多重地球化学背景下地球化学弱异常增强识别与信息提取  

Recognition and extraction of geochemical weak anomalies based on multiple geochemical background

作　　者：张焱[1,2] 周永章[1,2] 

机构地区：[1]中山大学地球科学系,广东广州510275 [2]广东省地质过程与矿产资源探查重点实验室,广东广州510275

出　　处：《地球化学》2012年第3期278-291,共14页Geochimica

基　　金：钦杭成矿带(南段)庞西垌地区矿产远景调查项目(1212010071012);国家青年科学基金(41004051);全国矿产资源潜力评价项目(国土资源部资[2007]038-01-18)

摘　　要：为对钦州湾-杭州湾成矿带(南段)庞西垌地区地球化学数据进行异常识别研究与信息提取,利用含量-面积法(C-A)得出庞西垌地区成矿主元素的异常下限,得到各元素异常分布图,并与已知矿(床)点进行叠加分析,发现已知矿(床)点与C-A法分析得到的异常区基本吻合,可根据该异常区预测未知矿床,从而为该研究区矿产资源潜力评价提供依据。为进一步从研究区复杂的地球化学背景中分离出与成矿有关的地球化学异常,采用分形滤波技术(S-A)提取致矿异常。研究表明,S-A法可在C-A法揭示的区域异常的基础上更深层次地提取出与矿化有关的局部异常用以反映研究区的多重地球化学背景,S-A法可有效地使弱异常增强进而提取出致矿异常,为庞西垌地区探寻隐伏矿体提供依据。Concentration-area method is applied to caculate lower limit of anomalous values and obtain abnormal maps for major elements in Pangxidong area, Qinzhou-Hangzhou tectonic joint belt. The known deposits are consistent with the anomalous area when analyzed with overlay method. The unknown mineral deposits can be predicted according to the anomalous area in the study region, providing usefull method for mineral resource potential evaluation. A fractal filtering technology are used to extract ore-forming anomaly from complicated geochemical backgrounds. The fractal filtering technology method can extract mineralization areas related to local anomalies on the basis of the concentration-area method, revealing the regional anomaly and reflect the multiple geochemical background. The fractal filtering method can effectively enhance the weak abnormal analyses, extract the ore-forming anomalies, and help exploring concealed orebody in Pangxidong area.

关 键 词：多重地球化学背景 弱异常增强识别 庞西垌 钦州湾-杭州湾成矿带(南段) 

分 类 号：P59[天文地球—地球化学] P61[天文地球—地质学]