祁连山北缘佛洞庙—红崖子断裂晚第四纪滑动速率研究

Research on Late Quaternary slip rates of the Fodongmiao-Hongyazi fault at the north margin of Qilianshan Mountain

佛洞庙—红崖子断裂是发育于祁连山北缘中段河西走廊南缘的一条重要的块体边界断裂,总体走向北西西,长约110 km。该断裂为一条全新世活动的逆-左旋走滑断裂,也是1609年红崖堡7 1/4级地震的发震断裂。断裂活动形成了一系列陡坎、断层崖以及冲沟和阶地左旋等断错地貌。我们通过详细的野外考察,选择典型断错地貌进行大比例尺差分GPS测量,结合所获相应地貌面的年代数据,得到该断裂晚第四纪平均垂直滑动速率为(0.61±0.28)mm/a,水平滑动速率为(1.27±0.58)mm/a,其结果与相邻断裂相吻合。

Fodongmiao-Hongyazi in an important margin fault which developed at the middle part of the north Qinlian Mountain and the south of Hexi-corridor,the main trending is NWW with length 110 km.The fault is a fault is a left-lateral reverse strike-slip fault during the Holocene periods,it is also the seismogenic fault of Hongyabao M7 1/4 earthquake in 1609.The activity of the fault formed a series of geomorphology like fault scarp,terrace and gully left-lateral.In this study,based on the detail field work,we choose the typical geomorphology cell carried on large scale differential GPS measure.Combined with the age dating date,we got the average vertical slip rates was（0.61±0.28）mm/a,and the horizontal slip rates was （1.27±0.58） mm/a,the result roughly same with adjacent fault