scholarly journals Trace Element Compositions of Fine- Grained CAIs and AOAs in Unaltered Carbonaceous Chondrites: Implications for Early Solar System Reservoirs

2020 ◽  
Author(s):  
Sara Russell ◽  
Alexander N. Krot
Keyword(s):  
Solar System ◽  
Trace Element ◽  
Carbonaceous Chondrites ◽  
Early Solar System ◽  
Fine Grained

scholarly journals Oxygen isotopic heterogeneity in the early Solar System inherited from the protosolar molecular cloud

2020 ◽  
Vol 6 (42) ◽  
pp. eaay2724
Author(s):  
Alexander N. Krot ◽  
Kazuhide Nagashima ◽  
James R. Lyons ◽  
Jeong-Eun Lee ◽  
Martin Bizzarro
Keyword(s):  
Solar System ◽  
Molecular Cloud ◽  
Limited Range ◽  
Terrestrial Planets ◽  
Carbonaceous Chondrites ◽  
The Sun ◽  
Early Solar System ◽  
Isotopic Heterogeneity ◽  
Oxygen Isotopic ◽  
O 24

The Sun is 16O-enriched (Δ17O = −28.4 ± 3.6‰) relative to the terrestrial planets, asteroids, and chondrules (−7‰ < Δ17O < 3‰). Ca,Al-rich inclusions (CAIs), the oldest Solar System solids, approach the Sun’s Δ17O. Ultraviolet CO self-shielding resulting in formation of 16O-rich CO and 17,18O-enriched water is the currently favored mechanism invoked to explain the observed range of Δ17O. However, the location of CO self-shielding (molecular cloud or protoplanetary disk) remains unknown. Here we show that CAIs with predominantly low (26Al/27Al)0, <5 × 10−6, exhibit a large inter-CAI range of Δ17O, from −40‰ to −5‰. In contrast, CAIs with the canonical (26Al/27Al)0 of ~5 × 10−5 from unmetamorphosed carbonaceous chondrites have a limited range of Δ17O, −24 ± 2‰. Because CAIs with low (26Al/27Al)0 are thought to have predated the canonical CAIs and formed within first 10,000–20,000 years of the Solar System evolution, these observations suggest oxygen isotopic heterogeneity in the early solar system was inherited from the protosolar molecular cloud.

The thallium isotope composition of carbonaceous chondrites — New evidence for live 205Pb in the early solar system

2010 ◽  
Vol 291 (1-4) ◽  
pp. 39-47 ◽  
Author(s):  
R.G.A. Baker ◽  
M. Schönbächler ◽  
M. Rehkämper ◽  
H.M. Williams ◽  
A.N. Halliday
Keyword(s):  
Solar System ◽  
Isotope Composition ◽  
Carbonaceous Chondrites ◽  
Early Solar System ◽  
New Evidence

An igneous-textured clast in the Peace River meteorite: insights into accretion and metamorphism of asteroids in the early solar system

2013 ◽  
Vol 50 (1) ◽  
pp. 14-25 ◽  
Author(s):  
Christopher D.K. Herd ◽  
Jon M. Friedrich ◽  
Richard C. Greenwood ◽  
Ian A. Franchi
Keyword(s):  
Solar System ◽  
Isotope Composition ◽  
Parent Body ◽  
Early Solar System ◽  
Element Abundances ◽  
Fine Grained ◽  
Peace River ◽  
Petrology And Geochemistry ◽  
Mineral Compositions ◽  
The Impact

The mineralogy, petrology, and geochemistry of an igneous-textured clast in the Peace River L6 chondrite meteorite was examined to determine the roles of nebular processes, accretion, and parent-body metamorphism in its origin. The centimetre-scale clast is grey and fine grained and is in sharp contact with the host chondrite. Two sub-millimetre veins cut across both the clast and host, indicating that the clast formed prior to the impact (shock) event(s) that produced the numerous veins present in the Peace River meteorite. The clast and host are indistinguishable in terms of mineral compositions. In contrast, there are differences in modal mineralogy, texture, as well as trace element and oxygen isotope composition between the clast and host. These differences strongly suggest that the clast was formed by impact melting of LL-group chondritic material involving loss of Fe–FeS and phosphate components, followed by relatively rapid cooling and incorporation into the Peace River host meteorite. Subsequent metamorphism on the Peace River parent body caused recrystallization of the clast and homogenization of mineral compositions and thermally labile element abundances between the clast and host. Shock metamorphism, including formation of shock melt veins, occurred post-metamorphism, during fragmentation of the L chondrite parent body. The results suggest that the formation of the Peace River parent asteroid included the incorporation of material from other asteroids and that the pre-metamorphic protolith was a breccia. Accordingly, we propose that the Peace River meteorite be reclassified as a polymict breccia.

scholarly journals Arrival and magnetization of carbonaceous chondrites in the asteroid belt before 4562 million years ago

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Timothy O’Brien ◽  
John A. Tarduno ◽  
Atma Anand ◽  
Aleksey V. Smirnov ◽  
Eric G. Blackman ◽  
...  
Keyword(s):  
Solar System ◽  
Arrival Time ◽  
Carbonaceous Chondrite ◽  
Parent Body ◽  
Asteroid Belt ◽  
Carbonaceous Chondrites ◽  
Early Solar System ◽  
Outer Disk ◽  
Main Asteroid Belt ◽  
Insight Into

AbstractMeteorite magnetizations can provide rare insight into early Solar System evolution. Such data take on new importance with recognition of the isotopic dichotomy between non-carbonaceous and carbonaceous meteorites, representing distinct inner and outer disk reservoirs, and the likelihood that parent body asteroids were once separated by Jupiter and subsequently mixed. The arrival time of these parent bodies into the main asteroid belt, however, has heretofore been unknown. Herein, we show that weak CV (Vigarano type) and CM (Mighei type) carbonaceous chondrite remanent magnetizations indicate acquisition by the solar wind 4.2 to 4.8 million years after Ca-Al-rich inclusion (CAI) formation at heliocentric distances of ~2–4 AU. These data thus indicate that the CV and CM parent asteroids had arrived near, or within, the orbital range of the present-day asteroid belt from the outer disk isotopic reservoir within the first 5 million years of Solar System history.

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