EOSC 114 Lecture Notes - Fourier-Transform Infrared Spectroscopy, Vise, Fluid Dynamics
Document Summary
Identify key properties (density, viscosity, silica content, & temperature) of different types of magma: magma: Magma viscosity: 10-10^15 (depends on temp, gas content and crystallization) Felsic rocks- 65%-75%- light colored high viscosty (sticky e. g rhyodlite, granite. Mafic rock 45%-55% - dark colored low viscosity (runny) e. g basalt. Temperature: 600-1200 hotter the less viscosity thus less silica. Gas content : less then 10% gas which decreases viscosity and density- thus causing it to rise. Explain why magma erupts or not: mafic- low gas, and viscosity= effusive, felsic high gas, and viscosity= explosive. Describe the different types of eruptions and how they are related to magma properties: non explosive- lava, explosive ash. List the different categories of volcanic rocks and explain the differences between the magmas they cooled from: basalt- mafic- hot, andesite and dacite- intremidate, rhyolite- felsic cool. Explain why some magmas erupt explosively (as pyroclastic material) and some magmas erupt effusively (as lava: viscosity!