青衣江河流沉积与阶地特征及其成因演化  

THE ORIGIN AND EVOLUTION OF QINGYI RIVER'S DEPOSITS AND TERRACES IN WEST SICHUAN,CHINA

作　　者：王继龙[1,2,3] 吴中海[2,3] 孙玉军[2,3] 徐昊[2] 周春景[2,3] 马晓雪[2,4] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质科学院地质力学研究所,北京100081 [3]国土资源部新构造运动与地质灾害重点实验室,北京100081 [4]首都师范大学资源环境与旅游学院,北京100048

出　　处：《地质力学学报》2016年第3期642-658,共17页Journal of Geomechanics

基　　金：中国地质调查局地质调查项目(12120114002101;DD20160268);国家自然科学基金项目(41571013;41171009)

摘　　要：在系统整理分析前人成果资料基础上,对龙门山西南部与古青衣江改道相关的名山—邛崃砾石层和丹棱—思濛砾石层的砾石成分、砾度及砾向等统计资料进行分析和总结,讨论了砾石层的物源区、成因、形成时代等特征;结合对青衣江干流阶地最新的调查和测量结果,梳理总结了河流阶地的分布特征、高度、结构、发育程度和年龄等资料数据,并利用卫星遥感图像和数字高程模型(DEM)数据提取构造地貌和水系特征,发现青衣江流域地形是梯级降低的,其穿过的褶皱形成时间应该早于第四纪,并且第四纪时期青衣江形成的阶地是可连续对比的,其中宝兴—芦山段的阶地有过抬升,可能与该区的盲逆冲断层活动有关。依据青衣江流域的阶地特征,对水系演化变迁过程进行综合分析后提出,青衣江改道很可能是由于新构造期间河流多次袭夺造成的,其中龙门山西南段的盲逆冲断层活动引起的局部隆升为袭夺提供了构造条件。Based on the analysis of previous research results,we analysed and summaried the gravel composition,gravel particle size and gravel direction of Mingshan-Qionglai and Danling-Simeng gravel layers related to ancient Qingyi River diversion in southwest of Longmenshan. Moreover,we discussed the characteristics of provenance region, origin and formation of the gravel layer.Combining with the latest survey and measurements to trunk stream terrace of Qingyi River,the distribution,height,structure and age of the terrace were sorted and summarized. We also used the satellite remote sensing image and Digital Elevation Model（ DEM） to extract tectonic geomorphology and water features,finding that the terrain of Qingyi River basin descends in a cascade manner,the fold passed through it should be earlier than the Quaternary,the terraces of Qingyi River formed in Quaternary can be continuously contrasted,the terrace in Baoxing-Lushan section ever uplifted,that may be caused by the underlying thrust fault. Based on the characteristics of Qingyi River terraces,we made a comprehensive analysis on the system evolution,then put forward that the diversion of the river is caused by the multiple captures of the river,the local uplift at the southwest segment of Longmenshan caused by the blind thrust fault has created good structure conditions.

关 键 词：青衣江 河流阶地 河流袭夺 新构造 盲逆断层 

分 类 号：P546[天文地球—构造地质学]