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	Mixing and mingling in petrogenesis of the Fangshan intrusion, Beijing.
	Qin Feng; Xu XiaoXia; Luo ZhaoHua
发表日期	2006
ISSN	1000-0569
EISSN	2095-8927
起始页码	2957
结束页码	2970
卷号	22 期号:12 页码:2723-2723
英文摘要	The Fangshan intrusion is mainly composed of a quartz monzodiorite unit and three granodiorite units with different structures. Macroscopic characteristics such as ubiquitous mafic microgranular enclaves, linear bands rich in mafic minerals, and the contact relationships between adjacent petrographic units indicate that the origin of the pluton is closely related to magma mixing. The electron mieroprobe profiles consisting of 122 plagioclase compositional points illustrate the range of An with a population mean of An29 (oligoclase). However, the plagioclases show an extremely wide range of compositional variation ( An = 14 similar to 56), and different parts of a plagioclase crystal exhibit rather different composition. The normal zone of the plagioclase has a lower An content (14 similar to 42), while the An content of the spike is much higher (24 similar to 56), indicating the participation of Ca-rich basic magma. The An amounts of the plagioclase crystals decrease gradually from the early to the late stages. However, the compositional ranges of plagioclases in the adjacent overlap one on another, implying the compositional control of plagioclases in different units by magma compositions instead of fractional crystallization. Plagioclase's oscillatory zone, especially the growth of spike, is powerful evidence of the magma mixing. The repeating injections of mafic magma not only modified the chemistry of host magma, but controlled its temperature, emplacement and structure futures of the rocks. Therefore, instead of fractional crystallization, the processes to form Fangshan intrusion include a history of multiple magma injections, and the effect of basic magma on the units granularly decreased from the outer to the inner.
关键词	CRYSTALLIZATION HISTORY PLAGIOCLASE MAGMA GRANITE TEXTURES ORIGIN ROCKS DISEQUILIBRIUM EMPLACEMENT DIFFUSION
英文关键词	Fangshan intrusion; granite; dusty zone; plagioclase; mafic microgranular enclave; electron microprobe analyze
语种	英语
WOS研究方向	Geology
WOS类目	Geology
WOS记录号	WOS:000245660400013
来源期刊	ACTA PETROLOGICA SINICA
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/556
推荐引用方式 GB/T 7714	Qin Feng,Xu XiaoXia,Luo ZhaoHua. Mixing and mingling in petrogenesis of the Fangshan intrusion, Beijing.[J]. 中国科学院青藏高原研究所,2006,22(12):2723-2723.
APA	Qin Feng,Xu XiaoXia,&Luo ZhaoHua.(2006).Mixing and mingling in petrogenesis of the Fangshan intrusion, Beijing..ACTA PETROLOGICA SINICA,22(12),2723-2723.
MLA	Qin Feng,et al."Mixing and mingling in petrogenesis of the Fangshan intrusion, Beijing.".ACTA PETROLOGICA SINICA 22.12(2006):2723-2723.