1. Review of 6th Grade Key Terms

2. Soil
Soil provides: housing for animals, water storage for plants, and minerals
Soil conservation: a method or prevent the soil from erosion and nutrient loss

3. Mature/ Immature Soil
Mature soil: normally has a soil profile with clearly defined horizons
Immature Soil: doesn’t have any of these properties. This is the soil that has exposed rock, and can never reach the topsoil-
(Caused by climate and temperature )

4. Weathering
Weathering: process by which rock materials are broken down by the action of physical or chemical means

5. Chemical Weathering
Process by which rocks break down as a result of chemical reactions
the agents are water, weak acids, and rain
acid precipitation and oxidation are examples of chemical weathering

6. Mechanical Weathering
Breakdown of rock into smaller pieces by physical means
The agents are wind, water, ice, gravity, plants, and animals
Ice wedging and abrasion are forms of mechanical weathering

7. Erosion/Deposition
Erosion – the movement of materials broken down due to the process of weathering- the process by which wind, water, ice, or gravity transport soil and sediment from one location to another
Deposition – the process is which material is laid down

8. Dust bowl
Dust Bowl: during the 1930s, a severe drought occurred in a section of the Great Plains that became known as the Dust Bowl

9. Sedimentary Rock
Sedimentary Rock: formed by compaction and cementation

10. Metamorphic Rock
Metamorphic Rock: formed from heat and pressure

11. Igneous: formed when rock melts ( magma ), and cools and hardens
Igneous Rock
Igneous: formed when rock melts ( magma ), and cools and hardens
* Extrusive ( forms on the Earth’s surface)
* Intrusive ( forms inside the Earth)

12. Continental Drift
Continental Drift: Wegener’s hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present location.

13. Pangaea
Pangaea: all the continents in one landmass- PROOF - similar fossils on separated landmasses

14. Tectonic Plates: are always MOVING

15. Geographic Poles
Geographic Poles: the north or south points of intersection of the earth’s surface with its axis of rotation – used as reference points for location on the Earth

16. Fault/Boundaries/Stress
Strike-Slip Fault/Transform Boundary – shearing Normal fault/Divergent Boundary – Tension Reverse Fault/Convergent Boundary – Compression

17. Sea Floor Spreading
Sea Floor Spreading: evidence for sea-floor spreading is magnetic reversals ( occurs at a divergent boundary)

18. Volcanoes
Volcanoes: a vent or fissure in the Earth’s surface through which magma and gases are expelled (resulting in a decrease in global temperature)

19. EARTHQUAKES Occur along the edges of tectonic plates
P Wave: move in a back-and-forth direction; travels through solids, liquids, and gases
S Wave: a seismic move in a side-to-side direction; cannot travel through the parts of Earth that are completely liquid
Surface Wave: moves up, down, and around

20. Water
Water Cycle:
evaporation, condensation, precipitation, runoff, and percolation
the water cycle is driven by energy from the sun (causes evaporation)

21. Ocean Water
Ocean water covers about 71% of Earth’s surface

22. Tides
Tides: Tides are caused by the sun and the moon, and they occur in a variety of cycles.

23. Atmosphere Atmosphere: a mixture of gases that surrounds Earth
Temperatures at different layers of the atmosphere vary because of the composition of gases in each layer
Troposphere
Stratosphere
Mesosphere
Thermosphere

24. Smog: Vehicle exhaust reacts with sunlight and ozone

25. Density
density = the ratio of the mass of a substance to the volume of a substance

26. Air Pressure
air pressure is strongest at the Earth’s surface because more air is above you; as altitude increases, air pressure decreases

27. Greenhouse Effect
Greenhouse Effect: the warming of the surface and lower atmosphere of Earth that occurs when water vapor, carbon dioxide, and other gases absorb and reradiate thermal energy

28. Climate
Climate: the weather conditions in an area over a long period of time- ocean currents effect climate

29. Hurricane: when warm and cold fronts meet over warm water

30. Tornado
Tornadoes: a funnel cloud that “pokes” through the bottom of a cumulonimbus cloud and hangs in the air