Technical  
Terms

 Vocabulary 34B 

Technical Terms from Reading:
All About Volcanoes

Volcanoes are special cone shaped
mountains with bowl-like craters at the
top. They contain vents which lead to
pools of melted rock below. The thin
top layer of the earth is solid and called
the crust. Beneath is the mantle, which
extends almost 2,000 miles down to the
core. The core is molten due to intense
heat at the center. Liquid rock under
the surface is called magma. If it flows
onto the surface, it is called lava.
          There are two main types of magma.
Granite magma
is sticky and flows very
slowly. It traps a lot of gas and steam
which can cause pressure to build up.
When the pressure is great enough, it
blows out in an explosive eruption. The
other type is called basalt magma. It
flows more easily and gases escape
rather than building up. Basalt magma
usually flows quietly and causes rivers
of rapidly moving, brightly glowing lava.
Using the article above, choose the best word.

The outer layer of the
earth is called the  ? .

1.    crust  

When underground,
liquid rock is called  ? .

2.  ________

Magma on the surface
is renamed as  ? .

3.  ________

The  ?  of the earth is
between the crust and
the molten core.

4.  ________

The very hot and molten
center of the earth is
called the  ? .

5.  ________

A  ?  is a bowl shaped
depression at the top
of most volcanoes.

6.  ________

 ?  are tubes which
connect a volcano
to pools of magma.

7.  ________

A sticky, slowly flowing
type of explosive molten
rock is called  ? .

8.  ________

Thinner liquid rock which
flows more easily as a
hot river is called  ? .

9.  ________