ESCI 401 Lecture Notes - Lecture 10: Igneous Rock, Reduced Properties, Mantle Plume

• School: UNH
• Department: Earth Sciences
• Course: ESCI 401
• Professor: Boettcher, Margaret S.

Document Summary

It"s less dense - more buoyant - and the overlying rock squeezes the magma upwards as the two plates pull apart. : when you stand in mud, it oozes up between your toes: what are three ways magma forms, where and why does magma form? i. ii. Divergent plate boundary: mid-ocean ridge: heat and decompression melting. Convergent plate boundary: subduction zones: heat and water melting, mantle plume hotspots, heat melting, *melting occurs due to: i. ii. iii. Reduced pressure on a piece of the mantle ( decompression melting ) mantle material moves upward. Add volatiles (i. e. : water) mid-ocean ridges. Add heat (heat from rising magma) hotspot: what process forms magma at mid-ocean ridges, partial melt. A rock doesn"t completely melt at a single temperature i: melt + crystals that are coexisting with possible volatiles, volatiles we"d likely see: water, carbon and sulfur dioxide, geotherm: earth"s temperature as a function of depth i. ii.