中文摘要:氢氧同位素研究表明团结沟金矿成矿热液水主要为大气降水来源,成矿W/R值较小(0.05~0.15)。通过对东露采区蚀变岩石的系统采样和氧同位素分析,获得氧同位素平面等值线趋势图,指示出矿体与高18O蚀变花岗斑岩有密切关系。利用大气降水二阶段理想演化定性解释了高18O蚀变岩石成因。一个浅钻岩心的氧同位素组成向深部具明显升高趋势,指示金矿主矿体还在深部。
Abstract:A fairly systematic oxygen (hydrogen) isotope study was made on different stages of ore-forming fluids and altered rocks in the Tuanjiegou gold deposit. It is known that for the two ore-forming stages(ⅠandⅡ)of chalcedonic quartz veins, δ18OH2O = -1.9 ~ +0.4‰, andδDH2O=-85~115‰, and that for hydrothermal solutions of the late ore-forming stage of carbonate-sulfide veins, δ18O = -3.8~-4.4%andδD=-85~-98‰. The oxygen(hydrogen)isotope Compositions of these characteristic ore-forming hydrothermalsolutions show convincingly that the Tuanjiegou gold deposit is a porphyry type deposit within the shattered alteration zone genetically characterized by meteoric-hydrothermal waters. The ratios of ore-forming water to rocks(W/R) are 0.05-0.15, and the oxygen(hydrogen)isotope inversion between hydrotherma1 solutions and altered rocks took place at the late stage. It is determined that theδD values of Mesozoic meteoric water are between -110‰and -120‰. Systematic planar sampling and oxygen isotope analysis were performed in the openpit working of the Tuanjiegou gold deposit, and the results reveal that the whole rock oxygen isotope Values of most altered granite porphyry samples get higher, and there exist close relations between mineralization and 18O-high altered granite porphyry. δ18O wall rock values of the altered porphyry are>12.0‰(mostly above 14.0‰), much higher than oxygen isotope value of the protolith(10‰),which seems to be an important characteristic of meteoric-hydrothermal deposits with low W/R ratios.On the Oxygen isotope contour map, the 18O-high altered rocks are quite coincident with the localities of gold orebodies, and thus a map showing planar relations between oxygen isotope compositions and orebodies has been compiled for the first time in China. It is pointed out that random sampling of rocks in an surface environment might be conducted to delineate the central domain of high oxygen isotope values and then to search for concealed orebodies. This is a complete new breakthrough subsequent to the theory of applying the low value center of oxygen isotopes to the prospecting for concealed orebodies.the obviously increasing trend of oxygen isotope compositions of sample cores with depth suggests that ore potentiality is encouraging at the depth of the ore deposit.
文章编号:
中图分类号:
文献标志码:
基金项目:地质行业科学技术发展基金资助项目
引用文本:
陈振胜,张理刚,王可法,刘敬秀.1993.团结沟金矿氧氢同位素组成特征与成矿关系的研究[J].矿床地质,12(2):174~181.1993.Oxygen (hydrogen) isotope compositions of the Tuanjiegou gold deposit in relation to the ore-forming process[J].Mineral Deposits12(2):174~181
图/表