Weathering and Erosion

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

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.

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

chemical changes.

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.

4. Sediment – Earth material deposited by erosion.

5. Deposition – Process by which sediment is laid down in new locations.

6. Permeable – Characteristic of a material that is full of tiny, connected air

spaces that water can seep through.

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. 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.

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