The enigmatic “red spots” on the Moon (so-called due to their high absorbance in the ultraviolet) are thought to be areas of silica-rich igneous material. But how silica-rich? What minerals and/or melts might be present? How do variables like water content and pressure of initial equilibration affect the assemblage and its mineralogical and spectral characteristics? Does silicate liquid immiscibility play a role?

I am exploring these questions and more with Dr. Malcolm Rutherford. In the Brown University experimental petrology lab, we are conducting experiments in the gas-medium apparatus (TZM) on a synthesized quartz monzodiorite composition.

Sample 15_e

Evidence of silicate liquid immiscibility in one of a set of ongoing experiments: Fe-rich melt blebs are scattered within silicate-rich melt, in between the large plagioclase and smaller clinopyroxene crystals.