P1 - The Earth in the Universe Flashcards
Describe one piece of evidence that shows that rocks are constantly being worn down
Colorado River has eroded the rock, leaving an impressive slash through the middle of Arizona
Cliffs being worn away by the sea
Describe one piece of evidence that shows that rocks are constantly being made
When lava from volcanoes sets, it forms brand new rock
Fossils show that rocks must have built around animals and plants
Describe one piece of evidence that shows that rocks are constantly being made
When lava from volcanoes sets, it forms brand new rock
Fossils show that rocks must have built around animals and plants
Give a brief description of the ‘rock cycle’
Erosion from existing rocks get washed into the sea and settle as sediment which overtime gets crushed together to form sedimentary rocks.
These can descend into the heat and pressure inside the Earth which changes the rocks structure as it gets heated and crushed or sometimes actually melts.
Or the rocks can be pushed up to reach the surface, the cycle starts again.
Give a brief description of the ‘rock cycle’
Erosion from existing rocks get washed into the sea and settle as sediment which overtime gets crushed together to form sedimentary rocks.
These can descend into the heat and pressure inside the Earth which changes the rocks structure as it gets heated and crushed or sometimes actually melts.
Or the rocks can be pushed up to reach the surface, the cycle starts again.
How can scientists tell how old some rocks are? And what does this tell us about when the Earth was formed?
Looking at the proportions of radioactive potassium-40, and the element it decays into, in certain rocks, scientists can get a good idea of when they were formed. So the Earth must have been around for at least 4 billion years as that the oldest rock found.
Describe two observations about the Earth that weren’t properly explained by the ‘land bridge’ theory?
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Describe two observations about the Earth that weren’t properly explained by the ‘land bridge’ theory?
Why coastlines of Africa and South America matched so well and why fossils from sea creatures had been found high in the Alps
How did Alfred Wegener’s theory account for these observations about the ‘land theory’?
‘Continental drift’ which is thought to be about 300 million years ago, Used to be just a ‘supercontinent’ called Pangea. Pangea broke into smaller chunks and these chunks are still slowly ‘drifting’ apart’
How did Alfred Wegener’s theory account for these observations about the ‘land theory’?
‘Continental drift’ which is thought to be about 300 million years ago, Used to be just a ‘supercontinent’ called Pangea. Pangea broke into smaller chunks and these chunks are still slowly ‘drifting’ apart’.
Coastlines due to drifting apart, mountains due to collisions
Suggest why the initial reaction to Wegener’s theory was hostile
Wasn’t convincing and movement wasn’t detectable. Wegener claimed that continents movement could be caused by tidal forces and Earth’s rotation, but other geologists showed that was impossible. Also Wegener wasn’t a proper geologist he was a meteorologist.
Suggest why the initial reaction to Wegener’s theory was hostile
Wasn’t convincing and movement wasn’t detectable. Wegener claimed that continents movement could be caused by tidal forces and Earth’s rotation, but other geologists showed that was impossible. Also Wegener wasn’t a proper geologist he was a meteorologist.
What evidence led scientists to accept most of Wegener’s theory about the movement of continents?
That magma rises through the sea flop, solidifies and forms underwater mountains that are roughly symmetrical either side of the ridge. Suggests that the sea floor was spreading.
Magnetic orientation of the rocks. As the liquid magma erupts out of the gap, iron particles in the rocks tend to align themselves with the Earth’s magnetic field.
What evidence led scientists to accept most of Wegener’s theory about the movement of continents?
That magma rises through the sea flop, solidifies and forms underwater mountains that are roughly symmetrical either side of the ridge. Suggests that the sea floor was spreading.
Magnetic orientation of the rocks. As the liquid magma erupts out of the gap, iron particles in the rocks tend to align themselves with the Earth’s magnetic field. This was convincing evidence that new sea floor was being created and continents were moving apart.
What evidence led scientists to accept most of Wegener’s theory about the movement of continents?
That magma rises through the sea flop, solidifies and forms underwater mountains that are roughly symmetrical either side of the ridge. Suggests that the sea floor was spreading.
Magnetic orientation of the rocks. As the liquid magma erupts out of the gap, iron particles in the rocks tend to align themselves with the Earth’s magnetic field. This was convincing evidence that new sea floor was being created and continents were moving apart.
