Extreme crustal metamorphism during Columbia supercontinent assembly:   Evidence from North China Craton

doi:10.1016/j.gr.2006.06.005

CORC > 北京大学 > 地球与空间科学学院

	Extreme crustal metamorphism during Columbia supercontinent assembly: Evidence from North China Craton
	Santosh, M. ; Sajeev, K. ; Li, J. H.
刊名	gondwana research
	2006
关键词	extreme crustal metamorphism spinel-quartz monazite geochronology Columbia supercontinent North China Craton ULTRAHIGH-TEMPERATURE METAMORPHISM SPINEL PLUS QUARTZ SOUTHERN INDIA GRANULITE BELT PB DIFFUSION MONAZITE GARNET KHONDALITES EVOLUTION OSUMILITE
DOI	10.1016/j.gr.2006.06.005
英文摘要	A vast supracrustal belt of khondalites (granulite facies metapelites) occur along the northern margin of the North China Craton. We report here for the first time. spinel +quartz equilibrium assemblage from these rocks in two textural settings: (1) high ZnO (up to 14.47 wt.%) spinel with quartz as inclusions within garnet porphyroblasts defining pressure above 12 kbar and temperature of 900 degrees C; and (2) low ZnO (down to 1.2 wt.%) spinel in association with quartz in the matrix assemblage formed during peak ultrahigh-temperature conditions (ca. 975 degrees C and 9 kbar). We present a unique case of decompression where the metamorphic conditions of the rocks traversed mostly through the spinel +quartz (extended) stability field. Monazite grains in textural association with both types of spinel + quartz textures were analysed for age determination, and the data define two age peaks at 1927 +/- 11 Ma and 1819 +/- 11 Ma. Since the peak thermal regime of the khondalites was close to or exceeded the theoretical closure temperature of Pb in monazite, we infer the 1819 +/- 11 Ma age as the timing of ultrahigh-temperature event in this craton. Our data lend support to the idea of ca. 1.9-1.8 Ga E-W collisional orogen at the northern margin of the North China Craton. We correlate the extreme crustal metamorphism with tectonics associated with the assembly of the North China Craton within the Columbia supercontinent. (c) 2006 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.; Geosciences, Multidisciplinary; SCI(E); 0; ARTICLE; 3-4; 256-266; 10
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/251320]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Santosh, M.,Sajeev, K.,Li, J. H.. Extreme crustal metamorphism during Columbia supercontinent assembly: Evidence from North China Craton[J]. gondwana research,2006.
APA	Santosh, M.,Sajeev, K.,&Li, J. H..(2006).Extreme crustal metamorphism during Columbia supercontinent assembly: Evidence from North China Craton.gondwana research.
MLA	Santosh, M.,et al."Extreme crustal metamorphism during Columbia supercontinent assembly: Evidence from North China Craton".gondwana research (2006).