Agua Emendada

This is a small eroded volcanic neck cutting Carboniferous sandstones and consisting principally of breccias and tuffs, but with some flows. The central part is composed of alnoite/monchiquite-type rocks containing phenocrysts of olivine, Ti-augite, pleonaste, perovskite and opaques in a groundmass of pyroxene, melilite and opaques. The flows are variably vesicular and contain phenocrysts of olivine, Ti-augite and (?)feldspathoid, in a groundmass of pyroxene, biotite, opaques and glass; anorthoclase xenocrysts are found in some areas.