在第四系覆盖区如何辨别基性岩体与铁矿引起的重磁异常

铁矿勘查工作采用重、磁手段一般非常有效,但在第四系覆盖区有基性岩体存在情况下,就会产生较强的重磁干扰,往往造成误判,因此,区分基性岩体与铁矿引起的重磁异常成为勘查工作的关键。以滦南杜蒿坨铁矿勘查为例,通过对磁法资料和重力资料的处理、解释,分析了基性岩体重磁异常特征及对铁矿异常的掩盖作用,总结了辨别铁矿异常的方法。并经钻探验证这些方法可靠和适用,在今后铁矿勘查工作中有一定的指导意义。

How to distinguish gravity and magnetic anomalies resulting from basic rock mass and those caused by iron deposit in Quaternary overburden area

Iron ore prospecting work with gravity and magnetic methods is generally very effective, but in the Quaternary cover area ultrabasic rocks would produce gravity and magnetic interference, which often causes the miscarriage of justice. Therefore the key problem in such an area is to distinguish the gravity and magnetic anomalies caused by basic rocks and those casued by iron deposits. With the exploration of the Duhaotuo iron ore deposit in Luannan area as an example and through the processing of magnetic and gravity data, the authors analyzed the basic rock gravity and magnetic anomalies and their masking effects on ore anomalies, and summarized the meth- ods for identifying iron anomalies. Drilling demonstrates that the means put forward by the authors are reliable and applicable, and the results achieved by the authors will be significant for ore-prospecting work in the future.