中国东南大陆中生代构造域的转换及其与成矿的关系——以闽西南地区为例

对中国东南大陆的重要构造及成矿单元———闽西南坳陷带及其外围的系统研究表明, 东南大陆在印支晚期至燕山早期存在从特提斯-喜马拉雅构造域向环太平洋构造域转换, 从而导致该区深部地球物理特征、构造-岩浆岩带展布、岩相古地理的演化、构造系统及区域成矿作用等方面发生明显的变化.构造系统分析表明, 该区构造格局的形成是在两大构造域相互复合、转换及叠加过程中完成的, 构造域转换的地球动力学机制主要是该区岩石圈横向及纵向上的不均一性及壳幔的相互作用.成矿作用及成矿年龄的研究表明, 伴随构造域的转换, 东南大陆在印支晚期至燕山早期应存在一期重要的多金属成矿作用. 

TRANSFORMATION OF MESOZOIC TECTONIC DOMAIN AND ITS RELATION TO MINERALIZATION IN SOUTHEASTERN CHINA: AN EVIDENCE OF SOUTHWESTERN FUJIAN PROVINCE

The systematic study of the depression belt in southwestern Fujian Province, one of the most significant tectonic and metallogenic unit in southeastern China, shows that the transformation from Tethyan Himalayan tectonic domain into circum Pacific tectonic domain in southeastern China from the Late Indo Chinese to the Early Yanshanian induced obvious changes in geophysics, tectono magmatic distribution, lithofacies and paleo geography, tectonic system and regional mineralization. Tectonic system analysis indicates that the tectonic regime in this area resulted from the amalgamation, transformation and superimposition between the two tectonic domains. The geodynamic mechanism of the transformation is mainly attributed to the latitudinal and longitudinal heterogeneities of lithosphere and to the interaction between crust and mantle. The analysis of the mineralization and that of the mineralization age show that the transformation of the tectonic regime was accompanied by one significant phase of the multi metal mineralization that should have occurred during the Late Indo Chinese to the Early Yanshanian in southeastern China.