Metamorphic Rocks

Controlling Factors:
        Heat, intrusions, burial - geothermal gradient is ~25°C/km; 
        Pressure, burial - confining pressure, tectonics - differential pressure;
        fluids, hydrothermal mineralization  

Effects: change minerals - affected by composition, temperature and pressure; recrystallization (quartz, calcite), growth of new minerals (clay >> mica, garnet)

contact metamorphism, high Temperature dominates, contact with hot magma, recrystallization and growth of new minerals; texture is not greatly changed, metamorphic aureole, effects decrease with distance from intrusion, hot fluids flow out from magma forming hydrothermal minerals and veins

regional metamorphism, high Temperature and Pressure; burial, mountain building, recrystallization and growth of new minerals; texture is changed, foliation, index minerals, metamorphic zones

dynamic metamorphism, high  Pressure; extreme shearing along fault zones; texture is changed

Classification :
contact metamorphism,
    mudrocks >>>hornfels
    limestone >>> marble
    quartz sandstone >> quartzite

regional metamorphism:

limestone >>> marble

quartz sandstone >> quartzite

mudrocks >>slate or schist
          sandy mudstone or felsics >>> gneiss

dynamic metamorphism:

mylonite

Compare and contrast contact and regional metamorphism in terms of conditions, cause, processes and resulting rocks. Why are marbles and quartzites the only rocks which can be formed as a result of either process?  What makes dynamic metamorphism so unique?

Define foliation. How does it form? What are the differences between slate, schist, and gneiss? Why aren't marble and quartzite foliated?