Al-Mg systematics of hibonite-bearing Ca,Al-rich inclusions from Ningqiang

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 天体化学和行星科学实验室

	Al-Mg systematics of hibonite-bearing Ca,Al-rich inclusions from Ningqiang
	Hsu, Weibiao 1,2,3; Guan, Yunbin 4; Wang, Ying1
刊名	METEORITICS & PLANETARY SCIENCE
	2011-05-01
卷号	46 期号:5 页码:719-728
关键词	EARLY SOLAR-SYSTEM ALUMINUM-RICH INCLUSIONS MURCHISON CARBONACEOUS CHONDRITE SHORT-LIVED NUCLIDES REFRACTORY INCLUSIONS ISOTOPIC COMPOSITION OXYGEN-ISOTOPE FERROMAGNESIAN CHONDRULES EXTINCT RADIOACTIVITIES ENSTATITE CHONDRITES
ISSN号	1086-9379
英文摘要	Hibonite-bearing Ca,Al-rich inclusions (CAIs) usually occur in CM and CH chondrites and possess petrographic and isotopic characteristics distinctive from other typical CAIs. Despite their highly refractory nature, most hibonite-bearing CAIs have little or no 26Mg excess (the decay product of 26Al), but do show wide variations of Ca and Ti isotopic anomalies. A few spinel-hibonite spherules preserve evidence of live 26Al with an inferred 26Al/27Al close to the canonical value. The bimodal distribution of 26Al abundances in hibonite-bearing CAIs has inspired several interpretations regarding the origin of short-lived nuclides and the evolution of the solar nebula. Herein we show that hibonite-bearing CAIs from Ningqiang, an ungrouped carbonaceous chondrite, also provide evidence for a bimodal distribution of 26Al. Two hibonite aggregates and two hibonite-pyroxene spherules show no 26Mg excesses, corresponding to inferred 26Al/27Al < 8 x 10-6. Two hibonite-melilite spherules are indistinguishable from each other in terms of chemistry and mineralogy but have different Mg isotopic compositions. Hibonite and melilite in one of them display positive 26Mg excesses (up to 25 parts per thousand) that are correlated with Al/Mg with an inferred 26Al/27Al of (5.5 +/- 0.6) x 10-5. The other one contains normal Mg isotopes with an inferred 26Al/27Al < 3.4 x 10-6. Hibonite in a hibonite-spinel fragment displays large 26Mg excesses (up to 38 parts per thousand) that correlate with Al/Mg, with an inferred 26Al/27Al of (4.5 +/- 0.8) x 10-5. Prolonged formation duration and thermal alteration of hibonite-bearing CAIs seem to be inconsistent with petrological and isotopic observations of Ningqiang. Our results support the theory of formation of 26Al-free/poor hibonite-bearing CAIs prior to the injection of 26Al into the solar nebula from a nearby stellar source.
学科主题	Geochemistry & Geophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Geochemistry & Geophysics
研究领域[WOS]	Geochemistry & Geophysics
关键词[WOS]	EARLY SOLAR-SYSTEM ; ALUMINUM-RICH INCLUSIONS ; MURCHISON CARBONACEOUS CHONDRITE ; SHORT-LIVED NUCLIDES ; REFRACTORY INCLUSIONS ; ISOTOPIC COMPOSITION ; OXYGEN-ISOTOPE ; FERROMAGNESIAN CHONDRULES ; EXTINCT RADIOACTIVITIES ; ENSTATITE CHONDRITES
收录类别	SCI
语种	英语
WOS记录号	WOS:000290393000007
公开日期	2012-08-07
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/4518]
专题	紫金山天文台_天体化学和行星科学实验室
作者单位	1.Purple Mt Observ, Nanjing 210008, Peoples R China 2.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Wuhan 430047, Peoples R China 3.China Univ Geosci, Fac Earth Sci, Wuhan 430047, Peoples R China 4.CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
推荐引用方式 GB/T 7714	Hsu, Weibiao,Guan, Yunbin,Wang, Ying. Al-Mg systematics of hibonite-bearing Ca,Al-rich inclusions from Ningqiang[J]. METEORITICS & PLANETARY SCIENCE,2011,46(5):719-728.
APA	Hsu, Weibiao,Guan, Yunbin,&Wang, Ying.(2011).Al-Mg systematics of hibonite-bearing Ca,Al-rich inclusions from Ningqiang.METEORITICS & PLANETARY SCIENCE,46(5),719-728.
MLA	Hsu, Weibiao,et al."Al-Mg systematics of hibonite-bearing Ca,Al-rich inclusions from Ningqiang".METEORITICS & PLANETARY SCIENCE 46.5(2011):719-728.