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辽西阜新中生代碱性玄武岩的K-Ar同位素年龄为84.76±1.67Ma, 其中含有丰富的深源岩石捕虏体, 包括角闪尖晶二辉橄榄岩、尖晶石二辉橄榄岩、含长角闪二辉石岩、二辉麻粒岩和辉石斜长片麻岩等。与新生代玄武岩中的同类捕虏体相比, 橄榄岩类捕虏体中橄榄石的成分相似 (Fo= 86~91), 透辉石具有富Al、贫Cr 和Ca 的特点, 尖晶石的成分以MgAl2 O4 为主, 有的橄榄岩捕虏体中含少量韭闪石。二辉麻粒岩捕虏体中的斜方辉石为紫苏辉石, 单斜辉石为普通辉石, 斜长石属于更长石。橄榄岩类捕虏体的平衡温度为1012.6℃~1272.1℃; 压力为1.825~2.935GPa, 二辉麻粒岩和片麻岩的平衡温度为892℃~1157℃。该类深源岩石捕虏体的发现对中国东部中生代上地幔和下地壳的研究均具有重要意义。
The K-Ar isotopic ages of Mesozoic basalts from Fuxin in western Liaoning are 84.76 ± 1.67Ma, which are rich in deep-source rock xenoliths, including hornblende spodumene lherzolite, spinel lherzolite, Hornblendite pyroxene, two plutonium granodiorite and plagioclase gneiss and so on. Compared with similar xenoliths in Cenozoic basalts, the olivine components in the peridotite xenoliths are similar (Fo = 86-91). Diopside has characteristics of Al-rich, Cr-poor and Ca-depleted. Spinel The main components of MgAl2O4, some peridot xenoliths contain a small amount of leeco-amphiboles. The orthopyroxene in pyroxenite xenoliths is peridotite, clinopyroxene is pyroxene, and plagioclase belongs to the longer feldspar. The equilibrium temperature of peridotite xenoliths is 1012.6 ℃ ~ 1272.1 ℃ and the pressure is 1.825 ~ 2.935GPa. The equilibrium temperature of diperfluses and gneisses is 892 ℃ ~ 1157 ℃. The discovery of these deep-source rock xenoliths is of great significance for the study of the upper mantle and the lower crust in the eastern China.