基于填充海拔的金沙江南流泄口位置

Outlet Location of South Flow of Jinsha River Based on Filling Elevation

长江的发育演化尤其是东西贯通的时限问题,是百余年来地学界的焦点问题,金沙江水系的演化重组是长江演化中的关键一环。基于填充海拔的模型模拟以及物源示踪的梳理结果,讨论了金沙江在夷平面上南流汇入红河的可能性。结果显示当海拔填充至2 000~2 200 m时,金沙江水系格局发生重大变化,表现为金沙江在金江街一改东流之势,沿宾川盆地汇入古红河;古雅砻江在攀枝花附近转而向西,沿金沙江河谷经宾川盆地流入古红河,形成古红河的一级支流。推断哀牢山-红河断裂带、程海-宾川断裂带的活动及山体隆升特别是鸡足山的隆升可能阻断了上述南流泄口,切断了金沙江与红河的联系,从而形成今日江水东流的水系格局,这为古金沙江南流路径的研究提供了新的思路和方向。

The Yangtze River originates from the Tibetan Plateau and flows into the Pacific Ocean.Its formation and evolution,especially the timing of the connection of the Three Gorges,have been the world interests of researchers for more than 100 years,while the recombination of Jinsha River is a critical part for this interest.This paper discusses the possibility of the south flow of Jinsha River into the Red River on the planation surface based on the simulation of the filling elevation model and the results of the tracing of the source.This study reveals that when the planation surface of 2 000 m and 2 200 m altitude exists in Yunnan Plateau,the Jinsha River can flow southward.The upper Jinsha River flows southward from the Shigu town,and flows through the western side of the Jianchuan Basin,while the lower Jinsha River flows southward from Binchuan Town.The activities of Ailao Mountain-Red River Fault and Chenghai-Binchuan fault combined with the uplift of mountains have broken the connection between Jinsha River and Red River,and resulted in current river systems in SE margin of Tibetan Plateau.