北天山地震带的航磁异常与深部构造

通过分析天山和邻近地区的航磁资料，划分出了４个较大的具有不同基底性质和深部构造特征的磁异常区。天山地区的地震大多数都发生在基底隆起或坳陷的附近，在深部磁场图像中，它们则位于天山高磁性块体与周围弱磁性区域之间，那里不仅是正负磁异常的转换带，而且是明显的大地构造边界。介质的磁性与其它地球物理资料一样，也是反映地震活动区域深部构造的一个重要标志。

AEROMAGNETIC ANOMALY AND DEEP TECTONICS IN THE NORTHERN TIANSHAN SEISMIC BELT

By analyzing the aeromagnetic data of the Tianshan region, four large anomalous ranges are recognized, with different basemental and deep tectonic features. Most earthquakes in the Tianshan are located around the basemental upwelling and depression. In a deeper mag netic field, they are distributed between the positive anomalies of the Tianshan and the neg tive anomalies of the surrounding areas, where are both transition belts from positive to meg tive anomalies and apparent geotectonic boundaries. Like other geophysic data, the mag netism of rocks is also an important mark of showing deep tectonic characteristics in the seis mic areas.