Determining Ages of Rocks

Geologists use this way to determine whether a rock is older or younger by comparing it to ages other rocks.

• Superposition

• Relative Dating

• Fossil

• Unconformity

Traces or remains of organisms that lived long ago

• Fossil
• Unconformity
• Superposition
• 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.

When determining the relative age of rocks, how do geologists 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.

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

Relative dating of rock layers tells us that the deeper we dig, _______.

• the younger the rocks get
• the smellier the rocks get
• the harder the rocks get
• the older the rocks get

The Law of Superposition helps scientists to determine what?

• The absolute age of rock layers
• The age of fossils
• The relative age of rock layers
• the super powers of rocks

The Geologic Time Scale is a record of what?

• old geologists
• sweet geology music
• the known history of rocks and fossils
• a list of every living thing ever

According to the law of superposition, the oldest fossils are found 

• At the top of the rock layers
• Near the bottom of the rock layers
• In the middle of the rock layers
• Somewhat near the surface