1

UNDERSTANDING EARTH’S

RESOURCES

Objectives

• Explain the difference between renewable and

nonrenewable resources.

• Identify four principal fossil fuels.

• Identify the sources of coal and petroleum.

• Identify the major alternative to fossil fuels.

• Define economic geology.

• Identify six ways in which minerals become

concentrated.

Renewable and nonrenewable

resources

• Natural resources and

ancient history

– Natural resource

• A useful material that is

obtained from the

lithosphere,

atmosphere,

hydrosphere, or

biosphere

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Renewable and nonrenewable

resources

• Renewable resource

– A resource that can be

replenished or regenerated

on the scale of a human

lifetime

• Nonrenewable resource

– A resource that cannot be

replenished or regenerated

on the scale of a human

lifetime

Energy Resources

• Resources and

modern society

– North America has the

highest per capita

usage of energy

resources.

3

Fossil Fuels• Fossil fuel

– Combustible organic matter

– Trapped in sediment or sedimentary rock

• Peat

– A biogenic sediment

– Accumulation and compaction of plant remains from bogs

and swamps

– Carbon content of about 25%

• Coal

– A combustible rock formed by the compression, heating,

and lithification of peat.

– 50-95% carbon

Fossil Fuels

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Lignite (low rank coal) in Tertiary sediments of North Dakota

Fossil Fuels

Fossil Fuels

• Petroleum

– Naturally occurring gaseous, liquid, and semi solid substances that

consist chiefly of hydrocarbon compounds

• Oil

– The liquid form of petroleum

• Natural gas

– The gaseous form of petroleum

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Fossil Fuels

Unconventional fossil fuels

• Tar sands

– A sediment or

sedimentary rock

in which the pores

are filled with

dense, viscous,

asphalt like oil

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Unconventional fossil fuels

• Oil shale

– A fine grained

sedimentary rock

with a high content

of kerogen

Fossil Fuels

• Relying on fossil fuels

– Most projections

indicate oil production

will peak and begin to

decrease before 2020.

– It will become

necessary to place

greater emphasis on

other sources of energy

besides fossil fuels

Renewable Energy Sources• Power from sun, wind,

and water

– Solar energy is 10,000

times greater than the

sum of all human energy

demands… (much more

abundant than wind,

tidal, etc.)

– But the best available

solar cells are still too

costly and inefficient for

most uses

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Renewable Energy Sources

• Power from sun, wind, and

water

– Biomass energy

• Any form of energy that is

derived from plant life

• Includes fuel wood, peat,

animal dung, and agricultural

wastes, ethanol

– Wind turbines

• Still expensive, but likely that

their cost will soon be

competitive with the cost of

coal burning electric power

plants

Renewable Energy Sources

• Power from sun,

wind, and water

– Hydroelectric energy

• Electricity generated

by running water

– Hydrogen

• Can be used to power

fuel cells

• No place to mine

hydrogen (must be

converted from water,

which uses as much

energy as it produces)

Renewable Energy Sources

• Nuclear and geothermal

power

– Nuclear reactors explore the

energy-producing process

called radioactive decay

– Geothermal energy used by

humans come from

hydrothermal reservoirs,

• These are underground

systems of hot water or

steam

• They circulate in fractured or

porous rock

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Renewable Energy Sources

Temporary storage of

radioactive waste

Yucca Mountain-approved for

permanent storage in 2002, but

terminated in 2009.

Mineral Resources

• Ore

– A deposit from which one or more minerals can be extracted

profitably

• Finding and assessing mineral resources

– Nonrenewable, countries that can meet their need today may

not be able to in the future

– Uneven distribution of exploitable deposits mean no nation

is self sufficient

– Shift of mineral exploration and production away from the

industrialized nations toward less developed countries

Mineral Resources

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Mineral Resources

• How mineral deposits

are formed

– Hydrothermal

– Metamorphic

– Magmatic

– Sedimentary

– Placer

– Residual

Mineral Resources

Mineral Resources

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Mineral Resources

• Will we run out?

– Many geologist fear that shortages of

nonrenewable resources will hamper

development

– Shortages of energy resources are more likely to

affect us in the short run