Term
|
Definition
| A mild acid formed when water and carbon dioxide chemically combine in the atmosphere and soil.This acid is a very important component in the development of cave decorations (speleothems). |
|
|
Term
chemical weathering [image] |
|
Definition
| The process that changes the chemical makeup of a rock or mineral at or near the Earth’s surface. Chemical weathering alters the internal structure of minerals by the removing and/or adding elements. Compare with mechanical weathering. |
|
|
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 form of chemical weathering in which ions from water replace equivalently charged ions from a mineral, especially a silicate. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Downslope movement of rock, soil, and mud |
|
|
Term
|
Definition
|
|
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
|
|
Term
|
Definition
Removal of electrons from an atom or ion. Usually by combining with oxygen ions. Minerals exposed to air may oxidize as a form of chemical weathering. |
|
|
Term
|
Definition
| The source from which a given soil is chiefly derived, generally consisting of bedrock or sediment |
|
|
Term
|
Definition
|
|
Term
|
Definition
| All loose, unconsolidated earth and organic materials above bedrock that support plant growth |
|
|
Term
|
Definition
|
|
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
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Weathering includes two surface or near-surface processes that work in concert to decompose rocks. Both processes occur in place. No movement is involved in weathering. Chemical weathering involves a chemical change in at least some of the minerals within a rock. Mechanical weathering involves physically breaking rocks into fragments without changing the chemical make-up of the minerals within it. Mechanical weathering includes processes such as water in cracks freezing and expanding, or changes in temperature that expand and shrink individual minerals enough to break them apart. |
|
|
Term
|
Definition
| A subsurface rock or sediment unit that is porous and permeable. To be an aquifer it must have these traits to a high enough degree that it stores and transmits useful quantities of water. |
|
|
Term
artesian formation [image] |
|
Definition
| Of, being, or concerning an aquifer in which water rises to the surface due to pressure from overlying water |
|
|
Term
evapotranspiration [image] |
|
Definition
| All methods of water moving from a liquid to water vapor in nature. Includes both evaporation and transpiration. |
|
|
Term
|
Definition
| A hot spring that intermittently erupts a spray of steam and hot water. Caused by the heating of ground water within a confined opening in hot rock |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A layer of rock, sediment or soil that does not allow water to pass through. This could be caused by a lack of pore space or pore spaces that are so small that water molecules have difficulty passing through. |
|
|
Term
|
Definition
| A measure of how well a material can transmit water. Materials such as gravel, that transmit water quickly, have high values of permeability. Materials such as shale, that transmit water poorly, have low values. Permeability is primarily determined by the size of the pore spaces and their degree of interconnection. Permeability measures are expressed in units of velocity, such as centimeters per second, and assume a gradient of one vertical foot of drop per linear foot |
|
|
Term
|
Definition
| The volume of pore space in a rock, sediment or soil. Usually expressed as a percentage. This pore space can include openings between grains, fracture openings and caverns |
|
|
Term
|
Definition
| Water added to an aquifer or other water body. An aquifer is recharged by precipitation in an area where the aquifer has a porous connection to the surface. |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| The movement of water between the atmosphere, ground and surface water bodies through the processes of evaporation, precipitation, infiltration, percolation, transpiration and runoff. Also known as the "hydrologic cycle". |
|
|
Term
|
Definition
| The surface that lies between the zone of aeration and the underlying zone of saturation. |
|
|
Term
|
Definition
| A form of mechanical weathering that occurs when loose fragments or particles of rocks and minerals that are being transported, as by water or air, collide with each other or scrape the surfaces of stationary rocks. |
|
|
Term
|
Definition
| A triangular deposit of sediment left by a stream that has lost velocity upon entering a broad, relatively flat valley |
|
|
Term
|
Definition
| The lowest level to which a stream can erode the channel through which it flows, generally equal to the prevailing global sea level |
|
|
Term
|
Definition
| A body of coarse particles that move along the bottom of a stream. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A fan-shaped deposit that forms where a stream enters a lake or ocean and drops its load of sediment |
|
|
Term
|
Definition
| A ridge that separates two adjacent drainage basins |
|
|
Term
drainage basin or watershed [image] |
|
Definition
| The geographic area that contributes runoff to a stream. It can be outlined on a topographic map by tracing the points of highest elevation (usually ridge crests) between two adjacent stream valleys. Also referred to as a "watershed". |
|
|
Term
|
Definition
|
|
Term
|
Definition
| An area of alluvium-covered, relatively level land along the banks of a stream that is covered with water when the stream leaves its channel during a time of high flow |
|
|
Term
|
Definition
A very small channel formed by running water. Gullies hold water for brief periods of time after a rain storm or snow melt. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A long continuous ridge built by people along the banks of a stream to contain the water during times of high flow. Natural levees can also be built along the banks of a stream. When the flood water decelerates upon leaving the channel, sediments quickly drop out of suspension and build a ridge over time. |
|
|
Term
|
Definition
| A stream that traverses relatively flat land in fairly evenly spaced loops and separated from each other by narrow strips of floodplain |
|
|
Term
|
Definition
| A crescent-shaped lake that forms when a meandering stream changes course. Such changes in course frequently occur during flood events when overbank waters erode a new channel |
|
|
Term
|
Definition
| A cylindrical or hemispherical hold in the bedrock of a stream that is formed from the continual swirling motion of sand and gravel by swirling currents |
|
|
Term
|
Definition
| A chemical weathering process in which a material is dissolved. Also, the transport of dissolved ions by the water of a stream. |
|
|
Term
|
Definition
| A classification system that represents the relative position of streams in a drainage basin. The highest tributaries in the basin are first order streams. These converge to form second order streams, which have only first order streams as their tributaries. Third order streams form by the confluence of two second order streams. The numbering system continues downstream resulting in higher stream orders. |
|
|
Term
|
Definition
| Transport of sediment by wind or water currents that are strong enough to keep the sediment particles continuously above the stream bottom or ground. (See traction and saltation for comparison.) |
|
|
Term
|
Definition
|
|
