Relative Dating Laws

Digging into
Relative Dating

Reorder

LET'S REVIEW!

Reorder the following the layers below to list them in order from YOUNGEST to OLDEST.

• 5

• 4

• 3

• 2

• 1

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Multiple Choice

What geological law did you use as your reasoning for the order of the layers in the previous slide?

• Law of Superposition

• Law of Thermodynamics

• Law of Buoyancy

• Law of Continental Drift

• states that sediment layers are deposited in horizontal or nearly horizontal layers due to gravity

​

The Principle of Original Horizontality

​This means that any "sloping" of layers must have occurred AFTER the layers formed!

Reorder

Reorder the following diagrams in the order in which they occurred (left = first; middle = second; right = third).

1

2

3

• 1
• 2
• 3

• states that the geologic feature which cuts another is the younger of the two features

• Types:

  • Fault

  • Intrusion

  • Unconformity

​

Cross-Cutting
Relationships

• a fracture or break in the Earth's crust where two blocks of rock can move relative to each other, essentially causing a displacement between the rock layers along the fault line

• The fault is YOUNGER than the rock layers around it!

​

Faults

​Can you spot the fault?!

Reorder

Put the layers in order from OLDEST to YOUNGEST.

**Pay close attention to layers A & B!**

• C

• D

• B

• A

1

2

3

4

• 1
• 2
• 3
• 4

• a body of igneous rock, formed from magma that cooled and solidified within the Earth's crust, which has pushed its way into existing rock layers

• The intrusion is YOUNGER than the rock layers around it!

​

Intrusions

Reorder

Reorder the following layers in order of YOUNGEST to OLDEST.

• 5

• 1

• 4

• 3

• 2

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

• caused by a period of erosion or a pause in sediment accumulation, followed by the deposition of sediments

• Angular Unconformity = a gap in the sedimentary record that occurs when younger, flat layers of rock are deposited on top of older, tilted layers of rock

Unconformity

Reorder

Reorder the following rock layers in order of OLDEST to YOUNGEST.

• D

• E

• F

• G

• H

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Draw

CREATE and LABEL a model of rock strata (layers) that demonstrate the following ideas:

1 - Law of Superposition

2 - Faults

3 - Intrusion

4 - Angular Unconformity

Your outcropping model must include at least 6 rock layers!

Word Cloud

What are the 2 most important words you worked with today?