LAUSR

Abstract Vesicle textures in submarine lavas have been used to calculate total (pre-eruption) volatile concentrations in mid-ocean ridge basalts (MORB), which provide constraints on upper mantle volatile concentrations and global mid-ocean ridge CO2 flux. In this study, we evaluate vesicle size distributions (VSDs) and volatile concentrations in a suite of 20 MORB samples that span the range of vesicularities and vesicle number densities observed in MORB globally. We provide recommended best practices for quantifying vesicularity, vesicle number densities, and VSDs based on synthetic vesicle populations and comparisons between traditional 2D estimates and X-ray computed micro-tomography results. For 2D measurements, we recommend analyzing multiple polished fragments with a cumulative area > 100 times the area of the largest observed vesicle and including >200 vesicles in stereological VSD reconstructions. For 3D measurements, we recommend analyzing sample volumes >0.01 cm3 at resolutions 0.1 cm3 with resolutions