Engage: Rock Observations

three pictures of different rock formations

How are these pictures alike?

Explore: How does sediment form?

How does sediment form?

Click on the image below and follow the steps to observe what happens.

shifting rock layers

What processes form sediment?

 

Let’s take a closer look at the process of compaction.

thinned rock layers due to increased pressure
How could you model compaction?

 

Let’s take a closer look at the process of cementation.

Click on the hand lens below and follow the steps to observe what happens.

hand lens

What is cementation and how could you model it?

 

Let’s look at an example of how sedimentary rock forms.

Click on the image below to watch the video.

particles cemented together

What are some examples of sedimentary rock?

Explain: What processes form sedimentary rock?

In order for sedimentary rock to form, the following processes must happen:

  • Cementation
  • Compaction
  • Erosion
  • Deposition
  • Weathering

Copy the flow chart into a notebook and complete it using all of these processes. Two or three processes belong in each box.

processes that form sedimentary rock flow chart
 

What might be found trapped in layers of sedimentary rock?

alligator in a swamp

 

What do fossils turn into over time?

Click on the image to begin the video.

oil well

Elaborate: How do fossil fuels form?

What do you know about fossil fuels? 

What are fossil fuels?
Where are they found?
How are they made?

Click here to learn more. Draw a picture to illustrate the process of fossil fuel formation in four steps, beginning with a living organism.

blue question mark with a person sitting on it

Evaluate

To retake the quiz, reload the page and then select "no" when the "Resume Quiz" dialog box appears.

Teacher Notes

Engage
Students may answer this question in a myriad of ways, but they should observe the layering of rock. These pictures are of sedimentary rocks, which are characterized by layering.  Examples of sedimentary rock include sandstone, limestone, and shale. The oldest layers of rock are on the bottom with the newest layers on top. 

Explore
Students should begin by clicking on the rock cycle image. It will bring up a PBS website with an online interactive. Instruct students to click on the black box that says “LAUNCH.” A pop-up site will appear. Students will need to read and follow directions on the interactive to observe the process of sedimentary rock formation. Instruct students to pay close attention to the vocabulary and definitions. They may need to go through the interactive a few times to grasp all of the concepts.

Sediment forms when wind, water, or ice weathers, or breaks down, rock. These agents then carry the sediment to a new location through the process of erosion. Eventually, the sediment is deposited, or dropped, in a new location. Students first learn about the processes of weathering, erosion, and deposition in fourth grade (TEKS (4)(7)(B)).

Students will learn how igneous and metamorphic rocks form in grade 6 (TEKS (6)(10)(B)). However, it might help students to see how the formation of sedimentary rock fits into the rock cycle.

Over time, sediment becomes layered.  As the weight of the sediment layers builds, the process of compaction occurs due to increased pressure. Compaction is the process of squishing air or water from between sediment particles. 

The process of compaction could be modeled by layering blankets or towels and then sitting or lying on top of them. The addition of weight squishes the air or water from between the layers, causing them to thin due to increased pressure. 

Students should begin by clicking on the hand lens image. This will bring up a website by the Geological Society of London. Students should click on the maroon box that says “Play Animation” located at the bottom of the water and sand image.  Allow students time to work through the cementation interactive. Instruct students to read the directions and pay close attention to the vocabulary.

Minerals between sediment grains cement, or stick, the individual sediment grains together. This process is called cementation. Once the sediment is cemented together, sedimentary rock is formed.
  
Cementation could be modeled a number of ways, such as pouring glue onto a pile of rice grains.

Examples of sedimentary rock include sandstone, limestone, and shale.

Explain
Use this time to further debrief the Explore activities.

Solid rock is weathered by wind, water, or ice. The small sediments that break off are eroded and deposited. The deposited sediment then goes through the processes of compaction and cementation to create sedimentary rock.

Fossils from dead plants and animals are found in sedimentary rock. However, students may not know that. If not, tell them that the picture offers clues to the question’s answer. If they look closely, they will see the alligator in the water.

Over time, fossils are changed into fossil fuels. Students will see this in the short video and will learn more about the process in Elaborate.

Elaborate
Instruct students to click on the image. It will bring up a website created by Earth Day Canada. Students will need to click on the “Start” button located on the blue “EcoKids” tablet to begin the interactive. They will need to read through the “Fossil Fuels” section followed by coal, oil, and natural gas. They can use the navigation keys to scroll up and down and to go back to the main menu.

Fossil fuels are made from the remains of ancient organisms that were buried under many layers of sediment millions of years ago. With increased heat and pressure, fossils are turned into fossil fuels. Fossil fuels are found in sedimentary rock, which is often located beneath a body or former body of water such as an ocean or swamp.

Fossil fuels are nonrenewable resources that include oil, natural gas, and coal. They either have to be mined or drilled from Earth and cannot be easily replaced in a short amount of time. Students should have begun learning about fossil fuels as nonrenewable resources in fourth grade (TEKS (4)(7)(C)).

Student illustrations of fossil fuel formation will vary. Generally, they should begin with a living organism such as a fish swimming. The following picture could be a dead fish lying on top of the sand. The next picture might be the fish covered with a few layers of sediment. The last picture would be of the fish as a pool of fossil fuel under several sediment layers.    

Evaluate
The quiz has five questions. Students will have three attempts to correctly answer a question before the next question is introduced. Each question provides the student with immediate feedback. Following the completion of the quiz, students may review the quiz in its entirety to view correct and incorrect answers.

Answer Key
1. true
2. sedimentation, compaction, cementation
3. weathering, erosion, deposition
4. Compaction is the process of squishing air or water from between particles of sediment. Cementation is the process of minerals sticking individual grains of sediment together.
5. plant and small organisms lying on top of sand, plant and small organisms under layers of sediment, plant and small organisms grayed out under more layers of sediment