华南地质与矿产
華南地質與礦產
화남지질여광산
GEOLOGY AND MINERAL RESOURCES OF SOUTH CHINA
2012年
4期
298-306
,共9页
石英斑岩%地球化学%岩石成因%成矿元素%湖南七宝山
石英斑巖%地毬化學%巖石成因%成礦元素%湖南七寶山
석영반암%지구화학%암석성인%성광원소%호남칠보산
quartz-porphyry%geochemistry%ore-forming elements%petrogenesis%Qibaoshan copper poly- metallic deposit.
湖南浏阳七宝山铜多金属矿床位于钦杭成矿带西南段,是湘东北规模最大的铜多金属矿床,其中矿区内的石英斑岩对成矿贡献非常大。七宝山矿区的石英斑岩是一套高钾(K20〉〉Na2O)、富铝、贫硅的亚碱性的粗面安山岩—安山岩—英安岩组合,地球化学上显示了富轻稀土(LREE)、大离子亲石元素(LILE)(Ba,K等)、成矿元素(Cu、Pb、Zn等),以及贫重稀土元素(HREE)特征。稀土元素配分模式为右倾,有轻微的Eu负异常,说明它具有部分幔源特征;而明显的Sr负异常,且与地壳丰度相似,加上较高Al2O3/TiO2、K2O/Na2O比值,投图后均显示岩石为地壳来源。综合上述特征本文认为该石英斑岩属壳幔同熔型花岗岩。矿体与岩体在空间、时间上关系密切,岩体很高的成矿元素含量正是形成矿体的物质来源。其作用过程是岩浆作为载体携带成矿元素从地幔到近地表,并且在各种导矿构造作用下充填交代成矿。
湖南瀏暘七寶山銅多金屬礦床位于欽杭成礦帶西南段,是湘東北規模最大的銅多金屬礦床,其中礦區內的石英斑巖對成礦貢獻非常大。七寶山礦區的石英斑巖是一套高鉀(K20〉〉Na2O)、富鋁、貧硅的亞堿性的粗麵安山巖—安山巖—英安巖組閤,地毬化學上顯示瞭富輕稀土(LREE)、大離子親石元素(LILE)(Ba,K等)、成礦元素(Cu、Pb、Zn等),以及貧重稀土元素(HREE)特徵。稀土元素配分模式為右傾,有輕微的Eu負異常,說明它具有部分幔源特徵;而明顯的Sr負異常,且與地殼豐度相似,加上較高Al2O3/TiO2、K2O/Na2O比值,投圖後均顯示巖石為地殼來源。綜閤上述特徵本文認為該石英斑巖屬殼幔同鎔型花崗巖。礦體與巖體在空間、時間上關繫密切,巖體很高的成礦元素含量正是形成礦體的物質來源。其作用過程是巖漿作為載體攜帶成礦元素從地幔到近地錶,併且在各種導礦構造作用下充填交代成礦。
호남류양칠보산동다금속광상위우흠항성광대서남단,시상동북규모최대적동다금속광상,기중광구내적석영반암대성광공헌비상대。칠보산광구적석영반암시일투고갑(K20〉〉Na2O)、부려、빈규적아감성적조면안산암—안산암—영안암조합,지구화학상현시료부경희토(LREE)、대리자친석원소(LILE)(Ba,K등)、성광원소(Cu、Pb、Zn등),이급빈중희토원소(HREE)특정。희토원소배분모식위우경,유경미적Eu부이상,설명타구유부분만원특정;이명현적Sr부이상,차여지각봉도상사,가상교고Al2O3/TiO2、K2O/Na2O비치,투도후균현시암석위지각래원。종합상술특정본문인위해석영반암속각만동용형화강암。광체여암체재공간、시간상관계밀절,암체흔고적성광원소함량정시형성광체적물질래원。기작용과정시암장작위재체휴대성광원소종지만도근지표,병차재각충도광구조작용하충전교대성광。
Qibaoshan Cu-ploymetallic section of Qinzhou-Hangzhou metallogenic deposit of Liuyang, belt. And it is the Hunan province, is occurred in the southwest largest Cu-polymetallic deposit in northeastern Hunan province. The quartz-porphyry is in a very large contribution to the mineralization of the Qibaoshan Cu-polymetallic deposit. The quartz-porphyry of the ore district is consist of trachyandesite, andesite and dacite with the geochemical feature of high K (K20〉〉Na20) and Al, low Si, and is characterized by significant enrich- ments in LREE, LILE ( Ba and K ), and minerogenetic elements (Cu, Pb, Zn etc.), as well as depletion in HREE. The slight right-dip model of REE and slight Eu negative anomaly considers that the source of magma is partly from the mantle. However, clear Sr negative anomaly is so similar to the crustal source magma. Higher Al2O3/TiO2, K20/Na20 ratio than ordinary granite is indicated that quartz porphyry is mainly coming from the crust. The quartz-porphyry may be the crnst-mantle syntectic granite. The ore bodies are so close with the quartz-porphyry which is rich in ore-forming elements in space and timing is indicated that the magma may provide the metals. The process is that the magma carries ore-forming elements from the mantle to the near surface, then mineralization after filling or metasomatism in a variety of structure.