| A | B |
|---|
| weathering | breakdown of rock at or near the earth's surface into smaller and smaller pieces |
| mechanical weathering | rock is broken or weakened physically |
| frost wedging | water freezes in cracks of rocks. as it freezes and expands, the force breaks the rock |
| chemical weathering | alters rock's chemical makeup by changing minerals that form the rock or combining them with new chemical elements |
| acid rain | pollutants that combine with water and return to earth as rain |
| erosion | the movement of weathered materials |
| agents of erosion | water, wind, glaciers |
| sediment | small particles of soil, sand, gravel |
| delta | the triangular sediment deposits at the mouth of a river |
| dust bowl | land stripped of plant life with little water, highly seceptible to wind erosion |
| loess | mineral-rich dust and silt |
| glaciers | huge, slow moving sheets of ice |
| moraines | ridgelike piles of rock or debris left behind by glaciers when they melt |
| "U" shaped valleys | formed by glaciers |
| "V" shaped valleys | formed by water |
| "Ice Age" | long periods of cold temperatures, when most of the earth was covered in ice |
| continental glaciers/ice sheets | broad, flat glaciers. found only in a few places throughout the world |
| valley/alpine glaciers | found throughout the world in high mountian valleys |
