Geologic Time (The Rock Cycle) - 9/3/17

Summary:

Geology is the study of Earth, as well as Earth's structure and the forces that shape it. James Hutton's principle is that geologic processes that operate today operated the same way in the past. As well as in other places that have the same conditions. Hutton's principal, uniformitarianism, allows us to estimate what happened to rocks long before humans were on Earth and can help us predict what may happen to Earth in the future. There are three types of rocks, igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks form when molten material from under the Earth's surface cools and hardens. Sedimentary rocks are made of sediments that were deposited and then pressed together to form a solid rock.  Metamorphic rock is an existing rock that has been changed by heat, pressure or chemical reactions. As well as there are ways to tell a rocks age. There is the Relative age, and the Absolute age. The Relative age is when the age of a rock is compared to other ages of rocks, where as the Absolute Age is when the number of years since a rock was first formed. Rocks come in layers, oldest being at the bottom, and youngest being at the top. 

S&EP: Using Models

In class, we conducted an experiment using starbursts to model the rock cycle. The way we represented sediments was by cutting up our two different color starbursts into bits and pieces and piling them on top of each other. Since sedimentary rocks are made up sediments that are pressed together to form a solid rock, we made the pieces of the sediments stick together, by using our fingers and sticking them. We made sure not to press to hard, as that was the next step. Then we represented metamorphic, since they are formed by heat and pressure we had to put the sedimentary rock into the bag and formed pressure, by pushing on it and making it turn into a flat surface. After turning it into a flat surface, we had rolled it into a ball and put it into a microwave, turning it into a igneous rock. Our rock was turned into igneous by putting into the microwave (volcano). This model was extremely useful in helping visualize the main changes from one type of rock to another.

XCC: Patterns

The rock cycle is a pattern that never stops ending. As seen In the image above, the cycle has many different paths for it to become each rock. Magma or lava becomes igneous, Igneous becomes sediments, sediments become sedimentary rocks, sedimentary rocks become metamorphic rocks, and lastly, the metamorphic rocks start back again at magma/lava. It starts out as something then eventually through a process becomes something else, and then that gets reused again through a different process and turns into something else. In fact, you could compare the rock cycle to recycling. Magma and crystallization become igneous, igneous and weathering, erosion and deposition become sediment, sediment and compaction and cementation become sedimentary rock, sedimentary and heat/pressure become metamorphic rock, and after melting the metamorphic, it returns to magma. It's all a never ending pattern.