地面高精度磁法在新疆哈密地区磁铁矿勘查中的应用

Application of the Ground High-Precision Magnetic Method to Magnetite Survey in the Hami Area, Xinjiang

利用地面CZM-3质子磁力仪,对新疆哈密某地区进行了1∶1万高精度磁法测量。在此基础上,着重阐释哈密某地区磁场结构及其地质意义,编制出这一地区成矿构造地质图。根据磁铁矿与辉绿岩脉的关系,都具有磁性的特点,进行间接找矿。辉绿岩属于基性岩,具有强磁性,这与磁铁矿相同,单一的磁法原本不能解决问题,但从地质上考虑磁铁矿与辉绿岩的产出关系,可以利用高精度磁法间接找磁铁矿。同时,对比分析已知铁矿床(体)磁场特征,建立磁铁矿地质-地球物理找矿模型,进行找矿预测。进而在重点区段实施初步工程验证,见矿率高,从而说明了地面高精度磁法测量找寻磁铁矿的可行性和有效性。

High-precision magnetic measurements on a scale of 1：10000 were made in the Hami area, Xinjiang using the CZM-3 proton magnetometer. The result revealed the NW- trending structure of the magnetic field and its geological significance was interpreted, and then the metallogenic-tectonic map was prepared for this area. According to relationship between magnetite and diabase and their common magnetic nature, we attempt to make an indirect prospecting. Diabase belongs to basic rock with strong magnetic property, which is similar to magnetite. Thus, it seemed that the single magnetib method could not work well. Whereas, the relationship between magnetite and diabase allowed us to carry out indirect magnetite prospecting in terms of high-precision magnetic measurements. Meanwhile, we also compared the magnetic field characteristics of the known ore deposits and established the geo- logical-geophysical prospecting models for ore searching and deposit prediction. The preliminary test at the key site shows the feasibility and efficiency of the high-precision ground magnetic method in searching magnetite.