蒙古及邻区内源磁场基本特征

利用第11代国际参考地磁场(IGRF)模型和NGDC-EMM-720-V3地壳磁场模型,分析蒙古及邻区垂直分量的主磁场、非偶极子场、长期变化、长期加速度,地壳磁异常在地表及地表以上不同高度分布特征,讨论了地壳磁异常与地质构造的关系.结果显示,蒙古及邻区主磁场各成分的空间变化较小,地壳磁异常呈团状、条带状、弧形状分布,分布形态相对复杂;乌兰乌德、乌兰巴托片区的异常中心位置较为稳定;杭爱山、阿尔泰山呈负磁异常,异常分布与山脉构造走向基本一致.正负磁异常过渡区与山脉和盆地分界基本吻合.

The basic characteristics of internal magnetic field in Mongolia and its adjacent

Based on the eleventh generation of international geomagnetic reference field (IGRF) model and the NGDC-EMM-720-V3 model of crustal magnetic field,this paper aims to analyze the vertical component of the main magnetic field,the non dipole field,secular variation,long-term acceleration and crustal magnetic anomaly above the surface and the surface of different height distribution in Mongolia and its adjacent area,and to discuss the relationship between the crustal magnetic anomalies and geological structure.The results show that spatial changes of the main magnetic field components in Mongolia and adjacent areas is small,crustal magnetic shows slug,ribbon,arc shaped and the distribution is relatively complex.The anomaly center of Ulam Uhde and Ulan Bator area are relatively stable.Mountain Hangai and Mountain Altai present negative magnetic anomaly,the anomaly distribution is consistent with the mountain tectonic trends.The transition area of positive and negative magnetic anomaly is basically consistent with the boundary of the mountain and basin.