Neoarchean recycling of O-18-enriched supracrustal materials into the lower crust: Zircon record from the North China Craton

doi:10.1016/j.precamres.2014.04.012

	Neoarchean recycling of O-18-enriched supracrustal materials into the lower crust: Zircon record from the North China Craton
	Zhang, Hong-Fu 1,2
刊名	PRECAMBRIAN RESEARCH
	2014-07-01
卷号	248 页码:60-71
关键词	Zircon Oxygen isotope Archean lower crust Supracrustal material recycling North China Craton
ISSN号	0301-9268
DOI	10.1016/j.precamres.2014.04.012
英文摘要	Oxygen isotope analyses were carried out using SIMS technique (Cameca-1280) on zircons from well-studied lower crust xenoliths/xenocrysts from the North China Craton (NCC). The results show that magmatic zircons with Archean-Paleoproterozoic (207)pb/Pb-206 ages have an extremely large variation in delta O-18 values that range from less than normal mantle value (4.74 +/- 0.28%. (2 sigma)) to O-18-enriched supracrustal value (8.88 +/- 0.40%. (2 sigma)) and differ in localities of the NCC (delta O-18(Qjndao) from 5.27 +/- 0.45%. to 8.88 +/- 0.40 parts per thousand; delta O-18(Hannuoba) from 6.78 +/- 0.23%. to 7.69 +/- 0.41 parts per thousand; delta O-18(Xruyan), from 4.74 +/- 0.28%. to 6.57 +/- 0.39 parts per thousand). Such a variation demonstrates that the Neoarchean lower crust beneath the NCC was highly heterogeneous in oxygen isotope compositions, even in an individual region. The fact that the predominant zircons have high delta O-18 values suggests that the recycling of O-18-enriched supracrustal materials into the Neoarchean lower crust indeed happened during zircon crystallization. Some zircons with core-rim texture have nearly identical delta O-18 both in core and its rim. On the other hand, others have a distinctive oxygen isotope ratio between the core and its rim, possessing slightly higher delta O-18 in the rim than its core or vice versa. Such an oxygen isotope feature in zoned zircons suggests a complicated evolutional history of ancient lower crust in the NCC. This study provides convincing evidence that a large amounts of the supracrustal materials have been recycled into the Neoarchean lower crust beneath the NCC, a process resulting in the highly heterogeneity in oxygen isotopes. (C) 2014 Elsevier B.V. All rights reserved.
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000338620000004
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/85360]
专题	中国科学院地质与地球物理研究所
通讯作者	Zhang, Hong-Fu
作者单位	1.NW Univ Xian, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Hong-Fu. Neoarchean recycling of O-18-enriched supracrustal materials into the lower crust: Zircon record from the North China Craton[J]. PRECAMBRIAN RESEARCH,2014,248:60-71.
APA	Zhang, Hong-Fu.(2014).Neoarchean recycling of O-18-enriched supracrustal materials into the lower crust: Zircon record from the North China Craton.PRECAMBRIAN RESEARCH,248,60-71.
MLA	Zhang, Hong-Fu."Neoarchean recycling of O-18-enriched supracrustal materials into the lower crust: Zircon record from the North China Craton".PRECAMBRIAN RESEARCH 248(2014):60-71.