ERTH 2415 Lecture Notes - Lecture 16: Extrusive Rock, Cinder Cone, Mount Vesuvius
28 Aug 2018
School
Department
Course
Professor
Document Summary
Composition: as a result of planetary differentiation: of the crust, 8 elements form 98% of the crust, silicon and oxygen account for 75% Intrusive igneous rocks: inside, cooling at depth, slow cooling, large crystals, most magmas solidify at depth and are later exposed by. Viscosity erosion: cooling at the surface, synonym: volcanic, fast cooling, small crystals, contact with the atmosphere or water, the less viscous a fluid, the faster it flows. Viscosity: viscosity is the most important property controlling and volatiles magma behaviour and, therefore, eruptive style. Materials: amount of solids in the melt, more solids, higher viscosity, ejecta, volcanic material extruded onto the earth"s surface and into the atmosphere, lava: magma that reaches the surface, pyroclastic material (syn. Tephra): material formed by volcanic explosion or aerial expulsion from a volcanic vent: volatiles: mainly h2o, co2, so2. Lava: high % sio2: viscous lava, flows slowly, lava flows with jagged upper surface aa.
