Let’s Break it Down

 Mechanical - Mechanical weathering is the process of breaking big rocks into little ones. Temperature also affects the land. The cool nights and hot days always cause things to expand and contract. That movement can cause rocks to crack and break apart. Roots and plants also push into the rocks and break them apart. Little animals also help by burrowing and digging through the ground.  Chemical - Chemical weathering includes the effect of weathering on molecules and atoms. For these chemical reactions to happen in nature, moisture, and heat must be present. Reactions such as oxidation, hydrolysis, and acidification can happen when all of the elements are together. Oxidation makes rocks softer. Since there is a lot of iron in many rocks, oxidation often happens. Hydrolysis usually causes rocks to expand and then mechanical weathering can begin. These chemical reactions are happening all of the time. When you see rocks next to each other that are different colors (often shades of red) then you know chemical reactions have taken place.

 Biological - Biological weathering would include the effect of animals and plants on the landscape. This is more than roots digging in and wedging rocks. Biological weathering is the actual molecular breakdown of minerals. There are things called lichens (combinations of fungi and algae) which live on rocks. Lichens slowly eat away at the surface of rocks. The amount of biological activity that breaks down minerals depends on how much life is in that area.

 Erosion is the process that breaks things down. As far as we're concerned, erosion is the breakdown of the continents and the land around you. In nature, large things are broken down into smaller things. Boulders become sand. Mountains are rained on and become hills. The pieces of the mountain become smaller pieces and go down the sides of hills. Weathering and erosion always happen in a downhill direction. Erosion is an easy idea to understand. If you see a rock, pull it out of a mountain. Then throw it down on the ground. You are now a part of the erosion of that mountain. You have taken a big object (a mountain) and started to make little objects out of it (a rock). When that rock hit the ground, it could have cracked and made some tiny pieces of rock (sand). Erosion is just that easy. When it rains, the same process happens. Rocks are washed down a mountain or down a stream. Soils are washed away. The ocean beats against a cliff and breaks it apart.

What causes erosion to be severe in some areas and minor elsewhere? amount and intensity of precipitation the texture of the soil, the steepness of the slope, and ground cover (from vegetation, rocks, etc.).

 Gravity Erosion  Landslides  Water erosion  Rivers  Streams  In all stages of stream erosion by far the most erosion occurs during times of flood when more and faster moving water is available to carry a larger sediment load.  Ice erosion  Glaciers  Wind erosion, also known as eolian erosion is the movement of rock and/or sediment by the wind. Windbreaks are often planted by farmers to reduce wind erosion. This includes the planting of trees, shrubs, or other vegetation, usually perpendicular or nearly so to the principal wind direction. (ScienceWorld)