This takes place at beaches, streams, desert enviornments,
and beneath glaciers. Sandblasting is one method of abrasion. It grinds away at the earth's surface creating
smooth surfaces, facets, on small pieces of rock such as pebbles to larger rocks such as boulders.
http://www.uh.edu/~jbutler/physical/chapter6.html
below the earth's surface rise to the top then the pressure decreases.
This expansion can cause sheet joints which are cracks in the landscape
parallel to the earth's surface. Rocks below the earth's surface support the overlying column
of rock. Erosion strips away the overlying rock cover and decreases pressure from buried
rocks. Because there is less pressure, the buried rocks then moves upward resulting in pressure
release fractions.
Sheeted granite along the Tioga Road in Yosemite National Park
http://www.geosci.unc.edu/faculty/glazner/Images/Weathering/weathering.html
