Geology and Geology and Nonrenewable MineralsNonrenewable Minerals

Chapter 12Chapter 12

Key ConceptsKey Concepts

Major geologic processesMajor geologic processes

Rocks and the rock cycleRocks and the rock cycle

Finding and extracting mineral resourcesFinding and extracting mineral resources

Environmental effects of miningEnvironmental effects of mining

Enough nonrenewable resources for the future?Enough nonrenewable resources for the future?

General Mining Law of 1872General Mining Law of 1872

Original purpose of the lawOriginal purpose of the law

Impact on US public landsImpact on US public lands

Benefits to mining companiesBenefits to mining companies

Costs to the publicCosts to the public

Environmental issuesEnvironmental issues

Laws in other countriesLaws in other countries

Fig. 12-1, p. 269

Internal Geologic ProcessesInternal Geologic Processes What is geology?What is geology? - the study dynamic processes occurring on the - the study dynamic processes occurring on the

Earth’s surface and in it’s interior.Earth’s surface and in it’s interior.

Earth’s internal structureEarth’s internal structure• CoreCore - solid inner part, surrounded by a liquid core of - solid inner part, surrounded by a liquid core of

semisolid material. semisolid material.• MantleMantle - surrounds the core. Solid rock over the - surrounds the core. Solid rock over the asthenosphersasthenosphers..

• CrustsCrusts (continental and oceanic) (continental and oceanic)

Plate tectonics - convection cells cause about 15 Plate tectonics - convection cells cause about 15 plates to move across the earth’s surface.plates to move across the earth’s surface.

Atmosphere

Biosphere

CrustLower mantle

AsthenosphereUpper mantle

Continentalcrust

Oceaniccrust

Lithosphere Vegetationand animals

Soil

Rock

Crust (soiland rock)

Atmosphere(air)

Biosphere(living and dead

organisms)Lithosphere

(crust, top of upper mantle)

Hydrosphere(water)

Core

Mantle

Fig. 3-5, p. 38

General Structure of the EarthGeneral Structure of the Earth

Fig. 12-2, p. 271

Oceanic crust(lithosphere)

Abyssalhills Abyssal

floorOceanic

ridgeTrench

Volcanoes

Folded mountain belt

Craton

Mantle (lithosphere)

Mantle (asthenosphere)

Ab

ys

sa

l p

lain

Continental crust(lithosphere)

Mantle(lithosphere)

Continentalrise

Continentalslope

Continentalshelf

Abyssal plain

Abyssalfloor

Earth’s Crust and Upper Mantle Earth’s Crust and Upper Mantle

Fig. 12-3, p. 272

Tectonicplate

Collision between two continents

Oceanic tectonicplate

Spreading center Oceanic tectonic

plateOcean trench

Plate movement Plate movement

Continentalcrust

Subductionzone

Oceaniccrust

Oceaniccrust

Continentalcrust

Mantle

Innercore

Hot outercore

Two plates movetowards each other.One is subductedback into the mantleon falling convectioncurrent.

Mantleconvectioncell

Hot materialrisingthroughthe mantle

Material cools as it reachesthe outer mantle

Cold densematerial fallsback throughmantle

Plate TectonicsPlate Tectonics

Inner core

Plate TectonicsPlate Tectonics

Tectonic platesTectonic plates

Lithosphere - outer most part of the mantelLithosphere - outer most part of the mantel

Plate tectonics and biological evolutionPlate tectonics and biological evolution - Populations became isolated and speciation - Populations became isolated and speciation

occurred.occurred.

Fig. 12-4, p. 273

EURASIAN PLATEEURASIAN PLATE

CHINACHINASUBPLATESUBPLATE

PHILIPPINEPHILIPPINEPLATEPLATE

INDIAN-AUSTRLIAN INDIAN-AUSTRLIAN PLATEPLATE

PACIFICPACIFICPLATEPLATE

JUAN DEJUAN DEFUCA PLATEFUCA PLATE

NORTHNORTHAMERICANAMERICAN

PLATEPLATE

SOUTHSOUTHAMERICANAMERICAN

PLATEPLATE

ANATOLIANANATOLIAN PLATEPLATE

ARABIANARABIAN PLATEPLATE

SOMALIANSOMALIAN SUBPLATESUBPLATE

ANTARCTIC PLATEANTARCTIC PLATE

Convergent plate boundaries Divergent boundaries

Earth’s Major Tectonic PlatesEarth’s Major Tectonic Plates

AFRICANAFRICAN PLATEPLATE

NAZCANAZCA PLATEPLATE

CARIBBEANCARIBBEAN PLATEPLATE

Transform faults

Types of Plate Types of Plate BoundariesBoundaries

DivergentDivergent Move apartMove apart ConvergentConvergent Pushed togetherPushed together TransformTransform Grind past one Grind past one

