地质论评2011，Vol.57Issue(6)：837-850,14.
云南个旧白沙冲和北炮台花岗岩岩石学、地球化学研究及成因探讨
Petrology, Geochemistry and Petrogenesis of the Baishachong and Beipaotai Granitic Stocks in Gejiu, Yunnan Province, Southwest China
摘要
Abstract
The Baishachong and Beipaotai granites are both located in the eastern part of the Gejiu orefield, Yunnan province. In lithology, the Baishachong granite is mainly equigranular biotite granite, whereas the Beipaotai granite is mainly porphyritic biotite granite. In this paper, a systematic petrological, geochemical, and Nd, Sr isotopic study is carried out. On the basis of previous zircon SHRIMP dating, combing the new data obtained in this study, the characteristics, evolution and petrogenesis of the two granitic stocks are documented. The results show that the Baishachong granite is a high-K calc-alkaline peraluminous granite while the Beipaotai granite belongs to shoshonitic metaluminous granite. Both of the Baishachong and the Beipaotai granitiods are enriched in Rb, Pb and U; and depleted in Ba, Sr, Nb, P and Ti. The Baishachong granite shows a lower 2REE, but stronger negative 8Eu anomaly than the Beipaotai granite. What' s more, the Baishachong granite reflects a tetrad-like effect with a shape of " M". Nd isotopic compositions suggest that the source of both the Baishachong and the Beipaotai granites are mainly derived in the crustal. Geochemical characteristics imply that both the Baishachong and the Beipaotai granites experienced a crystal fractionation process, while compared with the Beipaotai granite, the Baishachong granite experienced much stronger fractionated evolution process. The data of the Cretaceous granites around the Youjiang depression area located in southeastern Yunnan and western Guangxi Provinces, western South China, indicate that the granitic magmatism might be related to the lithospheric extension of the South China Block in late Mesozoic.关键词
花岗岩体/岩石学/岩石化学/Nd、Sr同位素/个旧/云南Key words
granite/petrology/petrochemistry/Nd, Sr isotopes/Gejiu orefield/Yunnan Province引用本文复制引用
李肖龙,毛景文,程彦博..云南个旧白沙冲和北炮台花岗岩岩石学、地球化学研究及成因探讨[J].地质论评,2011,57(6):837-850,14.基金项目
本文为国家自然科学基金重点项目(编号40930419)、国土资源部公益性行业科研专项(编号200911007-12)、云南锡业集团有限责任公司科研项目(编号2010-04A)和中央高校基本科研业务费专项资金资助项目(编号2-9-2010-21)的成果. （编号40930419）
