阿尔金断裂走滑位移的确定——来自阿尔金山东段构造成矿带的新证据

A determining on the displacement of the Altun Tagh sinistral strike-slip fault,NW China:New evidence from the tectonic metallogenetic belt in the eastern part of Altun Tagh Mountains

阿尔金断裂是中国西北地区最大走滑断裂之一,呈北东东向延绵近1500km,以其强烈的贯穿性、巨大的规模、强烈的活动性和巨大的位移量为特征。但是对于其左行位移量一直存在比较大的争议,一些学者认为300～500km,而另外一些学者认为700～800km,甚至900～1000km。最近十余年的找矿进展显示出阿尔金山东段是一条重要的铁铜金铅锌多金属成矿带,其矿床成因类型、不同矿种组合关系及其反映的成矿作用条件与北祁连山西段非常相似,可以认为阿尔金山东段成矿带是北祁连山西段成矿带的西延部分,即阿尔金山东段成矿带是北祁连山西段成矿带被阿尔金断裂左行走滑断错的部分。因此,依据阿尔金山东段成矿带与祁连山西段成矿带的可比性,将此作为标志物,作者认为阿尔金断裂左行走滑总位移量为400km左右。

Altun Tagh fault,as one of the largest strike-slip faults in NW China,extends about 1500km with a NEE-trending. It is characterized as violent penetrability,large scale,strong activity and long displacement. There are different viewpoints about the displacement of the fault,some geologists consider that the displacement is about 300~500km,but other geologist consider as 700~800km,even 900~1000km. The headway of ore-prospecting last teen years shows that the eastern part of Altun Tagh Mountains is an important Fe-Cu-Au-Pb-Zn multi metallogenetic belt. And the deposit genetic type,assemblage of different deposit and metallogenetic condition are well similar to the western part of the northern Qilianshan metallogenetic belt. So the eastern Altun Tagh metallogenetic belt is the west extension of the northern Qilianshan metallogenetic belt. In other words,eastern Altun Tagh metallogenetic belt is a part of the northern Qilianshan metallogenetic belt being dislocated by Altun Tagh fault as it sinistral strike-slip motion. Therefore,according to the corporation between Altun Tagh metallogenetic belt and Qilianshan metallogenetic belt,the writer believes that the displacement is about 400km.