中国南方印支—燕山期复合盆山体系与盆地原型改造

Composite basin-and-range system and reformation of basin prototype in Indosinian-Yanshanian in South China

在中国南方,印支期—燕山期发育了多个前陆型盆山体系。这些盆山体系互相影响、互相干扰、互相叠加,成为“复合盆山体系”。文中对上扬子复合盆山体系进行了典型解剖,揭示了复合盆山体系的成因是古特提斯多岛洋的闭合和多个块体的汇聚、碰撞和造山作用。研究结果表明,龙门山、大巴山、江南隆起构造带及其前陆盆地,在印支期以来的长期盆山耦合演化和复合演化过程中,除了两两交叉形成复合盆山体系外,还最终形成了“三山一盆”的巨型复合盆山体系———龙门山-大巴山-江南隆起复合盆山体系,简称上扬子复合盆山体系。在印支—早燕山期后,上扬子复合盆山体系与南方地区其他复合盆山体系一起,整体进入改造阶段,最终成为今天如此复杂的盆山结构与形貌。

Several basin-and-range systems of foreland-type were developed in Indosinian-Yanshanian in South China, and they became ＂a composite basin-and-range system＂ through mutual influence, interference and superimposition. Based on detailed analysis of the Upper Yangtze composite basin-and-range system, it is believed that the composite basin-and-range system has been formed through the closing of Paleotethys archipelagic ocean, the convergence and collision of multiple blocks and orogeny. The researches reveal that in the long-term evolution of basin-and-range coupling and composite evolution since Indosinian, Longmen Mountain, Daba Mountain, Jiangnan uplifted tectonic zone and their foreland basins have not only led to the formation of several composite basin-and-range systems but have also led to the final formation of the huge composite basin-and- range system with ＂three mountains and one basin＂, i.e. Longmen-Daba-Jiangnan uplift composite basin-and- range system, also called the Upper Yangtze composite basin-and-range system for short. After Indosinian - Early Yanshanian, the Upper Yangtze composite basin-and-range system, together with the other composite basin- and-range systems in South China, have entirely been reformed and finally resulted in the present complicated basin-and-range structures and appearances.