mainly of amphibole-spinel-lherzolite, spinel-lherzolite, lherzolite, plagioclase-bearing amphibole-web-sterite, two-pyroxene-granulite and clinopyroxene-plagioclase-gneiss. Study of the petrofabrics and mineral chemistry indicate that the ultramafic xenoliths could be derived from the upper mantle and that the granulite and gneiss xenoliths from the lower crust. The discovery of these xenoliths is of great significance to the study of the upper mantle and lower crust in eastern China.
出处
《地质论评》
CAS
CSCD
北大核心
1999年第S1期444-449,共6页
Geological Review
基金
国家自然科学基金(编号49733110)重点资助项目
关键词
辽西
中生代
粗面玄武岩
深源捕虏体
western Liaoning
Mesozoic
trachybasalt
deep-seated xenolith
