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Week 4: Jan 31-Feb 4

Phase diagrams
  • systems, components and phases
  • The phase rule
  • liquidus and solidus
  • What can be deduced from phase diagrams?
    • liquidus and solidus T for various compositions
    • numbers and kinds of co-existing phases for various P, T, and X
    • relative amounts of phases for P, T, and X
    • composition of melt and solids at any P, T, and X
  • 2 component system without solid solution and with congruently melting phases  (Di + An)
  • the eutectic
  • equilibrium crystallization, fractional crystallization, equilibrium melting, fractional melting
  • 2 component system with an incongruently melting phase (Fo - silica)
  • the peritectic
  • significance of Fo-silica diagram to undersaturated, saturated, and over saturated magmas

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