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Week 3: Jan 24-28
  • Review of  some important igneous minerals
    • elements/ions in the crust
    • coordination of ions
    • silicates
      • orthosilicates
      • sorosilicates
      • cyclosilicates
      • inosilicates
      • phyllosilicates
      • tectosilicates
    • silica minerals
      • high quartz
      • low quartz
      • cristobalite
      • tridymite
      • coesite
      • stishovite
      • physical properties of quartz
    • feldspars
      • comparison of structure of feldspar to quartz
      • K-feldpspar, albite and anorthite
    • pyroxenes
    • olivine
    • feldspathoids
    • amphiboles
    • micas
    • Fe-Ti oxides
  • Classification of igneous rocks
    • fundamental division based on texture: plutonic vs. volcanic
    • plutonic rock classification based on mineralogy (IUGS or Streckeisen classification)
      • M<90, QAPF diagram
      • M>90, olivine-cpx-opx diagram
      • gabbroic rocks
    • problem with IUGS volcanic rock classification
    • Le Bas chemical classification of volcanic rocks
    • Classification of volcanic rocks in the field
    • classification schemes based on chemistry
      • based on silica content (acid, intermediate, basic, ultrabasic)
      • based on silica saturation (oversaturated, saturated, undersaturated)
      • based on alumina saturation (peraluminous, metaluminous, peralkaline)
    • Rock suite classifications
      • variation diagrams
      • Harker diagrams
      • Peacock "alkali-lime index"
      • subalkaline and alkaline suites (SiO2 vs alkalis plot)
      • tholeiitic vs.calcalkaline suites (AFM diagram)
      • important conclusions from these diagrams
        • variations are not random
        • suites seem to correlate with general tectonic setting

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