{sup 53}Mn-{sup 53}Cr CHRONOMETRY OF CB CHONDRITE: EVIDENCE FOR UNIFORM DISTRIBUTION OF {sup 53}Mn IN THE EARLY SOLAR SYSTEM

Journal Article · Mon Nov 01 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/723/1/20· OSTI ID:21471310

Yamashita, Katsuyuki; Yamakawa, Akane; Nakamura, Eizo; Maruyama, Seiji ^[1]

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1. Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Study of the Earth's Interior, Okayama University, 827 Yamada, Misasa, Tottori-ken 682-0193 (Japan)

High-precision Cr isotope ratios for chondrules and metal grain separated from CB chondrite Gujba were determined. The {epsilon}{sup 54}Cr values ({epsilon}{sup i}Cr = [({sup i}Cr/{sup 52}Cr){sub sample}/({sup i}Cr/{sup 52}Cr){sub standard} - 1] x 10{sup 4}) for all samples were identical within the analytical uncertainty, with a mean value of +1.29 {+-} 0.02. Uniform {epsilon}{sup 54}Cr signatures of both chondrules and metal grains imply that the Cr isotope systematics of the meteorite was once completely equilibrated. The {epsilon}{sup 53}Cr values of the chondrules and metal grain, on the other hand, display a strong correlation with the {sup 55}Mn/{sup 52}Cr ratio. The {sup 53}Mn/{sup 55}Mn calculated from the slope of the isochron is (3.18 {+-} 0.52) x 10{sup -6}. This corresponds to absolute ages of 4563.7 {+-} 1.2 Ma and 4563.5 {+-} 1.1 Ma using angrites D'Orbigny and LEW 86010, respectively, as time anchors. These ages are consistent with the ages obtained using other short- and long-lived radio nuclides, supporting the uniform distribution of {sup 53}Mn in the early solar nebula.

• OSTI ID: 21471310
• Journal Information: Astrophysical Journal, Vol. 723, Issue 1; Other Information: DOI: 10.1088/0004-637X/723/1/20; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABUNDANCE
CHONDRITES
CHROMIUM 52
CHROMIUM 53
MANGANESE 53
MANGANESE 55
METEOROIDS
NUCLEAR REACTIONS
NUCLEOSYNTHESIS
SOLAR NEBULA
SOLAR SYSTEM
SOLAR SYSTEM EVOLUTION
BETA DECAY RADIOISOTOPES
CHROMIUM ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EVOLUTION
INTERMEDIATE MASS NUCLEI
ISOTOPES
MANGANESE ISOTOPES
METEORITES
NEBULAE
NUCLEI
ODD-EVEN NUCLEI
RADIOISOTOPES
STABLE ISOTOPES
STONE METEORITES
SYNTHESIS
YEARS LIVING RADIOISOTOPES