Petrogenesis of eucrite, howardite and diogenite meteorites

The mineralogical, textural and compositional characteristics of the eucrite meteorites suggest that they are the products of igneous processes. Howardites are polymict breccias containing a variety of fragments, the bulk of which are thought to have crystallised from eucrite and eucrite-related melts. Diogenites are orthopyroxene-rich stones which may represent cumulates from eucrite-related melts. I relate here experimentally determined phase equilibria to the igneous processes which produced the eucrites and their associates.