江西五里街地区地磁特征及综合信息找矿预测

Geomagnetic Characteristics and Prospecting Prediction Based on Comprehensive Information in the Wulijie Area,Northern Jiangxi Province

赣北五里街地区横跨长江中下游铜钼金铅锌成矿带与江南隆起东段钨锡钼成矿带,区内已发现钨钼矿(化)点4处,铜铅矿矿点1处及锡石(褐铁矿)化点1处,显示出良好的找矿前景。本文通过在五里街地区开展1∶5万地面高精度磁法测量工作,厘定了第四系覆盖区横山花岗岩体隐伏边界范围,并利用剩余重力异常数据三维人机交互反演了该岩体深部形态;以磁异常为主,识别出了不同的构造边界(断裂带或不同岩性侵入接触界线)及环形蚀变砂岩带;以地质为基础,将磁异常与化探水系沉积物综合异常进行对比研究,根据异常套合情况,有效地缩小了找矿范围,提高了矿产地质调查效率。根据大比例尺地、物、化示矿信息,指出了五里街地区寻找铜钼金等多金属矿的靶区,为该区后续开展找矿地质工作提供了重要依据。

The Wulijie area,northern Jiangxi Province straddles the middle-lower Yangtze River Cu-Mo-Au-Pb-Zn-fluorite metallogenic belt and the eastern section of Jiangnan uplift W-Sn-Mo metallogenic belts.Four tungsten-molybdenum ore(mineralization)spots,one copper-lead ore spot and one cassiterite(lignite)mineralization spot have been discovered in this area,indicating a good ore-prospecting prospect.By a 1∶50,000 high-precision magnetic survey,the boundary of the hidden Hengshan granite body in the Quaternary cover area is delineated.Meanwhile,by utilizing inversion of residual gravity anomalies and 3D man-computer interaction,its shape at depth is figured out.Different structural boundaries are identified mainly relying on positive magnetic anomalies,such as fault zones,intrusion contact lines of different lithologies and annular altered sandstone belts.By integrated application of geological,geophysical and geochemical methods,the prospecting area is narrowed down and the efficiency of prospecting is enhanced.According to indicators from geological,geochemical and magnetic data,two targets of the prospecting metallic ore deposits are determined,providing a basis for further ore-search efforts in this area.