青海尕林格Ⅴ矿群磁异常特征分析

ANALYSIS ON THE MAGNETIC ANOMALY OF GROUP V OF GALINGE OREFIELD IN QINGHAI PROVINCE

尕林格矿区矿体以磁铁矿为主,局部地段伴生铅锌、铜.区内几乎被第四系砂砾层覆盖,覆盖层厚度一般在180～300 m,矿体与围岩磁性差异明显,磁法勘探在该区找矿中是最为直接有效的方法.由于矿体埋深较大,地面测得的ΔT异常特征不明显,使得推断解释依据不充分,因此推断的结果存在较大误差或多解性.通过对该矿区Ⅴ矿群磁测资料进行化极、解析延拓及小波多尺度分解等新技术方法的应用,可供分析推断的信息增多,消除了浅部干扰因素,凸显出了异常细节特征,分析推断结果的准确性有了很大提高.确定了异常源的空间分布状态,为寻找深部磁铁矿、布设钻探工程提供了依据.通过212线上的3个钻孔验证,在深度450～650 m处发现平均厚度为50 m的磁铁矿体,为今后寻找深部盲矿体提供了参考与借鉴.

The Galinger orefieht is located on the edge of Qaidam Basin, with ore bodies of mainly magnetite, locally with lead, zinc and copper. The region is covered by Quaternary gravel overburden with thickness of 180 - 300 m. The obvious magnetic difference between the orebodies and surrounding rocks makes the magnetic survey in the area mostly direct and effective. Due to the great depth of the orebodies, the ground measured AT abnormal is unclear, thus the inference and interpretation for the ores exist errors or multiplicity. The new technology and methods of reduction to the pole, analytical continuation and wavelet multi-scale decomposition add information for analysis and eliminate the interference factors. The method is applied in the prospecting for Group V ores in Galinger orefield. A magnetite body with an average thickness of 50 meters was found in depth from 450 to 650 meters, which has been verified by drilling.