Earth Sciences 1022A/B Lecture Notes - Lecture 1: Phyllite, Gneiss

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Steve Hicock

Document Summary

Pressure: increases with depth: confining pressure: eg. burial pressure, under a lot of rocks, directed pressure: eg. from two plates coming together and forming a mountain belt; deforms rocks and the new metamorphic texture develops perpendicular to the directed pressure, chemical activity: ions in solution exchange with ions in minerals of the parent rock to form new. Local effect by magma intruding host rock: metamorphic aureoles form, minerals recrystallize but are not reoriented, marble (cooked limestone): coarse interlocking crystals of calcite, quartzite: coarse interlocking crystals of quartz, directed pressures orient (align) recrystallized minerals (foliation, most intense in the deepest part (roots) of the mountain belts.