CAJ | 학술논문

中国东南部印支期花岗岩对亚洲大陆东部的演化具有重要的构造指示意义。在浙江东阳大爽以及松阳县东部靖剧地区发现两个印支期花岗岩体，大爽岩体和靖剧岩体。岩性为斑状石英正长花岗岩，二者都侵入到元古代基底中。大爽石英正长岩的 LA-ICP-MS 锆石 U-Pb 年龄为241±2?1～229?6±2?5Ma，靖剧岩体斑状石英正长岩的 LA-ICP-MS 锆石 U-Pb 年龄分别为245?7±1?8Ma 和241?2±2?7Ma，表明这两个岩体均为早印支期岩浆活动的产物。地球化学特征显示，两个花岗岩体富钾、高铝，富集轻稀土 LREE 及 Rb、Th、U、K，亏损 Ba、Nb、Sr、P、Ti，接近 A 型花岗岩的配分模式，属于铝质 A 型花岗岩。中国东南部一系列 A 型花岗岩或碱性正长岩的发现，表明东南沿海在印支期已处于伸展构造环境下，这种伸展可能是华南板块与东南亚板块碰撞之后的转换伸展，使得区域上断裂重新活化，岩浆沿断裂侵入形成的。
중국동남부인지기화강암대아주대륙동부적연화구유중요적구조지시의의。재절강동양대상이급송양현동부정극지구발현량개인지기화강암체，대상암체화정극암체。암성위반상석영정장화강암，이자도침입도원고대기저중。대상석영정장암적 LA-ICP-MS 고석 U-Pb 년령위241±2?1～229?6±2?5Ma，정극암체반상석영정장암적 LA-ICP-MS 고석 U-Pb 년령분별위245?7±1?8Ma 화241?2±2?7Ma，표명저량개암체균위조인지기암장활동적산물。지구화학특정현시，량개화강암체부갑、고려，부집경희토 LREE 급 Rb、Th、U、K，우손 Ba、Nb、Sr、P、Ti，접근 A 형화강암적배분모식，속우려질 A 형화강암。중국동남부일계렬 A 형화강암혹감성정장암적발현，표명동남연해재인지기이처우신전구조배경하，저충신전가능시화남판괴여동남아판괴팽당지후적전환신전，사득구역상단렬중신활화，암장연단렬침입형성적。
The Late Permian-Triassic granites in southeastern China have important tectonic significance for the evolution of East Asia.Two Indosinian granites found in the town of Dashuang as well as eastern Jingju areas of Songyang in Zhejiang have intruded into the Proterozoic basement,which lithology are porphyritic quartz syenite.LA-ICP-MS zircon U-Pb age of Dashuang syenite is 241 ±2.1 ~229.6 ±2.5Ma,and LA-ICP-MS zircon U-Pb ages of Jingju porphyritic quartz syenites are 245.7 ± 1.8Ma and 241.2 ±2.7Ma, which indicate that these two plutones are products of early Indosinian magmatism.For geochemical characteristic,the two granites are potassium-rich,high alumina,enriched in LREE and Rb,Th,U,K, depleted in Ba,Nb,Sr,P,Ti,close to the distribution patterns of Indosinian A-type granites in SE China,which indicate that they are all aluminum A-type granite.A series of A-type granites distribution along the NE-trending fracture show extensional tectonic setting of southeastern China in early Indosinian, which may be caused by strike-slip conversion stretching after collision between SCB(South China block) and IB(Indochina block),making magma intrusion along the fault.