GEO 1401 Lecture 10: GEO Test 3
Document Summary
Divergent oceanic oceanic produces: mid oceanic ridge. Magma fluid located in the (mantle) asthenosphere. Olivine: liquid ions: 93 natural chemical elements. Magma fluid erupts from volcano and as the gases escape into the atmosphere it becomes lava. Consolidation forms igneous extrusive rocks (very small silicates: volcanic glass (sio2) with no internal structure (obsidian or pumice) Types of explosions: quiet explosion basaltic lava, pahoehoe: ropey texture, aa: ragged texture, fumaroles toxic gases (co2, so2, h2ov, explosive pyroclastic flow (volcanic glass, pyroclastic material ( fire fragments ) from smallest to largest. All volcanism in hawaii and emperor islands. Convergent oceanic continental, convergent oceanic oceanic, continental hotspots. Most violent and explosive: explosions= sound waves that create earthquakes, hot debris, fires, toxic gasses, landslides, and pyroclastic flow. Form the ring of fire in the pacific ocean. St. helens 1980: grew crooked dome from increasing amounts of large lava bulges, 5-9-minute eruption, 6 years of exploding. St. helens: part of the cascade mountains (composite)
