黑龙江先锋北山金矿区花岗闪长斑岩和石英闪长玢岩年代学及地质意义  

Chronology of granodiorite porphyry and diorite porphyry in Xianfengbeishan gold deposit of Heilongjiang,and their tectonic implications

作　　者：王庆双[1] 杨言辰[1] 张颖[2] 韦延兰 张国宾[4] 张富程[1] 

机构地区：[1]吉林大学地球科学学院,长春130061 [2]吉林大学东北亚国际地学研究与教学中心,长春130026 [3]中国地质科学研究院岩溶地质研究所,广西桂林541004 [4]辽宁工程技术大学矿业学院,辽宁阜新123000

出　　处：《世界地质》2015年第1期67-77,共11页World Geology

基　　金：中国地质调查局地质调查项目(1212011120342;12120113098300)

摘　　要：先锋北山金矿区内侵入脉岩为花岗闪长斑岩和石英闪长玢岩。花岗闪长斑岩具有高硅、富碱、富钙和贫镁等特征;轻稀土元素(LREE)相对富集,重稀土元素(HREE)相对亏损,无明显铕异常;富集大离子亲石元素(LILE)Rb、Th、K,亏损高场强元素(HFSE)Nb、Ta、P、Ti等,地球化学特征显示其属于过铝质钙碱性I型花岗岩。矿区石英闪长玢岩具有富碱、富镁和贫磷等特征,轻稀土元素(LREE)相对富集,重稀土元素(HREE)相对亏损,无铕异常;富集大离子亲石元素(LILE)Rb、Th,K等,亏损高场强元素(HFSE)Nb、Ta、P、Ti等。地球化学特征显示其属于准铝质高钾钙碱性岩石。花岗闪长斑岩及石英闪长玢岩的La--ICP--MS U--Pb同位素测年结果分别为128.3±2.6 Ma和113.2±1.7 Ma,为早白垩世。结合完达山地区地质资料,认为先锋北山花岗闪长斑岩和石英闪长玢岩是古太平洋板块构造体制由挤压变为伸展背景下的产物。Granodiorite porphyry and diorite porphyry exposed in the Xianfengbeishan gold deposit. The authors studied the chronology of the dikes and the tectonic setting. The results indicate that the granodiorite porphyry was emplaced in the Early Cretaceous with age of 128. 3 ± 2. 6 Ma,belonging to peraluminous medium-K calc-alkaline I-type granites,and display characteristics of high silicon,alkali and calcium and low magnesium.They are enriched in light rare earth elements（ LREEs） and large ion lithophile elements（ LILEs; e. g. Rb,Th,K）,and depleted in heavy rare earth elements（ HREEs） high field strength elements（ HFSEs; e. g. Nb,Ta,Pand Ti） with on obvious Eu anomalies. Meanwhile,the diorite porphyry was emplaced in the Early Cretaceous with age of 113. 2 ± 1. 7 Ma,belonging to metaluminous high- K calc-alkaline rocks,and featured by high alkali and magnesium and low phosphorus. They are characterized by enrichment in light rare earth elements（ LREEs） and large ion lithophile elements（ LILEs; e. g. Rb,Th,K）,depletion in heavy rare earth elements（ HREEs） high field strength elements（ HFSEs; e. g. Nb,Ta,P and Ti） with on Eu anomalies. Based on the geological data in the Wandashan region,it is proposed that the granodiorite porphyry and diorite porphyry from the Xianfengbeishan were emplaced in a transformation setting from convergence to extension,which was closely related to the subduction of the Paleo-Pacific Oceanic plate and the amalgamation of the Jiamusi and Wandashan blocks.

关 键 词：先锋北山 花岗闪长斑岩 石英闪长玢岩 锆石U-PB年龄 I型花岗岩 

分 类 号：P597[天文地球—地球化学]