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How The Dinosaurs Became
Extinct
Dinosaurs are reptiles that lived on Earth over 65 million years ago.
There are two main theories on how the giant beasts era ended. By
volcanic eruptions and by asteroid impact. Many scientists believe in
different theories because of the amount of proof that is found. Certain
theories have more evidence to support them which is why a larger
amount of scientists accept them as a logical answer to the question
`How did the dinosaurs become extinct?'…read more

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MAIN THEORY ­ Volcanic
Eruptions
Many scientists think that volcanic eruptions caused the dinosaurs to
become extinct. This is because there is a significant amount of proof to
back this theory. They discovered 4 waves of eruptions that emitted
massive amounts of sulphur dioxide.
Premise: According to scientists, the dinosaurs would have become
extinct by volcanoes ­ Erupting ­Releasing clouds Sulphur Dioxide etc,
dust and ash.
Sulphur ­ The Sulphur Dioxide would have caused acid
rain, acidifying the rivers, lakes and maybe even the top layer of the
ocean. Killing off the smaller and weaker creatures. The Dinosaurs
would drink this acidified water.
Dust and Ash- The dust and ash would have been enough
to cover the atmosphere, blocking the sunlight. With no sunlight, the
temperature would have rapidly dropped causing the dinosaurs to die
out as they were poorly adapted.
Others say that, volcanic eruptions caused the temperature to rise making it
too hot and the dinosaurs were again poorly adapted.…read more

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Volcanoes....Evidence For &
Against
FOR AGAINST
· Lava ­ Some flows of lava in the Deccan · Quite a bit of evidence for volcanic
region of India cover nearly 200,000 square eruptions applies to the asteroid theory.
meters of land. 6,500 feet in some places. · There is no proof that the volcanic
Eruptions like this show how big an impact
eruptions could have caused enough dust
could have made on the dinosaurs. Also
massive beds of lava were found that went back
and ash to block out the Sun.
to the times of the dinosaurs. · Volcanic eruptions only happened in
· Iridium ­ A rare metal that is found only certain parts of the world. Most of it
near the core of the Earth and in space. probably wouldn't have been affected.
Volcanoes are directly connected to the core · Sea life wouldn't have been affected but
and it is found near dinosaur fossils. some still became extinct.
· Fractured Crystals (shock-quartz) ­ They
show a distinctive pattern that is apparently
caused by high energy impacts or explosions. A
volcano could have caused.…read more

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MAIN THEORY ... Asteroid
Impact
A lot of scientists also thing that asteroid impacts might have
killed the dinosaurs. The reason for this is because there are very
obvious pieces of evidence that you can see on the Earth today.
How asteroid impact could have led to dinosaur extinction:
Asteroids, small metallic rocky bodies orbiting the Sun, fall at
an extremely fast speed through space. If it was aimed at Earth
then it could have blocked off the Sun causing extreme drop of
temperature and killing off the dinosaurs. Huge craters in the
Earth prove this theory to be correct. Also, plants were not able
to photosynthesise so died out as well, therefore the dinosaurs
starved to death.…read more

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Asteroid Impact....Evidence For &
Against
FOR AGAINST
·.Craters - Just off of the Yucatan Peninsula, · Quite a bit of evidence for asteroid
there is an 150km wide crater. Scientists say impact applies to the volcano theory.
that it must have been a 10km asteroid that · The crater would not have had enough
caused it. It would have been travelling at
impact to destroy all dinosaurs around the
around 30kph. This big an impact would
instantly kill any living creature within its
world.
grasp.
· Ejecta ­ It was once molten rock. It is
evidence that an immense explosion happened
and was able to melt bedrock and furthermore,
to drive it more than 100miles away from its
source.
· Iridium ­ A rare metal that is found only near
the core of the Earth and in space. An asteroid is
a good source of this.…read more

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