Transcript Alfred Wegener 1880-1930

Alfred
Wegener
1880-1930
How Wegener Proved His theory
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Continental Fit
Matching Fossils
Matching Mountains
Sea Floor Age
Mesosaurus
Describe what
is happening in
this
photograph.
Time
Two countries
Plate movements
Everest
What causes plates to move
Caused by thermal convection currents
• 1. Hot rock moves like tar
• 2. Hot interior of the earth
Types of plate margins
• Divergent – constructive
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Plates pull apart
Hot magma released to the surface
New oceans can form – mid atlantic ridge
Continents pull apart at 2.5 cm per year.
Types of plate margins
• Convergent - Destruction of Crust
When two plates collide, one plate travels
beneath another. This is known as
subduction
Types of Convergent Plates
• Oceanic – Cceanic Convergence
• Oceanic - Continental Convergence
• Continental – Continental Convergence
Oceanic – Oceanic Plates
• The smaller plate slips below the thicker
plate
• A Trench forms where the plate subducts
• Example – The Mariana Trench where the
Pacific and Phillipines plates collide
Oceanic – Continental Plates
• The oceanic crust is heavier and sinks
beneath the continental crust
• The continental plate deforms forming a
mountain range
• Exampe Nazca Plate and South American
Plate converge to form the Andes
Andes
Mountains
Oceanic –
Continental
Plate
Convergence
Continental - Continental
• The two plates are very light
• Neither plate subducts
• They fold upwards to form a mountain
range
• Example the Indian Plate and the Eurasian
Plate began to form the Himalayas 50
million years ago
Red Sea
Africa
Pulling
Apart.
Separating
Plates form
the Agen
and the
Red Seas