GEO 1111 Lecture Notes - Lecture 9: Metamorphic Rock, Protolith, Wollastonite

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: David Schneider

Document Summary

Lecture 9: metamorphic rocks: metamorphic rocks are those that have undergone solid-state alteration of preexisting rocks. Morphe = form: the preexisting rocks that are altered during metamorphism are called protoliths. Metamorphism can alter any protolith (igneous, sedimentary, or metamorphic). Metamorphism: = process by which temperature, pressure and chemical reactions alter mineral content. & structure of pre-existing rock (without melting, solid-state only: occurs when t & p break some atomic bonds, metamorphic rocks produced from (potential protoliths) : igneous rocks sedimentary rocks. Other metamorphic rocks: all metamorphic rocks start as some other rock, so 3 questions: Protoliths: protoliths undergo changes in texture and mineralogy, these changes are due to variations in temperature, pressure, tectonic stress, and the amount of reactive water. In this case, limestone (left) is metamorphosed into marble (right): metamorphism changes the mineralogy of the protolith but chemical composition is identical. Protolith: red shale, made of quartz, clay, and iron oxide.