Pyroxene exsolution in mafic granulites from the Grove Mountains, East;Antarctica: constraints on Pan-African metamorphic conditions

doi:10.1127/0935-1221/2003/0015-0055

	Pyroxene exsolution in mafic granulites from the Grove Mountains, East;Antarctica: constraints on Pan-African metamorphic conditions
	Liu, XC 5; Zhao, ZR ; Zhao, Y ; Chen, J ; Liu, XH
刊名	EUROPEAN JOURNAL OF MINERALOGY
	2003
卷号	15 期号:1 页码:55-65
关键词	pyroxene exsolution inverted pigeonite mafic granulite metamorphic conditions Pan-African Grove Mountains
ISSN号	0935-1221
DOI	10.1127/0935-1221/2003/0015-0055
英文摘要	Exsolution textures were observed in clinopyroxenes in mafic granulites from the Grove Mountains, East Antarctica. The first generation of exsolution occurs only in subcalcic augite megacrysts, in which coarse orthopyroxene lamellae exsolved parallel to the (100) plane. Electron microprobe reintegration of such augites yields a pre-metamorphic igneous temperature of ca. 970degreesC. The second generation of exsolution develops in both igneous and metamorphic clinopyroxenes. In metamorphic clinopyroxenes, two sets of very narrow pigeonite lamellae, subsequently inverted to orthopyroxene, exsolved parallel to (100) and (001) planes, respectively with 0degrees and 113degrees deviation to c-axis of the host. A peak metamorphic temperature of ca. 850degreesC was obtained from the reintegrated compositions of exsolved clinopyroxene, and an exsolution temperature of 740-770degreesC from the orientations of exsolved lamellae.;The preservation of augite megacrysts and appearance of equilibrium assemblages suggests that mafic granulites from the Grove Mountains were formed during a single episode of high-grade metamorphism. Temperature estimates for original pyroxene crystallization and pigeonite exsolution from clinopyroxene host provide a good constraint on the peak conditions for this metamorphic event. In contrast with the Prydz Bay area, it is proposed that the Pan-African metamorphism in East Antarctica had reached a higher temperature of ca. 850degreesC, and later underwent a slow cooling process, which probably resulted from the magmatic underplating of the lower crust.
学科主题	变质岩岩石学
WOS关键词	OPTIMAL PHASE BOUNDARIES ; LARSEMANN-HILLS ; EXPERIMENTAL CALIBRATION ; CRUSTAL EVOLUTION ; HIGH-TEMPERATURE ; ENDERBY-LAND ; PRYDZ-BAY ; GARNET ; LAMELLAE ; PRESSURE
WOS研究方向	Mineralogy
语种	英语
出版者	E SCHWEIZERBARTSCHE VERLAGS
WOS记录号	WOS:000181030500006
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37613]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Geomech, Beijing 100081, Peoples R China. 2.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. 3.Peking Univ, Elect Microscopy Lab, Beijing 100871, Peoples R China. 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China. 5.中国地质科学院地质力学研究所
推荐引用方式 GB/T 7714	Liu, XC,Zhao, ZR,Zhao, Y,et al. Pyroxene exsolution in mafic granulites from the Grove Mountains, East;Antarctica: constraints on Pan-African metamorphic conditions[J]. EUROPEAN JOURNAL OF MINERALOGY,2003,15(1):55-65.
APA	Liu, XC,Zhao, ZR,Zhao, Y,Chen, J,&Liu, XH.(2003).Pyroxene exsolution in mafic granulites from the Grove Mountains, East;Antarctica: constraints on Pan-African metamorphic conditions.EUROPEAN JOURNAL OF MINERALOGY,15(1),55-65.
MLA	Liu, XC,et al."Pyroxene exsolution in mafic granulites from the Grove Mountains, East;Antarctica: constraints on Pan-African metamorphic conditions".EUROPEAN JOURNAL OF MINERALOGY 15.1(2003):55-65.