natural resource		principle stating the geologic process operating today operated in the past
permeable		process by which water, ice, wind, or gravity moves weathered rock or soil
natural resources		solid rock beneath the soil
decomposer		layer of soil that differs in color and texture from the layers above or below it
litter		planting of different crops in a field each year to maintain the soil's fertility
humus		rock formed when particels sediments are pressed and cemented together
loam		the series of processes that change rocks from one type to another
conservation plowing		loose, weathered materials on Earth's surface in which plants can grow
soil		description of a substance that turns blue litmus paper red
topsoil		formed when rocks are changed by pressure, heat or chemical reaction
acidic		chemical change in which a substance combines with oxygen
igneous rock		anything in the environment that humans use
smelting		earth materials deposited by erosion
metamorphic rock		Great Plains area in the 1930s where wind erosion caused soil loss
ice wedging		process of melting ore to seperate useful material from other elements
weathering		plowing fields along the curves of a slope to prevent soil loss
crop rotation		description of a substance that turns red litmus paper blue
crystal		rock that contains a metal or useful mineral
uniformitarianism		chemical and physical processes that break down rock at Earth's surface
subsoil		dark-colored organic material in soil
sediment		solid in which atoms are arranged in a repeating pattern
mineral		anything in the environment that humans use
sedimentary rock		thick mass of grass roots and soil
rock cycle		process that breaks down rock through chemical changes
chemical weathering		management og soil to prevent its destruction
erosion		method used to hold the soil in place by keeping dead stalks from the previous harvest
nonrenewable resource		weathering in which rock is physically broken into smaller pieces
ore		natural inorganic solid with crystal structure and chemical composition
abrasion		layer of soil beneath the topsoil
soil conservation		grinding away of rock by other rock particles carried in water, ice, or wind
bedrock		loose layer of dead plant leaves and stems on the surface of the soil
basic		physical characteristic that allows water to seep through
fertility		process of splititng rocks by water seeping into cracks, freezing and expanding
Dust Bowl		measure of how well soil supports plant growth
soil horizon		rock formed by the cooling of melten rock
contour plowing		natural resource that is not replaced in a useful time frame
oxidation		rich, fertile soil that is made up of about equal parts of clay, sand, and silt
sod		organism that breaks down wastes and dead organisms
mechanical weathering		the varitey of components that make up the topmost layer of soil