南岭于都——赣县矿集区银坑示范区重磁资料探测花岗岩分布研究

A study of the distribution of granite detected by gravity and magnetic data in Yinkeng Demonstration Area of Nanling Yudu-Ganxian ore concentration area

银坑示范区位于中国东南部南岭东段于都—赣县矿集区内的银坑镇,具有良好的找矿前景。该区花岗岩与成矿关系密切。因此,系统探查花岗岩体分布是深部找矿的关键问题之一。笔者主要利用重力、磁力平面资料,并结合物性、地质、电法、地震等资料,综合研究了该区花岗岩空间分布特征。首先研究推断了该区6个花岗岩体的平面分布,其中,江背岩体、长潭岩体、高山角岩体为部分隐伏岩体;柳木坑岩体、葛凹圩浅部岩体和葛凹圩深部岩体为完全隐伏岩体。6个岩体总体走向为NE和NNE向。然后利用研究区内4条剖面重(磁)资料反演了花岗岩的空间分布,进一步揭示了上述6个岩体的空间分布特征,其推断成果与利用平面重、磁资料推断成果一致,也与电法、地震剖面解释结果一致。

Located in Yinkeng Town,Yududu-Ganxian ore concentration area,east Nanling Mountains,Southeast China,the Yinkeng Demonstration Area has a good prospect of mineralization,where the granite is closely related to mineralization. Therefore,systematic exploration of granite distribution is one of the key problems in deep prospecting. In this paper,the spatial distribution characteristics of regional granite were comprehensively studied by using gravity and magnetic data,combined with physical,geological,electrical and seismic data. Firstly,the planar distribution of six granite masses in this area was studied and deduced,among which Jiangbei rock mass,Changtan rock mass and Gaoshanjiao rock mass are partially concealed,whereas Liumukeng rock mass and the shallow and deep rock masses of Ge’aowei are completely concealed. It is concluded that the rock mass mainly trends in NE and NNE direction. Then,four gravity( or gravity and magnetic) profiles in the study area were used to invert the spatial distribution of granite,which further revealed the spatial distribution characteristics of the above six rock masses. The inferences are consistent with those obtained by plane gravity and magnetic method as well as the results derived from electrical method and seismic profile interpretation.