Week 11 Blog Post

What did you do in lab?

        -     In lab this week, we talked about the Law of Superposition, which explains that the layers of a sedimentary rock go from oldest to youngest, and also go in a horizontal direction, which is explained by the Principle of Original Horizontality. We also learned how to determine the order of the rock layers from oldest to youngest when looking at a picture. One last thing we did in lab was look at various types of sand under a microscope and list their characteristics. We saw sand of many different colors, various sizes, smooth texture, rough texture, different shapes, etc. 

What did you learn in lecture?

        -     This week in lecture I learned that an objects buoyancy is related to the density of the object and its comparison to the density of water. We tested out multiple cans with liquid inside of them to see which ones would sink and which would float. We found that the cans with liquids that had sugar in them sunk, while those without sugar floated. This is because the density of sugar is higher than the density of water. I also learned that in order to determine if geodes are hollow, you can use the equation for specific gravity. The equation is Specific Gravity = W (air)/(W (air) - W (water)). Using this equation we determined whether or not a chosen rock was hollow, and it was. 

Textbook questions:

        -     What did you learn?

                -     In the reading I learned the difference between intrusive igneous rocks and extrusive igneous rocks. Intrusive igneous rocks have magma that cools slowly underground and inside of the Earth. Because of it being inside of the Earth, it has lots of protection and creates large crystals. On the other hand, extrusive igneous rocks have magma that cools more quickly in water and on the surface of the Earth. This time, smaller crystals are formed. 

        -     What was most helpful?

                -     Something that I found helpful in the reading was the image of the rock cycle. At times it can get confusing understanding how each rock is formed, but this image displays how each rock (igneous, sedimentary, and metamorphic) is formed, and also how they relate and transform into the other kinds of rocks. 

        -     What do you need some more information on?

                -     Something that I would like more information/practice on is using the specific gravity formula to determine if a geode is hollow or solid. In lecture I had a bit of trouble getting the correct answer, so I think that I just need some more practice using the formula.

What questions, concerns, and/or comments do you have?

        -     I have some prior knowledge on weathering and erosion so those are concepts that I feel I understand very well.