Unit 3: Reshaping the Land Vocabulary

Mechanical Weathering The type of weathering in which rock is physically broken into smaller pieces.

Abrasion The grinding away of rock by other rock particles carried in water, ice, or wind.

Ice Wedging Process that splits rock when water seeps into cracks, then freezes and expands.

Chemical Weathering The process that breaks down rock through chemical changes.

Oxidation A chemical change in which a substance combines with oxygen, as then iron oxidizes, forming rust.

Permeable Characteristic of a material that is full of tiny, connected air spaces that water can seep through.

Bedrock The solid layer of rock beneath the soil

Soil Horizon The layer of soil that differs in color and texture from the layers above or below it.cc

Topsoil Mixture of humus, clay, and other minerals that forms the crumbly, topmost layer of soil

Natural Resource Anything in the environment that humans use.

Soil Conservation The management of soil to prevent its destruction.

Mass Movement Any one of several processes by which gravity moves sediment downhill.

Runoff Water that flows over the ground surface rather than soaking in the ground.

Tributary A stream or smaller river that feeds into a main river.

Groundwater Water that fills the cracks and spaces in underground soil and rocks layers.

Continental Glacier A glacier that covers much of a continent or large island.

Moraine A ridge formed by the till deposited at the edge of a glacier.

Till The sediment deposited directly by a glacier.

Deflation Wind erosion that removes surface materials.

Subsoil The layer of soil beneath the topsoil that contains mostly clay and other minerals.