Continental Drift
What is the Continental Drift Theory?
The idea that Earth’s continents moved apart from a single large continent called Pangaea
What is the theory of plate tectonics?
The theory that that earth’s crust is broken into large pieces called plates.
What are the 3 types of plate boundaries?
Divergent Plate Boundaries
Convergent Plate Boundaries
Transform Plate Boundaries
What is created at a Continental/Oceanic Boundary?
Volcanoes form on the continent.
What is Pangea?
A supercontinent that all continents were once part of.
Who proposed the Continental Drift Theory?
Alfred Wegener
What causes the plates to slowly and continuously move?
convection currents
What is a Transform Plate Boundary, and what does it create?
A boundary that forms when two plates slide past each other. Plates slip sideways past each other creating earthquakes.
What is created when two oceanic crusts collide and push against each other?
The older crust goes below the other one and creates a volcanic arc of islands.
What are fossils?
The preserved remains of ancient plants and animals.
Why were scientists skeptical of Wegener's hypothesis?
Although Wegener had evidence to suggest that continents were on the move, he could not explain how they moved.
What are plates made up of?
The crust and upper mantle (lithosphere)
What is a Convergent Plate Boundary?
Convergent plate boundaries form where two plates collide.
What is created when two continental crusts collide and push against each other?
folded mountains
(created due to the pressure causes both plates to rise)
What are Tectonic Plates?
Large, rigid pieces of the Earth's lithosphere that move and interact at their boundaries, causing seismic and volcanic activity
When was the concept of Continental Drift finally accepted? and What theory did it become part of?
the 1960's. It became part of the Theory of Plate Tectonics.
What is seafloor spreading?
The process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge
What is created when two oceanic crusts diverge?
A mid-ocean ridge (mountains under the ocean). New crust is created (This process is call sea-floor spreading)
Which convergent plate interaction is NOT a subduction zone?
Continental/Continental Boundary
What is a Subduction Zone?
A region where one tectonic plate is forced beneath another into the mantle, typically occurring at convergent plate boundaries.
What evidence supports Alfred Wegener's Continental Drift Theory?
• Fossil evidence
• Continental fit
• Glacial evidence
• Landforms & rock layers evidence
What are the seven main tectonic plates?
North American
Eurasian
African
South American
Indian-Australian
Pacific
Antarctic
What is created when continental crusts diverge?
A rift valley. New crust is created (Example is the Great Rift Valley in Africa)
What is a Deep Ocean Trench?
A deep, narrow depression in the ocean floor, typically formed at a subduction zone where one tectonic plate is forced beneath another.