岩石矿物学杂志2018，Vol.37Issue(2)：175-196,22.
赣南珠兰埠复式岩体成因及其构造意义
Petrogenesis of the Zhulanbu composite pluton and its implications for tectonic setting
摘要
Abstract
There are two composite plutons,Fucheng and Zhulanbu,emplaced in the Huichang region of the northern Nanling Mountains.Nevertheless,very insufficient researches have been conducted on the Zhulanbu composite pluton,and its age and petrogenesis remain problems of much controversy.The Zhulanbu composite pluton consists of early intrusive coarse-grained biotite mozonite and late intrusive fine-grained mozonite,and LA-ICP-MS zircon dating suggests that they were formed in Indosinian (228 Ma) and Late Yanshanian (135 ～133 Ma),respectively;however,the Fucheng composite pluton was emplaced in Indosinian.Chemical analyses of major and trace elements indicate that both the early and late granitic intrusive bodies of the Zhulanbu composite pluton are characterized by intermediate-strong peraluminous nature,high content of Si,A1,K,low content of Ca,Mg,enrichment of Rb,Th,U,and depletion of Sr,Ba,P,Ti,Eu.They also have lower ∑REE (＜ 165 × 10-6 on average) and Zr + Nb + Ce + Y content (＜ 350 × 10-6).These geochemical characteristics suggest S-type granites.The whole rock SrNd isotopic analysis results show that the early intrusive granite exhibits higher (87Sr/86Sr) i than the late counterparts (0.715 6 ～0.726 0 and 0.710 5 ～ 0.716 4,respectively),but they exhibit the same variation of εNd(t)values (ranging from-10.0 to-7.0).Zircon in-situ Lu-Hf isotopic analysis indicates their similarities of εHf(t)values (-12.9 ～-7.7 and-15.1 ～-10.5,respectively) and tCDM(2.0 ～ 1.7 Ga and 2.1 ～ 1.8 Ga,respectively).The elemental and isotopic results suggest that the Zhulanbu composite pluton probably originated from the partial melting of a mixed crustal source involving the Paleoproterozoic metapelite and minor metagreywacke.The Fucheng composite pluton and the early intrusive granite of Zhulanbu composite pluton were formed in a compressive background of the Tethys tectonic domain during the Indosinian;in contrast,the late intrusive granite of Zhulanbu composite pluton was formed in the intraplate extensional environment of the paleo-Pacific tectonic domain during the Yanshanian period.关键词
珠兰埠复式岩体/S型花岗岩/Sr-Nd-Hf同位素/岩石成因/印支期/燕山期Key words
Zhulanbu composite pluton/S-type granite/Sr-Nd-Hf isotopes/petrogenesis/Indosinian/Yanshanian分类
天文与地球科学引用本文复制引用
王洪作,赵友东,陈培荣,凌洪飞,吴俊奇..赣南珠兰埠复式岩体成因及其构造意义[J].岩石矿物学杂志,2018,37(2):175-196,22.基金项目
国家自然科学基金青年基金(41703042) （41703042）
南京大学内生金属矿床成矿机制研究国家重点实验室开放基金(2017-LAMD-K06) Natural Science Foundation of China Youth Fund(41703042) （2017-LAMD-K06）
Open Fund of State Key Laboratory for Mineral Deposits Research,Nanjing University(2017-LAMD-K06) （2017-LAMD-K06）
