The Changing World

Are the continents moving? People noticed many centuries ago that the coastlines of the continents seem to fit together like pieces of a jigsaw puzzle. They did not fully understand why, but suspected that at one point, these pieces probably formed a single, continuous continent. It was only in 1912 that a German scholar, Alfred Wegener worked out the theory of continental drift, which explains the movements in the Earth’s crust and the position of continents and oceans. According to him, the continents
are in constant motion, this theory was only proven in the mid-20th century. Glomar Challenger, an American drillship played a key role in this.

(66–23
million years ago)

The Alpide and circum-Pacific
belts start
to form.
Australia
separates
from Antarctica,
North and
South America
are joined,
Africa gets
closer to Europe.

(around 4.6–2.5 billion years ago)

The hot Earth begins to cool down. The lith­osphere and
the primordial atmosphere
form, followed
by the Pan­­thalassic Ocean. Life starts to form in the oceans.

(around 2.5–0.57 billion years ago)

A period of orogenic processes.
The first
animals
appear.

(570–486
million years ago)

Life exists only
in the seas. A united
continent
called
Gondwana is located in the South while
the northern continent
breaks apart.

(486–443
million years ago)

Most of the northern hemisphere is
still covered
by an ocean.
As the ozone
layer forms,
life spreads
on dry land
as well.

(443–419
million years ago)

Baltica and Laurentia
are joined
during the Caledonian Orogeny.

(419–358
million years ago)

Period of sedimentation. Formation of the pedo­sphere.

(358–299
million years ago)

Laurasia,
a single supercontinent
on the northern hemisphere,
forms during
the Variscan Orogeny.

(299–252
million years ago)

A single supercontinent, Pangaea,
forms,
surrounded
by the gigantic Panthalassic Ocean.

(252–201
million years ago)

A period of sedimentation. Large
quanti­ties
of lime­stone
form.

(201–145
million years ago)

Pangaea
splits into
Laurasia and Gondwana.
The Atlantic
Ocean starts to form.

(145–66
million years ago)

Pangaea
breaks further apart.
India and Madagascar separate
from Africa.

(23–2.5
million years ago)

The continents head toward
their modern positions.
Oceans
dominate
the planet’s
surface.

(2.5 million years ago – today)

Present
form of flora
and fauna develops.
The age
of human evolution.

Palaeozoic era, Cambrian
period

Palaeozoic era, Ordovician
period

Palaeozoic era, Silurian
period

Palaeozoic era, Devonian
period

Palaeozoic era, Carboniferous period

Palaeozoic era, Permian
period

Mesozoic era, Jurassic
period

Mesozoic era, Cretaceous
period

Cenozoic era, early Tertiary
period

Cenozoic era,
late Tertiary
period

Cenozoic era, Quaternary
period