中国地质2012，Vol.39Issue(6)：1670-1689,20.
粤西大金山花岗岩体地球化学特征及岩石成因探讨
Geochemical features and petrogenesis of the Dajinshan granites in west Guangdong Province
摘要
Abstract
This paper aims at reporting the petrology and the geochemistry of the buried granite stock in Dajinshan area, which is composed mainly of medium to fine grained biotitic granitic rock and porphyritic biotic granitic rock. These granites are characterized by richness of silica and alkali and depletion of magnesium and calcium. In this study, all samples from Dajinshan are high-K calc-alkaline rocks, which are enriched in Rb, Th, U and depleted in Nb, Eu, Ti in the primitive mantle-normalized spidergrams. The REE values of medium to fine grained biotite granite and porphyritic biotite granite are 203.36×10-6～248.42×10-6 and 243.76×10-6～255.08× 10-6 respectively. The medium to fine grained biotite granite body is slightly enriched in HREE whereas the porphyritic biotite granite is enriched in LREE. They all show prominent negative Eu anomalies with 8Eu values being 0.004～0.009 and 0.059～0.13. The ε Hf (t) values and two-stage Hf model ages of medium to fine grained biotite granite and porphyritic biotite granite are-2.05～-8.64,-0.92～-6.57 and 1277～1692Ma, 1204～1556Ma, respectively. Based on regional geological and granite geochemical data, it can be concluded that the Dajinshan granites were derived from the partial melting of the Mesoproterozioc continental crust under a crustal extension geodynamic setting during the Late Yanshanian period.关键词
地球化学/Sr-Nd-Pb-Hf同位素/岩石成因/大金山花岗岩体Key words
geochemistry/Sr-Nd-Pb-Hf isotope/petrogenesis/Dajinshan granite分类
天文与地球科学引用本文复制引用
余长发,赵海杰,陈懋弘,罗大略,王志华..粤西大金山花岗岩体地球化学特征及岩石成因探讨[J].中国地质,2012,39(6):1670-1689,20.基金项目
国家自然科学基金项目(40930419)、国家重点基础研究发展计划973课题(2012CB416704)和中国地质调查局地质调查工作项目(1212011120831)联合资助. （40930419）
