雅鲁藏布江彭错林至塔玛河段新构造运动及对工程的影响

New tectonic movement of Pengcuolin-Tama river reach of Yaluzhangbu River and its effect on project

在对雅鲁藏布江中上游河段的规划中,发现彭错林至塔玛约50km河段两岸无阶地发育,而两岸的洪积扇却十分发育,并连片延伸至河床形成库岸,说明该河段地壳在早期的Q1～Q3时期一直处于上升状态,至Q3之后处于下降状态。在塔玛坝址的钻孔中,孔深至121m也未揭穿覆盖层,说明该河段地壳自Q3之后Q4以来一直处于下降状态。另外在工程区分布有多条断裂带,沿断裂带多有地震和温泉分布。以上说明规划河段内及周边的新构造运动十分活跃,对工程有一定影响。

In the planning of middle and upper reaches of Yaluzhangbu River, it is found that no terrace development occurs in the reach from Pengcuolin to Tama but its deluvial sector develops and stretches to river bed forming a bank, which shows such river reach raised in the early Q1～Q3 stage and then went down after Q3 stage. In the boring in Tama dam site, we had bored up to the depth of 121 m but cannot bore through the coverage, which shows its earth crust has gone down after Q3 stage and since Q4 stage. In addition, several faults are distributed in the project area and along these faults, earthquake zones and thermal springs distribute. Therefore new tectonic movement is very active in the planned river reach and its surroundings so that it has certain effects on the project.