How Soils Form

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How Soils Form
Image T. Loynachan
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Physical weathering breaks rocks into small
mineral particles that accumulate on the Earths
surface.
Images Martin Miller, NRCS
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Chemical weathering dissolves and changes
minerals that have accumulated on the Earths
surface.
Images National Cooperative Soil Survey,
University of Nebraska
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Decomposing organic material from plants and
animals mixes with accumulated soil minerals.
Images NRCS, Soil Classifiers of Michigan
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Accumulated soil materials contain voids filled
with air or water.
Image T. Loynachan
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Continued physical and chemical changes over
hundreds to thousands of years produce layers
called soil horizons.
Image National Cooperative Soil Survey
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The Formation of Soils
Image T. Loynachan