Tectonic Theory
- Created by: saoirse: )
- Created on: 15-02-17 17:22
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- Tectonic Theory
- Theories
- 17th century -people noticing South America & Africa looked like they could fit together - jigsaw
- suggestions that continents might once have been joined together
- 1912 - Wegener proposed the theory of continental drift
- suggested continents were once joined as a super continent - PANGAEA
- Based his theory on geological evidence and fossil evidence
- he couldn't back it up with a mechanism that explained how the continents moved
- 1950s- palaemagnetism provided evidence that supported continental drift
- 1960s- process of sea floor spreading was discovered providing the mechanism for continental drift
- theory was then developed further by scientists -> grew into the theory of plate tectonics
- 17th century -people noticing South America & Africa looked like they could fit together - jigsaw
- Evidence for the theory
- Geology
- Areas of South America and Africa have rocks of the same age and composition
- You can also match up the age, the rock type and distribution of mountain ranges
- these rocks and mountains must have formed under the same conditions
- Fossil Records
- By fitting land masses together you can match up the distribution of some fossils
- It's very unlikely that species migrated across thousands of miles of water or that they evolved in different places
- Fossil records suggest that these places were joined together when the organisms were alive - hundereds of millions of years ago
- Living Species
- The same living organisms can also be found on different continents
- Climatology
- Evidence that past climates of some continents were similar - despite being thousands of miles away now
- Suggests that they were located together and in a different place on earth to where they are now
- Evidence that past climates of some continents were similar - despite being thousands of miles away now
- Palaeo-magnetism
- Study of the history of the Earth's magnetic field
- Every 200,000 years the Earth's magnetic field reverses polarity
- Provided evidence for the process of sea floor spreading
- Geology
- Theories
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