in your own backyard

View of the Grand CanyonWhen you think of "geological processes," maybe the first thing that comes to mind is the Grand Canyon, pictured at the right. You know that the Grand Canyon got the way it is mostly because of erosion -- the wearing away of the land by water. But of course there are several kinds of erosion, and other processes than erosion that alter the geological landscape, and many of these processes can be seen and studied in your own area.

These processes are so numerous and varied that we can't go into them in detail here. However, just to give you a taste of the world of geological processes, more technically thought of as the study of geomorphology, here's a chart put together from my notebook from back when I took a college course in geomorphology:


  1. Caused by events at the Earth's surface
    1. Processes that bring things down to a common level
      • Weathering (disintegration of rock in place)
        1. Physical
          • Expanding because of heating
          • Crystal growth
          • Removal of heavy weight above
          • Activity of plants & animals
        2. Chemical
          • Hydration
          • Hydrolysis
          • Oxidation
          • Carbonation
          • Solution
      • Mass wasting or removal by gravity
        1. Landslides
        2. Mudflows
      • Erosion
        1. Running water
        2. Groundwater
        3. Waves, currents, tides & tsunami
        4. Wind
        5. Glaciers
    2. Processes that build things up
      • Running water
      • Groundwater
      • Waves, currents, tides & tsunami
      • Wind
      • Glaciers (more info)
    3. Work of living things, including humans
  2. Caused by events inside the Earth
    1. Continental drift (more info)
    2. Volcanism
  3. Caused by events off the Earth
    1. Meteorites