1. Section 24.2: Resources from Earth’s Crust
Pages 682 to 686

2. Land Resources Land provides the following: Space to grow crops
Forests
Grasslands
Wilderness areas

3. Publicly Managed Land
828 million acres of land in the US is managed by federal, state and local governments.
These areas have multiple uses including
Recreational uses
Grazing
Mineral resources
Energy resources
National Forests – recreational areas as well as lumber (renewable)
Wilderness areas – Protected wildlife area

4. National Parks
These are protected areas that are used to sustain wilderness.
These areas are used for recreation and the preservation of natural spaces

5. National Wildlife Refuges
Protected habitats
Breeding areas for wildlife
Protection of endangered species (some)
Some of these Refuges allow
Fishing
Trapping
Farming
Logging

6. Soil Top soil is important for the growth of crops Top Soil Loss
This type of soil retains water and nutrients to enable plants to grow
It can take up to 1000 years for soil to form
Top Soil Loss
It can be lost due to erosion
Also clear cutting areas enable erosion to occur at a much higher rate
On average 7% of the worlds top soil is lost each year

7. Soil Desertification Mini Video Lab
Occurs when soil is lost in an area
This can happen from over grazing, clear cutting and other human and animal activities
When soil is lost the ground can no longer retain water and the area become arid
Mini Video Lab
From the video why would raking leaves be problematic?

8. Aggregates They are naturally occurring products including Location
Sand
Gravel
Crushed stone
Location
Accumulate naturally near or on the Earth’s surface
Construction uses
Cement, lime and other materials to produce concrete, mortar and asphalt
Lava Rock can be used to prevent slipping on the ground when there is ice

9. Bedrock Is located underneath top soil and aggregate
It consists of solid rock
Limestone
Granite
Marble
Other rocks
It is used in construction and can be ground into aggregate

10. Ores Natural resources that can be mined for money
The cost of gathering the mineral must be less than the profit made (that is you earn money)
This means that a mineral that costs too much to gather would not be classified as an ore.
Examples of ores: Gold and copper

11. Settling of Crystals (figure 8 image 1 page 685)
Ores that are found at the bottom of a cooling Magma bed
These crystals are only found in igneous rock
Examples include Iron, Chromium and Platinum

12. Hydrothermal Fluids (Figure 8 Image 2 page 685)
Includes most of the most important metals
Metals like gold and copper take a long time to cool
They fill the gaps/veins in rocks as they are fluids longer than the surrounding rock
As the hydrothermal fluids reach the surface of the Earth they solidify

13. Chemical Precipitation (Figure 8 Image 3 Page 685)
The formation of bands through chemical precipitation
The exact process of these formations is not known
They are believed to have formed during the Precambrian time period (Figure 1 Page 620)

14. Placer Deposits (Figure 8 Image 4 page 685)
These deposits are found in places where current in the water slows
For example when there is a curve in a river.
This means that larger heavier sediments have the chance to sink and come to rest on the bottom
Examples: Gold, diamonds, platinum, gemstones, tin and titanium oxides

15. Effects of Mining
It can damage the environment physically and chemically
It changes the contours of the land
There is waste rock left behind
Toxic chemicals can be released including mercury and arsenic
This can affect ground and surface water causing it to no longer be potable
Also Mining is one of the most dangerous occupations in the world and has the highest yearly death rate

16. Assignment
Section Review
Page 686 # 1 to 6