Geochemistry of late Mesozoic adakites from the Sulu belt, eastern China: magma genesis and implications for crustal recycling beneath continental collisional orogens

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	Geochemistry of late Mesozoic adakites from the Sulu belt, eastern China: magma genesis and implications for crustal recycling beneath continental collisional orogens
	Guo, F ; Fan, WM ; Li, CW
刊名	GEOLOGICAL MAGAZINE
	2006
卷号	143 期号:1 页码:40556
关键词	geochemistry lower continental crust adakites Late Mesozoic Sulu belt
ISSN号	0016-7568
通讯作者	guofengt@263.net
中文摘要	Both low-Al and high-Al adakitic andesites erupted at similar to 114 M a in the Sulu collisional belt, eastern China, provide evidence for recycling of continental crust into the mantle more than 100 million years after the Triassic (similar to 240 Ma) collision between the North China and Yangtze blocks. These rocks display similar normalized trace element patterns, with enrichments in large ion lithophile elements (LILE), light rare earth elements (LREE) and depletions in Nb, Ta and Ti, and have highly radiogenic Sr and non-radiogenic Nd isotopic compositions (high-Al: Sr-87/Sr-86(i) = 0.70645-0.70715 and epsilon(Nd)(t) = -20.1 to -19.1; low-Al: Sr-87/Sr-86(i) = 0.70593-0.70598 and epsilon(Nd)(t) = -17.1 to -15.8). The high-Al (Al2O3 > 15 %) adakitic andesites are compositionally comparable with experimental slab melts, whereas the low-Al series (Al2O3 similar to 13 %) have higher MgO, Cr and Ni, and higher Sr/Y ratios, and are compositionally comparable with slab melts hybridized by mantle peridotites. Combined major- and trace-element and Sr-Nd isotope data indicate that the two types of adakitic andesites have been derived from a LILE- and LREE-enriched eclogitic lower continental crust; in the case of the high-Al adakitic andesites, the melts underwent insignificant mantle contamination, whereas the low-Al magmas reacted with peridotites. Generation of the two types of late Mesozoic adakitic andesites favours a model of lithospheric delamination, leading to asthenospheric upwelling and extensive melting of lower continental crust, including a delaminated block, in the Sulu belt.
学科主题	Geosciences, Multidisciplinary
收录类别	SCI
原文出处	CAMBRIDGE UNIV PRESS
WOS记录号	WOS:000236366000001
公开日期	2011-07-03
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/4420]
专题	南海海洋研究所_中科院边缘海地质重点实验室
推荐引用方式 GB/T 7714	Guo, F,Fan, WM,Li, CW. Geochemistry of late Mesozoic adakites from the Sulu belt, eastern China: magma genesis and implications for crustal recycling beneath continental collisional orogens[J]. GEOLOGICAL MAGAZINE,2006,143(1):40556.
APA	Guo, F,Fan, WM,&Li, CW.(2006).Geochemistry of late Mesozoic adakites from the Sulu belt, eastern China: magma genesis and implications for crustal recycling beneath continental collisional orogens.GEOLOGICAL MAGAZINE,143(1),40556.
MLA	Guo, F,et al."Geochemistry of late Mesozoic adakites from the Sulu belt, eastern China: magma genesis and implications for crustal recycling beneath continental collisional orogens".GEOLOGICAL MAGAZINE 143.1(2006):40556.