Let’s think through this step by step.
We’re looking at a diagram of rock layers — like slices of cake stacked on top of each other. In geology, when we see layers like this, the oldest layer is usually at the bottom, and the newest (youngest) is on top. This is called the “Law of Superposition.” It’s like if you poured sand into a jar over time — the first sand you pour ends up at the bottom, and the last sand you pour sits on top.
In the picture, there are five boxes pointing to different layers. We need to label them from 1 (oldest) to 5 (youngest).
So let’s go from bottom to top:
- The very bottom layer → that’s the oldest → label it
1
- The next layer up → second oldest → label it
2
- Then the middle layer → third oldest → label it
3
- Then the layer above that → fourth oldest → label it
4
- The topmost layer → youngest → label it
5
Now, for question 1:
*Why is the layer you labeled #1 the oldest?*
Because in undisturbed rock layers, the bottom layer was deposited first. Everything else piled on top of it later. So #1 had to be there before any of the others.
For question 2:
*What type of rock would form in the area shown with plant fossils?*
Plant fossils are usually found in sedimentary rock — especially shale or coal — because plants get buried under mud or swamp water, which turns into rock over time. Igneous rocks come from lava or magma — too hot for fossils. Metamorphic rocks are changed by heat and pressure — also bad for preserving fossils. So sedimentary rock is the answer.
Final Answer:
Label the boxes from bottom to top as:
Bottom box = 1
Next up = 2
Middle = 3
Above middle = 4
Top box = 5
Answer to Question 1: Layer #1 is the oldest because it was deposited first — all other layers formed on top of it later.
Answer to Question 2: Sedimentary rock — because plant fossils are preserved in layers of mud, sand, or organic material that harden over time.
Parent Tip: Review the logic above to help your child master the concept of fossil record worksheet.
