中文摘要:凡口铅锌矿床是世界上著名的大型有色金属矿床。关于矿床的成因,一直以来争议很大。前人的研究主要是针对硫化物矿石矿物的,但事实上,凡口铅锌矿的矿体主要赋存于中、上泥盆统和下石炭统碳酸盐岩建造中,且以热液方解石为代表的碳酸盐矿物是凡口铅锌矿最主要的脉石矿物,因此,有必要对矿床中的碳酸盐矿物进行研究,从而通过一个新的角度阐述凡口铅锌矿床的成因。本文对凡口铅锌矿床围岩和矿体矿石中的碳酸盐矿物(主要是方解石)的包裹体特征和C-O-Sr同位素组成进行研究,并对矿床的成因进行了初步的讨论。研究显示:凡口矿中方解石可分为早期、中期和晚期3种类型,其中中期方解石与硫化物矿石矿物共生,是凡口矿主成矿期的产物。经系统观察和冷热台测定,早期和晚期方解石包裹体的均一温度和盐度都较低, δ13CV-PDB值变化区间较大,在-3.1 ‰ ~ 3.6 ‰之间,δ18OV-SMOW值在12.2 ‰附近;中期方解石包裹体的均一温度和盐度最高, δ13<.sup>CV-PDB值小于-4.0 ‰,δ18OV-SMOW值主要在17.0 ‰附近。凡口热液方解石的矿物包裹体均一温度和盐度数据表明该矿成矿溶液与深层热液和海水有关,C-O-Sr同位素组成则表明凡口主要矿体为海底热泉喷流沉积成因。
Abstract:Fankou lead-zinc deposit is a famous large-scale lead-zinc deposit in China. Its ore bodies are mainly hosted in the carbonate formations of Middle-Upper Devonian and Lower Carboniferous strata. Country rocks and ores of the deposit contain lots of carbonates, such as calcites etc. Former research of the Fankou lead-zinc deposit almost focused on the fields of sulfides, the importance of carbonates were neglected, so it is necessary to reveal the cause of formation of the Fankou lead-zinc deposit by means of carbonates. In this paper, we discuss the characters of carbonates inclusions in the ore bodies. The fluid inclusions of calcites from Fankou lead-zinc deposit are divided into three stages. Pre-ore and late-ore stage fluid inclusions are characterized by low homogeneous temperature and low salinity, the values of δ13CV-PDB range from -3.1 ‰ to 3.6 ‰, and δ18OV-SMOW are around 12.2 ‰. Ore stage fluid inclusions are characterized by higher homogeneous temperature and salinity, the values of δ13CV-PDB are lower than -4.0 ‰, the δ18OV-SMOW are around 17.0 ‰. Based on the study of hydrothermal calcites and fluid inclusions, it indicates that deep source hydrothermal solution and sea water play an important role during the ore forming, the Fankou is a submarine exhalative sedimentary Pb-Zn deposit.
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基金项目:广东省自然科学基金项目(970123)
引用文本:
梁业恒,孙晓明,陆红锋.2009.粤北凡口超大型铅锌矿热液方解石流体包裹体特征和C-O-Sr同位素组成[J].矿床地质,28(Z):79~88.2009.Fluid inclusions and C-O-Sr isotopic compositions of hydrothermal calcite in Fankou superlarge scale Pb-Zn deposit[J].Mineral Deposits28(Z):79~88
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