least silica) mafic intermediate felsic (most silica) magma forms from melting rock mafic igneous rocks form at mid-ocean ridges hot spots subduction zones intermediate rocks form at subduction zones felsic igneous rocks form at ocean-continent subduction zones felsic magmas form from mix of plate, sediment, water, mantle material, and continental material Reading: Lecture 9 notes , Chapter 4 Lecture 10: Volcanoes volcanoes happen mostly at plate boundaries and hot spots form lavas and pyroclastic materials lava type determines eruption explosivity mafic high melting temperature, low silica, and low structural complexity give low viscosity felsic low melting temperature, high silica, and high structural complexity give high viscosity the higher the viscosity, the more explosive the eruption (all other things being equal) what types of volcanoes happen at what kinds of plate tectonic environments divergent boundaries: mafic volcanism hot spots: mafic volcanism convergent boundaries mafic-to-felsic volcanism depends on mix of materials in the melt Reading: Lecture 10 notes , Chapter 5 Lecture 11: Weathering weathering breaks down rocks 3 main kinds physical chemical biological examples of physical weathering mechanisms frost wedging heat/cold cycles unloading abrasion examples of chemical weathering mechanisms dissolution oxidation hydration know what affects weathering rate climate soil absence/presence exposure time rock type massive or fractured types of minerals making up rock resistance of those minerals to weathering relative resistance of minerals/rocks to weathering (i.e., which weathers most quickly, etc.) Table 6.2.
(all; weathers most quickly; ) (most silica) magma forms from melting rock mafic igneous rocks; form; L:at mid-ocean ridges hot spots) (minerals; making up; rock resistance of those minerals) (heat/cold cycles; unloading; abrasion examples of chemical weathering mechanisms) (all other things; being; equal) (lava type; determines; eruption explosivity mafic high melting temperature, low silica, and low structural complexity) (dissolution oxidation hydration; know; what affects weathering rate climate soil absence/presence exposure time rock type massive or fractured types of minerals)
all most silica) magma forms from melting rock mafic igneous rocks minerals heat/cold cycles all other things lava type dissolution oxidation hydration
weathers most quickly form making up unloading being determines know
L:at mid-ocean ridges hot spots
rock resistance of those minerals
abrasion examples of chemical weathering mechanisms
equal
eruption explosivity mafic high melting temperature, low silica, and low structural complexity
what affects weathering rate climate soil absence/presence exposure time rock type massive or fractured types of minerals