Relative Age Worksheet worksheet - Free Printable

Let’s go step by step through each question using the rules of relative age dating. These rules help us figure out which rock layer or event happened first (older) and which happened later (younger).

The main rules we’ll use:
1. Law of Superposition: In undisturbed layers, the bottom layer is oldest, top is youngest.
2. Cross-Cutting Relationships: If something cuts across a rock layer (like a fault or intrusion), it must be younger than the layer it cuts.
3. Inclusions: If a rock contains fragments of another rock, those fragments are older than the rock that holds them.

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Question 1: Layer A or Layer C

Look at the diagram — Layer C is at the very bottom, then B, then A on top. So by superposition, C is older than A.

→ Older: Layer C

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Question 2: Layer C or Layer B

Again, looking at the order from bottom to top: C → B → A. So C is below B → C is older.

→ Older: Layer C

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Question 3: Intrusion D or Layer A

Intrusion D cuts through Layer B and goes up into Layer A. That means D had to happen AFTER both B and A were already there. So Layer A is older than Intrusion D.

→ Older: Layer A

Wait — let’s double-check. The intrusion D cuts through B and also appears in A? Actually, looking again — D starts in C, goes through B, and stops before reaching the top of A? Or does it cut A?

Actually, in the diagram, D cuts through B and ends within A — meaning A was already there when D intruded. So yes — A is older than D.

But wait — if D cuts through A, then D is younger. Let me re-express:

If an intrusion cuts through a layer, the intrusion is younger. Since D cuts through B and also seems to cut through part of A (or at least reaches into it), then D is younger than A.

So Layer A existed before D came in.

→ Older: Layer A

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Question 4: Layer A or Fault E

Fault E is a crack that cuts through Layers A, B, and even Intrusion D. That means Fault E happened AFTER all of those were formed. So Layer A is older than Fault E.

→ Older: Layer A

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Question 5: Intrusion D or Fault E

Fault E cuts through Intrusion D. That means Fault E happened after D was already there. So Intrusion D is older than Fault E.

→ Older: Intrusion D

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Now moving to the second diagram (questions 6–10):

This one has tilted layers (Q, O, N, M, L) and then horizontal layers on top (H, I, J, K). Also, there’s an intrusion P cutting through some layers.

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Question 6: Layer H or Layer K

Layers H, I, J, K are stacked horizontally on top. H is at the bottom of this stack, K is on top. So by superposition, H is older than K.

→ Older: Layer H

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Question 7: Intrusion P or Layer H

Intrusion P cuts through the tilted layers (including Q, O, N, etc.) but does NOT cut through Layer H. In fact, Layer H sits on top of everything, including where P might have ended. So P must have happened before H was deposited. Therefore, Intrusion P is older than Layer H.

Wait — actually, look carefully: Does P cut into H? No. H is above all the tilted stuff and above P. So P happened before H was laid down.

→ Older: Intrusion P

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Question 8: Layer M or the fragments in M

Layer M contains fragments (pieces) of other rocks inside it. Those fragments had to exist BEFORE they got stuck in M. So the fragments are older than Layer M.

→ Older: the fragments in M

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Question 9: Intrusion P or Layer Q

Intrusion P cuts through Layer Q. That means P is younger than Q. So Layer Q is older.

→ Older: Layer Q

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Question 10: Layer H or the tilting of Q-L

The layers Q, O, N, M, L are tilted. Then, on top of them, we have flat-lying layers H, I, J, K. That means the tilting happened BEFORE Layer H was deposited. So the tilting event is older than Layer H.

→ Older: the tilting of Q-L

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Final Answer:
1. Layer C
2. Layer C
3. Layer A
4. Layer A
5. Intrusion D
6. Layer H
7. Intrusion P
8. the fragments in M
9. Layer Q
10. the tilting of Q-L