Week 10: Rock Cycle

Learning in Lab:

This week in lab we looked closer at what constitutes as a rock and how the three different rock types are created. We started with a formative assessment where we were given a list of items and had to determine if they were considered a rock, and why we thought that. After completing the assessment, we learned that a rock is naturally made, therefore items like a gravestone or marble statue are not considered rocks since they were make by humans. Limestone, cooled lava, and sediments are considered rocks because they are made through natural processes. We then experimented with the rock cycle by creating the three different types of rock, sedimentary, igneous, and metamorphic. Sedimentary is when materials are cemented and tightly packed together. We created this by cheese grating three different colors of starburst, then compacting them together into a little ball to represent the small minerals combined together. For our igneous rock, we took two different colored starbursts and melted them together with the torch. This represents and igneous rock because we melted the two starbursts and then they cooled as one new type of starburst. Finally, we made a metamorphic rock by using the heat and pressure of our hands to combine three different colored starbursts together. If I were to do this activity again, I would try and complete the rock cycle by only using the same three starbursts the whole time. 

Examples of Sedimentary Rock

Learning in Lecture:

This week in lecture we talked more about the rock cycle and plate tectonics. We started by discussing the different plate boundaries that occur within the Earth, convergent, divergent, and transform. Convergent boundaries are when the plates converge together and create mountains or trenches. Divergent boundaries are when the plates move apart from each other and create ridges. Transform boundaries are when the plates slide past each other and create earthquakes. Hot spots are areas on Earth where magma rises to the surface and cools. Hawaii is an example of a hot spot that created islands, Maui is the youngest island and Kauai is the oldest island. We then moved on to talk about evidence of Pangea such as the continents fitting together like a puzzle piece or fossil evidence of the same species being found in different continents. Finally, we talked about the rock cycle and related our learning to the lab section. Rocks can also be displaced in different ways such as weathering with wing, water, or glaciers. The two types of weathering and erosion is mechanical and chemical. Mechanical weathering is just breaking down the rock into smaller pieces. Chemical weathering happens when chemical reactions changes the composition of the rock such as rust. 

Example of an Igneous Rock

Textbook Connections:

1. What did you learn?

I learned that the Earth has four layers, the crust, mantle, outer core, and inner core. The crust is the outermost layer and is thin compared to the other layers. This layer is made up of rocks and is broken into many pieces called plates. Plates can be both oceanic and continental. The next layer is the largest and it is called the mantle. The upper part of the mantle is made of magma and causes the plates in the crust to move, which forms trenches, volcanos, mountains, etc. The last layers are make up the Earth's core, the outer core is liquid and comprised of iron and nickel. The flow of these liquids creates Earth's magnetic field which is why our compasses point North. The inner layer is also made of nickel and iron, but it is solid because it is always under intense pressure. I also learned about the three tectonic plate boundaries, transform (plates sideswipe each other), divergent (plates pull apart), and convergent (place push into each other). Convergent boundaries can form mountains on land, trenches underwater, or a volcano with a continental and oceanic plate converge. Divergent plates create mid-ocean ridges or a large crack in the ground. Around 80% of Earth's surface has come from a volcanic eruption. There are two types of eruptions, and effusive eruption where lava slowly flows onto the ground, and explosive eruptions where magma is fiercely and rapidly expelled from the volcano. Earthquake happens when a rock moves along fault lines at transform boundaries and cannot easily pass, building up stress and pressure until the rock snaps and is released as seismic waves. Fossils and the Law of Superposition help give scientists an idea of how old or how long ago something was formed. 

2. What was most helpful?

The most helpful part of this chapter was the video on how the Hawaiian islands were formed. This is a interesting topic that I have never heard of before. The video helped me get an idea of how exactly the islands were formed by hit spot volcanos on the Pacific Plate. 

3. What do you need more information on?

Something I would like more information on is the three different types of plate boundaries. The pressbook briefly touched on and described each boundary, but I think it would be helpful to see a simulation of how a volcano or earthquake actually forms through the shifts in the plates. 

4. What questions, concerns, or comments to do you have? 

Will there be a time that plate tectonics shift all of the continents back together like another Pangea?

All Rock Formation Examples