Viscosity 13 : Measure of the fluidity of a substance. Taffy and molasses are very viscous; water has low viscosity. (Teacher's Packet). Basalt is less viscous than dacite
U.S. Department of the Interior, U.S. Geological Survey, US Geological Society (USGS), Glossary of Volcano and Related Terminology, USGS/Cascades Volcano Observatory, Vancouver, Washington, USA 2006. http://vulcan.wr.usgs.gov/Glossary/volcano_termino logy.html, (ND/ Volc Sci - Amer) {493}