贵州福泉高洞铝土矿床成矿地质地球化学特征  

Geological and Geochemical Characteristics of Mineralization in the Gaodong Bauxite Deposit,Fuquan,Guizhou Province

作　　者：金中国 郑明泓 刘玲 骆军 董光贵 陈兴龙 JIN Zhong -guo;ZHENG Ming -hong;LIU Ling;LUO Jun;DONG Guang -gui;CHEN Xing -long(Guizhou Nonferrous Metal ＆ Nuclear Industry Geological Exploration Bureau, Guiyang, Guizhou 550005;Geophysical and Chemical Exploration Team of Guizhou Nonferrous Metal ＆ Nuclear Industry Geological Exploration Bureau Duyun, Guizhou 558000)

机构地区：[1]贵州省有色金属和核工业地质勘查局,贵州贵阳550005 [2]贵州省有色金属和核工业地质勘查局物化探总队,贵州都匀558000

出　　处：《地质与勘探》2018年第3期522-534,共13页Geology and Exploration

基　　金：国家十二五科技支撑计划重点项目(编号:BAB201104B04);贵州省地勘基金项目(编号:ZZKC2012-06);贵州省公益性;基础性项目(编号:2016-07)联合资助

摘　　要：贵州福泉高洞铝土矿床是近年在贵州新的铝土矿成矿区探明的中型矿床之一,其含矿岩系为下石炭统九架炉组,铝土矿呈层状、似层状产于上泥盆统高坡场组碳酸盐岩古侵蚀面之上,与上覆中二叠统梁山组和下伏上泥盆统高坡场组均呈假整合接触,矿床成因类型为古风化壳沉积型。通过对含矿岩系中敏感元素Ga、Ba、Sr、Th含量及B/Ga、Rb/K、V/Zr比值特征分析,认为铝土矿主要形成于陆相沉积环境;δCe、Ni/Co、Th/U、Sr/Cu、V/Cr特征揭示铝土矿成岩成矿过程主要为氧化环境。含矿岩系中Al与Zr、Hf、Nb、Ta、Th、U等呈正相关性反映出铝土矿成矿过程中具同迁移、显著富集特征;含矿岩系中微量元素含量与下伏高坡场组碳酸盐岩相比,总体成强烈富集态势。与黎彤值对比,含矿岩系中高温成矿元素(W、Sn、Mo、Bi)、高场强元素(Nb、Ta、Th、U、Hf、Zr)、粘土矿物易吸附元素(Li、V)及细碎屑岩中高地球化学背景元素(Sb)富集强度高。LREE与HREE分馏作用明显,推测为次生风化淋滤过程中离子半径较小的HREE向下渗滤迁移的速率大于离子半径较大的LREE所致。The bauxite deposit in the Gaodong area of Guizhou Province is one of the newly discovered mid-sized bauxite deposits in recent years. Its ore-bearing strata are the Jiujialu Formation of the Lower Carboniferous. Layered and layered-like bauxite lies on the ancient erosion surface of the carbonate rocks in the Upper Devonian System,contacting the overlying Liangshan Formation of the Middle Permian System and underlying Gaopochang Formation of the Upper Devonian System in a disconformable manner. The genesis of the deposit is of an ancient weathering crust depositional type. Analyzing the characteristics of Ga,Ba,Sr and Th contents and B/Ga,Rb/K and V/Zr ratios in the ore-bearing rocks suggests that the bauxite formed in a continental sedimentary setting. The features δCe,Ni/Co,Th/U,Sr/Cu and V/Cr reveal that the diagenesis and mineralization process of the bauxite was in an oxidative environment. The positive correlation between Al and Zr,Hf,Nb,Ta,Th and U in the ore-bearing rocks indicates that the bauxite has the same migration and significant enrichment characteristics. The content of trace elements in the ore-bearing rock series is strongly enriched compared with that of the carbonate rocks of underlying strata Gaopochang Formation. Compared with the value of Li Tong,the high-temperature metallogenic elements（ W,Sn,Mo and Bi）,high-field strength elements（ Nb,Ta,Th,U,Hf and Zr）,clay mineral easily adsorbed elements（ Li and V） and the high-grade geochemical background element（ Sb） in fine-grained rocks are highly enriched. Fractionation of LREE and HREE is obvious. It is inferred that the migration rate of HREE with smaller ionic radius is larger than LREE with larger ionic radius in the process of secondary weathering leaching.

关 键 词：铝土矿 地质地球化学特征 成矿环境 高洞 贵州 福泉 

分 类 号：P595[天文地球—地球化学]