TY - JOUR
T1 - The effect of Ni on element partitioning during iron meteorite crystallization
AU - Chabot, Nancy L.
AU - Saslow, Sarah A.
AU - McDonough, William F.
AU - McCoy, Timothy J.
PY - 2007/10
Y1 - 2007/10
N2 - 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 safety neglect effects from Ni when considering the full range of iron meteorite compositions.
AB - 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 safety neglect effects from Ni when considering the full range of iron meteorite compositions.
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U2 - 10.1111/j.1945-5100.2007.tb00534.x
DO - 10.1111/j.1945-5100.2007.tb00534.x
M3 - Article
AN - SCOPUS:38949179873
VL - 42
SP - 1735
EP - 1750
JO - Meteoritics and Planetary Science
JF - Meteoritics and Planetary Science
SN - 1086-9379
IS - 10
ER -