Hybrid origin of the absarokite-shoshonite-banakite Series, Absaroka Volcanic Field, Wyoming

Textural and mineralogical features of potash-rich basaltic rocks of the absarokite-shoshonite-banakite series strongly suggest that most of the large crystals and aggregates in these rocks are xenocrysts and microxenoliths, not true phenocrysts as was previously thought. A hybrid origin, involving assimilation of gabbro by high-temperature syenitic magma, is proposed.