摘要
黑河口断层位于张掖西南约３０ｋｍ，是一条走向北西，倾向南西的逆断层。黑河沿岸的一个天然剖面上见断层面向南西陡倾，奥陶系向北东逆冲于晚更新世河流砾石层之上，垂直断距１７ｍ。断层活动在黑河阶地上形成了一个断层陡坎。年龄约为５ｋａＢ．Ｐ．的阶地被垂直错断２ｍ，年龄约为１０ｋａＢ．Ｐ．的阶地被垂直错断４ｍ，年龄约为１３ｋａＢ．Ｐ．的阶地被垂直错断９ｍ。这些错距及断层附近的沉积物反映断层至少有３次活动，每次活动的垂直位移为２～５ｍ，活动时间间隔为３～５ｋａ，平均活动速率为１．６７～０．４ｍｍ／ａ。
The Heihekou fault ,being apart 30 km from Zhangye in the southwest ,is a reversed fault which trends to the northwest and dips to the southwest. It is found that the fault on a natural section along the bank of the Heihe River dips steeply to the southwest. and that the Ordovician system thrusts to the northeast on the Late Pleistocene alluviam with a throw of 17 m.A fault scarp was formed in the faultmovement on terraces of the Heihe River.The terrace with an estimated age of 5ka B. P. is vertically dislocated by 2 m,age of 10 ka B. P by 4 m,and age of 13 kaB. P. by 9 m.These dislocations and the sediments near the faul indicate there hadbeen 3 movement enents at least.The vertical dislocation is 2～5 m each,the aver-age recurrence interval is 3～5ka ,and the average slip rate is 1. 67～0. 4mm/a.
出处
《北京大学学报（自然科学版）》
CAS
CSCD
北大核心
1995年第3期351-357,共7页
Acta Scientiarum Naturalium Universitatis Pekinensis
基金
国家教委博士点基金
关键词
阶地位错
活动周期
晚更新世
断层活动
甘肃
Heihekou fault
terrace dislocation
recurrence interval
slip rate
