【作者】 夏明哲；

【导师】 姜常义；

【作者基本信息】 长安大学 ， 矿床普查与勘探， 2009， 博士

【摘要】 新疆北部康古尔-黄山韧性剪切带发育有一系列镁铁-超镁铁质岩体，其中土墩、香山、黄山、黄山东、葫芦和图拉尔根岩体产出有工业矿床，二红洼和黄山南岩体中均发现了不同程度的铜镍硫化物矿化。近年来，随着勘探深度和网度的加大，资源量得到了大幅增加，使得该带目前已成为我国第二个世界级的岩浆铜镍硫化物矿床成矿带。论文选择二红洼、香山、黄山南、黄山、黄山东、葫芦岩体为研究对象，紧扣岩浆硫化物矿床的关键岩石学问题：①岩浆源区的性质和原生岩浆的组成；②是否有同化混染作用，混染物的类型和混染程度，同化混染作用与硫化物分凝之间的关系；③分离结晶、岩浆演化过程。通过岩石学、矿物学、元素地球化学以及Nd、Sr、Pb同位素地球化学方法，就含矿岩体与弱矿化岩体、含硫化物矿床岩体与含氧化物矿床岩体进行系统研究，主要获得以下几方面的成果：（1）含矿岩体岩相分带清楚，岩石蚀变较强；弱矿化岩体岩相分带较差，岩石新鲜，蚀变弱，岩石组合中橄榄岩相所占比例小。（2）含矿岩体与弱矿化岩体稀土元素地球化学特征存在较大差异，含矿岩体稀土元素总量高于弱矿化岩体，其轻重稀土元素之间以及轻、重两组稀土元素内部分馏程度明显强于弱矿化岩体。（3）含矿岩体均发生了不同程度陆壳物质的混染，黄山东和葫芦岩体分别遭受了约5%、5%-10%中-上陆壳物质的混染，黄山、香山岩体遭受了不同程度中-下地壳的混染，而弱矿化的黄山南岩体局部遭受较弱同化混染作用，二红洼岩体基本没有遭受陆壳混染。（4）利用Mg^#以及液相线橄榄石Fo分子约束原生岩浆的MgO含量。除香山岩体原生岩浆MgO含量下限值稍低（5．0%）外，含矿岩体原生岩浆均为高镁拉斑玄武质岩浆。其中，黄山东岩体的原生岩浆MgO含量为11．6%，黄山岩体和葫芦岩体原生岩浆MgO含量下限值分别为9．2%，7．1%；而弱矿化的二红洼岩体原生岩浆MgO含量为7．1%，黄山南岩体原生岩浆MgO含量下限值为5．7%。（5）含矿岩体地球化学特征表明，导致硫化物过饱和熔离的主要原因是岩浆结晶分异和同化混染作用过程中富Si组分的加入。（6）香山中含铜镍矿岩体和香山西含钒钛磁铁矿岩体具有不同成矿专属性的岩石系列。香山中含铜镍矿岩体中无原生磁铁矿出现，岩石化学成分明显富MgO，贫FeO_T、TiO₂，具有较弱的正、负铕异常。含矿岩相m/f值（3．97-5．53），为铁质超基性岩。香山西含钒钛磁铁矿岩体中有一定数量的原生磁铁矿，岩石富FeO_T、TiO₂、Al₂O₃，普遍具有显著的正铕异常。钛铁辉长岩的m/f值（0．68-0．90），属于铁质基性岩。岩浆自身演化过程和流体的广泛参与，应该对形成CuNi-VTi复合型矿床起到了主要作用。（7）Nd、Sr、Pb同位素及相关微量元素研究表明，岩体具有相似的岩浆源区。岩浆源区由被消减板片交代的地幔楔物质和软流圈地幔物质组成。岩石圈根部拆沉和软流圈地幔上涌过程中生成了黄山岩带的镁铁-超镁铁岩体。更多还原

