Tectonic Processes Flashcards
What did the world look like 220 million years ago?
The world had a supercontinent named Pangea.
When was Pangea’s existence proposed and by who?
Pangea was proposed to exist in 1912 by a man named Alfred Wegener as a part of his theory of continental drift.
What was Wegener’s evidence for Pangea?
-the same types of fossilised animals and plants are found in South America and Africa.
-the shape of the east coast of South America fits with the west coast of Africa, like pieces in a jigsaw puzzle.
-matching rock formation and mountain chains are found in South America and Africa.
What are the parts of the structure of the earth?
Inner core, Outer core, Mantle and the Crust.
What is the thickest layer in earth’s structure?
The mantle is the thickest layer.
What is in the mantle?
It is full of molten (liquid) and semi-molten (melting) rocks called magma.
What is convection current?
It is when the heat from the melting rocks inside the earth which is generated by radioactive decay in the core. The convection currents move the plates.
Earth’s crust is broken up into what?
Plates.
What do plates cause?
Earthquakes and Volcanoes.
What is it called when two plates meet?
A plate boundary.
Where are earthquakes and volcanoes most likely to occur?
They are most likely to occur either on or near plate boundaries.
What do convections do to heat in the mantle?
They move heat into the mantle.
How do continents drift apart?
Hot magma rises towards the crust and when the magma reaches the crust, it starts to spread out.
In what different ways can plates move?
-Plates move toward each other.
-Plates move away from each other.
-Plates slide past each other.
-Plates slide under another plate.
What is an Earthquake?
It violently shakes the earth’s crust.
