Accumulated phenocrysts and origin of feldspar porphyry in the Chanho area, western Yunnan, China

doi:10.1016/j.lithos.2009.06.034

	Accumulated phenocrysts and origin of feldspar porphyry in the Chanho area, western Yunnan, China
	Xu, Xing-Wang 1; Jiang, Neng 1; Yang, Kai 2; Zhang, Bao-Lin 1; Liang, Guang-He 1; Mao, Qian 1; Li, Jin-Xiang 1; Du, Shi-Jun 1; Ma, Yu-Guang 1; Zhang, Yong 1
刊名	LITHOS
	2009-12-01
卷号	113 期号:3-4 页码:595-611
关键词	Accumulated phenocryst Origin Porphyry Antecrysts Chanho Western Yunnan
ISSN号	0024-4937
DOI	10.1016/j.lithos.2009.06.034
文献子类	Article
英文摘要	The No. 1 feldspar porphyry in the Chanho area, western Yunnan, China is characterized by the development of deformed glomeroporphyritic aggregates (GA) that contain diagnostic gravity settling textures. These textures include interlocking curved grain boundaries caused by compaction, bent twins, and arch-like structures. The GAs are accumulated phenocrysts (AP) and antecrysts. The unstable textural configurations such as extensive penetrative microfractures that are restricted within the AP and fractured cores of zircon grains, all suggest that the GAs are transported fragments of fractured cumulates that formed in a pre-emplacement magma chamber rather than form in situ at the current intrusion site. Compositions of minerals and melt as represented by different mineral aggregates formed at various stages of the magmatic process and their relations to the composition of porphyry bodies in the Chanho area indicate that the porphyritic melt for the No. 1 feldspar porphyry experienced two stages of melt mixing. Pulses of potassic melt flowed into a pre-emplacement magma chamber and mixed with crystallizing dioritic magma containing phenocrysts resulted in the first hybrid alkaline granitic melt. The mixing caused denser phenocrysts to settle and aggregate to form cumulates. Secondly, new dioritic melt was injected into the magma chamber and was mixed with the previously formed hybrid alkaline granitic melt to produce syenitic melt. Geochron data, including U-Pb age of zircon and (39)Ar/(40)Ar age of hornblende and oligoclase phenocrysts, indicate that hornblende and oligoclase phenocrysts, as well as the core of zircon grains, were antecrysts that formed in a number of crystallization events between 36.3 and 32.78 Ma. Gravity settling of phenocrysts took place at about 33.1 to 32.78 Ma and melts with deformed GAs were transported upwards and emplaced into the current site at 32 Ma. Results of this research indicate that the No. 1 feldspar porphyry was a shallow intrusion of mixed melts that contained phenocrysts and GAs, both of which formed in a deeper transitional magma chamber. (C) 2009 Elsevier B.V. All rights reserved.
WOS关键词	U-PB GEOCHRONOLOGY ; PLAGIOCLASE PHENOCRYSTS ; YELLOWSTONE CALDERA ; LAYERED INTRUSIONS ; VOLCANIC-ROCKS ; MAGMA CHAMBER ; IGNEOUS ROCKS ; CRATER LAKE ; BEIYA AREA ; ZIRCON
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000272787200017
资助机构	CAS(kzcx2-yw-107-2) ; CAS(kzcx2-yw-107-2) ; National 973 Project(2002CB412605) ; National 973 Project(2002CB412605) ; NSFC(40572131) ; NSFC(40572131) ; CAS(kzcx2-yw-107-2) ; CAS(kzcx2-yw-107-2) ; National 973 Project(2002CB412605) ; National 973 Project(2002CB412605) ; NSFC(40572131) ; NSFC(40572131) ; CAS(kzcx2-yw-107-2) ; CAS(kzcx2-yw-107-2) ; National 973 Project(2002CB412605) ; National 973 Project(2002CB412605) ; NSFC(40572131) ; NSFC(40572131) ; CAS(kzcx2-yw-107-2) ; CAS(kzcx2-yw-107-2) ; National 973 Project(2002CB412605) ; National 973 Project(2002CB412605) ; NSFC(40572131) ; NSFC(40572131)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/70324]
专题	中国科学院地质与地球物理研究所
通讯作者	Xu, Xing-Wang
作者单位	1.Chinese Acad Sci, Key Lab Mineral Resources, Inst Geol & Geophys, Beijing 100029, Peoples R China 2.CSIRO Explorat & Ming, N Ryde, NSW, Australia
推荐引用方式 GB/T 7714	Xu, Xing-Wang,Jiang, Neng,Yang, Kai,et al. Accumulated phenocrysts and origin of feldspar porphyry in the Chanho area, western Yunnan, China[J]. LITHOS,2009,113(3-4):595-611.
APA	Xu, Xing-Wang.,Jiang, Neng.,Yang, Kai.,Zhang, Bao-Lin.,Liang, Guang-He.,...&Qin, Ke-Zhang.(2009).Accumulated phenocrysts and origin of feldspar porphyry in the Chanho area, western Yunnan, China.LITHOS,113(3-4),595-611.
MLA	Xu, Xing-Wang,et al."Accumulated phenocrysts and origin of feldspar porphyry in the Chanho area, western Yunnan, China".LITHOS 113.3-4(2009):595-611.