Rock Layers
Half-Life
Geologic Time
Random Stuff
Vocabulary
100
Intrusions are always (younger/older) than the layers around them.
What is younger?
100
If you start with 500 atoms of an element, how many remain after 1 half-life?
What is 250 atoms?
100
Cenozoic, Paleozoic, and Mesozoic are _________.
What are Eras?
100
A foot print of an animal is an example of a (trace/index) fossil?
What is trace?
100
Hardened remains of once living things.
What is fossil?
200
The oldest layer is found at the _______.
What is the bottom?
200
If you start with 500 atoms of an element, how many remain after 2 half-lives?
What is 125 atoms?
200
The Jurassic Period is during which Era?
What is Mesozoic?
200
Fossils are not found in which type of rock? Sedimentary, metamorphic, or igneous?
What is igneous?
200
The dieing out of a species.
What is extinct?
300
When a fault is found in a rock layer sample, what should you do first to decide which layer is the oldest?
What is line up the layers?
300
After 2 half-lives, you have 1000 atoms. How many did you start with?
What is 4000 atoms? (1000x2)= 2000 (2000x2) = 4000
300
If something died out 310 million years ago, what epoch did it die out during?
What is Pennsylvanian?
300
An element that is able to decay is referred to as?
What is radioactive?
300
The age of something compared to another item.
What is relative age?
400
If you see a rock layer with a sea shell, what can you infer about that area?
What is it was once under water/part of the sea?
400
The half-life of element x is 5000 years. If you start with 60 atoms of element x, how long would it take to end up with 15 atoms?
What is 15000 years?
400
What is the oldest Period?
What is Precambrian?
400
The Law of Superposition states that __________ rock layers are found above _________ ones.
What is younger--older? (must be in that order)
400
A fossil that is used as a comparison to other fossils and helps determine geologic age.
What is index fossil?
500
If rock layer x is below rock layer y, which is older?
What is rock layer x?
500
If the half-life of element Y is 200 years. How long would it take for 4 half-lives?
What is 800 years.
500
What Epoch are we currently in?
What is Holocene?
500
What is older, the first fish or the formation of the Great Lakes?
What is the first fish?
500
Rock layer that forms on the surface and is younger than the layers around it.
What is extrusion?
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