EAS100 Lecture Notes - Lecture 13: Isostasy, Lithosphere, Metamorphic Rock

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS100
• Professor: Alessi,Daniel

Document Summary

Eas 100 lecture 13 plate motion and tectonic mechanisms. Plate boundaries: divergent, constructive margins in which the plates are coming apart, which means new plate material is being created. Divergent plate boundaries: two plates move apart, centres spread further and further away, but this can cause weakness in the crust! Continental-continental divergent will heat up from the convection forces underneath and will eventually create a rift: new plate is being made to replace it, passive margins not violent cause of earthquakes. Magma rises up and forms continental arc volcanoes: benioff zone is the zone of shallow and deep focus earthquakes within the subduction zone boundary. In an oceanic-oceanic convergence, typically one plate subducts and carries water with it, as well as rock at some point we will see melting; water reduces the melting point! If there was an ocean basin or body of water, when the continental plates collide, it will disappear.