PARTITIONING BEHAVIOR OF NI, CO, MO, AND W BETWEEN BASALTIC LIQUID AND NI-RICH METAL - IMPLICATIONS FOR THE ORIGIN OF THE MOON AND LUNAR CORE FORMATION

A recent model of the origin of the Moon in a giant impact put forth by O'Neill [1991a and b] states that the bulk abundances of siderophile elements in the Moon would be provided by the impactor plus a late reduced veneer. A small Ni-rich core would then separate setting the siderophile element abundance pattern in the lunar mantle. I test this hypothesis using simple mass balance and the results of an experimental study that I have conducted on the partitioning of moderately siderophile elements between basalt and Ni-rich metal. I find this hypothesis to be viable under a limited set of conditions.