吉林省大石头镇北部青茶馆-元宝山花岗斑岩锆石U-Pb年龄及地球化学特征  

Zircon U-Pb ages and geochemical characteristics of the granite porphyry in Qingchaguan-Yuanbaoshan area,northern Dashitou Town,Jilin Province

作　　者：高峰[1] 魏俏巧[2] 牟静涛 邱宏[1] 于雷 马骏雨 

机构地区：[1]中国建筑材料工业地质勘查中心吉林总队,吉林长春130033 [2]吉林大学地球探测科学与技术学院,吉林长春130031

出　　处：《地质通报》2017年第11期2172-2180,共9页Geological Bulletin of China

基　　金：中国地质调查局项目<吉林1:5万东沟屯(K52E004011);黑水(K52E004012)幅区域地质矿产调查>(编号:12120114029001)

摘　　要：青茶馆-元宝山花岗斑岩具有高硅、富铝、稀土元素含量较高、相对富集轻稀土元素、亏损重稀土元素的特征,负Eu异常明显,稀土元素配分图解具有右倾"V"字形的特征,并相对富集大离子亲石元素。锆石具有典型的岩浆振荡生长环带和较高的Th/U值(0.49~1.07),反映了岩浆成因特征。测得LA-ICP-MS锆石U-Pb年龄为116.8±1.5Ma(n=13,MSWD=1.13)。以上特征表明,青茶馆-元宝山花岗斑岩为高钾钙碱性高分异I型花岗岩,为后造山花岗岩,其形成可能与古太平洋板块俯冲作用有关。The granite porphyry in Qingchaguan-Yuanbaoshan area,northern Dashitou Town,Jilin Province,is characterized by high Si O2,rich aluminum,high rare earth elements(REE) and high large ion lithophile elements(LILE).The REE patterns are characterized by enrichment of LREEs relative to HREEs and distinct negative Eu anomalies in chondrite-normalized REE patterns,with right oblique and"V"shaped feature.The zircons from the granite porphyry show oscillatory growth zonation of typical magmatic origin and high Th/U ratios(0.47~1.07),indicating a magmatic origin for the zircons. The LA-ICP-MS dating of a zircon sample yielded U-Pb age of 116.8±1.5 Ma(n=13,MSWD=1.13). These features suggest that the granite porphyry belongs to I-type granite of high potassium calc-alkaline and differentiation,being post-collisional granitoid,and its formation may be associated with the subduction of the ancient Pacific plate.

关 键 词：花岗斑岩 LA-ICP-MS锆石U-PB测年 I型花岗岩 后造山环境 

分 类 号：P597.3[天文地球—地球化学] P588.121[天文地球—地质学]