论文部分内容阅读
错坝断裂走向NW50°、长约26km、展布在川藏交界海拔4000m以上高山,属于甘孜-玉树断裂带的一条分支断裂。研究错坝断裂活动特征有助于了解甘孜-玉树断裂带东南段南西侧分支断裂的活动性。错坝断裂的断错地貌现象丰富,有基岩断崖、断层沟、坡中谷、冲沟水平扭曲。这些现象分布在拔河高度上百米的山体。实测17个地层热释光测年样品,其中7个样品断错了距今18～51ka地层,其余10个样品为地貌面地层年代样品。结合地层测年及地貌面分析,厘定错坝断裂的最新活动时代为距今18～16ka之间,属于晚更新世晚期活动断裂。错坝断裂晚更新世晚期的左旋走滑活动速率约为1.4mm/a,垂直活动速率约为0.3～0.7mm/a。该断裂在晚更新世时期至少有过3次活动。
Fault dam is NW50 ° long and about 26km long, spreading at an altitude of 4000m above the junction of Sichuan and Tibet. It belongs to a branch fault of the Garze-Yushu fault zone. Studying the characteristics of fault dam activities helps to understand the activity of the southwestern branch of the Ganzi-Yushu fault zone in the southwestern part of China. Fault fault rupture fault phenomenon is rich in bedrock cliffs, fault ditch, slope valley, gully level distortion. These phenomena are located in the mountains of the height of a hundred meters of the tug of war. Seventeen thermofluorescent dating samples were measured, of which seven were faulty dating from 18-51 ka, and the remaining ten samples were geochronostratigraphic dating samples. According to the dating of strata and the analysis of geomorphology, the latest activity time of fault rupture was 18 ~ 16 ka dating from the late Pleistocene active fault. The slip rate of left-lateral strike-slip was about 1.4mm / a in late Late Pleistocene, and the vertical activity rate was about 0.3 ~ 0.7mm / a. The fault had at least 3 events during the Late Pleistocene.