la teoria della deriva dei continenti e della tettonica a zolle
& The plate
THIS WORK HAS BEEN COMPLETED THANKS TO THE GREAT HELP OF THE ENGLISH TEACHER AND THE SUPPORT OF SCIENCE TEACHER .
•The Earth was born 4.6 billions of years ago,
after the big Bang .
In the beginning it was an incandescent globe.
•There was a lot of rains on the
Earth, because of the
condensation of aqueos steam:
by this way the HYDROSPHERE
In 1912 ALFRED WEGENER a German
geophysicist elaborated the CONTINENT ‘S GRIFT
He hypothized that the continent are slowly drifting
around the Earth.
At the beginnig there was
only a supercontinent called
PANGEA surrounded by the
PANTHALASSA , that was
formed by the water .
After 200 millions of
years the Pangea
divided into two parts :
135 millions of years ago
separated respectively into
NORTH AMERICA and SOUTH
AMERICA ,INDIA and EURASIA
. Phanthalassa was divided
ATLANTIC OCEAN .
of the lands was
reached about one
million of years ago.
WEGENER’S THEORY PROOFS:
1) Continet’s borders compatibility ;
2) Border’s rocks equality;
3) Presence of “ Mesosaurum” in the SouthernAfrica and SourthenAmerica;
4) Presence of “ Glossopteris” in SouthernAmerica, SouthernAfrica, India, Antartis and Australia
Wegener died in 1930 and his theory was believed wrong because he couldn’t explain how the continent’s motions were possible.
THE PLATE TECTONICS
The plate tectonics theory was introduced by the scientists MORGAN & MCKENZIE.
This theory explains the phenomena that are involved in the
Earth’s crust changes such as the seismic activity, the
orogeny, the presence of the volcanos on the territory and the
formation of the oceanics trenches.
The cause of plate
movements is in the
Earth’s mantle , precisely
in the middle layer called
where the convective
the Ocean floor
During these motions the oceanic crust breaks. The magma rises and form the oceanic ridges. In addition , the ocean floor expands and there is volcanic activity.
If the clumps formed by the
Earth’s crust slide over next to
1) A transform fault is formed 2) Litosphere neither created or destroied 3) There are earthquakes
If the clumps formed by the Earth’s
crust approaching to each other , the
heavier plate goes in subduction and
mountains and volcanoes are formed.
OCEANIC PLATES ARE
Island arcs are formed There are earthquakes
There are volcanism Earth's crust is destroied CONTINENTAL PALTES
1) A mountain range is formed : this phenomenon is called alpine orogeny 2) Earth’s crust is destroied 3) There are erthquakes
CONTINENTAL PLATE &
OCEANIC PLATE ARE
1) Oceanic trenches are formed 2) There are vulcanism
3) There are erthquakes
4)Earth’s crust is destroied 5)this phenomenon is called coastal orogeny
THIS WORK HAS BEEN MADE BY :
CLASSE III D