浅析金沙江中游河段梯级电站区域构造稳定性

Elementary Analysis of the Regional Tectonic Stability at the Cascade Stations along the Middle Reach of Jinshajiang River

本文从所处的构造部位、多种构造体系，地球物理场、岩浆活动、变质作用和地震活动等方面，说明研究区区域构造背景的复杂性；从新构造运动观点对“长江第一弯”的形成和虎跳峡谷狭窄而上游突变为宽谷的成因提出看法；以多种方法和充分资料分析了现今构造应力场特征；并根据主要发震断裂，建立了研究区近代地震构造破裂模式．从复杂的地震地质环境中划出地震活动期和地震时空分布特点．通过综合分析较合理地评价了金沙江中游河段梯级电站的区域构造稳定性．

The complicated background of regional tectonization has been studied from the aspects of tectonic positions, tectonic systems, geophysical field, magmatic activities, metamorphism and seismic actiies; New considerations are suggested about the causes both of the formation of 'The First Yangtze River Bend' and the valley suddenly becomes wider before' The Tiger Leaping Gorge'; Characteristics of present tectonic stress field has been analyzed by means of various methods and sufficient data; According to primary earthquake-triggering fractures, modern seismotectonic fractural modes are established in this region. Seismically active period and features of seismic space-time regionalization are delimited from complicated seismic geological conditions.After having comprehensive analyzed, rational evaluation is made for the regional tectonic stability at the cascade stations along the middle reach of Jinshajiang River.