• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Describe the evidence for continental drift. (12 marks)

Extracts from this document...


Describe the evidence for continental drift. (12 marks) The study of rocks and fossils formed over millions of years has helped geologists establish a time chart. It is evident that the Earth's surface has changed greatly. There is a noticeable jigsaw like fit between South America and West Africa. Other similar shaped coastlines on different continents can also be noticed. There is evidence that all the continents were joined together as one large super continent, which was named 'Pangaea'. The evidence for Wegener's theory (above) can be collected into 3 groups, they are, biology, geology and climatology. In India and Antarctica a similar plant fossil was found as well as a reptile, named 'Mesosaurus' which existed only in South Africa and Brazil. This showed that similar vegetation and wild life existed in places that are thousands of miles away from each other now, as it is unlikely the animals could travel distances by sea. ...read more.


This evidence shows that some continents and countries could not have been where they are now at present because of the biological, geological and climatological reasons. But there are three more recent pieces of evidence found since Wegener made his theory in 1912. It was realised that the mountainous range of islands in the Atlantic were volcanic and recent. This showed that magma was rising from between cracks in the Earths surface: the plate boundary, and forming new volcanoes. The sea floor is spreading, the evidence for this is that the newest rocks have been found near the North Atlantic Ridge, and the oldest rock near North America. Therefore shows that the Atlantic is spreading apart, therefore the Eurasian plate and North American are moving further and further apart. Another piece of recent evidence is the magnetic fields that have been studied, it shows that periodically the magnetic poles have been alternating many times, and is identical on both sides of the ridge e.g. ...read more.


But because the Earth is neither shrinking nor getting larger, there is not enough space for the new crust and the old, so some of the older oceanic crust must be destroyed in another place on Earth. This destroying of oceanic crust happens at destructive plate margins, or subduction zones. This is when an oceanic plate and continental plate moves towards each other. Oceanic crust is heavier therefore it will sink beneath the continental crust and be destroyed forming a deep-sea trench as it returns back into molten magma. In other places in the world e.g. the Himalayas, where two continental plates are converging, neither will sink like at a destructive margin but it will form Fold Mountains. Mount Everest has risen since it was last climbed. Two plates are passive when they are sliding past each other either in the same direction at different speeds or in opposite directions, this is all due to convectional currents beneath the crust in the mantle. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Hazardous Environments section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Hazardous Environments essays

  1. Continental Drift

    As technology improved and exploration of the oceans floors became more efficient, it was discovered that the rocks forming the ocean floor were mainly volcanic, and highly magnetic. With further emphasis put on the exploration of the mountain range discovered along the centre of the Atlantic Ocean, even more of

  2. The first will be about Health and Safety at Graham School. The second will ...

    The employees have to take extreme car when handling this chemical. Hydrofluoric Acid is a possible mutagen if it comes into contact with skin. A mutagen is a chemical which has the ability to change DNA meaning that this chemical needs to also be handled with extreme care.

  1. The Crust, The Mantle and The Core

    Tiny grains of dirt, sand, mud and clay are worn off and washed into streams, rivers, lakes and oceans. When these tiny bits of sand and dirt settle to the bottom of the water, they are called sediment. Minerals in the water and microscopic, or very tiny sea animals also

  2. Volcanoes. All volcanoes are formed by the accumulation of magma. Most volcanoes have steep ...

    Cinder cones are among the most common volcanic landforms found in the world and are also the simplest type of volcano. They are built from particles and blobs of congealed lava ejected from a single vent. As the gas-charged lava is blown violently into the air, it breaks into small

  1. The origin of the Earth

    Scientists think that the material either dissolved in the core, or was able to sink through the mantle but not into the core because of its density. Lower mantle: depth of 650-2,890 kilometers The lower mantle is probably composed mainly of silicon, magnesium, and oxygen.

  2. Continental Drift - the evidence that supports the theory.

    Exploration of the seafloor had been in progress at a slow but gradually accelerating pace during the nineteenth century and the first four decades of this century. There was a rapid increase in geological and geophysical exploration of the seafloor after the Second World War.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work