- Join over 1.2 million students every month
- Accelerate your learning by 29%
- Unlimited access from just £6.99 per month
The first 200 words of this essay...
Plate tectonic theory
The location of continents today of far removed from what it was millions of years ago, when it is believed that all continents were joined to one land mass. Alfred Wegener put forward a theory regards their movement in 1912 with his theory of Continental Drift. His theory was based on observations such as:
Biological: Coal is found in UK but needs warm, wet, humid conditions to form.
Observational: The shapes of countries appear to 'fit'one another, for example, S.America And Africa.
In the 1940's-1960's the theory was revised and Plate Tectonic theory emerged. It is based on the premise that the lithosphere (crust and rigid upper mantle) is divided into plates, which are moved by convection currents coming from the earth's core.
Plates and Plate Movement
Characteristics of the crust
There are 2 main types of crust that lie on plates and each has its own characteristics:
Oceanic Crust (Sima)
Young (under 200 million years), thin, dense and heavy, will sink. Always being created and destroyed. For example, Basalt.
Continental Crust (Sial)
Old, light, thick (up to 150km under mountains) permanent, does
Found what you're looking for?
- Start learning 29% faster today
- Over 150,000 essays available
- Just £6.99 a month
Not the one? We have 100's more
Hazardous Environments (view all)
- Discuss the degree to which the theory of plate tectonics is...
- The hazards presented by volcanic activity have the greatest...
- The extent to which earthquakes are hazardous depends on whe...
- Compare and contrast the Philippines and Californian hotspot...
- Choose either the Philippines or California and explain why ...
- 'The hazards presented by volcanic and seismic events have t...
- Evaluate how plate tectonics theory helps our understanding ...
- Explain why tectonic processes produce a variety of contrast...
- The Human Impacts of Tectonic Landforms & Hazards
- Tectonic Activity - A general introduction
""Zoey. University Student.
""Lex Fawste. English, Biology, Physics, Maths, and Chemistry. A Level Student.