A divergent boundary occurs when two tectonic plates move away from each other. Along these
boundaries, ________________________. Frequent earthquakes strike along the rift. Beneath the rift,
magma—molten rock—rises from the mantle. It oozes up into the gap and hardens into solid rock,
______________________________. Magma from the mantle solidifies into basalt, a dark, dense rock
that underlies the ocean floor. Thus at divergent boundaries, oceanic crust, made of basalt, is
created. When two plates come together, it is known as a convergent boundary. The impact of the two
colliding plates buckles the edge of one or both plates up _____________________, and sometimes
bends the other down into a deep seafloor trench. A chain of volcanoes often forms parallel to the
boundary, to the mountain range, and to the trench. Powerful earthquakes shake a wide area on both
sides of the boundary. _______________________, it is forced down into the mantle where it begins
to melt. Magma rises into and through the other plate, solidifying into new crust. Magma formed
from melting plates solidifies into granite, a light colored, low-density rock
_______________________. Thus at convergent boundaries, continental crust, made of granite, is
created, and oceanic crust is destroyed. Two plates sliding past each other forms a transform plate
boundary. Natural or human-made structures _____________________. Rocks that line the boundary are
pulverized as the plates grind along, creating a linear fault valley or undersea canyon. As the
plates alternately jam and jump against each other, earthquakes rattle through a wide boundary
zone. In contrast to convergent and divergent boundaries, __________________. Thus, crust is
cracked and broken at transform margins, but is not created or destroyed.

1.      that makes up the continents

2.      lava spews from long fissures and geysers spurt superheated water

3.      no magma is formed

4.      if one of the colliding plates is topped with oceanic crust

5.      that cross a transform boundary are offset—split into pieces and carried in opposite
directions

6.      forming new crust on the torn edges of the plates

7.      into a rugged mountain range