地壳磁化强度模型和居里等温面

A CRUSTAL MAGNETIZATION MODEL AND CURIE ISOTHEM

利用卫星观测的长波磁异常，用等效偶极源方法推导了中国地区的视磁化强度分布．因卫星的高度远大于磁性地壳的厚度，将视磁化强度转换成磁化强度的垂直积分，它代表地壳内磁性物质的区域变化，利用视磁化强度与地表热流相应关系，计算了中国的新疆和东部一些地区居里等温面的深度．新疆地区的居里面深度为35-50km，其分布形态与塔里木盆地和准噶尔盆地的地貌比较相似；中国东部一些地区居里面深度在20-40km之间，与一些作者用航磁等数据得到的居里深度十分接近．

Long wavelength magnetic anomalies have been deduced from Magsat data collected over the Chinese region in order to stUdy the deep structure of the crust. In this paper,the apparent magnetisation distribution is derived from these anomalies using the equivalent source method. Because the altitude at which the satellite data were observed is large compared with the thickness of the magnetic crust, which is a few tens of kilometres, it is very easy to convert the apparent magnetisation into the vertical integral of magnetisation in the lithosphere. The magnetisation model essentially expresses the lateral variation of magnetic material in the crust There is a correlation between the regional patterns of heat flow and the apparent magnetisation contrast over much of the region. An estimate of the regional Curie depth can be computed using this relation.