GEOL 101 Lecture Notes - Lecture 2: Oceanic Crust, Convergent Boundary, Basalt
Document Summary
Earth"s magnetic field: it"s like there is a huge magnet in the center of the earth. Apparent polar wandering: you can check cooled magma to tell where the continental plates were before they moved. Much thinner (distance from gmu to dc; 7-10 km) composition: basalt. Density: heavier (more likely to sink) recycled: continental: Much thicker (about 20-70 km) composition: granite. Three kinds of plate boundaries: divergent: plates move apart. Mantle moves up through the oceanic ridges and makes new oceanic crust. Ex: the red sea: convergent: plates move together. The denser plate will go underneath the lighter plate as they come together (subduction zone) Continent-continent: transform: plates slide past one another. 2 pieces of crust slide past each other with tension in between them and then move a great distance. Occur mostly in the ocean and can be found on continents every once in a while.
