南岭地区与金矿有关岩浆岩成矿专属性初探  

Metallogenic Specialization of the Magmatic Rocks Associated with Gold Deposits in the Nanling Region

作　　者：王成辉[1] 刘善宝[1] 郭春丽[1] 黄凡[1] 陈振宇[1] 陈郑辉[1] 应立娟[1] 

机构地区：[1]国土资源部成矿作用与资源评价重点实验室中国地质科学院矿产资源研究所,北京100037

出　　处：《大地构造与成矿学》2014年第2期276-288,共13页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(批准号:41202025);中央级公益性科研院所基本科研业务费项目(编号:K1325);中国地质大调查项目“南岭地区岩浆岩成矿专属性研究”(编号:1212011120989)、“中国矿产地质与区域成矿规律总结”(编号:1212011220369)资助

摘　　要：南岭地区,尤其是赣南粤北地区,以富产钨锡钼铋等有色金属矿床著称,贵金属不是很发育,特别是金矿床不多,但南岭周边地区金矿不少。究竟是什么原因,导致这两类金属矿的空间产出差异？这一问题日益引起重视。本文初步总结了南岭地区与金矿具有较明显成因联系的岩浆岩的地质特征及地球化学特点,并与成钨锡矿岩浆岩进行了初步对比,探讨了该类岩浆岩的起源特征。研究表明,与金成矿有关的岩浆岩一般为浅成的中性、中酸性岩,通常呈岩株、岩筒或岩脉产出。在地球化学特征上, SiO2含量较低,变化在51.42%~68.59%之间,具有低分异特点；全碱含量较低, K2O＋Na2O一般＜7%, K2O〉Na2O, A/CNK值较小,一般为准铝-弱过铝质高钾钙碱性系列岩石；高CaO、MgO、FeO＋Fe2O3、TiO2。以富集亲铁元素和亏损Nb、Ta、Ba、Sr、Ti、P等元素为特征；LREE/HREE比值大；Eu亏损不强烈或略有亏损。上述特征显示,与金矿有关岩浆岩和与钨锡矿有关岩浆岩明显不同,其在起源方面具有多来源的特点,壳幔相互作用明显,多来源多演化可能正是其成金的重要条件。The Nanling region in South China is one of the most important nonferrous producing districts in the world, where the noble metals （especially gold） deposits are not common. However, there are lots of gold deposits in areas adjacent to the Nanling region. What factors caused the regional difference in nonferrous and noble metals deposits distribution？ Focus on the relationship between gold deposits and magmatic rocks, this paper summarizes the geological and geochemical characteristics of the magmatic rocks and makes a preliminary comparison with the magmatic rocks associated with tungsten-tin deposits. The study indicates that the rocks associated with gold deposits are intermediate and intermediate-acidic, hypabyssal, usually in the forms of stocks, dikes, and rock pipes. And the rocks are characterized by low SiO2 （51.42%-68.59%）, and low magmatic differentiation （DINa2O） and belong to high-K calc-alkaline series, metaluminous to peraluminous. Additionally, the rocks are enriched in CaO, MgO, FeO＋Fe2O3, TiO2 and some siderophile elements, depleted in Nb、Ta、Ba、Sr、Ti and P. The rocks are characterized by relatively enriched in LREE with negative or weakly negative Eu anomalies. Apparently, the geochemical characteristics of the magmatic rocks associated with gold deposits are different from those of the rocks associated with tungsten-tin deposits. It is reasonable to suggest that the magmatic rocks associated with gold deposits are multiple sources with crust-mantle interaction.

关 键 词：南岭地区 金矿 岩浆岩 成矿专属性 

分 类 号：P617[天文地球—矿床学] P59[天文地球—地质学]