Name: ____________________________________________________ Date: ____________ Period: _____
Guided Notes: Relative Dating
What can rocks tell us?

Rocks hold a record of ____________________________________________________________________

Uniformitarianism means that the __________________________________________________________
_______________________________________________________________________________________
o Examples: ____________________________________
Relative Dating

Relative Dating tells us ___________________________________________________________________
_______________________________________________________________________________________

Which is an example of relative dating?
______This rock is 500 million years old and this rock is 3,000 years old
______This rock formed first and then this rock formed next
Rules of Relative Dating
1. _______________________________________
4. _______________________________________
2. _______________________________________
5. _______________________________________
3. _______________________________________
6. _______________________________________
Principal of Superposition

The law of superposition states that in an undisturbed layer of rock, the oldest rocks are on the
_________________ and the rock layers become younger going _____
In the diagram below label the layers: oldest, 2nd oldest, 3rd oldest, youngest
__________________________
__________________________
__________________________
__________________________

In the Grand Canyon, the oldest layer is located on the
_______________________ while the youngest layer is on _______________________.
Principle of original horizontality

The principle of original horizontality means that layers of sediment are ___________________________
_______________________________________________________________________________________
Label the younger and the older hill. Then draw an arrow pointing from the younger hill to the older hill.
Name: ____________________________________________________ Date: ____________ Period: _____
Principle of Cross-Cutting Relationships

The principle of cross-cutting relationships states that when a fault cuts through rock layers or when
magma intrudes other rocks and crystallizes (_________), we can assume that _____________________
_______________________________________________________________________________________
For each picture below order the layers from youngest to oldest. Put a 1 next to the youngest layer and a 2 next
to the next youngest and so forth.
Principal of Inclusion

Inclusions are ___________________________________________________________________________

Rocks containing inclusions are _____________________________________________________________
In the picture below, which rock is younger A or B? ______
Unconformities

An unconformity represents a long period during which deposition stopped, erosion removed previously
formed rocks, and then deposition resumed
o In easier terms, ____________________________________________________________________
o Deposition _______________________________________________________________________
o Erosion __________________________________________________________________________

An unconformity is essentially ______________________________________________________________

The types of unconformities are:
1. _____________________________
2. _____________________________
3. _____________________________
Name: ____________________________________________________ Date: ____________ Period: _____
Angular Unconformity

An _________________________________ indicates that during the pause in deposition, a period of
deformation (folding or tilting) and erosion occurred.

A _____________________________ is when the erosional surface separates older metamorphic or
intrusive igneous (non-horizontal rock) rocks from younger sedimentary rocks (horizontal rock).

A _____________________________ is when two sedimentary (horizontal) rock layers are separated by an
erosional surface.
Label each picture with the correct type of unconformity
Principal of Faunal Succession
 _______________________________________________________________________________________
_______________________________________________________________________________________

_______________________________________________________________________________________
Attempt to put the following rock layers in order from youngest to oldest
Oldest
______
→
______
→
______
→
______
Youngest
______
Name: ____________________________________________________ Date: ____________ Period: _____
Relative Dating Practice
Use the laws of superposition, inclusions and cross-cutting relationships to determine the relative ages of the
following cross-sections. Determine the OLDEST bed FIRST.
A cut column out of rock is known as a stratigraphic column.