oldest

youngest

Put these cars in age order. Put the oldest car on the bottom and youngest car at the top.

A

E

D

C

B

B

A

D

E

C

Topic: Relative Dating

Put these recording devises in age order.

youngest

oldest

A

E

C

B

D

B

C

D

A

E

Relative Dating:

Age of a rock or event in relation to other rocks or events.

Principles of Relative Dating

The layers and jagged rocks of the reef, Capitol Reef , Utah

Orange Layer

Red Layer

Green Layer

1. Principle of Superposition - oldest rocks are at the bottom.

Superposition in the Grand Canyon

2) Original Horizontality: Rocks are usually deposited horizontally.

Taughannock Falls, NY - Horizontal Strata

Normal faults are nicely exposed at several points within the canyon walls. Red Rock Canyon State Park near Mojave, California

3. Law of Deformed Strata: Tilts, folds or faults are younger

than the rocks.

Folded Strata

Undeformed Strata

Faulted Strata

Tilted Strata

4. Cross-cutting relationships- Igneous intrusions are

younger than rocks they intrude.

Before the lava & magma cools

After the magma and lava cools

Igneous Intrusions causes Contact Metamorphism Contact metamorphism with pegmatite Orchard Beach, Bronx

Hot Magma touches surrounding rocks

Heat

Granite Intrusion

Pre-existing rock

Pre-existing rock

Contact Metamorphism: shown by hachure marks

5. Included fragments: Older rocks break off into younger layers

Limestone

Uplift

Weathering & Erosion

Curved, wavy surface shows erosion

Unconformity

6) Unconformity Buried erosional surface

wavy line with

layer on top.

Gap of time missing.

Put it together using the Principle of Original Horizontality and the Principle of superposition

What are the relative ages of the rocks in this section?

D

C

B

A oldest

youngest

FQ: Place the letters in order from oldest to youngest

____ Youngest

____

____

____

____

____

____Oldest G

F

E

D C

A

B

Sequence 1: Uplift & Erosion

5. Erosion

4. Uplift

3. Shale Deposited

2. Sandstone Deposited

1. Limestone Deposited

Sequence 2: Faulting

4. Faulting

3. Shale Deposited

2. Sandstone Deposited

1. Limestone Deposited

Sequence 3: Folding

4. Folding

3. Shale Deposited

2. Sandstone Deposited

1. Limestone Deposited

Sequence 4: Igneous Intrusion

4. Igneous Intrusion

(contact metamorphism)

3. Shale Deposited

2. Sandstone Deposited

1. Limestone Deposited