云南新平大红山铁铜矿床地球化学特征及找矿分析

【作者】 廖声林；

【导师】 李俊；

【作者基本信息】 昆明理工大学 ， 构造地质学， 2009， 硕士

【摘要】 大红山铁铜矿区位于云南省新平县戛洒、老厂、新化三乡(镇)的交界部位,以赋存“大红山式铜、铁矿”和铜铁资源高度集中而全国闻名。大红山铜矿的生产规模虽然在不断扩大,但矿山隐伏的资源危机已逐渐显现。因此,进一步加强大红山铜矿的矿床地球化学特征的研究,为下一步大红山铜矿开展深—边部和外围找矿工作奠定基础,显得十分必要和紧迫。本论文以科研项目《云南省新平县大红山铜矿深—边部及外围成矿预测》为依托,在分析研究前人资料的基础上,经现场地质调查,采集岩、矿石标本和样品,通过对样品的分析测试及其综合研究,获得了以下认识和成果：1、常量元素化学特征。区内矿石与围岩在常量元素组成上并没有明显的差异,说明大红山铜矿床的矿石与围岩具有近似或相同的形成条件和环境。2、微量元素地球化学特征。围岩与含矿层的富集元素基本相同,后者的Cu、Mn、Co相对更富集,说明两者在微量元素种类及其组合上存在一致性,但富集顺序不尽一致,可能存在环境的变异性,受成岩期成矿影响的结果,使元素富集顺序改变。3、稀土元素地球化学特征。大红山群含矿岩系稀土总量普遍较低,∑REE含量为47.4-2811ppm,且明显富集轻稀土,LREE/HREE比值为1.17-9.18,钇族稀土含量相对较低,铈族稀土相对含量较高,属轻稀土富集型,其(La/Yb)比值均>1(DT-5为0.91),介于1.07-8.8之间。4、同位素地球化学特征。(1)铅同位素：据大红山铜矿床的11个铅同位素数据说明,这种铅显然是不同源的,是在不同u和(ω)值环境中演化、不同时间形成的混合铅。(2)硫同位素：大红山铜矿床硫化物的硫同位素测定结果表明,铜矿床硫化物的硫同位素组成-3.4-12.41‰,大多数为正值。大红山铁矿的硫同位素组成也和大红山铜矿床硫同位素一样,是非平衡状态形成,硫也可能是火山与海水两种来源的硫混合而成。(3)氢、氧同位素：从获得的大红山式铜矿床3件石英,1件方解石和1件石榴子石的δ18O (SMOW)和δD数据看,矿物的δ18O值在9.12-13.48%之间,表明成矿热液有岩浆水、变质水和大气降水参与流动,愈到成矿晚期大气降水的作用愈明显。。(4)K/Ar同位素年龄。从已有K/Ar和本次获得的K/Ar同位素年龄来看,平均主要集中在8.00Ma±20,530-590 Ma±20,300-366±7Ma,表明K/Ar同位素年龄反映的是“大红山式”铜铁矿床后期变质改造的事件,不代表原岩的同位素年龄,代表了晋宁运动期间火山作用、变质作用及铀矿化的时间,也是大红山铜矿床的改造年龄。5、找矿有利度分析。根据成矿系列的观点,用地理信息系统分层次进行预测,共圈定了找矿有利地段5处。其中：Ⅰ级找矿有利地段2处,Ⅱ级找矿有利地段3处。更多还原

【Abstract】 Dahongshan copper area locates in the Junction site of Gasa county, Laochang county and Xinhua in Xinping, Yunnan. It’s well-known as high concentration of copper and iron resources. Though the yielding scale of Dahongshan copper is increasing, the mine has been gradually emerging resource crisis. Therefore, further strengthening the Dahongshan geochemical characteristics of copper deposits"in the study for further development of deep Dahongshan copper-edge and peripheral lay the foundation for the work of prospecting, it is extremely necessary and urgent.This paper has scientific research "Dahongshan Xinping County, Yunnan Copper Mine-edge and external ore project," Relying on the analysis of research data on the basis of their predecessors, after on-site geological survey, collecting rocks, minerals specimens and samples. Through the analysis of test samples and its integrated research, awareness and access to the following results:1. Constant element chemical characteristics. Ore zone with the constant element in the composition of rock, and there is no significant difference, indicating Dahongshan copper deposits of ore and rock formation with a similar or identical conditions and environment.2. Trace element geochemistry. Surrounding rock and the enrichment of ore bed containing the same elements, the latter Cu, Mn, Co relatively more enriched in trace elements shows that both types and combinations there consistency, but the enrichment of the order are not consistent, there may be environmental variability, subject to the results of the impact of diagenetic mineralization period, so that changes in the order of element enrichment.3. Rare earth elements geochemistry. The Red Hills of total rare earth ore-bearing rocks is generally low, SREE content of 47.4-281ppm, and markedly enriched light REE, LREE/HREE ratio is 1.17-9.18, Y family of rare earth content is relatively low, the relative content of rare earth cerium family high, are LREE-enriched type, the (La/Yb) ratios were> 1 (DT-5 is 0.91), ranging between 1.07-8.8.4.Isotope geochemistry. (1) Lead isotope:It Dahongshan copper bed 11 lead isotope data suggest that this lead is obviously different sources at differentμand (ω) the value of the environment in the evolution of the formation of mixed lead at different times. (2) sulfur isotopes:Dahongshan sulphide copper deposits of sulfur isotopic results show that the copper deposits of sulfide sulfur isotopic composition of-3.4-12.41‰, most of them positive. Dahongshan sulfur isotopic composition of iron ore and copper deposits of sulfur isotopes Dahongshan as a non-equilibrium formation of volcanic sulfur may also be two sources of sulfur and seawater mixture. (3), hydrogen and oxygen isotopes:From the get-type copper deposit Dahongshan 3 quartz, calcite, and a garnet one of d180 (SMOW), and dD data shows that the mineral d180 values between 9.12-13.48%, indicating that ore-forming hydro thermal there magmatic water, metamorphic water and meteoric water involved in movement, the more to the ore-forming role of precipitation in the more advanced significantly. (4) K/Ar isotopic age. From the existing K/Ar and the current obtained K/Ar isotopic age shows that on average mainly in 800Ma±20,530-590 Ma±20,300-366±7Ma, that K/Ar isotopic ages reflects " Dahongshan-style "post-metamorphic transformation of iron and copper deposits of the event, does not mean that the original rock isotopic ages, representing Jinning campaign period volcanism, metamorphism and uranium mineralization of the time, is a large copper deposit in the transformation of the Hongshan age.5. Benefit Analysis. According to metallogenic series point of view, using geographic information systems at different levels to predict a total of delineation of the ore-finding area 5. Of which:I grade ore-finding area 2, II grade ore-finding area 3.更多还原