Themes of the Day:

• More Chemical Classification, Plotting, and Trends
• Physical Properties of Magmas
• Field Relationships (for a few lava shots)
• Chapter 4 figures

More Chemical Classification, Plotting, and Trends

• Compositional Variation - Primary Cause of Different Behaviors
• IUGS Diamond for Volcanic Rocks
• IUGS Diamond for Volcanic Rocks (General)
• Color Index vs. wt% SiO₂
• Chemical Classification for Volcanic Rocks
• Harker Variation Trends
• Calc-Alkaline vs. Tholeiitic Trends on an AFM Triangle
• Spider Diagrams

Physical Properties of Magmas

• Compositional Variation - Primary Cause of Different Behaviors
• Intensive Variables (independent of volume)
• Example: Viscosity
  • Effect of Composition
  • Effect of Temperature
  • Effect of Pressure
  • Effect of Volatiles
  • Effect of Crystals
  • Effect of Bubbles (Vesiculation)
• Density