THE CHROMIUM ISOTOPIC COMPOSITION OF THE UNGROUPED CARBONACEOUS CHONDRITE TAGISH LAKE

Journal Article · Wed Jul 20 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/736/1/23· OSTI ID:21578341

Petitat, M; Gounelle, M ^[1]; Birck, J -L

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1. Laboratoire de Mineralogie et Cosmochimie du Museum (LMCM), CNRS and Museum National d'Histoire Naturelle, UMR 7202, 57 rue Cuvier, 75005 Paris (France)

Early solar materials bear a variety of isotopic anomalies that reflect compositional differences deriving from distinct stellar nucleosynthetic processes. As shown in previous studies, the stepwise dissolution with increasing acid strengths of bulk rock carbonaceous chondrites liberates Cr with both excesses and deficits in {sup 53}Cr and {sup 54}Cr relative to the terrestrial standard. The magnitude of the {sup 54}Cr variations within a meteorite decreases in the sequence CI1 > CR2 > CM2 > CV3 > CO3 > CK4 and correlates with the degree of metamorphism of each carbonaceous chondrite class. This study shows that the Tagish Lake meteorite presents the highest excesses in {sup 54}Cr ever measured in a bulk silicate phase. According to this study, the Tagish Lake meteorite is composed of the least re-equilibrated material known at this time. The magnitude of {sup 54}Cr variation decreases now in the following sequence: Tagish Lake (ungrouped CI2) > Orgueil (CI1) > Murchison (CM2) > Allende (CV2). Moreover, this study shows that excesses in {sup 53}Cr relative to Earth can be interpreted as representing the extent of aqueous alteration on meteorite parent bodies. Finally, the high {sup 54}Cr anomalies measured in this meteorite make Tagish Lake one of the major targets to decipher the host of these anomalies.

• OSTI ID: 21578341
• Journal Information: Astrophysical Journal, Vol. 736, Issue 1; Other Information: DOI: 10.1088/0004-637X/736/1/23; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CHONDRITES
CHROMIUM
CHROMIUM 53
CHROMIUM 54
ISOTOPE RATIO
SUPERNOVAE
VARIATIONS
BINARY STARS
CHROMIUM ISOTOPES
DIMENSIONLESS NUMBERS
ELEMENTS
ERUPTIVE VARIABLE STARS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPES
METALS
METEORITES
NUCLEI
STABLE ISOTOPES
STARS
STONE METEORITES
TRANSITION ELEMENTS
VARIABLE STARS