ERS 100 Lecture Notes - Lecture 16: Metasomatism, Protolith, Shock Metamorphism

• School: University of Maine
• Department: Earth Sciences
• Course: ERS 100
• Professor: Kelley

Document Summary

Recrystallization: changes to shape and size of grains related to heat and/or pressure (sugary/ granular texture common) (sandstone to quartzite) Phase change: one mineral to another with change in crystal structure. Neocrystallization: growth of new mineral crystals (shale to mica schist). Pressure solution: unequal pressure causes solution and re-precipitation of minerals (ice skating) Plastic deformation: pressure at high temperatures causes clasts to deform plastically. Direct stress is pressure that is greater in one orientation. The two kinds of direct stress is normal and sheer. Increased foliation some foliation created by the growth of platy minerals. The larger the minerals, the greater the degree of foliation. Foliation created by the growth of platy minerals creates metamorphic rock texture called cleavage . Foliation can also be produced by compositional bands. Non-foliated: no growth of platy minerals: classified by composition (quartzite, marble, amphibolite, hornfels): metamorphic facies are mineral assemblage from a specific protolith at specific pressure and temperature conditions.