中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Does fractional crystallization occur in granitic magma? Some crucial questions oil granite study (2)

文献类型:期刊论文

作者Zhang, Q.; Pan, G. Q.; Li, C. D.; Jin, W. J.; Jia, X. Q.
刊名ACTA PETROLOGICA SINICA
出版日期2007-06-01
卷号23期号:6页码:1239-1251
关键词granitic magmas basaltic magmas dioritic magmas fractional crystallization harker diagrams bowen reaction series
ISSN号1000-0569
文献子类Article
英文摘要It has been well accepted that basaltic magmas are derived from the mantle and most granites are generated by fractional crystallization of basaltic magmas. The evidence for the fractional crystallization of basaltic magmas and even andesitic magmas is there is corresponding cumulate, however, cumulate is rarely associated with Si-rich granitic magmas, therefore, it is unlikely that fractional crystallization happened in granitic magmas. This is probably because (1) granitic magmas have higher viscosity such that the crystallization of minerals (i.e., plagioclase) have been obstructed to form euhedral crystals and high density minerals (i.e., hornblende) have been blocked to settle down; and (2) primary minerals (e.g., plagioclase) have similar density to that of granitic magmas. We argue that plagioclase is unlikely fractionally crystallized from granitic magmas although the process was reported in numerous literature on the basis of the Harker diagrams. We argue that the Harker diagrams are more suitable for basalts rather than granites because granites are totally different from basalts in magma source and composition. We also argue that the Bowen reaction series, the principal of the Harker diagrams, is unlikely happened to form a continuous sequence from basalt through andesite and dacite to rhyolite. The unit and super-unit mapping method of granites is not suitable for regional geological mapping. Mesozoic granites in East China and Tanncherfi granites in Morocco are taken as two examples to indicate the fractional crystallization of granitic magmas is impossible. Variable compositions of granites mainly result from the composition of magma source, temperature, pressure, volatile composition, degrees of partial melting, mixing and differentiation process. Among them the composition of magma sources is the most crucial to the diverse compositions of granite whereas fractional crystallization of granitic magmas has rarely effect on the compositional variation of granites. Therefore, the role of fractional crystallization in the evolution of granite should be appreciated in a limited scale rather than a large scale.
WOS关键词I-TYPE ; AUSTRALIA ; BELT ; PLUTON
WOS研究方向Geology
语种英语
WOS记录号WOS:000248791900002
出版者SCIENCE CHINA PRESS
源URL[http://ir.iggcas.ac.cn/handle/132A11/67472]  
专题中国科学院地质与地球物理研究所
通讯作者Zhang, Q.
作者单位1.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
2.Nanjing Univ, Dept Earth Sci, Nanjing 210093, Peoples R China
3.Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
4.Tianjin Inst Geol & Mineral Resources, Tianjin 300170, Peoples R China
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GB/T 7714
Zhang, Q.,Pan, G. Q.,Li, C. D.,et al. Does fractional crystallization occur in granitic magma? Some crucial questions oil granite study (2)[J]. ACTA PETROLOGICA SINICA,2007,23(6):1239-1251.
APA Zhang, Q.,Pan, G. Q.,Li, C. D.,Jin, W. J.,&Jia, X. Q..(2007).Does fractional crystallization occur in granitic magma? Some crucial questions oil granite study (2).ACTA PETROLOGICA SINICA,23(6),1239-1251.
MLA Zhang, Q.,et al."Does fractional crystallization occur in granitic magma? Some crucial questions oil granite study (2)".ACTA PETROLOGICA SINICA 23.6(2007):1239-1251.

入库方式: OAI收割

来源:地质与地球物理研究所

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