Earth Sciences 1022A/B Lecture 7: Earth Science Lecture January 28 2016

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

Document Summary

Rocks can be deeply buried, intruded by magma or squeezed: they are subjected to heat, pressure, and chemically active fluids. Parent rock: metamorphic rock retains much the same chemistry at the parent. Heat: drives chemical reactions that crystallize mineral in the parent rock as it bakes. Heat from magma intrusion and from deep i the earth. Pressure: confining pressure or directed pressure under which minerals realign to form a new texture. From all directions, by colliding lithospheric pates, foliation. Chemical activity: water is important in mineral transformations. Commonly loaded with ions in the rock"s pore spaces and water is also released from minerals on heating to react with minerals in the parent rock to form new minerals. The intensity of metamorphism: increases mainly with temperature as indicated by index minerals in metamorphic rocks. Caused by magma intrusion into cooler parent rocks: results in metamorphic aureoles with decreasing effect away from the intrusion.