Comment: 17:04 - 17:49 (00:45)
Source: Annenberg/CPB Resources - Earth Revealed - 15. Weathering and Soils
Keywords: weathering, soil, climate, "geologic time", rock, "Midwestern United States", "fertile soil", tropic
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Our transcription: Climate and time also play important roles in the evolution of soil.
As time passes and the soil matures, it progressively loses the signature of the rock it was formed from and takes on characteristics determined by the climate.
Fertile soil doesn't come into existence quickly.
It took about 15,000 years for this layer of transported soil less than a meter thick to develop in the American Midwest.
Soils in the tropics can develop faster, in a few thousand years.
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Geology School Keywords
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