花海断裂几何展布及新活动特征

Distribution and Active Characteristics of the Huahai Fault

一、引言花海断裂是河西走廊西部地区较大的一条北北西向活动断裂。它北起双泉子经花海和金塔盆地以西地区,沿SE15°方向延伸直插祁连山,长约36km。1987年以前对此断裂很少进行系统研究,1987年以后进行四○四工程时才对该断裂加以注意,先后收集了大量的物探、人工地震、钻探等资料,开展了卫、航片解译、野外调查及探槽揭露和年龄测试等工作,为研究该断裂提供了宝贵资料。分析认为,此断裂切错了阿尔金断裂、金塔盆地、酒西盆地和祁连山隆起等,是一条发震断层。因此,研究花海断裂的分布及其新活动有着重要的实际意义。

In this paper, the Huahai fault is regarded as locating in the west area of the Hexi corridor, which is one of large active NNW faults, according to the data of gravity, magnetic, seismic sounding, well drilling, trenching, airview-salellite photographs, sample dating, historical earthquake and focal machanism. The Huahai fault right-laterally cut off two great fault blocks in the Aerjin fault boundary, or Beishan fault block and Qilian mountain block. The activity of fault have an obvious classification: the Huahai fault is not active from Late Pleistocene to Holocene at north of Aerjin fault; It is active in the neotectonic period (N_2—Q_1) to present between the Aerjin fault and Qilian mountain.