What are some Physical examples of erosion and weathering?
MECHANICAL WEATHERING Mechanical is physical disintegrating. Smaller pieces are formed, cliffs break off into pebbles and the pebbles into sand. Only the size changes, not the chemical composition. Frost, wetting and drying, plants and animals, and roots are part of mechanical erosion. When water freezes, it has an unusual property. Most materials expand when heated and contract when cooled. This is true of water as well, except when it is cooled from 4*C to 0*C. At these temperatures, water expands. Water expands most when it solidifies into ice. WHen water becomes ice, it takes up 9%-10% more space. This exerts incredible pressure on rocks and then splits apart rocks. When water gets into tiny pores, it is called ice wedging or frost action. Ice wedging occurs in porous rocks and in rocks with cracks. This causes pot holes. Wetting and drying is very effective at breaking up clay. It swells and shrinks and then falls apart. PLants, such as lichens, mosses, and tiny roots, wedge their