another another

Fig. 12-5, p. 274

Fig. 12-5a, p. 274

Lithosphere

AsthenosphereOceanic ridge at a divergent plate boundary

Types of Plate BoundariesTypes of Plate Boundaries

Fig. 12-5b, p. 274

Lithosphere

Trench Volcanic island arc

Asthenosphere

Risingmagma

Subductionzone

Trench and volcanic island arc at a convergent plate boundary

Types of Plate BoundariesTypes of Plate Boundaries

Transform fault connecting two divergent plate boundaries

Fig. 12-5c, p. 274

Fracture zone

Transformfault

Lithosphere

Asthenosphere

Types of Plate BoundariesTypes of Plate Boundaries

External Earth ProcessesExternal Earth Processes

ErosionErosion - material is dissolved, loosened, or worn away- material is dissolved, loosened, or worn away

Physical (mechanical) weathering: frost wedgingPhysical (mechanical) weathering: frost wedging

Chemical weatheringChemical weathering

Biological weatheringBiological weathering

Question of the DayQuestion of the Day

As the Tsunami crest approaches shore, As the Tsunami crest approaches shore, the wave height _________, the velocity the wave height _________, the velocity __________, and the period _____.__________, and the period _____.

Choices: DecreasesChoices: Decreases

IncreasesIncreases

Remains constant Remains constant

Fig. 12-6, p. 275

Igneous RockGranite,pumice,basalt

Metamorphic RockSlate, marble, gneissquartzite

Magma(molten rock)

Heat, pressure, stress

Heat, pressure

Melting

Sedimentary Rock

sandstone, limestone

Deposition

TransportationErosion

Weathering

The Rock CycleThe Rock Cycle

Cooling

Mineral ResourcesMineral Resources

Generally nonrenewableGenerally nonrenewable

Metallic, nonmetallic, and energy resourcesMetallic, nonmetallic, and energy resources

OresOres - rock containing enough of one or more - rock containing enough of one or more metallic minerals to be mined profitably.metallic minerals to be mined profitably.

Categories of Mineral ResourcesCategories of Mineral Resources

IdentifiedIdentified

UndiscoveredUndiscovered

ReservesReserves

OtherOther

Fig. 12-7, p. 276

Finding Mineral ResourcesFinding Mineral Resources

Aerial and satellite imagesAerial and satellite images

Radiation detectorsRadiation detectors

MagnetometersMagnetometers

GravimetersGravimeters

Seismic surveysSeismic surveys

Chemical analysesChemical analyses

Extracting Mineral DepositsExtracting Mineral Deposits

Surface miningSurface mining

Subsurface miningSubsurface mining

Overburden - soil and rockOverburden - soil and rock

Spoils - discarded overburden or Spoils - discarded overburden or waste materialwaste material

Mining MethodsMining Methods Open-pit (surface mining) Bingham UtahOpen-pit (surface mining) Bingham Utah

Area strip mining (surface)Area strip mining (surface)

Contour strip mining (surface)Contour strip mining (surface)

Mountaintop removal (surface)Mountaintop removal (surface)

The Surface Mining Control and Reclamation Act of 1977The Surface Mining Control and Reclamation Act of 1977

Subsurface miningSubsurface mining

Hazards and environmental tradeoffs of subsurface miningHazards and environmental tradeoffs of subsurface mining

Open-pit MineOpen-pit Mine

Fig. 12-8, p. 277

Spoil from an Unrestored Area Spoil from an Unrestored Area Strip MineStrip Mine

Fig. 12-9, p. 277

HighwallCoal seamOverburden

Coal seam

PitBench

Undisturbed Land

Overburden

Spoil Banks

Contour Strip MiningContour Strip Mining

Fig. 12-10, p. 277

Mountaintop MiningMountaintop Mining

Fig. 12-11, p. 278

Environmental Effects of Environmental Effects of Using Mineral ResourcesUsing Mineral Resources

Disrupting the land surfaceDisrupting the land surface

SubsidenceSubsidence

Toxic mining wasteToxic mining waste

Acid mine drainageAcid mine drainage

Air pollutionAir pollution

Toxic holding pondsToxic holding ponds

Steps Environmental Effects

Exploration, extraction

MiningDisturbed land; mining accidents; health hazards; mine waste dumping;oil spills and blowouts; noise; ugliness; heat

Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat

Processing

Transportation, purifi-cation, manufacturing

Use

transportation or trans-mission to individual user,eventual use, and discarding

Noise; ugliness; thermal water pollution; pollution of air, water, and soil;solid and radioactive wastes; safety and health hazards; heat

Fig. 12-12, p. 279

Environmental Effects of Mineral UseEnvironmental Effects of Mineral UseNatural Capital Degredation

Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources

Processing of Mineral ResourcesProcessing of Mineral Resources

Ore mineral - the desired metalOre mineral - the desired metal Gangue - (“gang”) the waste materialGangue - (“gang”) the waste material

Tailings - piles of waste produced by Tailings - piles of waste produced by processingprocessing

Smelting - separates the metal from other Smelting - separates the metal from other elements in the ore mineralelements in the ore mineral

ProductsProducts Disposal or recyclingDisposal or recycling

Surface mining

Metal ore

Separationof ore fromgangue

Recycling

Discarding of product(Scattered in environ-ment)

Conversion to product

Melting metal

Smelting

Fig. 12-13, p. 279

Typical Life Cycle of a Metal Typical Life Cycle of a Metal ResourceResource

Reuse

Environmental Limits to Environmental Limits to Resource ExtractionResource Extraction

Environmental damage: a major mining problem Environmental damage: a major mining problem which will limit their availability, not exhaustion of which will limit their availability, not exhaustion of suppliessupplies

Ore grade - higher-grade ores exploited firstOre grade - higher-grade ores exploited first

Including environmental costs in productsIncluding environmental costs in products

Supplies of Mineral ResourcesSupplies of Mineral Resources Available supply and how rapidly it is usedAvailable supply and how rapidly it is used

Minerals become “Economically depletion” not “totally depleted”Minerals become “Economically depletion” not “totally depleted”

Five choices after depletionFive choices after depletion

• Recycle or reuseRecycle or reuse• Waste lessWaste less• Use lessUse less• Find a substituteFind a substitute• Do withoutDo without

Depletion time is how long it takes to use 80% of the reservesDepletion time is how long it takes to use 80% of the reserves

Economics determines what part of the known supply is extracted Economics determines what part of the known supply is extracted and usedand used

Finding alternativesFinding alternatives

Fig. 12-14, p. 280

Present Depletiontime A

Depletiontime B

Depletiontime C

Time

Pro

du

ctio

n

C

B

A

Recycle, reuse, reduceconsumption; increasereserves by improvedmining technology,higher prices, andnew discoveries

Recycle; increase reservesby improved miningtechnology, higher prices,and new discoveries

Mine, use, throw away;no new discoveries;rising prices

Depletion Curves for a Depletion Curves for a Nonrenewable ResourceNonrenewable Resource

Economics and Supplies of Economics and Supplies of Nonrenewable ResourcesNonrenewable Resources

Roll of economics in miningRoll of economics in mining

Standard economic theory = supply and demandStandard economic theory = supply and demand

Limited free market in developed countriesLimited free market in developed countries

Government subsidies of miningGovernment subsidies of mining

1872 US General Mining Law1872 US General Mining Law

Economic problems of developing new minesEconomic problems of developing new mines

http://www.storyofstuff.com/index.phphttp://www.storyofstuff.com/index.php

Mining Lower-grade OresMining Lower-grade Ores

New extraction technologies are neededNew extraction technologies are needed

Factors that limit mining lower-grade oresFactors that limit mining lower-grade ores

• CostsCosts

• Supplies of freshwaterSupplies of freshwater

• Environmental impactsEnvironmental impacts

Biomining: microorganisms and Biomining: microorganisms and in-situin-situ mining mining

Nanotechnology RevolutionNanotechnology Revolution

NanotechnologyNanotechnology

BuckyballsBuckyballs

Molecular economyMolecular economy

Possible achievements of nanotechnologyPossible achievements of nanotechnology

Possible environmental and health threatsPossible environmental and health threats

Likely need for guidelines and regulationsLikely need for guidelines and regulations

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QuickTime™ and a decompressor

are needed to see this picture.

Ocean MiningOcean Mining

Ore deposits in the oceanOre deposits in the ocean

Minerals from seawaterMinerals from seawater

Minerals in ocean sedimentsMinerals in ocean sediments

Hydrothermal depositsHydrothermal deposits

Manganese-rich nodulesManganese-rich nodules

Mining issues in international watersMining issues in international waters

Environmental issuesEnvironmental issues

Fig. 12-15, p. 283

Magma

Black smoker

Sulfidedeposit

White crab

Tube worms

Whitesmoker

White clam

Hydrothermal Ore Deposits on Hydrothermal Ore Deposits on the Ocean Floorthe Ocean Floor

Finding Substitutes for Scarce Finding Substitutes for Scarce Mineral ResourcesMineral Resources

Materials revolutionMaterials revolution

Ceramic substitutesCeramic substitutes

High-strength plastics and compositesHigh-strength plastics and composites

Finding some substitutes may be impossibleFinding some substitutes may be impossible

Some substitutes are inferiorSome substitutes are inferior