关于弧后扩张机制的新看法  

New Idea on Back-Arc Spreading Mechanism

作　　者：彭澎[1] 翟明国[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：《世界地质》2002年第1期1-8,共8页World Geology

摘　　要：为了探讨弧后扩张的内在机制 ,计算得出了一些弧后扩张背景下板舌参数及边缘海资料的特征 ,综合古地磁、地热、重力、地震等信息 ,认为弧后扩张可能与板舌舌端地质行为有关 ,具体形成机制可能是 :可能已经发生正断的板舌舌端发生熔融分异 ,低密度部分上升膨胀 ,高密度部分下沉 ,在合适条件下形成物质对流环 ,导致弧后扩张。这种模式可以更好地解释弧后扩张的可能发生过程和演化旋回 。In this paper, the authors study on back-arc spreading mechanism, and have some characteristics of some plate tongue variations and back-arc basins of background of back-arc spreading. By analysising some information of paleo-magnetism, terrestrial heat, gravity, seism etc. The authors argue that back-arc spreading may be caused by tongue end of plate tongue. Differentiation by liquation takes places in tongue end, which is low temperature conductivity and may be have some form faults. Lower dense part would rise up and dilate, while high dense part would sink. Thus a convection circulation will work. Under proper conditions, it will cause back-arcspreading. This mechanism gives us a model on procession andcycle of back-arc spreading.And italso gives us a proper idea on forming ofarchipelago.

关 键 词：弧后扩张 边缘海 板舌 内在机制 弧后盆地 

分 类 号：P541[天文地球—构造地质学]