Top 5 Things to Help You Pass the Class

I am a geology major about to graduate in April. Since I have been a TA for Geology 101 classes and seen some students struggle while others succeed, I've decided to give my "Top 5 Things to Help You Pass the Class." These are simple tips, but could help make the difference between an "A" and some "other" grade. My first post deals with tip #5.

5. Be sure you know the difference between sedimentary rocks, intrusive rocks, extrusive rocks, and metamorphic rocks. In the walk-in labs I TAed, students would often get confused between the different types of rocks, particularly the granitic(intrusive rocks) and metamorphic rocks. A metamorphic rock is any kind of rock (sedimentary, intrusive, extrusive, or even metamorphic) that has been exposed to high pressures and temperatures causing deformation. If you look at the rock and the minerals look kind of melted it is most likely a metamorphic rock. Intrusive rocks have larger crystals (because they cooled more slowly) while extrusive rocks have smaller crystals. Sedimentary rocks are pretty easy. If they aren't intrusive, extrusive, or metamorphic then they're sedimentary.