<u>Answer:
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The build-up of three oxygen created our ozone layer around two billion years ago.
<u>Explanation:
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- The ozone layer is a part of the stratosphere which is located right after the troposphere in the atmosphere of the Earth.
- The ozone gas is made up of the abundance of three oxygen molecules combining with the ultraviolet radiation emitted by the Sun.
- The development of the ozone layer happened around two billion years ago when the oxygen concentration levels on the planet began to rise slowly and gradually.
The fact that volcanic rock has often been found early in the rock record but less frequently in later rock layers suggest to scientists the following conclusion about early earth: <span>volcanic activity was more common in the past than it is today.
</span>Besides volcanic activity in general, also huge volcanic eruptions<span> were much </span>more common than today<span>.</span>
After some research, I'd say that the international treaties outlining proper use of international waters for fishing <span>has had the greatest impact on the fishing industry in north America. </span>I hope that this is the answer that you were looking for and it has helped you.
