Page 107 - Science Course 2 (Book 2)
P. 107
Mo10-L4c: What Formed Mountains?
When two continents collide at a convergent plate
Mo10-L4c What Formed Mountains? boundary, large mountain ranges form.
Over millions of years, tectonic motion can move
KEY CONCEPTS: mountain chains.
1. How does plate movement form mountains?
Vocabulary A-Z
Let us learn some vocabulary
mid-ocean ridge
long, narrow mountain range on the ocean f oor;
formed by magma at divergent plate boundaries.
The Appalachian Mountains in North America and
the Caledonian mountains in Eurasia formed at the
same convergent boundary. Over time, plate motion
separated the mountains.
Let’s Begin
Ocean Basins
When a volcano erupts, lava hardens and forms new
crust.
At an oceanic divergent plate boundary, the newly
formed crust is added to the edges of the plates as
new ocean crust.
As the plates move apart, more lava f lls in the space
and forms more ocean crust.
Mid-ocean ridges are long, narrow mountains
formed by magma at divergent boundaries.
Most mountains form near plate boundaries where
folding and crumpling of Earth’s crust usually occurs.
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