Petrology, mineralogy, and oxygen isotope compositions of aluminum-rich chondrules from CV3 chondrites

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

	Petrology, mineralogy, and oxygen isotope compositions of aluminum-rich chondrules from CV3 chondrites
	Wang, Ying1 ; Hsu, Weibiao 1; Li, Xianhua 2; Li, Qiuli 2; Liu, Yu 2; Tang, Guoqiang 2
刊名	METEORITICS & PLANETARY SCIENCE
	2016
卷号	51 期号:1 页码:116-137
英文摘要	Bulk major element composition, petrography, mineralogy, and oxygen isotope compositions of twenty Al-rich chondrules (ARCs) from five CV3 chondrites (Northwest Africa [NWA] 989, NWA 2086, NWA 2140, NWA 2697, NWA 3118) and the Ningqiang carbonaceous chondrite were studied and compared with those of ferromagnesian chondrules and refractory inclusions. Most ARCs are marginally Al-richer than ferromagnesian chondrules with bulk Al2O3 of 10-15 wt%. ARCs are texturally similar to ferromagnesian chondrules, composed primarily of olivine, pyroxene, plagioclase, spinel, Al-rich glass, and metallic phases. Minerals in ARCs have intermediate compositions. Low-Ca pyroxene (Fs(0.6-8.8)Wo(0.7-9.3)) has much higher Al2O3 and TiO2 contents (up to 12.5 and 2.3 wt%, respectively) than that in ferromagnesian chondrules. High-Ca pyroxene (Fs(0.3-2.0)Wo(33-54)) contains less Al2O3 and TiO2 than that in Ca, Al-rich inclusions (CAIs). Plagioclase (An(77-99)-Ab(1-23)) is much more sodic than that in CAIs. Spinel is enriched in moderately volatile element Cr (up to 6.7 wt%) compared to that in CAIs. Al-rich enstatite coexists with anorthite and spinel in a glass-free chondrule, implying that the formation of Al-enstatite was not due to kinetic reasons but is likely due to the high Al2O3/CaO ratio (7.4) of the bulk chondrule. Three ARCs contain relict CAIs. Oxygen isotope compositions of ARCs are also intermediate between those of ferromagnesian chondrules and CAIs. They vary from -39.4& to 13.9 parts per thousand in delta O-18 and yield a best fit line (slope = 0.88) close to the carbonaceous chondrite anhydrous mineral (CCAM) line. Chondrules with 5-10 wt% bulk Al2O3 have a slightly more narrow range in delta O-18 (-32.5 to 5.9 parts per thousand) along the CCAM line. Except for the ARCs with relict phases, however, most ARCs have oxygen isotope compositions (>-20 parts per thousand in delta O-18) similar to those of typical ferromagnesian chondrules. ARCs are genetically related to both ferromagnesian chondrules and CAIs, but the relationship between ARCs and ferromagnesian chondrules is closer. Most ARCs were formed during flash heating and rapid cooling processes like normal chondrules, only from chemically evolved precursors. ARCs extremely enriched in Al and those with relict phases could have had a hybrid origin (Krot et al. 2002) which incorporated refractory inclusions as part of the precursors in addition to ferromagnesian materials. The occurrence of melilite in ARCs indicates that melilite-rich CAIs might be present in the precursor materials of ARCs. The absence of melilite in most ARCs is possibly due to high-temperature interactions between a chondrule melt and the solar nebula.
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 ; FERROMAGNESIAN CHONDRULES ; CARBONACEOUS CHONDRITE ; ORTHO-PYROXENE ; REFRACTORY INCLUSIONS ; CONTEMPORANEOUS FORMATION ; ALLENDE METEORITE ; BULK COMPOSITIONS ; NEBULA ; ORIGIN
收录类别	SCI
语种	英语
WOS记录号	WOS:000368019100007
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/16096]
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.Chinese Acad Sci, Purple Mt Observ, Key Lab Planetary Sci, Nanjing 210008, Jiangsu, 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	Wang, Ying,Hsu, Weibiao,Li, Xianhua,et al. Petrology, mineralogy, and oxygen isotope compositions of aluminum-rich chondrules from CV3 chondrites[J]. METEORITICS & PLANETARY SCIENCE,2016,51(1):116-137.
APA	Wang, Ying,Hsu, Weibiao,Li, Xianhua,Li, Qiuli,Liu, Yu,&Tang, Guoqiang.(2016).Petrology, mineralogy, and oxygen isotope compositions of aluminum-rich chondrules from CV3 chondrites.METEORITICS & PLANETARY SCIENCE,51(1),116-137.
MLA	Wang, Ying,et al."Petrology, mineralogy, and oxygen isotope compositions of aluminum-rich chondrules from CV3 chondrites".METEORITICS & PLANETARY SCIENCE 51.1(2016):116-137.