Show:
Relative Age
Fossils
Absolute Age
Geologic Time Scale
More Geologic Time Scale
100

The idea that geologic processes occurring today are similar to those that have occurred in the past.

What is uniformitarianism

100
These are any remains, trace, or imprint of a living thing that has been preserved in Earth's crust.
What are fossils?
100
This is when radioactive elements break apart naturally into other elements.
What is radioactive decay?
100
These are the four Era's of Earth's history in order from oldest to newest.
What are Precambrian, Paleozoic, Mesozoic, and Cenozoic?
100
This is how long ago the Dinosaurs became extinct.
What is 65 MYA
200
This idea states that lower layers of rocks in a series are older and upper layers of rocks are younger.
What is superposition?
200
Most often, fossils are formed in these places where layers of sediment quickly cover anything.
What is a body of water?
200
This is the time it takes for half of the mass of an original element to change into a new product.
What is Half-Life?
200
This is how long ago the Earth was formed.
What is 4.6 Billion Years ago?
200
Several of these cold periods have occurred during the Cenozoic Era.
What are ice ages?
300

The idea that conditions and creatures on Earth change in quick, violent events.

What is catastrophism?

300
Specific fossils are the remains of living things that were widespread but only lived for a short period in Earth's history.
What are index fossils?
300
This is the age, in years, of a rock which is determined by comparing the amount of original element to the amount of decay product.
What is Absolute age?
300

The first organisms on Earth.

What are bacteria, single-celled organisms and jelly fish?

300

If the time scale was represented as a clock, this is the time that humans show up.

What is 11:58?

400
Sometimes telling the relative age of rocks is not as simple as looking at the layers because the crust can do this over the course of time.
What is move, tilt, fold, crack, overturn? (any of these answers works)
400

Evidence of the activity of an ancient organism. 

What are trace fossils?

400

This might be used to date some ancient Egyptian mummies

What is carbon-14?

400

This is the Era we currently live in.

What is the Cenozoic Era?

400

If Earths Timeline were a football field, humans would show up nearest the

What is the 1 yard line?

500
This is the age of a rock as compared to another rock.
What is relative age?
500
The soft parts of organisms decay quickly, but fossils form out of the harder parts of the organism. These are 3 examples.
What are teeth, bones, shells, seeds, pollen grains, wooden stems. (name 3 for the points)
500
This is the amount of decay product that is there after the first half-life passes.
What is 50%?
500
This is the Era during which dinosaurs roamed the Earth.
What is the Mesozoic Era?
500
These are the three periods during the Mesozoic Era.
What are Triassic, Jurassic, and Cretaceous?