Loading...
The Yamato-type (CY) carbonaceous chondrite group: Analogues for the surface of asteroid Ryugu?
Krietsch, D Busemann, H Clay, PL Schofield, PF
Krietsch, D
Busemann, H
Clay, PL
Schofield, PF
Citations
Altmetric:
Advisors
Editors
Other Contributors
Affiliation
EPub Date
Issue Date
20/08/2019
Submitted Date
2019-11-20
Subject Terms
Carbonaceous chondrite
Aqueous alteration
Thermal metamorphism
Asteroids
Meteorites
Ryugu
Hayabusa-2
Aqueous alteration
Thermal metamorphism
Asteroids
Meteorites
Ryugu
Hayabusa-2
Collections
Files
Research Projects
Organizational Units
Journal Issue
Other Titles
Abstract
We report new mineralogical, petrographic and noble gas analyses of the carbonaceous chondrite meteorites Y-82162 (C1/2ung), Y-980115 (CI1), Y-86029 (CI1), Y-86720 (C2ung), Y-86789 (C2ung), and B-7904 (C2ung). Combining our results with literature data we show that these meteorites experienced varying degrees of aqueous alteration followed by short-lived thermal metamorphism at temperatures of >500 °C. These meteorites have similar mineralogy, textures and chemical characteristics suggesting that they are genetically related, and we strongly support the conclusion of Ikeda (1992) that they form a distinct group, the CYs (“Yamato-type”). The CY chondrites have the heaviest oxygen isotopic compositions (δ17O ˜12‰, δ18O ˜22‰) of any meteorite group, high abundances of Fe-sulphides (˜10 ‒ 30 vol%) and phosphates, and contain large grains of periclase and unusual objects of secondary minerals not reported in other carbonaceous chondrites. These features cannot be attributed to parent body processes alone, and indicate that the CYs had a different starting mineralogy and/or alteration history to other chondrite groups, perhaps because they formed in a different region of the protoplanetary disk. The short cosmic-ray exposure ages (≤1.3 Ma) of the CY chondrites suggest that they are derived from a near-Earth source, with recent observations by the Hayabusa2 spacecraft highlighting a possible link to the rubble-pile asteroid Ryugu.
Citation
A.J. King, H.C. Bates, D. Krietsch, H. Busemann, P.L. Clay, P.F. Schofield, S.S. Russell, The Yamato-type (CY) carbonaceous chondrite group: Analogues for the surface of asteroid Ryugu?, Geochemistry, Volume 79, Issue 4, 2019, 125531, ISSN 0009-2819, https://doi.org/10.1016/j.chemer.2019.08.003.
Publisher
Journal
Research Unit
PubMed ID
PubMed Central ID
Embedded videos
Type
Journal Article
Item Description
2019 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/). The attached file is the published pdf.
NHM Repository
NHM Repository
Series/Report no.
ISSN
0009-2819
EISSN
ISBN
ISMN
GovDoc
Test Link
License
openAccess