Key Concept What is the theory of plate tectonics? Directions: On each line, write the term from the word bank that correctly completes each sentence. Some terms
may be used more than once.
centimeters continental continents
crust
deform
evidence
fossils
mantle
mountain
plates
surface
The theory of plate tectonics states that Earth's (1.)
is
broken into rigid (2.)
that slowly move aeross Earth's
(3.)
Before the theory of plate tectonics, scientists debated a
hypothesis called (4.)
drift. This hypothesis states that
continents move. Some scientists believe that there was once one large continent, called
Gondwana. In time, the continents broke apart and drifted to other parts of Earth.
Scientists found (5.)
that seemed to support this hypothesis.
Among the evidence were similar (6.)
found on continents that
were very far apart. Scientists believe that the only way these animals could have existed on
landmasses separated by great occans was if the (7.)
connected
once were