After two semesters taking "general education" courses: Intro to Geology, Fossils and Evolution of Life class, Mineralogy (with a semester of mineral identification and another for optical interpretation), and a Geochemistry class which was great but more on the theoretical side, I I was plenty ready to begin taking more field and rock based courses. The fall of 2010 semester did not disappoint and certainly validated my choice to major in geology.
Igneous and Metamorphic Petrology
Igneous and Metamorphic Petrology happened to be a reprise of Geochemistry for the first couple weeks, with a solid review of Bowen's reaction series, the layers of the Earth and of the three major plate tectonic margins. I did however begin to better appreciate that tectonic motion is strongly tied to mantle convection and my first introduction to thermodynamics as they apply to earth systems was a refreshing change from the more elementary chemistry and physics explanations I had received in college. Our textbook for the class
Principles of Igneous and Metamorphic Petrology 2nd Edition by John D. Winter is really a great reference and was the first geology text I wanted to make sure I kept.
My main take away from the course however was how igneous and metamorphic
textures of minerals within a rock aid in determining the
petrogenetic history of that rock. Phase and Ternary diagrams were also used to their full effect in this class, and these really helped me to understand the basics of the processes occurring within magma chambers during crystallization, melting, and recharge events. Overall though, it was nice to actually deal with rocks in hand sample (even if we did get a bit sick of basalts) and to use thin sections and to find which skills we acquired in optical mineralogy were most useful was also a thrill.
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Mafic enclave within rhyolitic or dacitic rock in Cleophus Canyon, near Ft. Selden, NM. Access is limited since there are petroglyphs within the area as well. |