粤西天堂铜多金属矿床斑岩地球化学特征分析  

Analysis on Geochemical Characteristics of Porphyry in Tiantang Copper Polymetallic Deposit,Western Guangdong Province

作　　者：梁锦[1,2] 李强强[1] 周永章[1,2] 李红中[2,3] 马占武[4] 

机构地区：[1]中山大学地球科学系,广东广州510275 [2]广东省地质过程与矿产资源探查重点实验室,广东广州510275 [3]中国科学院地质与地球物理研究所,北京100029 [4]北方民族大学土木工程学院,宁夏银川750021

出　　处：《金属矿山》2014年第4期125-128,共4页Metal Mine

基　　金：中国地质调查局项目(编号:1212011085412)

摘　　要：通过对粤西天堂铜多金属矿床的二长花岗斑岩进行地球化学分析，结果显示其常量元素中SiO2含量为69．92％～76．06％，平均为74．03％，Al2O3含量为12．76％-15．34％，平均为13．53％，K2O含量为4．37％-7．48％，平均为5．64％，岩石的A／CNK值平均为1．10，A／NK值平均为1．31，这些特征表明天堂矿区斑岩为高硅、高碱、富铝的过铝质高钾钙碱性系列的二长花岗斑岩。天堂矿区斑岩的微量元素Rb含量平均为396．36×10^-6，Ba平均为343．76×10^-6，Sr平均为103．30×10^-6。经原始地幔标准化，该斑岩的微量元素蛛网图表现为富集Rb、K、Th、u，强烈亏损Ba、Sr、P、Ti。该斑岩的稀土总量平均为245．36×10^-6，轻重稀土元素含量比值平均为9．87，δLa／δYb值平均为3．50，δEu值平均为0．28。经球粒陨石标准化，天堂矿区斑岩的稀土配分曲线图上总体显示为右倾且强烈Eu负异常。微量元素δRb-δ（Y＋Yb）、δRb-δ（Yb＋Ta）判别图示踪结果指示天堂样品吻合syn—COLG（同碰撞花岗岩）特征，推测为陆陆碰撞后续演化的产物。The geochemical characteristics of the monzonitic granite porphyries in Tiantang copper polymetallic deposit in western Guangdong province, are analyzed. According to the analysis results, contents of SiO2 are 69. 92% - 76. 06% with the average value at 74. 03% ,contents of Al2O3 are 12. 76% - 15.34% with the average value at 13.53% ,and contents of K20 are 4. 37% - 7.48% with the average value at 5.64%. The mean values of A/CNK and A/NK are 1.10 and 1.31 respectively. The above geochemical characteristics indicated that the porphyries in Tiantang copper deposit are the peraluminous high-K calcalkaline series of monzonitic granite porphyry that are enriched in silicon and aluminum with high alkalinity. Trace elements of the porphyry in Tiantang Mining area such as Rb, Ba, Sr, average content values of them are 396. 36×10^-6, 343.76×10^-6,103.30×10^-6 respectively. Normalized by the trace element of primitive mantle, these porphyries are exhibited enrichment of Rb, K, Th, U and strong loss of Ba, Sr, P, Ti. The average Y. REE value of the porphyries in Tiantang mining area is 245.36×10^-6,the average value of LREE/HREE is 9. 87 ,the average values of δLa/δYb and δEu are 3.50 and 0. 28 respectively. Normalized by the REE of chondrite, REE distribution diagrams of the porphyries in Tiantang mining area have the fight trend and strong negative Eu anomaly. According to the discrimination diagrams of δRb-δ（ Y ＋ Yb） and δRb-δ（ Yb ＋ Ta）, the characteristics of these porphyries samples in Tiangtang mining area are identical with that of syn-COLG（ collision of granite）. It is speculated that, the porphyries in Tiantang mining area are the products of the subsequent evolution of continental collision.

关 键 词：天堂地区 铜矿床 斑岩 地球化学 

分 类 号：P595[天文地球—地球化学]