Periodic Table--Chromium

Chromium-53 is the radiogenic decay product of ⁵³Mn. Chromium isotopic contents are typically combined with manganese isotopic contents and have found application in isotope geology. Mn-Cr isotope ratios reinforce the evidence from ²⁶Al and ¹⁰⁷Pd for the early history of the solar system. Variations in ⁵³Cr/⁵²Cr and Mn/Cr ratios from several meteorites indicate an initial ⁵³Mn/⁵⁵Mn ratio that suggests Mn-Cr isotope systematics must result from in-situ decay of ⁵³Mn in differentiated planetary bodies (Birck and Allegre, 1985, 1988). Hence ⁵³Cr provides additional evidence for nucleosynthetic processes immediately before coalescence of the solar system.

In addition to the evidence from radiogenic ⁵³Cr, abundances of non-radiogenic ⁵⁴Cr may also provide constraints on the origin of solar-system material. ⁵⁴Cr abundances in chondrite samples indicate a mixing of multiple nucleosynthetic components in the formation of the solar-system (Rotaru et al., 1992).

Source of text: This review was assembled by Eric Caldwell, primarily from Dicken (1995).

References:

Birck, J.L. and Allegre, C.J. (1985). "Evidence for the presence of ⁵³Mn in the early solar system." Geophys. Res. Lett., 12: 745-748.

Birck, J.L. and Allegre, C.J. (1988). "Manganese-chromium isotope systematics and the development of the early solar-system." Nature, 351: 579-584.

Dicken, A.P. (1995). Radiogenic Isotope Geology. Cambridge University Press, New York, 452 pp.

Rotaru, M., Birck, J.L. and Allegre, C.J. (1992). "Clues to early solar-system history from chromium isotopes in carbonaceous chondrites." Nature, 358: 465-470.

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