铜陵矿集区水系沉积物中主成矿元素空间分布模式-基于变差函数的分析  

Geochemical patterns of the major ore-forming elements in stream sediments of the Tongling area-a geostatistical semivariogram analysis

作　　者：孟刚刚 张苗苗 林鑫[1,2,3] 付亚龙 常海钦 MENG Ganggang;ZHANG Miaomiao;LIN Xin;FU Yalong;CHANG Haiqin(School of Earth Sciences and Resources,Chang'an University,Xi'an 710054,China;International Center on Global-scale Geochemistry,Langfang 065000,China;MLR Key Laboratory of Geochemical Exploration,Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang 065000,China)

机构地区：[1]长安大学地球科学与资源学院,西安710054 [2]全球尺度地球化学国际研究中心,廊坊065000 [3]国土资源部地球化学探测技术重点实验室,中国地质科学院地球物理地球化学勘查研究所,廊坊065000

出　　处：《物探化探计算技术》2020年第1期84-94,共11页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：科技部重点研发计划项目(2016YFC0600601)。

摘　　要：成矿及伴生元素空间分布模式的研究对矿产勘查有着重要意义。然而,当前关于定量刻画元素空间分布特征的研究仍较为缺乏。这里基于安徽铜陵地区1:200000水系沉积物地球化学数据,展开了单元统计分析以及不同范围内主成矿元素(Cu、Au、Pb和Zn)变差函数分析,定量刻画其空间分布特征。结果表明:在全区范围内,①Cu和Au的高含量值沿近东西向(83.5°和88.6°)呈现最大连续性,空间上与近东西向铜陵戴汇基底断裂带吻合;②Pb和Zn的高含量值则沿北东-南西向(62.1°和49.7°)呈现最大连续性,空间上与二叠系、三叠系碳酸盐岩和北东向断裂高度吻合。缩小研究范围后发现,Au、Pb和Zn的最大连续性方向分别为94.6°、48.2°和42.0°,变化幅度较小(6°、13.9°和7.7°),Cu则由近东西向(83.5°)变为北北东向(35.3°),变化幅度明显(48.2°),此时呈现出与区内矽卡岩型铜矿控矿岩体(如铜官山岩体)的空间相关性,可能是由于范围的变化引起Cu的空间分布模式发生变化。综上所述,认为研究区水系沉积物中Cu的分布受成矿岩体控制,Au受到区域主断裂及邻近次级断裂控制,Pb和Zn则受到二叠系、三叠系地层控制。因此,在未来矿产勘查中,应重点检查与上述地质单元有关的成矿及伴生元素异常,加强其空间分布模式的研究,为后期的勘查找矿提供借鉴。The study of spatial distribution pattern of ore-forming and associated elements is of great significant to mineral exploration.However,current researches on quantitatively characterizing the spatial distribution of elements are still in need.Based on 1:200,000 stream sediment geochemical data in the Tongling area of Anhui province,univariate and geostatistical semivariogram analyses of main ore-forming elements(Cu,Au,Pb and Zn)were conducted to quantitatively characterize their spatial distribution patterns.The results show that:①the high concentrations of Cu and Au show the greatest continuity along the east-west direction(83.5°and 88.6°)in the whole region,and this is consistent with the EW-striking Tongling-Daihui basement fault zone;②The high contents of Pb and Zn show the greatest continuity at the northeast-southwest direction(62.1°and 49.7°)consistent with the permian and triassic carbonate rocks in space.When the area of the study area decreases,it was found that the greatest continuity of Au,Pb and Zn are 94.6°,48.2°and 42.0°,respectively and their variation ranges are small(6°,13.9°and 7.7°).However,for Cu,the greatest continuity has changed from EW(83.5°)to NNE direction(35.3°),and the variation range is obvious(48.2°),showing the spatial relation with the skarn copper deposits-associated intrusive rocks in the area(such as the Tongguanshan rock mass).It is possible that the spatial distribution pattern of Cu changes due to a change in range.In summary,we concluded that the distribution of Cu in the stream sediments of the study area is controlled by ore-related intrusive rocks,and that of Au is controlled by major faults and adjacent secondary faults,whilst that of Pb and Zn are controlled by the permian and triassic strata.Therefore,in future mineral exploration,it is important to examine geochemical anomalies associated with the above-mentioned geological units,and strengthening the study of their spatial distribution patterns provides a scientific basis for later exploration and p

关 键 词：铜陵 水系沉积物 勘查地球化学 变差函数 

分 类 号：P632[天文地球—地质矿产勘探]