【Abstract】 A series of mafic-ultramafic intrusions occur in the Kangguer-Huangshan shear zone in northXinjiang,including Tudun,Xiangshan,Huangshan,Huangshandong and Tulargen economic mineralizedintrsions,Erhongwa and Huangshannan intrsions with variable degrees of copper-nickel sulphidemineralization.In recent years,with the increasing exploration depth and density,reserves has substantialincreased,Kangguer- Huangshan zone has now become the second world-class magmatic copper-nickelsulfide deposit metallogenic zone in China.Erhongwa,Xiangshan,Huangshannan,Huangshan,Huangshandong,Hulu intrusions were selected for detailed study,focusing on the key petrology issues ofmagmatic sulfide deposits:①the nature of magma source and the composition of primary magma;②whether the intrusion has underwent crustal contamination or not,the type of hybrids and the degree ofcrustal contamination,the relationship between crustal contamination and sulphide segregation;③fractional crystallization,magma evolution.Systematically comparison between economic mineralizedintrusions and uneconomic mineralized intrusions,oxides deposits and sulfide deposits respectively werecarried out based on petrology,mineralogy,element geochemistry,Nd,Sr,and Pb isotope geochemistry.The following are the main results:（1） The economic mineralized intrusions have clear facies and highly altered,while the uneconomicmineralized intrusions are fresh.there are a few peridotite.（2）Geochemistry characteristics of rare earth element has obvious difference between the economicmineralized intrusions and the uneconomic mineralized intrusions.The economic mineralized intrusionshave significantly higher content of the total rare earth elements than that of the uneconomic mineralizedintrsions,and the degree of the LREEs fractionation of the formers,as well as the HREEs,are also strongerthan that of the latters.（3） The economic mineralized intrusions underwent crustal contamination to some extent.For example,Huangshandong and Hulu intrusion were subjected to comtaminated about 5%,5%～10% byupper-intermediate continental crust.Huangshan intrusion and Xiangshan intrusion contamination hascome from the intermediate-lower crust.In contrast,the uneconomic mineralized intrusions,such asHuangshannan intrusion,only experienced partially contamination,Erhongwa intrusion didnot have theimpact of crustal contamination.（4） The Fo molecules of olivine and Mg^# are used to restrict the MgO content of the primary magma. Rearch proves that the MgO content of the economic mineralized intrusions are higher than that of theuneconomic mineralized intrusions,although the minimum MgO content of Xiangshan intrusion is 5.0%.Among the economic mineralized intrusions,the MgO content of primary magma of Huangshandonginstrusion is 11.6%;the minimum MgO content of primary magma of Huangshan instrusion and Huluintrusion is respectively 9.2%,7.1%,While among the uneconomic mineralized intrusions,the MgOcontent of primary magma of Erhongwa intrusion is 7.1%,and the minimum MgO content of primarymagma of Huangshannan instrusion is 5.7%.（5） Magmatic crystallization and crustral contamination comeing from Si-rich component lead to sulfidesaturation in economic mineralized intrusions.（6） Xiangshanzhong intrusion of Cu-Ni deposit and Xiangshanxi intrusion of V-Ti-Fe deposit have differentwith rock series.Xiangshanzhong intrusion have no primary magnetite,with rich in MgO,low in FeO_T,TiO₂ and positive/negative Eu anomalies.The m/f ratio of rock is 3.97-5.53 and belong to ferruginousultrabasic rocks.However Xiangshanxi intrusion have some primary magnetite,are rich in FeO_T,TiO₂ andhave obvious positive Eu anomalies.The m/f ratio of Fe-Ti gabbro is 0.68-0.90 and belong toferruginous basic rocks.Participating in fluid and magmatic evolution itself are the key to from theCuNi-VTi composite deposits.（7） Nb、Sr、Pb isotope and trace element geochemistry characters indicate that magma source of theseintrusions were similar and composed of wedge matasomasised by subducting slab and aesethenospherecomponents.The mafic-ultramafic intrusions of Huangshan terrane are the result of the lithosphericdelamination at the root and the upwelling of asthenosphere components.更多还原