Abrasion - to wear down by being rubbed against.
Alluvial fan - a fan-shaped body of deposited material typically built where a stream leaves a steep mountain valley.
Angular - a shape with sharp, pronounced edges. Brittle - breaks under stress.
Clay - soil type composed of small particles, usually reddish to gray in color.
Continent - one of the great divisions of the land on the globe.
Continental drift - the slow, lateral movements of continents across the surface of the Earth.
Convection currents - currents within a medium caused by a difference in temperature.
Crust - the outermost and thinnest of the Earth's layers.
Delta - a body of sediment deposited by a stream where it flows into standing water.
Deposition - the depositing of eroded material.
Erosion - the process where rock or soil particles are loosened and removed.
Expansion - to grow larger.
Geyser - a hot spring equipped with a system of plumbing and heating that causes intermittent eruptions of water and steam.
Glacial flow - the slow downhill movement of a glacier.
Glacier - a body of ice, consisting largely of recrystalized snow, that shows evidence of downslide movement due to its own weight.
Groundwater- all the water contained in pore spaces in the soil and bedrock.
Humus - the decomposed residue of plant and animal tissues.
Magma core - the inner layer of the Earth composed of molten rock.
Mantle - the thick shell of dense, rocky matter that surrounds the magma care.
Moisture content - the amount of water present in snow.
Organic material - undecayed plant and animal material present in soil.
Pangea - the name given to a supercontinent that formed by collision of all the continental crust.
Particle - a minute part of matter.
Pore space - spaces within a body of rock or soil.
Porous - containing pores which are interconnected.
Plastic- bends under stress.
Relative age- determining the age of sediment layers in relation to each other.
Sand - fine particles of rock in a loose state.
Saturated - completely filled with water.
Sediment - rock and soil particles that have been transported and deposited by water.
Sedimentary rock - any rock formed from sediment.
Silt - soil type composed of extremely fine sediment particles.
Soil profile - the succession of distinctive layers in a soil from the surface down to the bedrock.
Stress - to produce a strain or pressure on an object.
Transport - the moving of eroded rock or soil particles.
Water table - the upper surface of the saturated zone of groundwater.
Weathering - the chemical and physical breakdown of rack materials during exposure to air and water.