ESS261H1 Lecture Notes - Lecture 9: Oceanic Basin, Seafloor Spreading, Rock Cycle
Document Summary
This is the scientific theory that describes the large-scale motion of earth"s lithosphere. This theoretical model builds on the concept of continental drift, which was developed during the first few decades of the 20th century: lithospheric plates. Two types of crust come to mind: oceanic crust and continental crust. Oceanic plate: mafic/basaltic rocks or sima = rich in iron & magnesium = thinner yet denser. Continental plate: felsic or granitic = granitic rock = thicker yet less dense. Distinction b/w lithosphere and asthenosphere: rigidity of lithosphere floats allows this to float on the plastic asthenosphere. Lithosphere: located uppermost mantel and includes the two different plates. Plate boundaries marked by earthquakes, volcanoes, mountain belts as their movement varies from 0 to 100 mm annually. Where plates meet, their relative motion determines the type of boundary: convergent, divergent, or transform. Is a linear feature that exists b/w two tectonic places that are moving away from eachother.
