Geologic History

What can we learn from fossils?

• How earthquakes formed.
• How erosion changed mountains
• How Earth's magnetic field was formed
• How Earth's environment has changed

What might you conclude if a fish fossil was found on top of a mountain in Kentucky?

• An Earthquake happened there.
• A Volcano erupted there.
• A forest covered that area for a while.
• A Sea once covered the area.

What occurred during the Paleozoic Era?

• a great number of organisms evolved

• mammals evolved

• reptiles spread widely

Scientists chose where units of geologic time began and ended based on major changes in life forms at certain times.

• true

• false

Relative age of a rock is the number of years that have passed since the rock formed?

• true

• false

A rock formed with 500 atoms of a radioactive parent element, but only contains 125 radioactive parent atoms today.  If the half-life is 1000 years, how old is the rock?

• 2000 years
• 500 years
• 250 years
• 125 years

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

How old do Paleontologists believe the Earth is?

• 2015 years old
• 3.6 billion years old
• 4.6 billion years old
• 4.6 million years old

What type of rock do fossils form in?

• Igneous
• Sedimentary
• Metamorphic
• Classic