1. What agent of metamorphism is considered the most important agent? Why? 2. Distinguish between confining pressure and differential pressure. 3. Briefly define foliation. 4. Briefly describe the difference between slate, phyllite, schist, and gneiss. 5. Distinguish between slate and phyllite. 6. List at least two characteristics of nonfoliated metamorphic rocks. 7. Compressional stress plays a dominant role in what type of metamorphism? 8. Which type of plate boundary is typically associated with regional metamorphism? 9. How do minerals/particles align themselves when subjected to differential stress? 10. If you were on a class field trip and found an outcrop of nonfoliated light-colored rock, how would you determine whether it was quartzite or marble? How would you determine quartzite from quartz sandstone?.