"Supercontinent" is a term used for
a large landmass formed by the convergence of multiple continents.
The most frequently referenced supercontinent is known as "Pangaea"
(also "Pangea"), which existed approximately 225 million
years ago. It is thought that all major continents at that time
were assembled into the Pangaea supercontinent.
The supercontinent of Pangaea subsequently fragmented
and the pieces now account for Earth's current continents. The
geography of Pangaea and the more recent continent movements
are shown the the map sequence below.
The theory of plate tectonics provides an explanation
for these continent movements. According to this theory Earth's
outer shell is divided into a series of plates. These plates
consist of the crust and a small amount of the underlying mantle.
The plates slide over a weak zone in the mantle at a rate of
a few centimeters per year. Convection currents in the mantle,
caused by the escape of heat from Earth's interior, are what
drives the movement of these plates.
If you study the maps below you will see that the Atlantic
Ocean is getting wider as a result of the plate movement. Also,
the Pacific Ocean is closing. A new supercontinent might form
when the Pacific Ocean completely closes and the continents
surrounding it converge.
The current continent of Eurasia could be considered
a supercontinent. The Ural Mountains separate Europe from Asia
and mark a line of compression and deformation where the two
continents crushed into one another.