川西高原杂谷脑河阶地的形成  

Formation of the Zagunao River Terraces in Western Sichuan Plateau, China

作　　者：刘勇[1,2] 赵志军[1,2] 李才林[1,2] 张茂恒[1,2] 陈晔[1,2] 

机构地区：[1]江苏省环境演变与生态建设重点实验室 [2]南京师范大学地理科学学院,南京210097

出　　处：《地理学报》2006年第3期249-254,共6页Acta Geographica Sinica

基　　金：国家自然科学基金项目(40201007)~~

摘　　要：根据野外实地地貌调查,确定了川西高原杂谷脑河理县段发育了8级阶地,并对阶地沉积物进行了ESR年代测试,初步确定杂谷脑河第II,III,IV,VI级阶地约形成于距今54,125,248,481ka。阶地成因分析表明这些主要阶地序列主要是构造隆升的结果,因此,杂谷脑河各级主要阶地分别代表了川西高原中更新世以来的几次隆升事件。根据阶地高程和阶地形成年代确定的杂谷脑河下蚀速率为0.39m/ka,与大地测量获得的龙门山隆升速率(0.3￣0.4m/ka)相一致。Our field investigation identified eight river terraces at Zagunao, Lixian county of Western Sichuan Plateau along the Zagunao River, a main tributary of the Minjiang River. Applying ESR dating method, we successively determined ages of T2, T3, T4 and T6, which are 54, 125, 248 and 481 ka BP respectively. The development of the terrace sequences here was prominently under the control of regional tectonic uplift, and they should record phased uplift events of the Western Sichuan Plateau since the middle Pleistocene. The average incision rate of Zagunao River is calculated to be around 0.39 m/ka, which is coincident with the geodesic uplift rate of the Longmen Mountain （0.3-0.4 m/ka）.

关 键 词：川西高原 杂谷脑河 ESR年代 下蚀速率 

分 类 号：P931.1[天文地球—自然地理学]