The history of our planet is recorded in the igneous, sedimentary and metamorphic rocks that formed throughout the development of the earth. In these rocks we find the evidence for ancient volcanic eruptions, shallow inland seas, and extensive mineralogical and structural changes which occurred deep beneath the earth's surface.
Geology 12 is the study of the igneous and metamorphic rocks and the processes which form them. Together, these rocks comprise 95% of the earth's crust and are exposed over approximately one-third of the continental land masses.
Petrology begins with a review of the classification of igneous rocks, followed by a study of the field occurrences, mineralogy, textures, compositions and origins for the major extrusive and intrusive rock associations. As the semester proceeds, experimental evidence is evaluated which can shed light on the origin and crystallization of magmas. During the second half of the term, metamorphic rocks, processes, and structures are considered from a field, laboratory, and experimental perspective. Igneous and metamorphic rocks and processes are considered at all scales, from global plates, mountain ranges, large outcrops, and hand-samples, through microscopic and submicroscopic observations.
Laboratory work emphasizes hand sample and microscopic analysis of rocks and rock suites, often in the context of their natural field occurrences. Field identification and interpretation of igneous and metamorphic rocks will be one of the major goals of the course. Weather permitting, we will visit several igneous and metamorphic rock localities late in the semester.
