Relative Dating and Geologic Time

Used to determine whether an object is older or younger than other objects

• Superposition
• Relative Dating
• Fossil
• Unconformity

States that younger rocks lie above older rocks if the layers have not been disturbed

• Law of crosscutting
• Law of superposition
• Relative Dating
• Unconformity

A break in the geologic record that is made when rock layers are eroded over a long period of time

• Law of Superposition
• Law of Crosscutting
• Relative Dating
• Unconformity

Traces or remains of organisms that lived long ago

• Fossil
• Unconformity
• Superposition
• Column

An ordered arrangement of rock layers that is based on the relative ages of the rocks

• Superposition
• Unconformity
• Layered
• Geologic Column

What is the law of superposition?

• The age of sedimentary rock not found in the original layers.
• Metamorphic rock is younger than the nearby igneous rock.
• Sedimentary rock in it's original position is older than layers above it.
• Metamorphic rock is older because it was deposited to nearby sedimentary rock.

How does the law of crosscutting explain the age of a fault?

• The fault is younger than the rocks above it.
• The fault is younger than the rocks it cuts through.
• The fault is older than the rocks above it.
• The fault is older than the rocks it cuts through.

Analyze the seashell found in the white layer.  Which statement is true of the rock layer that contains this fossil?

• It could also contain a fossil from the bottom layer.
• It is older than the layers below it.
• It is younger than the layers above it.
• It is older than the layers above it.

How do geologists use relative dating?

• Placing rocks in order from youngest to oldest
• Placing rocks in order by minerals they contain
• Classifying rocks by different textures
• Classifying rocks by different isotopes

What are the relative ages of the features in order from oldest to youngest?

• Limestone, Basalt, Fault, Siltstone
• Siltstone, Fault, Basalt, Limestone
• Limestone, Fault, Basalt, Siltstone
• Limestone, Siltstone, Fault, Basalt