复杂地质背景下化探数据分区处理的意义——以陕西省平利县大贵镇一带为例  

The significances of geochemical data zoning processing in complex geological background--a case study of Dagui area,Pingli County in Shaanxi Province

作　　者：贺争锋 张亚峰 王星 孔文年 张清盛 仵桐 赵江林 袁璋 HE Zhengfeng;ZHANG Yafeng;WANG Xing;KONG Wennian;ZHANG Qingsheng;WU Tong;ZHAO Jianglin;YUAN Zhang(Shaanxi Center of Mineral Geological Survey,xi,an 710068,Shaanxi,China;Shaanxi lnstitute of Geological Survey,Xi,an 710054,Shaanxi,China)

机构地区：[1]陕西省矿产地质调查中心,陕西西安710068 [2]陕西省地质调查院,陕西西安710054

出　　处：《矿产勘查》2021年第10期2106-2114,共9页Mineral Exploration

基　　金：陕西省公益性地质勘查项目《陕西省安康市老县等四幅1∶5万区域地质矿产调查》项目(20180101);《陕西省南秦岭成矿带佛坪隆起南缘茅坪地区基础地质调查》项目(202102)联合资助。

摘　　要：水系沉积物测量是地质找矿的主要工作手段,在我国找矿工作中已取得显著成果。本次在陕西省安康市平利县北部大贵镇一带开展的四幅1∶5万水系沉积物测量数据处理过程中,因区内存在多个地质背景区,采用全区统一异常下限圈定异常的化探数据处理方法成图效果较差,不能很好的指导找矿工作。根据地球化学场的展布特征,结合地质背景,对工作区先进行分区,然后采用衬度值方法对化探数据进行分区处理、统一编图。这种方法既解决了低背景低值区圈不出异常的问题,同时又解决了高背景高值区异常普遍偏大的问题。根据以上方法,最终将研究区分为:赤炎-铜钱关地球化学区(Ⅰ区)、县河-石门地球化学区(Ⅱ区)、田坝-大贵地球化学区(Ⅲ区)、三阳-洛河地球化学区(Ⅳ区),共四个地球化学分区,不同分区分别采用不同的异常下限进行数据处理,最后全区采用衬度值统一进行编图。经后期异常查证,在梅子垭组新圈定的综合异常中取得了钒钼矿找矿新发现,佐证了在多背景区采用衬度值方法进行分区数据处理的有效性和可靠性。Stream sediment survey is the main means of geological prospecting,which has got remarkable achievements of mineral exploration in China.During the four 1∶50000 stream sediment survey data processing in Pingli County,Ankang City,Shaanxi Province,there are many geological background areas in the area,so the geochemical data processing method adopting the unifying anomaly threshold for delineating the anomalies in the whole area has poor mapping effects,which can not guide the prospecting work well.According to the distribution characteristics of geochemical field,combined with the geological background,the working area is divided firstly,and then the geochemical exploration data is processed by the method of contrast value to make a unified map.This method can not only solve the problem that the low background region is not abnormal,but also solve the problem that the high background region is generally large.According to the above methods,the study is finally divided into four geochemical zones:Chiyan-Tongqianguan geochemical zone(zone I),Xianhe-Shimen geochemical zone(zone II),Tianba-Dagui geochemical zone(zone III),Sanyang-Luohe geochemical zone(Zone IV).Different zones are adopted different lower limit of anomaly for data processing,and finally the whole area uses the contrast value for the unified mapping.It has been proved that the new discovery of vanadium molybdenum ore has been discovered in the newly delineated anomaly area of Meiziya formation,which demonstrates the validity and reliability of the method of contrast value in the multi-background areas.

关 键 词：水系沉积物 异常下限 衬度值 地球化学分区 找矿 

分 类 号：P632.3[天文地球—地质矿产勘探]