ESS 101 Lecture Notes - Lecture 2: Peridotite, Himalayas, Andes

• School: UW
• Department: Earth and Space Sciences
• Course: ESS 101
• Professor: Swanson Terry

Document Summary

Melt phase < always different composition > solid phase. Melt phase: more sio2 rich (felsic, less fe-mg rich (matic, less dense, lighter mineral color, lower mt (melting point) minerals. Solid phase: less sio2 rich, more fe-mg rich, more dense, darker colored mineral because fe-mg, higher mt minerals. Ocean-ocean lithosphere convergence (subduction: examples: japan & philippines, ocean crust =/= ocean lithosphere. Ocean-continent lithosphere convergence (subduction: examples: andes mountains & cascade mountains. Continent-continent lithosphere collision (no subduction: examples: himalaya mountains and european alps (1) partial melt of garnet peridotite mantle yields basalt (2) partial melt of subducted ocean lithosphere yields andesitic magma - andesite rock. Mechanisms that drive subduction of ocean lithosphere: ridge push, plate sliding or slab pull. Transform boundaries: typically form along mid0ocean rift zones. Spreading rate differs and the rigid ocean crust is offset along the transform fault. Andesite is a volcanic rock formed @ subduction zones. Ocean-continental convergence and formation of a continental volcanic arc.