气候变化领域集成服务门户(CCPortal): Episodic formation of refractory inclusions in the Solar System and their presolar heritage

CCPortal

DOI	10.1016/j.epsl.2020.116088
	Episodic formation of refractory inclusions in the Solar System and their presolar heritage
	Larsen K.K.; Wielandt D.; Schiller M.; Krot A.N.; Bizzarro M.
发表日期	2020
ISSN	0012821X
卷号	535
英文摘要	Refractory inclusions [Ca-Al-rich Inclusions (CAIs) and Amoeboid Olivine Aggregates (AOAs)] in primitive meteorites are the oldest Solar System solids. They formed in the hot inner protoplanetary disk and, as such, provide insights into the earliest disk dynamics and physicochemical processing of the dust and gas that accreted to form the Sun and its planetary system. Using the short-lived 26Al to 26Mg decay system, we show that bulk refractory inclusions in CV (Vigarano-type) and CR (Renazzo-type) carbonaceous chondrites captured at least two distinct 26Al-rich (26Al/27Al ratios of ∼5 × 10−5) populations of refractory inclusions characterized by different initial 26Mg/24Mg isotope compositions (μ26Mg0). Another 26Al-poor CAI records an even larger μ26Mg0 deficit. This suggests that formation of refractory inclusions was punctuated and recurrent, possibly associated with episodic outbursts from the accreting proto-Sun lasting as short as <8000 yr. Our results support a model in which refractory inclusions formed close to the hot proto-Sun and were subsequently redistributed to the outer disk, beyond the orbit of Jupiter, plausibly via stellar outflows with progressively decreasing transport efficiency. We show that the magnesium isotope signatures in refractory inclusions mirrors the presolar grain record, demonstrating a mutual exclusivity between 26Al enrichments and large nucleosynthetic Mg isotope effects. This suggests that refractory inclusions formed by incomplete thermal processing of presolar dust, thereby inheriting a diluted signature of their isotope systematics. As such, they record snapshots in the progressive sublimation of isotopically anomalous presolar carriers through selective thermal processing of young dust components from the proto-Solar molecular cloud. We infer that 26Al-rich refractory inclusions incorporated 26Al-rich dust which formed <5 Myr prior to our Sun, whereas 26Al-poor inclusions (such as FUN- and PLAC-type CAIs) incorporated >10 Myr old dust. © 2020 The Authors
关键词	26Al episodic outburst Mg isotope presolar dust refractory inclusion Solar System formation
英文关键词	Dust; Heat treatment; Isotopes; Meteorites; Orbits; Silicate minerals; Solar system; Ca-al-rich inclusions; Carbonaceous chondrites; episodic outburst; Isotope compositions; Mg isotopes; Mutual exclusivities; Solar system formation; ^26Al; Refractory materials; carbonaceous chondrite; episodic event; isotopic composition; Jupiter; magnesium; planetary atmosphere; refraction; solar activity; solar system
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202718
作者单位	Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, DK-1350, Denmark; Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at ManoaHI 96822, United States
推荐引用方式 GB/T 7714	Larsen K.K.,Wielandt D.,Schiller M.,et al. Episodic formation of refractory inclusions in the Solar System and their presolar heritage[J],2020,535.
APA	Larsen K.K.,Wielandt D.,Schiller M.,Krot A.N.,&Bizzarro M..(2020).Episodic formation of refractory inclusions in the Solar System and their presolar heritage.Earth and Planetary Science Letters,535.
MLA	Larsen K.K.,et al."Episodic formation of refractory inclusions in the Solar System and their presolar heritage".Earth and Planetary Science Letters 535(2020).