地质科技情报2018，Vol.37Issue(1)：79-87,9.DOI:10.19509/j.cnki.dzkq.2018.0111
北秦岭宝鸡地区早志留世鸡冠崖高分异碰撞型花岗岩年龄、地球化学特征及地质意义
Age and Geochemical Features of the Early Silurian Jiguanya Highly Fractionated Syn-collisional Granites in the Baoji Area of North Qinling Orogen and Their Geological Significance
摘要
Abstract
Jiguanya granite is located in Baoji area of North Qinling Orogen,and its LA-ICP-MS zircon U-Pb geochronological and petrogeochemical data are determined in this paper.The results show that the zircon 206pb/238pb weighted average age of Jiguanya granite is (435±2) Ma (MSWD=0.13,n=22),indicating that the granite formed in Early Silurian.Jiguanya granite has high SiO2 (72.770-77.71％),K2O (3.51％-6.32％),and low Fe2O3T(0.71％-1.30％,Fe2O3T/MgO=2.71-7.29),MgO(0.14％-0.31％) and P2O5 (0.05％-0.10％) contents,and belongs to calc-alkaline series with metaluminous/peraluminous feature (A/CNK=0.94-1.10,AR=2.95-4.10).In addition,the graniteis poor in total REE contents (32× 10-6-102× 10-6),with obvious Eu anomalies (δEu=0.22-13.83).The trace elements show the enrichment in Rb,U,Th,Nd,Zr and Hf,and the depletion in Ba,Nb,Ce,P and Ti,with geochemical characteristics of the highly fractionated syn-collisional granites.Combined with regional data,the Jiguanya granite was formed in the syn-orogenic tectonic setting,and derived from partial melting of low crust materials.关键词
鸡冠崖花岗岩/宝鸡地区/北秦岭造山带/碰撞型花岗岩/早志留世Key words
Jiguanya granite/Baoji area/North Qinling Orogen/syn-collisional granite/Early Silurian分类
天文与地球科学引用本文复制引用
徐通,郭歧明,陈清敏,王强,张拴厚,左文乾,任仓智..北秦岭宝鸡地区早志留世鸡冠崖高分异碰撞型花岗岩年龄、地球化学特征及地质意义[J].地质科技情报,2018,37(1):79-87,9.基金项目
陕西省公益性地勘专项项目(20130301) （20130301）
