中国东部中生代岩浆活动与太平洋板块向西俯冲有关吗?  

Is the Mesozoic magmatism in eastern China related to the westward subduction of the Pacific plate?

作　　者：张旗[1] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029

出　　处：《岩石矿物学杂志》2013年第1期113-128,共16页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金重大研究计划资助项目(91014001)

摘　　要：通常认为，中国东部中生代岩浆活动与太平洋板块的向西俯冲有关，而本文的研究表明，中生代时中国东部不属于环太平洋构造带，不处于安第斯活动陆缘环境，没有岛弧玄武岩和岛弧花岗岩。许多资料表明，在中生代早期，太平洋板块基本上是向北俯冲的，至早白垩世中期（125Ma左右）才转向西俯冲，而中国东部大规模岩浆活动主要发生于侏罗纪一早白垩世（约180130Ma），因此，中国东部中生代大规模岩浆活动与太平洋板块的向西俯冲无关。太平洋板块真正向西俯冲的时间非常短暂，只有125～110Ma和43～0Ma两个时段。在前一时段，中国东部岩浆活动仅限于中国东部沿海；在后一个时段，中国东部岩浆活动几乎绝迹。因此，中国东部中生代大规模岩浆活动与太平洋板块向西俯冲有关的命题是错误的。It is usually thought that the Mesozoic magmatism in eastern China was related to the westward subduction of the Pacific plate. However, the researches conducted by the author show that eastern China did not belong to circum-Pacific tectonic belt in Mesozoic. It was not in the Andean active continental margin tectonic environment, and there were no island arc basalts and island arc granites. Lots of research work shows that the Pacific plate basically subducted northward in the early Mesozoic and turned to west in the middle early Cretaceous （at about 125 Ma）. The large-scale magmatism in eastern China mainly occurred in Jurassic-early Cretaceous period （about 180 N 130 Ma）, and during this period the Pacific plate basically subducted northward. Therefore, the Mesozoic large-scale magmatism in eastern China was not related to the subduction of the Pacific plate. The westward subduction of the Pacific plate only lasted for a very short period, i.e., during 125-110 Ma and 43-0 Ma. During 125-110 Ma, magmatism of eastern China was confined to the east coast of China; during 43-0 Ma, the magmatism in eastern China was almost gone. So the proposition that Mesozoic magmatism in tem China was related to the westward subduction of the Pacific plate is a wrong unwarranted proition.

关 键 词：中国东部 中生代 岩浆活动 花岗岩 太平洋板块 俯冲 古地磁 

分 类 号：P511.4[天文地球—地质学] P542