Sample 67955 - A description and a problem

Abstract

Clasts in breccia sample 67955 contain relatively coarse olivine and plagioclase in part enveloped by poikilitic hypersthene and diopside. This distinctive texture is concluded to result from high temperature crystallization in the presence of a fluid phase, probably a silicate melt. A problem posed by this rock is whether the bulk chemistry, characterized by a high Mg/Fe ratio but low total Fe + Mg, is the result of primary igneous processes on the moon or whether it is the residual end product of a multiple distillation process resulting from repeated meteorite impacts.