Petrography and geochemistry of the enriched basaltic shergottite Northwest Africa 2975

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

	Petrography and geochemistry of the enriched basaltic shergottite Northwest Africa 2975
	He, Qi 1; Xiao, Long 1; Balta, J. Brian 2; Baziotis, Ioannis P.3; Hsu, Weibiao 4; Guan, Yunbin 5
刊名	METEORITICS & PLANETARY SCIENCE
	2015-12-01
卷号	50 期号:12 页码:2024-2044
英文摘要	We present a study of the petrology and geochemistry of basaltic shergottite Northwest Africa 2975 (NWA 2975). NWA 2975 is a medium-grained basalt with subophitic to granular texture. Electron microprobe (EMP) analyses show two distinct pyroxene compositional trends and patchy compositional zoning patterns distinct from those observed in other meteorites such as Shergotty or QUE 94201. As no bulk sample was available to us for whole rock measurements, we characterized the fusion crust and its variability by secondary ion mass spectrometer (SIMS) measurements and laser ablation inductively coupled plasma spectroscopy (LA-ICP-MS) analyses as a best-available proxy for the bulk rock composition. The fusion crust major element composition is comparable to the bulk composition of other enriched basaltic shergottites, placing NWA 2975 within that sample group. The CI-normalized REE (rare earth element) patterns are flat and also parallel to those of other enriched basaltic shergottites. Merrillite is the major REE carrier and has a flat REE pattern with slight depletion of Eu, parallel to REE patterns of merrillites from other basaltic shergottites. The oxidation state of NWA 2975 calculated from Fe-Ti oxide pairs is NNO-1.86, close to the QFM buffer. NWA 2975 represents a sample from the oxidized and enriched shergottite group, and our measurements and constraints on its origin are consistent with the hypothesis of two distinct Martian mantle reservoirs: a reduced, LREE-depleted reservoir and an oxidized, LREE-enriched reservoir. Stishovite, possibly seifertite, and dense SiO2 glass were also identified in the meteorite, allowing us to infer that NWA 2975 experienced a realistic shock pressure of similar to 30 GPa.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Geochemistry & Geophysics
研究领域[WOS]	Geochemistry & Geophysics
关键词[WOS]	PHYRIC MARTIAN BASALTS ; LA-ICP-MS ; HIGH-PRESSURE ; OXYGEN FUGACITY ; LOS-ANGELES ; ELEMENT GEOCHEMISTRY ; ELECTRON-MICROPROBE ; SHOCK METAMORPHISM ; RAMAN-SPECTROSCOPY ; OXIDATION-STATE
收录类别	SCI
语种	英语
WOS记录号	WOS:000368018600005
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/16110]
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.China Univ Geosci, Sch Earth Sci, Planetary Sci Inst, Wuhan 430074, Peoples R China 2.Univ Pittsburgh, Dept Geol & Planetary Sci, Pittsburgh, PA 15217 USA 3.Agr Univ Athens, Lab Mineral & Geol, GR-11855 Athens, Greece 4.Chinese Acad Sci, Purple Mt Observ, Lab Astrochem & Planetary Sci, Nanjing 210008, Jiangsu, Peoples R China 5.CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
推荐引用方式 GB/T 7714	He, Qi,Xiao, Long,Balta, J. Brian,et al. Petrography and geochemistry of the enriched basaltic shergottite Northwest Africa 2975[J]. METEORITICS & PLANETARY SCIENCE,2015,50(12):2024-2044.
APA	He, Qi,Xiao, Long,Balta, J. Brian,Baziotis, Ioannis P.,Hsu, Weibiao,&Guan, Yunbin.(2015).Petrography and geochemistry of the enriched basaltic shergottite Northwest Africa 2975.METEORITICS & PLANETARY SCIENCE,50(12),2024-2044.
MLA	He, Qi,et al."Petrography and geochemistry of the enriched basaltic shergottite Northwest Africa 2975".METEORITICS & PLANETARY SCIENCE 50.12(2015):2024-2044.