Transcript 1 Relative Dating

Topic: Relative Dating
What is the usual order these
meals are eaten during the day?
C
A
B
D
Typical Order
D
B
C
A
Relative Dating:
--
Principles of Relative Dating
Orange
Layer
Red
Layer
Green
Layer
The layers and jagged rocks of the reef, Capitol Reef , Utah
1. Principle of Superposition –
Superposition in the Grand Canyon
2) Original Horizontality -
Normal faults are nicely
exposed at several points
within the canyon walls. Red
Rock Canyon State Park near
Mojave, California
3. The Law of Deformed Strata:
-
Tilted Strata
Normal Strata
Folded Strata
Faulted Strata
4. Cross-cutting relationships-
Before the lava & magma cools
After the magma and lava cools
Igneous Intrusions causes Contact Metamorphism
Pre-existing
rock
Preexisting
rock
H
e
a
t
Hot Magma
touches
surrounding
rocks
Granite
Intrusion
Contact metamorphism with pegmatite Orchard Beach, Bronx
Contact
Metamorphism:
shown by
hachure marks
5. Included fragments: -
6) Unconformities
Buried erosional surface -
Weathering
& Erosion
Curved, wavy surface shows erosion
Uplift
Limestone
Unconformity
Layers are formed according to superposition.
Something happens to uplift the area folding,
faulting, etc.
Erosion wears away the uppermost layers
Area submerges and deposition begins again.
Here’s the
unconformity
 Place
Final Question:
the letters in order from oldest
to youngest
–
–
–
–
–
–
–
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Sequence 1: Uplift & Erosion
1.
2.
3.
4.
5.
Limestone
deposited
Sandstone
deposited
Shale Deposited
Uplift
Erosion
Sequence 2: Faulting
1.
2.
3.
4.
-
Sequence 3: Folding
1.
2.
3.
4.
-
Sequence 4: Igneous Intrusion
1.
2.
3.
4.
-