Experimental Constraints on Homogenization of Plagioclase-Hosted Melt Inclusions From Plagioclase Ultraphyric Basalts

Study of melt inclusions (MIs) is a commonly applied method for defining the composition magmas present at depth prior to mixing, fractionation, and degassing. Our ability use data from MIs complicated by post-entrapment processes (PEP) that can modify their during transport eruption. Many PEP be reversed heating temperatures near those which MI its host were formed. However, process reversing homogenization may introduce changes in compositions, making interpretation difficult. We series low high pressure experiments on plagioclase-hosted Plagioclase Ultraphyric Basalts (PUBs) designed develop methodology recovering time entrapment MIs. These included (1 bar) conducted as 30 min, 4 h, 1 day, days, 8 days), 7.5 kbar 2 days. The used was based CO -based pressures determined this sample. Experiments run times days exhibited compositional drift, most notably form increasing MgO This drift not observed kbars or shorter atm experiments. results are consistent with model where caused crystal relaxation driven internal within (the formed), together lower confining bar). Therefore, will produce least amount if runs made short periods (∼30 min) entrapment.