Premium
The effect of Ni on element partitioning during iron meteorite crystallization
Author(s) -
Chabot Nancy L.,
Saslow Sarah A.,
McDonough William F.,
McCoy Timothy J.
Publication year - 2007
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2007.tb00534.x
Subject(s) - meteorite , crystallization , trace element , metal , nickel , iron meteorite , partition coefficient , materials science , chemistry , metallurgy , astrobiology , physics , chromatography , organic chemistry
— ‐Iron meteorites exhibit a large range in Ni concentrations, from only 4% to nearly 60%. Most previous experiments aimed at understanding the crystallization of iron meteorites have been conducted in systems with about 10% Ni or less. We performed solid metal/liquid metal experiments to determine the effect of Ni on partition coefficients for 20 trace elements pertinent to iron meteorites. Experiments were conducted in both the end‐member Ni‐S system as well as in the Fe‐Ni‐S system with intermediate Ni compositions applicable to high‐Ni iron meteorites. The Ni content of the system affects solid metal/liquid metal partitioning behavior. For a given S concentration, partition coefficients in the Ni‐S system can be over an order of magnitude larger than in the Fe‐S system. However, for compositions relevant to even the most Ni‐rich iron meteorites, the effect of Ni on partitioning behavior is minor, amounting to less than a factor of two for the majority of trace elements studied. Any effect of Ni also appears minor when it is compared to the large influence S has on element partitioning behavior. Thus, we conclude that in the presence of an evolving S‐bearing metallic melt, crystallization models can safely neglect effects from Ni when considering the full range of iron meteorite compositions.