Geological Time
What does the geological timeline tell us?
All of the major events of Earth's history
What are plate tectonics?
The different pieces that Earth's crust is broken into.
What are the three different types of plate boundaries?
Divergent, convergent, transform
How long has Earth exsited?
4.6 billion years
What was the main weakness of Wegener’s argument for his theory of continental drift?
He did not provide a reasonable explanation for how such large slabs of rock could move.
What is the driving force of plate tectonics?
Convection currents
What are 2 effects of plate boundaries that people across the world could experience?
Earthquakes and volcanic eruptions
Using your geological timeline. . .
How long has there been life on Earth?
3.5 billion years
Which of the following did Wegner NOT give as evidence of continental drift?
A. Fit of continents
B. Rock sequences
C. Fossil evidence
D. Sea-floor spreading
D. Sea-floor spreading
How did scientists prove that the sea - floor was spreading at the plate tectonics?
They found that the rocks closest to the mid-ocean ridge were a lot younger than the rocks further away; indicating that new rock was being created.
What happens when two plates move apart from each other?
Magma fills the empty space, creating new crust (sea-floor spreading)
Using your geological timeline. . .
How long did dinosaurs exist on Earth?
175 million years
Which observations supported Alfred Wegener’s theory of continental drift during his lifetime? Choose 3 answers.
A. Shapes of continents resemble puzzle pieces
B. Volcanoes erupt frequently on the plate boundaries
C. Similar fossils found oceans apart
D. Age of seafloor increases with distance from Mid-Atlantic Ridge
E. Himalayas continue to grow
F. Similar rock layers found oceans apart
A. Shapes of continents resemble puzzle pieces
C. Similar fossils found oceans apart
F. Similar rock layers found oceans apart
Draw a picture of how convection currents move a convergent plate boundary
See Ms. Douglass
What happens to Earth's rock when two plates move towards each other?
One plate will be subducted underneath the other, the rock will melt into magma, and be recycled back into the Earth.
Using your geological timeline. . .
What percentage of Earth's history are humans involved?
about 4%
Because the continents are drifting, two types of landforms are created in the ocean, what are they, and what happens here?
Trenches -> old rock is destroyed
Ridges -> new rock is created
Draw a picture of how convection currents move a convergent plate boundary
See Ms. Douglass
What is the driving force that helps explain why one plate can be subducted underneath the other?
Density differences