长江中下游地区基底与成矿

Basement and Metallogeny Belt of the Middle-Lower Yangtze River,Eastern China

长江中下游地区,北以郯-庐断裂及襄阳-广济断裂与桐柏—大别造山带相邻,南缘大致以常州—宜城—高坦—九江南—上朱—监利—桑植一线与江南地体为界,为扬子板块东段北缘,是我国中东部著名的中生代金属成矿带,是沿长江工业带的矿产供应基地,在我国甚至世界上具有鲜明特点。长江中下游地区成矿大地构造背景和过程经历了由板缘-板内的过程,成矿作用发生在挤压向伸展的转换过程。长江中下游地区成矿作用贯穿于"燕山运动"的始终,记录了太平洋板块俯冲作用的影响。长江中下游地区成岩成矿受基底构造和深部作用控制,与本区特有的基底有关。本区前震旦纪基底,由于绝大部分被掩覆于盖层之下,长期存在争议,对地层时代归属、划分对比、基底原始建造类型及大地构造意义等,均有不同的看法。长江中下游地区基底与成矿特征表明,长江中下游主要成矿带落在基底隆起带上,两个不同的基底的结合带有利成矿。

The Mesozoic metallogenic belt along the middle lower Yangtze River is a famous concentrated district of minerals in central eastern China, which is well known as the base to supply minerals for the Industrial Corridor by Yangtze River. The geological evolution and metallogenic dynamics, the metallogenic belt are considered with distinguishing features in China, even in the world. The tectonic background had undergone the transforming from plate margin to intra plate and the mineral concentration occurred the process from compression to extension. “Yanshanian” movement went through the process of the ore forming within the belt, which records the influences of the subduction of Pacific Plate during late Jurassic to early Cretaceous. The different magmatic activity and mineralization in the belt is associated with its basement. The basement of middle to lower reaches of Yangtze River is controversial in ages and assignatim for a long time. The characteristics of basement and metallogenic belt along the middle lower Yangtze River indicate that the main metallogenic belt along the middle lower Yangtze River falls on the basement uplift and the junction zone of two different basement is favorable for mineralization.