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Juan de Fuca Ridge creates new oceanic crust that moves away from the ridge at 3.5cm/year c.Takes 10 million years for the new crust formed at the ridge, to get to coast. d.The slab-pull of the oceanic crust is the main driving mechanism, but the upwelling magma creating a Ridge-push is also important. e.At the coast (i.e. Juan de Fuca trench), the heavy oceanic crust of the Juan de Fuca Plate submerges under the North American Plate. f.Responsible for forming the Cascade Volcanic Arc on the West-Coast of Canada and the United States. 2)Major spreading ridges – especially the mid-Atlantic ridge and the East Pacific rise a.Oceanic crust spreads away from the ridge axis. ■New crust is closer to the ridge; older crust farther away. ■Oldest oceanic crust is found at the far edge of the basin. b.Mid-Atlantic ridge: ■Oldest ocean floor (furthest from ridge) is 180 million years old ■Separates at about 2.5cm/year ■Bains sink as you get further from ridge (much deeper than east pacific because it’s slower) c.East Pacific rise ■Moves a lot faster than Mid-Atlantic ridge ■Bains sink as you get further from ridge 3)General classification and subclassification of igneous rocks (i.e. Granitic/Basaltic and then felsic, intermediate, mafic, ultramafic etc..)