1. Weathering and Erosion

2. 1.Weathering – The chemical and physical processes that break-down rock at Earth’s surface. 2.Mechanical weathering – The type of weathering in which rock is physically broken into smaller pieces. Weathering and Erosion Vocabulary

3. Examples of mechanical weathering: Ice wedging (freezing/thawing ) – Water expands as it freezes and acts like a wedge. This is a process called ice wedging. Release of pressure – When pressure on rock is reduced, it causes outside rock to crack. Growth of Plants – Plant roots can pry apart and crack rocks. Animal Actions – Burrowing can break apart rocks. Abrasion – Rock particles carried by wind, water, and ice wear away a rock.

4. 3.Chemical weathering – the process that breaks down rock through chemical changes.

5. Examples of chemical weathering: Water – It can weather rocks by dissolving them. Oxygen – It can cause oxidation of certain rocks because it reacts with the metals in the rocks, like iron. Carbon Dioxide –It mixes with water to form carbonic acid which dissolves marble and limestone. Living Organisms – Lichens and tree roots produce weak acids that weather rocks. Acid Rain – Elements like sulfur which combine with water to make acid rain causes very rapid weathering.

6. 4.Sediment – Earth material deposited by erosion. 5.Deposition – Process by which sediment is laid down in new locations.

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

8. 7.Erosion – The process by which water, ice, wind, or gravity moves weathered rock and soil. 8.Runoff – Water that flows over the ground surface rather than soaking into the ground.

9. 9.Soil – The loose weathered material on Earth’s surface in which plants can grow. 10. Mass movement – Any one of several processes by which gravity moves sediment.

10. 11.Groundwater – Water that fills the cracks and spaces in underground soil and rock layers. 12.Conservation - the careful use of natural resources (such as trees, oil, etc.) to prevent them from being lost or wasted. groundwater