Formation of Dense Pyroclasts by Sintering of Ash Particles During the Pre-climactic Eruptions of Mt. Pinatubo in 1991

James E Gardner, University of Texas at Austin, Department of Geological Sciences, Jackson School of Geosciences, Austin, TX, United States, Yining Wang, The University of Texas at Austin, Jackson School of Geosciences, Austin, TX, United States and Richard P Hoblitt, USGS-Cascades Volcano Observat, Vancouver, WA, United States