Page 106 - Science Course 2 (Book 2)
P. 106
Mo10-L4b: What are Volcanoes?
The volcanoes in Washington and Oregon, such as Mount Rainier and Mount St. Helens formed above the
subducting Juan de Fuca Plate.
Key Concept At other times, volcanoes erupt explosively, blowing
ash high into the atmosphere.
What are Volcanoes?
Where do most volcanoes form?
Sometimes, lava spreads over large areas of Earth’s SUMMARY
surface as a lava f ow before cooling and hardening. What are Volcanoes?
Volcanic mountains form at subduction zones,
where the plate melts and magma erupts
through Earth’s crust.
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