This week of class was the most eventful of the year. We finished up our rock identification lab packet. Also, this week was the final week leading up to our first exam. We got a chance to review and ask questions on friday but the majority of the info came from monday and wednesday’s classes. On monday we looked further into rock identification and info leading into the lab for the week. We looked online at pictures and properties of the various minerals that we will need to learn and memorize for the mineral property id quiz coming up next week. Also, we finalized the correct identification of the rocks we had to guess at based on the tests we put each one through. I can honestly say that I missed probably over half of the minerals. After clearing each one up with the correct names and composition, I now have a better understanding of what I was doing wrong in conducting the tests.
On wednesday we looked at the many principles in geoligic rock formations and why each formation occurs like so. One that we looked at was the principle of super position, which is the ideal that when layers of rocks and minerals form over time, they stack up as time goes on. The obvious explanation for this concept is that the bottom most layer would be the oldest layer of the group and the youngest layer would be the most recent added one, which would appear on top of the older, bottom layers. Another principle we looked at in class is the principle of origional horizontality. To explain this one we looked at a picture of a man standing next to a rock formation in which the rock is standing almost completely virticle showing that somehow that rock was meddled with over time to be shifted upright. The next principle is where one series of rock cuts through an older formation of rock so that the older piece is intruded on. This principle is known as the principle of cross-cutting relationships. We looked at a picture where a layer of basalt cuts through a layer of granite giving the image that there are two layers of granite, though there is only one that is intruded on.
We also looked at formations that were out of the ordinary that are called unconformities. One of these unconformities we looked at was an angular unconformity. This formation showed three layers or so on top of a series of layers that bent and curved almost as if they were waves in the ocean. I thought the interesting feature in the angular was that some of the layers curved up in to the flat layers and appeared as if they dissapeared.
During my review for the exam, I found that I actually took pretty good notes because judging by the study guide, I can almost just study my notes. I think I will be fine for this exam and I’m really hoping for a good grade so I can start out right.