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What is Biological Weathering?

- McNair; Fort Lee, VA


Surface weathering of rocks makes smaller pieces. There are two main types: mechanical and chemical. Biological weathering isn't really a process, but living organisms can cause both mechanical and chemical weathering to occur.

For example: tree roots can grow into fractures in a rock and pry the rock apart, causing mechanical fracturing. Moss and fungus can also grow onto a rock. In this case, the roots will produce a weak acid that dissolves the rock and does two important things (at least as far as the plant is concerned): gain nutrients (food), and make little holes for the rootlets to grow into. Either way, the rock is weathered (and the plant lives).


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