带约束的化极在低纬度、高剩磁地区的应用——以柬埔寨Oyadao金矿为例

Application of constrained pole change in low latitude and high residual geomagnetic field area:results from field application to Oyadao gold deposit Cambodia

在剩余磁场磁化方向与地磁场方向不一致的低纬度、高剩磁地区,很难选择合适的磁场参数及有效的低纬度化极方法进行化极。为解决这个问题,提出了带约束的化极,该流程以已知高磁性体露头位置、正负对等的较低缓异常梯度最大值位置等特殊位置为约束,通过不断改变磁倾角后化极,使化极后ΔZ异常中心位置与约束位置逼近的方式,得到较好的化极结果。将带约束的化极应用于低纬度、高剩磁且剩余磁场磁化方向与地磁场方向不一致的柬埔寨Oyadao金矿区高精度磁法测量中,取得了良好的应用效果。

It is very difficult to choose the parameters of geomagnetic field and lower latitude pole change method in low latitude and high residual geomagnetic areas where the the magnetization direction of the residual magnetic field is inconsistent with the direction of the geomagnetic field.Thus,this paper propose a new pole change method which called constrained pole change.Through constantly changing angle of magnetic inclination to make the abnormal center ofΔZ close to the known geological body or some other special position.Applied this method process to high-accuracy magnetic data which observed in Oyadao gold deposit Cambodia where the magnetization direction of the residual magnetic field is not consistent with that of the geomagnetic field and the satisfied results are obtained.