摘要
本文根据华南含钨锡花岗岩的稀土元素分布特征,将花岗岩分为四类,即稀土正常型,轻稀土富集型,重稀土富集型和稀土亏损型,并从稀土元素地球化学角度讨论了四类岩石的成因问题。
In terms of REE geochemical characteristics the tin/tungsten-bearing granites of transformation series or S-type in South China can be subdivided into four distribution patterns: (1)REE-normal type, characterized by ΣREE=250-50ppm, ΣCe/ΣY≥1 and δ Eu<0.4, and examplified by Hukeng, Denbuxian, Huashan, Dajishan and Huangsha granites; (2)Light REE-enriched type, characterized by ΣREE>250ppm, ΣCe/ΣY>6, and examplified by Malage gra- nite: (3) Heavy REE-enriched type, characterized by ΣREE>250 ppm and ΣCe/ΣY<0.15, and examplified by Xihuashan, Yinyan and Xishan granites; (4) REE-depleted type, characterized by ΣREE<50 ppm and examplified by Yashan and Limu granites. These geneses can be interpreted as caused by different histories in the formation and evolution of granitic magma. These features result from the differences in nature of source rocks and their initial REE background, degree of partial melting, completeness of deep-seated differentiation in the magmatic chamber and in-situ differentiation at higher levels after their emplacement, remelting of underlying crystalline basement and younger granitic rocks which had not been completely consolidated and effects of F, CO_2 and other volatile components. A combination of these factors might account for the geneses of Sn/W-bearing granites.
出处
《矿床地质》
CAS
CSCD
北大核心
1989年第3期21-31,共11页
Mineral Deposits
