Erosion A Capsule Summary

The energy that powers terrestrial processes is derived primarily from the sun and from the Earth s internal heat production (mostly radioactive decay). Solar energy drives atmospheric motions, ocean circulation (tidal energy is minor), the hydrologic cycle, and photosynthesis. The Earth s internal heat drives convection that is largely manifested at the Earth s surface by the characteristic deformation and volcanism associated with plate tectonics, and by the hotspot volcanism associated with rising plumes of especially hot mantle material. 

Chemical weathering is more important in warm moist regions, whereas physical weathering is more important in cold dry areas. 

ContribuHons made by chemical weathering are greater in regions where there is much vegetation. 

Contributions made by physical weathering are much greater in steep terrains (i.e., more primary minerals remain), and overall weathering rates are higher. 

Equivalent igneous and metamorphic lithologies appear to weather about twice as rapidly in island-arc and younger volcanic 

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