Vesicular Pores of Pumice by Mercury Intrusion

Abstract The pore size distribution of pumice was measured with a mercury intrusion porosimeter. Effects of particle to particle pores were minimized by use of separates based on size and density. Vesicular pores constituted about 98% of the fine porosity (<120µ diameter) in 1–0.5 mm fractions of pumice. Average diameters of internal pores of pumice were found to be in the range of 3 to 7µ. Distinctive curves were obtained for samples from Mt. Mazama, Glacier Peak, and Newberry Crater.