【作者】 李延鑫；

【导师】 张铭杰；

【作者基本信息】 兰州大学 ， 地球化学， 2009， 硕士

【摘要】 与镁铁-超镁铁质岩密切相关的铜镍硫化物矿床是铜、镍、铂族元素（PGE）资源的重要矿床类型。黄山铜镍硫化物矿床于中亚造山带的南部,黄山-镜儿泉成矿带。岩体岩相发育良好,主要包括橄榄岩、辉石岩、辉长岩和闪长岩。本文通过对最新两个深钻孔岩心,在岩石学、地球化学研究的基础上,选择新鲜的橄榄石及单斜辉石采用改进的分步加热质谱计法进行流体化学组成研究,得到了如下结论:1、黄山铜镍硫化物矿床镁铁-超镁铁质岩组成矿物的流体挥发份在分步加热过程中阶段性释出。橄榄石中的流体挥发份在200⁵00℃、500¹000℃和1000¹200℃三个温度段释出,单斜辉石在200⁴00℃、400¹000℃和1000¹200℃三个温度段释出。2、黄山铜镍硫化物矿床镁铁-超镁铁质岩组成矿物的流体挥发份以H₂和N₂+CO为主要成分,其次是SO₂、CO₂和H₂S,以及微量的O₂、CH₄和Ar等气体。3、黄山铜镍硫化物矿床镁铁-超镁铁质岩组成矿物在不同温度段释出的挥发份总量不同,中温段释出的挥发份的量最高,平均2474.57mm³.STP/g;低、高温段相对较低,分别为133.04mm³.STP/g和433.05mm³.STP/g。H₂、N₂+CO、SO₂、CO₂和H₂S等主要组分在不同温度段的含量也不相同。4、根据岩浆矿物结晶特征、挥发份释出温度段及化学组成,黄山铜镍岩浆硫化物矿床组成矿物中的流体挥发份可分为:成矿岩浆流体挥发份、岩浆期后热液流体挥发份和后期改造作用流体挥发份。成矿岩浆流体挥发份以高温段释出的SO₂及N₂+CO为主要组分,其次是H₂、CO₂和H₂S;岩浆期后热液流体挥发份中温段释出的主要的组分是H₂,次要组分是N₂+CO,H₂S和CO₂以及低温阶段释出的以N₂+CO为主的后期作用流体挥发份。5、黄山铜镍硫化物矿床成矿岩浆流体挥发份早期表现出了原始地幔来源特征,随结晶作用的进行,有外来氧化性流体组分的混入;岩浆期后热液流体挥发份总量最高,以还原性流体挥发份为主,对主要成矿元素起到搬运、富集的作用;后期蚀变作用流体挥发份成分与大气组分相似,对矿床起了一定的改造作用。更多还原

【Abstract】 Cu-Ni sulphide deposit related to mafic-ultramafic rocks is the main type of copper, nickel,platinum group elements（PGE） deposits.Huangshan Cu-Ni sulphide deposit, Xinjiang,west China is located in the southern part of Central Asian Orogenic Belt.The lithologies of the ore-bearing intrusion are well developed,and mainly include peridotite,, pyroxenite,gabbro and diorite.The fluid composition of fresh olivine and clinopyroxene separates from the two dvilling cores have been measured by the improved vacuum stepwise heating mass spectrometers on the basis of their petrological and seochemcal research.The results are as follows:（1） The volatiles of different minerals from the mafic-ultramafic intrusion from the Huangshan Cu-Ni sulphide deposit have been released by stages during stepwise heating, The volatiles in olivine separates are released at the temperature intervals of 200-500℃, 500-1000℃and 1000-1200℃,whereas volatiles in clinopyroxene separates are released at 200-400℃,400-1000℃and 1000-1200℃（2） The volatiles of the minerals are composed mainly of H₂ and N₂+CO,secondary by SO₂,CO₂ and H₂S,with the minor O₂,CH₄ and Ar etc.（3） Volatiles released at different temperature interval have different contents of volatiles in minerals Huangshan Cu-Ni sulphide deposit.Volatiles released at mid-temperature interval has the highest contents（av.2474.57mm³.STP/g）,and those at low and high temperature intervals are relatively lower（av.133.04mm³.STP/g and 433.05mm³.STP/g,respectively）.The contents of major volatiles such as H₂,N₂+CO,SO₂, CO₂ and H₂S are vary with temperature intervals.（4） Based on crystallization characteristics of magmatic minerals and chemical compositions of the volatiles at different temperature intervals,the volatiles of the minerals in Huangshan Cu-Ni sulphide deposit can be divided into three parts: ore-forming magmatic volatiles,post-magmatic hydrothermal volatiles and secondary processes volatiles.Ore-forming magmatic volatiles represented by the volatiles released at high temperatures are composed mainly of SO₂ and N₂+CO,with minor H₂,CO₂ and H₂S.Post-magmatic hydrothermal volatiles represented by the volatiles released at middle temperatures consisted of N₂+CO,H₂S and CO₂,secondary processes volatiles represented by the volatiles released at low temperatures and are mainly composed N₂+CO.（5） Metallogenic volatiles are characterized by primitive mantle in an early stage of magmatism,and then mixed with external oxidized fluids during crystallization in Huangshan Cu-Ni sulphide deposit.The post-magmatic hydrothermal volatiles have highest content of volatile and are dominated by reduced volatiles,which play an important role in transporting and precipitating the major metallogenic elements,increase evidently,and show the opposite characteristics to volatiles at the early stage.The volatiles in the secondary alteration are dominated by N₂ ect.air-devived components which deformed and alfer existed deposit in some extent.更多还原