ESCI 1001 Lecture Notes - Lecture 5: Crystallization, Viscosity, Asthenosphere
Document Summary
Liquidus conditions at which rock completely melts. Solidus conditions at which rock starts to melt. Geotherm temperature as a function of depth. Magma formation: decompression melting decrease pressure; no change in temp, continental rifts, mid-ocean ridges, asthenosphere melts, fluid-induced melting decrease melting temp by adding water, subduction zones a. i. Water reduces melting temp of mantle a. iii. Magma structures and volcanoes: addition of heat, hot spots / mantle plumes. Continental crust = essentially composition of granite; felsic. Oceanic crust = essentially composition of basalt; maphic. Magmatic differentiation: fractional crystallization progressive formation of crystals & settling of those crystals, early forming crystals are mafic, partial melting start with rock and heat until it melts, first to melt will be felsic. Dike a planar intrusion that crosscuts layering. Sill planar intrusion that is parallel to layering. Plutons blob-like intrusion forms deep within earth (5-40 km) Batholiths collection of pluton > than 100 km2.
