地质通报2017，Vol.36Issue(2)：209-223,15.
广西六万山印支早期花岗岩地球化学特征及锆石U-Pb年龄
Zircon U-Pb ages and geochemical characteristics of Early Indosinian Liuwanshan granites
摘要
Abstract
The Liuwanshan granites consist mainly of cordierite-bearing biotite monzogranite, which can be divided into four em-placement units according to rock structure and the emplacement relationship. LA-ICP-MS zircon U-Pb dating shows that the 206Pb/238U weighted average ages of zircons from these emplaced units are 252.8±1.9Ma(MSWD=0.92), 249.2±1.9Ma(MSWD=1.2), 248.3±3.2Ma(MSWD=2.1), and 246.8±2.8Ma(MSWD=2.2), respectively. Geochemical data reveal that these granites are characterized by enrichment of large ion lithophile elements (LILE, such as Rb and K) and relative depletion of high field strength ele-ments (HFSE, such as Nb, Ta and Ti), suggesting geochemical characteristics of typical subduction-related arc magmatic rocks. REE distribution patterns show right-inclined shape with obvious Eu negative anomaly and relative enrichment of HREE, which is consis-tent with crust-source granites distribution patterns. La-La/Sm diagram indicates that the Liuwanshan granites were mainly formed by partial melting and experienced a certain degree of fractional crystallization. Combined with petrochemical characteristics, trace ele-ments geochemeical characteristics and tectonic setting discrimination diagrams, the authors have reached the conclusion that Liuwan-shan granites were formed in a tectonic setting of early ocean-continent subduction and later continental collision.关键词
六万山/LA-ICP-MS锆石U-Pb年龄/地球化学/花岗岩成因Key words
Liuwanshan/LA-ICP-MS zircon U-Pb dating/geochemestry/genesis of granites分类
天文与地球科学引用本文复制引用
黄诚,沈睿文,南争路,傅良刚,刘胜,蔡砥柱,王慧,余杨忠..广西六万山印支早期花岗岩地球化学特征及锆石U-Pb年龄[J].地质通报,2017,36(2):209-223,15.基金项目
中国地质调查局项目《广西钦杭成矿带西段博白县、六万山幅1:5万区域地质矿产调查》(编号:12120113072000) （编号:12120113072000）
