青藏高原航磁异常及居里面研究

CURIE SURFACE AND AEROMAGNETIC ANOMALY IN QINGHAI-TIBET PLATEAU

在对青藏高原航磁异常及地质构造特征进行定性分析的基础上 ,利用频率域三维磁性层反演方法对青藏高原居里面埋深进行了定量计算。反演结果表明 ,青藏高原居里面埋深相对较浅 ,一般为 2 0～ 2 3km ,羊八井、那曲地热田附近居里面埋深 14～ 18km。依据反演结果对该地段地震测深的强反射亮点群及大地电磁测深的低阻高导构造的性质进行了讨论 ,并对青藏高原的地震及地壳隆升机制进行了探讨。

On the basis of qualitative analysis of the aeromagnetic anomaly and geologic structure features in Qinghai-Tibet plateau, the buried depth of Curie surface in the plateau is quantitatively computed by using 3-D magnetic layer inversion method in frequency domain. Inversion results show that buried depth of the Curie surface is relatively shallow, generally 20～23 km in the plateau and the depth is 14～18 km around Yangbajing and Naqu geothermal fields. According to inversion results, authors explore different features among strong reflection bright spot groups from deep seismic sounding and low resistance and high conduction structures from magnetotelluric sounding around Yangbajing and Naqu geothermal fields, and discuss dynamic mechanism of earthquake and of crust uplift in Qinghai-Tibet plateau.