GEOG201 Chapter Notes - Chapter 4: Regolith, Impact Crater, Silicate Minerals

• School: University of Waterloo
• Department: Geography and Environmental Management
• Course: GEOG201
• Professor: Mike Stone

Document Summary

Sediment is derived from underlying bedrock which, having been broken down by weather, is then transported down-slope by processes of mass movement and water erosion. River bank erosion also produces a significant proportion of the sediment transported in river channels. Inputs of sediment to the channel network are highly variable over both space and time. I(cid:374)(cid:448)ol(cid:448)es physi(cid:272)al (cid:271)reakdo(cid:449)(cid:374) a(cid:374)d (cid:272)he(cid:373)i(cid:272)al de(cid:272)o(cid:373)positio(cid:374) of ro(cid:272)ks a(cid:374)d lose (cid:373)aterial i(cid:374) situated at earth"s surface. Parent materials are exposed to environmental conditions at surface and rocks become unstable. Produces primary source of sediment for removal by processes of erosion and mass wasting. Involves mechanical breakdown of rocks into smaller fragments without any change taking place of their chemical condition. In mountainous regions, temperature regularly fluctuates above and below zero, freeze-thaw action is very effective breakdown process. Water expands when it freezes, repeated formation and melting of ice crystals can exert considerable stresses. Disintegration of rock by mechanical forces concentrate along rock fractures.