南沙微板块的层块构造

综合分析了南海南部海域近5万千米的综合地球物理剖面资料和相关的地质资料,从宏观上,在南沙微板块内初次划分出了南沙超壳层块,曾母壳体层块,南薇-安渡壳体层块,礼乐-北巴拉望壳体层块,安渡-毕生基底层块,礼乐-半月基底层块等不同级别的层块构造,讨论了它们的基本特征。提出了层块构造的“立交传输运动”概念,根据多元动力成因观,探讨了各级层块构造的形成机制和主导动力,指出了俯冲板片拆沉-幔隆力,地幔流牵引力,地球转速变化惯性力,区域板块边界力等是驱动超壳层块的主要动力,重力失稳-壳内流塑层降升-牵引力是驱动壳体层块和基底层块的主要动力。

Layer-block tectonics of the Nansha microplate

Based on an analysis of the data obtained from 50000 km of in tegrated geophysical profiles and relevant geological materials,layer-blocks of different orders have been distinguished within the Nansha mi-croplate;th ey are the Nansha ultra-crustal layer-block,Zengmu crustal layer-block,Nan wei-Andu and Liyue-North Balawan crustal layer-block,Bisheng-Andu and Liyue-Banyue basement layer-block.The basic characteristics of these layer-bloc ks are discussed.The concept of "cross-deck bridge-like"movement of laye r-block tectonics is proposed.In light of the view of the multi-geodynamic origin,the formation mechanism and main driving forces of these layer-blocks are probed.The subducted slab delaminating-mantle upwarping force,mantle flo w drawing force,inertial force of earth rotation and regional plate boundary f orce are considered as the main forces driving the ultra-crust layer-block,an d the gravity in-stability force and intracrustal rheological-plastic layer up lift force are considered as the forces driving the crust layer-blocks and base ment layer-blocks.