Download 6.4 NOTES What is plate tectonics? Objectives: Name some crustal

6.4 NOTES
What is plate tectonics?
Objectives: Name some crustal plates. Describe the theory of plate
tectonics
Earth’s lithosphere is made up of crust and the solid upper mantle. The
lithosphere is broken up into large pieces called tectonic plates. There
are 7 large tectonic plates, and 14 smaller ones.
Part of the mantle that has rock that flows like a liquid, is called the
athenosphere. It is located just below the uppermost part of the
mantle. Tectonic plates float on the athenosphere like a raft on a lake.
The continents and oceans are carried along on these plates.
The theory of plate tectonics combines the theories of continental drift
and seafloor spreading. It states that Earth’s lithosphere is broken into
plates that float on the upper mantle.
Many geologists believe that most of today’s continents could rejoin as
one giant continent in about 350 million years. The Pacific Ocean will
be much larger, and the Atlantic Ocean will become a small sea. This
future world may be called Pangaea Ultima