Term
|
Definition
| weak acid (H2CO3) that forms from the reaction of water and carbon dioxide. Most rain water is a very weak carbonic acid solution formed by the reaction of rain with small amounts of carbon dioxide in the atmosphere. |
|
|
Term
chemical weathering [image] |
|
Definition
| The breaking down of surface rock material by solution or chemical alteration. Common alteration processes are oxidation and hydrolysis |
|
|
Term
|
Definition
| The slowest form of mass movement, measured in millimeters or centimeters per year and occurring on virtually all slopes. cross bed A bed made up of particles dropped from a moving current, as of wind or water, and marked by a downward slope that indicates the direction of the current that deposited them. |
|
|
Term
|
Definition
| The process by which particles of rock and soil are loosened, as by weathering, and then transported elsewhere, as by wind, water, ice, or gravity. |
|
|
Term
|
Definition
| A physical weathering process in which concentric layers of rock are removed from an outcrop. |
|
|
Term
|
Definition
| A chemical reaction involving water that results in the breakdown of mineral material |
|
|
Term
|
Definition
When water infiltrates fractures in rock and freezes, the force of expansion is great enough to break the rock into smaller pieces. |
|
|
Term
|
Definition
| A downslope movement of rock and soil over a failure surface and under the influence of gravity. Slumps, earthflows, debris flows and debris slides are examples |
|
|
Term
|
Definition
| A general term used for any downslope movement of rock, soil, snow or ice under the influence of gravity. Includes: landslides, creep, rock falls and avalanches. |
|
|
Term
mechanical weathering [image] |
|
Definition
A general term applied to a variety of weathering processes that result in the particle size reduction of rock materials with no change in composition. Frost action, salt crystal growth and pressure relief fracturing are examples. Also known as physical weathering.
|
|
|
Term
|
Definition
| A type of mass movement composed mainly of clay-size materials with a high enough water content that it flows readily. |
|
|
Term
|
Definition
| chemical reaction in which substances combine with oxygen. For example, the combination of iron with oxygen to form an iron oxide. |
|
|
Term
|
Definition
| The source from which a given soil is chiefly derived, generally consisting of bedrock or sediment |
|
|
Term
|
Definition
The soil that is remaining after the soluble elements have been dissolved
- residual clay |
|
|
Term
|
Definition
| The top few meters of regolith, generally including some organic matter derived from plants |
|
|
Term
|
Definition
| Soil erosion is the process of detachment and movement of soil particles |
|
|
Term
|
Definition
| A vertical strip of soil stretching from the surface down to the bedrock and including all of the successive soil horizons |
|
|
Term
|
Definition
| is the layer of soil under the topsoil on the surface of the ground. The subsoil may include substances such as clay and has only been partially broken down by air, sunlight, water etc., to produce true soil |
|
|
Term
|
Definition
| Topsoil is the upper, outermost layer of soil, usually the top 2 to 8 inches. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| The process by which exposure to atmospheric agents, such as air or moisture, causes rocks and minerals to break down. This process takes place at or near the Earth's surface. Weathering entails little or no movement of the material that it loosens from the rocks and minerals. See also erosion |
|
|
