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汉诺坝新生代玄武岩中下地壳镁铁质二辉麻粒岩 (为主 )和紫苏辉石麻粒岩捕虏体兼有火成变晶结构及麻粒岩相变质重结晶作用特征 ,其锆石年代学和REE地球化学研究表明 ,中生代晚期 (12 0～ 140Ma)的基性岩浆底侵下地壳形成镁铁质堆晶岩 ,再经麻粒岩相变质作用形成了现今下地壳的高密度、高速度壳底层 ,提出幔源岩浆底侵作用是显生宙以来大陆地壳垂向增生的重要方式 ,同时提供了壳 幔相互作用的新证据 .
The Cenozoic basalts of the Hannoba Dam are mainly composed of mafic diperflam rocks (mainly) and peridotite pyrite granulite xenoliths characterized by both the metamorphism and metamorphic recrystallization of granulite. The zircon geochronology and REE geochemical studies show that the mafic emplacement of the Late Mesozoic (12 0 ~ 140 Ma) intruded into the crust to form mafic pluton, followed by granulite facies metamorphism to form the present lower crust High-density and high-velocity crust bottom. It is suggested that mantle-derived magmatic underplating is an important way of vertical crustal accretion in the continental crust since the Phanerozoic and provides new evidence for crust-mantle interaction.