Establishing the liquid phase equilibrium of angrites to constrain their petrogenesis

Abstract

Angrites are a series of differentiat-ed meteorites, extremely silica undersaturated and with unusally high Ca and Al contents [1]. They are thought to originate from a small planetesimal parent body of ~ 100-200 km in radius ([2-3]), can be either plutonic (i.e., cumulates) or volcanic (often referred to as quenched) in origin, and their old formation ages (4 to 11 Myr after CAIs) have made them prime anchors to tie the relative chronologies inferred from short-lived radionuclides (e.g., Al-Mg, Mn-Cr, Hf-W) to the absolute Pb-Pb clock [4]. They are also the most vola-tile element-depleted meteorites available, displaying a K-depletion of a factor of 110 relative to CIs.