What are trace fossils
The way scientists organize earth's history.
What is geologic time scale
This is when a species dies off due to a cataclysmic event
What is an extinction event
These are different layers of earth we can use to help identify the relative age depending on location bottom layer vs top layer
What is strata
The is how old scientist believe the earth is
What is 4.6 billion years
This type of fossil is the remains of an ancient shell fish similar to a Horeshoe crab
What is a trilobite
What is geology
An area in the ocean of pyroclastic activity where sea floor spreading occurs
What is the mid oceanic ridge
What i known as 10s of millions of years
What is a Period
This type of fossil is an impression in the sediment
What is the oldest
When debris from a lower layer of strata is found in an upper layer of strata
What is an inclusion or the law of inclusion
What is Pangaea
What is the term for 100s of millions of years
What is an era
This type of fossil is located 3 dimensional where a body fossil is replaced by a mold
What is a cast fossil
This type of dating is used when comparing layers of younger strata with older strata with the principal of superposition
What is relative dating?
If a lower layer of igneous rock cuts through a upper layer of strata it is considered younger.
What is crosscutting?
This is what happens to the continents due to sea floor spreading
THis is the term for Millions of years
What is an epoch
This type of fossil is found in multiple locations at the same strata layer
What is a index fossil
This type of dating uses radio isotopes and half lives to come to an accurate date
What is Absolute dating?
The deeper the layer the older the strata
What is superposition
This type of fossilization when minerals replace the organic material.
What is petrified or petrification?
The term for billions of years
What is a eon