Maxwell板状体反演在航空瞬变电磁法找矿实践中应用及效果

Applications of Maxwell plate modeling in airborne TEM survey for exploration

航空瞬变电磁法在寻找隐伏和埋深较大的多金属矿产方面具有明显优势。VTEM航空瞬变电磁观测系统2013年引进到国内,先后在多个省区开展了多金属矿产勘查工作,均取得了明显的地质找矿效果。在航空瞬变电磁法找矿实践中,也逐步形成了一套完整的数据处理和资料解释理论及方法。Maxwell板状体反演是航空瞬变电磁数据解释的一种重要技术方法,把复杂地质结构简化为板状体模型来进行研究,获得地下地质地球物理体(或矿体)在三维空间上的分布特征,有效地确定钻探钻孔的位置和参数,直接用于找矿工程实践。文章重点介绍航空瞬变电磁Maxwell板状体反演的目标异常的选择、模型参数定义、典型板状体的正演响应、反演数据准备和正演拟合及反演,并以黑龙江和青海2个已知矿区为例说明Maxwell板状体反演在航空瞬变电磁找矿实践中的应用及效果。

Airbone TEM has an obvious advantage in exploration of blinded and deep-buried polymetallic minerals. The most advanced VTEM system,introduced into China in 2013,was used for polymetallic minerals exploration in some provinces and autonomous regions. A complete set of data processing and interpretation theory and methods has been gradually taken shape. Maxwell plate modeling is an important technique for data interpretation of airborne TEM which simplifies the complicate geological structure to a plate model to underground geology and geophysical target（ or bore） distribution in 3 D space. It can effectively help to determine the location and parameters of drilling boreholes and directly used for prospecting practice. The paper focused on selection of target anomaly for Maxwell plate modeling,definition of model parameters,forward response of typical plate models,data preparation,forwarding and inversion,in addition,introduced the applications effect of Maxwell plate modeling in Heilongjiang and Qinghai.