Carbonaceous chondrite meteorites experienced fluid flow within the past million years

doi:10.1126/science.abc8116

GSTDTAP > 气候变化

DOI	10.1126/science.abc8116
	Carbonaceous chondrite meteorites experienced fluid flow within the past million years
	Simon Turner; Lucy McGee; Munir Humayun; John Creech; Brigitte Zanda
	2021-01-08
发表期刊	Science
出版年	2021
英文摘要	Carbonaceous chondritic meteorites are thought to be fragments broken off parent bodies that orbit in the outer Solar System, largely unaltered since their formation. These meteorites contain evidence of reactions with liquid water that was thought to have been lost or completely frozen billions of years ago. Turner et al. examined uranium and thorium isotopes in several carbonaceous chondrites, finding nonequilibrium distributions that imply that uranium ions were transported by fluid flow. Because this signature disappears after several half-lives of the radioactive isotopes, the meteorites must have been exposed to liquid within the past million years. The authors suggest that ice may have melted during the impacts that ejected the meteorites from their parent bodies. Science , this issue p. [164][1] Carbonaceous chondritic meteorites are primordial Solar System materials and a source of water delivery to Earth. Fluid flow on the parent bodies of these meteorites is known to have occurred very early in Solar System history (first <4 million years). We analyze short-lived uranium isotopes in carbonaceous chondrites, finding excesses of 234-uranium over 238-uranium and 238-uranium over 230-thorium. These indicate that the fluid-mobile uranium ion U6+ moved within the past few 100,000 years. In some meteorites, this time scale is less than the cosmic-ray exposure age, which measures when they were ejected from their parent body into space. Fluid flow occurred after melting of ice, potentially by impact heating, solar heating, or atmospheric ablation. We favor the impact heating hypothesis, which implies that the parent bodies still contain ice. [1]: /lookup/doi/10.1126/science.abc8116
领域	气候变化 ; 资源环境
URL	查看原文
引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/310446
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Simon Turner,Lucy McGee,Munir Humayun,et al. Carbonaceous chondrite meteorites experienced fluid flow within the past million years[J]. Science,2021.
APA	Simon Turner,Lucy McGee,Munir Humayun,John Creech,&Brigitte Zanda.(2021).Carbonaceous chondrite meteorites experienced fluid flow within the past million years.Science.
MLA	Simon Turner,et al."Carbonaceous chondrite meteorites experienced fluid flow within the past million years".Science (2021).