Earth science 4.1

Post on 16-May-2015

625 views 2 download

Tags:

Transcript of Earth science 4.1

4.1 Energy and Mineral Resources

Renewable and Nonrenewable Resources

• A renewable resource can be replenished over fairly short time spans such as months, years, or decades.

• By contrast, a nonrenewable resource takes millions of years to form and accumulate.

Fossil Fuels

• A fossil fuel is any hydrocarbon that may be used as a source of energy.

• They include coal, oil, and natural gas.

Coal

• Coal forms when heat and pressure transform plant material over millions of years.

• Power plants primarily use coal to generate electricity.

Petroleum and Natural Gas

• Petroleum and natural gas form from the remains of plants and animals that were buried in ancient seas.

• Petroleum formation begins when large quantities of plant and animal remains become buried in the ocean floor sediments.

Tar Sands and Oil Shale

• Energy experts believe that fuels derived from tar sands and oil shales can become good substances for dwindling petroleum supplies.

Tar Sands

• Usually mixtures of clay and sand combined with water and varying amounts of black, thick tar called bitumen.

• Mining tar sand causes substantial land disturbance.

Oil Shale

• Oil shale is a rock that contains a waxy mixture of hydro carbons called kerogen. It can be mined and heated to vaporize the kerogen.

Formation of Mineral Deposits

• Practically every manufactured product contains substances that come from minerals.

• Ore is a useful metallic mineral that can be mined for a profit.

Mineral Resources and Igneous Processes

• Igneous processes produce important deposits of minerals such as gold, silver, mercury, lead, platinum, and nickel.

Hydrothermal Solutions

• Generate some of the most best-known ore deposits.

• Most form from hot, metal-rich fluids that are left during the late stages.

Placer Deposits

• Form when eroded heavy minerals settle quickly from moving water while less dense particles remain suspended and continue to move.

Nonmetallic Mineral Resources

• Nonmetallic mineral resources are extracted and processed either for the nonmetallic elements they contain or for their physical and chemical properties.