01:460:100 Lecture Notes - Lecture 6: Source Rock, Igneous Rock, Basalt

• School: Rutgers University
• Department: Geological Sciences
• Course: 01:460:100
• Professor: Mark Feigenson

Document Summary

Chapter 6 - up from the inferno: magma and igneous rocks. Solidifies molten rock [which freezes at high temp. ] Melted rock can cool above or below ground: [intrusive. Cool slowly underground] [extrusive - cool quickly at the surface] The base of the crust is hot enough to melt mantle rock. Due to high pressure, the rock does not melt. Rising magma carries mantle heat, this raises the temperature in crustal rock, and crustal rock melts at a lower temp. Cause rock to melt at much lower temp [water, carbon dioxide], adding volatiles to hot, dry rocks initiates melting. Geothermal gradient varies from place to place. Solid - solidified mineral are carried by the liquid. Liquid - the melt itself is comprised of mobile ions. Gas - volatiles dissolved in the melt [dry magma has no volatiles, wet magma has up to 15% of volatiles] Magma composition - composition controls density, temp, and viscosity. Silica-rich magmas are thick and viscous.