Laws of
Relative Dating
Earthquakes and
Volcanoes
Layers of
the Earth
Plate
Tectonics
Potpourri
100
This law says: Younger rocks are on the top. Older rocks are on the bottom.
What is the Law of Superposition?
100
These are the first waves to arrive when an earthquake occurs
What are P waves?
100
The thinnest layer of the Earth
What is the crust?
100
The San Andreas fault in California is an example of this type of plate boundary
What is a transform boundary?
100
This is the location on the surface of the Earth directly above an earthquake's focus
What is the epicenter?
200
This law says: Anything cutting across a rock layer is younger - the rock layer had to be there first.
What is the Law of Cross-Cutting Relationships?
200
An earthquake that happens under the ocean can cause this destructive giant wave
What is a tsunami?
200
The number of major layers of the earth?
What is four?
200
This type of boundary can cause mountain building or deep ocean trenches
What is a convergent boundary?
200
Alfred Wegener proposed the theory of _________ ______
What is continental drift?
300
This law states that all rock layers were originally horizontal.
What is the Law of Original Horizontality?
300
Hawaii was formed due to this thin portion of the Earth's crust
What is a hot spot?
300
This layer is made up of the crust and the upper mantle
What is the lithosphere?
300
This type of boundary is where new crust is formed
What is a divergent boundary?
300
Pangaea is thought to have existed at this time
What is 200-270 million years ago?
400
These are the three types of unconformities
What are disconformities, angular unconformities, and nonconformities?
400
These are low profile volcanoes formed from basalt lava flows (Hawaii is made of this type of volcano)
What are shield volcanoes?
400
Partially melted layer of the mantle where convection currents occur
What is the asthenosphere?
400
The Himalayan mountains occur at this type of plate boundary
What is a convergent boundary?
400
When one plate dives under another plate at a convergent boundary
What is subduction?
500
This law states: The present is the key to the past. Things happened in the past the same way that they happen in the present.
What is the law of uniformitarianism?
500
This instrument is used to measure the strength of an earthquake
What is a seismograph?
500
The only liquid layer of the Earth
What is the outer core?
500
This process occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge
What is seafloor spreading?
500
This word is defined as the forcible entry of magma into or between other rock formations
What is an intrusion?
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