Answer:
Zicrons
Explanation:
The oldest of the zircons in the study, which came from the Jack Hills of Western Australia, were around 4.3 billion years old—which means these nearly indestructible minerals formed when the Earth itself was in its infancy, only roughly 200 million years old.
Convection currents occur in the MANTLE. The mantle is the second layer of the earth after the crust. The mantle is approximately 2900 km thick. Convection currents are triggered or fueled by the heat from the Earth's core.
The part of the mantle closest to the core gets heated. It then becomes less dense than the layers above so it rises. When this rising plume interacts with the crust it cools and becomes more dense than the layers below and so it sinks and this circular motion continues to form convection currents.
Yes, organic material in soil is more productive.
Are those suppose to be words?
Human activities such as mining, pollution, minerals processing, landfills, etc have an effect on the flow pattern.
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Effect of pollution</h3>
It should be noted that pollution is usually difficult to control because it is often the result of human infrastructure around a river.
For example, sewage and effluent are discharged into rivers in some areas and this can lower the pH of the water, and hence affect the organisms.
Also, human activities such as mining, pollution, minerals processing, landfills, impact negatively on the quality of water and the flow pattern in the upper reaches of the blood river in Limpopo.
Learn more about pollution on:
brainly.com/question/24704410
