Chapter 1 Study Guide – Plate Tectonics
Section 1 – Earth’s Interior
1. What are the two main types of evidence to learn about the Earth’s interior?
a. direct from rock samples
b. indirect from seismic waves
What are the three main layers of the Earth and what are they made up of?
a. crust – a layer of solid rock that includes both dry land and ocean floor
b. mantle – very hot rock that is solid
c. core – made mostly of iron and nickel. It has a liquid outer core and a solid
inner core
Continental Drift
What was Wegener’s hypothesis?
-All of the continents had once been joined together in a single landmass and have
since drifted apart
Why did scientists reject Wegener’s hypothesis?
-He could not provide a satisfactory explanation for the force that pushes or pulls
the continents
Bonus Question:
What 3 types of evidence supported Wegener’s hypothesis?
a. land features
b. fossils
c. climate changes
What was the name of the single landmass?
-Pangaea
Sea Floor Spreading
What is sea floor spreading?
-the process by which molten material adds new oceanic crust to the ocean floor.
Bonus Question: What were the 3 types of evidence that supported Hess’s theory of
sea floor spreading?
a. eruptions of molten material
b. magnetic stripes in the rock of the ocean floor
c. the ages of the rocks
What is subduction?
-the process by which the ocean floor sinks beneath a deep ocean trench and back
in to the mantle.
The theory of plate tectonics
What is a plate?
-a section of the lithosphere that slowly moves over the asthenosphere, carrying
pieces of continental and oceanic crust.
What is the theory of plate tectonics?
-it explains the formation, movement, and subduction of Earth’s plates