Download The Earth`s Drifting Continents

The Earth’s Drifting Continents
Theory of Continental Drift


Alfred Wegener suggested that the continents were once
and have since drifted
.
Was not accepted until
years later.
Pangea

The earth had a single
large pieces, which has since moved
that broke up into
.
Evidence to Support Continental Drift





Fossils- preserved
Rock
limestone, salt, etc.
Mountain
Coal
Glacial
if organisms
and
; coal,
The Earth’s Spreading Ocean Floor
Mid-ocean Ridges

Under water
and
Trenches


V shaped valleys at the
usually found on the
.
Deepest part of the
of oceans, which are
of continents and
Ocean Floor Spreading


.
Lava erupts at rift valleys and
ocean
.
Explains how the continents move.
to form new
Subduction



Process in which
.
Rocks are pushed
are
They
crust plunges back into the
into trenches where they
by the heat of the earth.
.
Evidence to Support Ocean Floor Spreading


Rock ageand
rocks are found near rift valleys
rocks are found near
.
Magnetic Stripes- magnetic rock line up with the
equally on
sides of the mid-ocean
.