7th Grade

Unit 8: Natural Events that Change

the Environment

Lesson 2: Effects of Weathering and

Erosional Deposition

Vocabulary of Instruction:

Video:

Basics of Geology

1. Abrasion• Refers to the

grinding away of rock by rock particles carried by water, ice, wind, or gravity.

2. Bioerosion• The process by

which animals, through drilling, grazing, and burrowing, erode hard substances such as rocks and coral reefs.

Crossbedded rippled burrowed sandstone.

3. Carbonation• Is a form of

chemical weathering where carbonate and bicarbonate ions react with minerals that contain calcium, magnesium, potassium, and sodium.

4. Chemical Weathering• The process that

breaks down rocks through chemical changes.

5. Climate• General pattern of weather conditions

for a region over a long period time.

Moist Climate Dry Climate

6. Deposition• Where the

agents of erosion (water, wind, animals, etc.). lay down sediments.

7. Exfoliation• The breaking off

of thin concentric shells, sheets, scales, plates, and so on, from a rock mass; measuring less than a centimeter to several meters in thickness, the loosened rock is spalled or fragmented, peeled, or stripped.

8. Gravitational Erosion• Caused by gravity

and involves both large scale mass wasting and smaller scale erosion. Forms of gravitational erosion include avalanche, landslide, debris flow, mudflow, and sinkhole formation.

9. Hydrolysis• The chemical

reaction of a compound with water. Hydrolysis is an important component of soil formation, and of chemical weathering.

10. Ice Wedging• Wedges of

ice in rocks widen and deepen cracks.

11. Mass Movement

• Any one of several processes that causes a down slope movement of sediment, soil, and rock material.

12. Mechanical Weathering

• The type of weathering in which rocks is physically broken into smaller pieces.

13. Oxidation• Is when a substance

reacts with oxygen to form a type of compound known as an oxide that contains at least one oxygen atom.

14. Thermal Expansion• Characteristic

property of most solids and liquids which causes their volume to increase when they are heated.

15. Weathering• Physical,

chemical, or biological breakdown of rocks and minerals into smaller sized particles.