长江源地区通天河段水系格局演化与构造活动的关系

于洋,王先彦,李一泉,戴岩,鹿化煜

The evolution of drainage pattern and its relation to tectonic movement in the upstream Yangtze catchment

YU Yang,WANG Xianyan,LI Yiquan,DAI Yan,LU Huayu

图9 研究区走滑断层活动引起的构造样式导致的水系变迁的示意图(a. 北西—南东向的水系发育,形成宽谷(在分水岭处还有保留,形成风口);b. 走滑活动在局部分别形成挤压脊和断陷洼地;挤压脊处老年期谷地抬升形成局部分水岭,分水岭西北河段倒流;东南河段流入拉伸形成的洼地;c. 逆冲抬升导致南西—北东向通天河的支流快速溯源侵蚀;d. 通天河南西—北东向支流最终切穿抬升区域,袭夺了老的河流,形成北东向峡谷等)

Fig. 9 Schematic diagram of drainage changes caused by strike-slip fault movements (a. Development of the NW-trending drainage system and the wide valleys; b. Pressure ridges and pull-apart basins produced by strike-slip fault movement. Fossil Valleys in the uplifted pressure ridges that became drainage divides: the channels to the northwest of the local divides flowed backward, and the channels to the southeast flowed to the pull-apart basins; c. Headward erosion of the tributaries of the Tongtian River increased as a result of the uplift of the NE-trending thrusting; d. The tributaries of the Tongtian River finally cut through the uplifted area and captured the NE-trending wide channels.)