Flashcards
Theory of plate tectonics
Flashcards do conjunto (14)
- 1Define plate tectonics theoryExplains global distribution of a geographical phenomena such as seismicity, volcanism, continental drift and mountain building in terms of the formation, destruction, movement and interaction of the Earth's lithospheric plates
- 21620Frances Bacon, countries either side of the Atlantic fit together
- 31909Mohorovicic, seismic waves change speed when travelling through the Earths centre
- 41912Alfred Wenger,
- Pangea
- Laurasia and Gudwana
- 7 major plates
- 15 major and 40 minor
- Continental drift - 5Name the 8 pieces of evidence for the plate tectonics theory1. Continental fit
2. Geological evidence
3. Climatological evidence
4. Paleomagnetism
5. Convection Currents
6. Biological evidence
7. Mid Atlantic Ridge discovery, 1948
8. Sea floor spreading - 6Continental fit- Seem to fit together
- Jigsaw fit
- Not perfect due to the difference in erosion, weathering and sea levels
- South America and Africa West Coast - 7Geological evidence- Rocks of the same age, type and formation in South East Brazil and South Africa
- Glacial deposits in Antartica, South America and India
- Mountain structures in Eastern USA and North West Europe are similar (Appalachian and GlenCo, Scotland) - 8Climatological evidence- Similar age coal deposits which all must have developed in tropical conditions in Antarctica, UK and North America
- These moved apart and drifted away from tropical climates - 9Biological evidence- Similar fossil formations on either side of the Atlantic
- Plant remains from humid swamps forming coal deposits in India and Antarctica
- Mesosarus remains in South Africa and Eastern South America (fresh water animal)
- Marsupials only in Australia as it drifted away before they were wiped out - 10Mid Atlantic Ridge, 1948- Continuous mountain range along the ocean bed
- 100km wide and 2.5 km high
- Composed of recently formed volcanic rock, with newest rocks nearest ridge
- Iceland has rocks under 1 million years
- Oldest rocks in USA and Carribean
- 5cm per year spreading - 11Paleomagnetism- Stripes of normal and reverse polarity rocks, a mirrored pattern either side of the ridge
- Iron particles in the lava are aligned with the magnetic field of the Earth
- The direction of the force changes every 400,000 years
- New rocks added equally to either side - 12Convection currents- The driving force of the movement of plates
- Caused as radioactive particles in the mantle decay and give off heat - 13Two adjacent convection currents sinkDestructive
- 14Two adjacent convection currents riseConstructive
Informações
- Descrição
- A Level Geography (Plate tectonics and associated hazards) FlashCards sobre Theory of plate tectonics, criado por Nicola Bywater em 10-09-2014.
- Criado por
- Nicola Bywater · set 2014
- Atualizado
- 19 fev 2016
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- 32
- Avaliação