Magma mixing for the origin of granodiorite: Geochemical, Sr-Nd isotopic and zircon Hf isotopic evidence of dioritic enclaves and host rocks from Changshannan granodiorite in the Jiaodong Peninsula, eastern China.

	Magma mixing for the origin of granodiorite: Geochemical, Sr-Nd isotopic and zircon Hf isotopic evidence of dioritic enclaves and host rocks from Changshannan granodiorite in the Jiaodong Peninsula, eastern China.
	Hu, FF ; Fan, HR ; Yang, JH ; Zhai, MG ; Jin, CW ; Xie, LW ; Yang, YH
刊名	ACTA PETROLOGICA SINICA
	2005-05-01
卷号	21 期号:3 页码:569-586
关键词	Microdioritic Enclave Granodiorite Geochemistry Zircon Hf-isotope Magma Mixing Changshannan Jiaodong Peninsula
ISSN号	1000-0569
文献子类	Article
英文摘要	A large number of directional microgranular dioritic enclaves occur in Changshannan granodiorite from Kunyushan granitoids in the Jiaodong Peninsula, eastern China. Microgranular dioritic enclaves, commonly showing ellipsoidal and spindled shapes, display igneous textures and range from meter- to centimeter-sized fragments. The enclaves are darker-colored and finer-grained than their hosting granodiorite, and exhibit a very similar mineralogy to those of their granitic hosts. The enclaves have higher contents of ferro-magnesian phases and plagioclase, and lower contents of quartz and K-feldspar than those found in the hosting granodiorite. The chemical composition of biotite and hornblende within the dioritic enclaves is mostly similar to those of the same phases found in the host granodiorite, but the mineralogy display obvious disequilibrium structure. Acicular apatite is common in the enclaves. Those observations suggest that the enclaves are derived from a hybrid-magma formed as a result the intrusion of a mafic magma into the base of a felsic magma chamber. Geochemical data show dioritic enclaves and hosting granodiorite are enriched in LILEs and LREEs and depleted in HFSEs. Enclaves and hosting granodiorite, similar in Sr- and Nd- isotopic compositions, have low initial Sr-87/Sr-86 ratios (0.70784 similar to 0.70818) and negative epsilon(Nd) (t) values ( -15.0 similar to -15.5), and display a trend characterized by a linear Correlation between major elements. Petrological and zircon Hf isotopic features indicate the occurrence of magma mixing between mafic magma and felsic magma in the original processes of Changsharman granodiorite. During the magma mixing, the Sr and Nd isotope and later crystallized minerals can much quickly homogenize, but major element and Hf isotope of high temperature mineral such as zircon have preserved some information of the primary magmas. The results indicate that although magma mixing has produced similar Sr and Nd isotopic compositions in the enclaves and the hosting granodiorite, the zircon Hf isotope has not easily reached equilibrium and has more effectively traced the hybrid-magma sources and the magma mixing processes.
WOS关键词	LACHLAN FOLD BELT ; MICROGRANITOID ENCLAVES ; LU-HF ; SOUTHEAST AUSTRALIA ; GOLD MINERALIZATION ; MAFIC ENCLAVES ; SIERRA-NEVADA ; SM-ND ; MANTLE ; GRANITOIDS
WOS研究方向	Geology
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000231179000002
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/64804]
专题	中国科学院地质与地球物理研究所
通讯作者	Hu, FF
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Hu, FF,Fan, HR,Yang, JH,et al. Magma mixing for the origin of granodiorite: Geochemical, Sr-Nd isotopic and zircon Hf isotopic evidence of dioritic enclaves and host rocks from Changshannan granodiorite in the Jiaodong Peninsula, eastern China.[J]. ACTA PETROLOGICA SINICA,2005,21(3):569-586.
APA	Hu, FF.,Fan, HR.,Yang, JH.,Zhai, MG.,Jin, CW.,...&Yang, YH.(2005).Magma mixing for the origin of granodiorite: Geochemical, Sr-Nd isotopic and zircon Hf isotopic evidence of dioritic enclaves and host rocks from Changshannan granodiorite in the Jiaodong Peninsula, eastern China..ACTA PETROLOGICA SINICA,21(3),569-586.
MLA	Hu, FF,et al."Magma mixing for the origin of granodiorite: Geochemical, Sr-Nd isotopic and zircon Hf isotopic evidence of dioritic enclaves and host rocks from Changshannan granodiorite in the Jiaodong Peninsula, eastern China.".ACTA PETROLOGICA SINICA 21.3(2005):569-586.