Minerals & MiningChapter 15

General Mining Law (1872)• 1872 – do you think it was good or bad??• Encouraged settlement of western states

• Anyone can stake a mining claim on federal lands, buy for $2.50 - $5 per acre, extract the resources, & keep all profits.

• No provisions for environmental protection

…General Mining Law (1872)

More than 50 of the 100,000 to 500,000

abandoned mines in the US are Superfund sites!

Cleanup of all Superfund mining sites will cost an estimated

$12.5-$17.5 billion.

Minerals

• Elements or compounds of elements that occur naturally in Earth’s crust.– Ex: steel (mixture), aluminum, copper, concrete

(mixture), sulfur, salt, quartz, gold, … you get it.

• Changed the course of history…– Britain = explored for tin.– Bronze Age = ruled by the alloy of copper & tin.– New World = explored for gold & silver.– California = gold rush (1840s)– Rain forests destruction = gold

…Minerals

• Mineral Groups:– Sulfides (S + another

element)– Oxides (O + metals)– Halides (F, Cl, Br, I)– Silicates (Si + O)– Carbonates (C + O)– Native Elements (any

pure element)

• Can be:– Metallic – Nonmetallic

• Rocks = combo of minerals + other stuff

• Ore = rock that contains a large enough concentration of a mineral that makes it profitable to mine for.– High-grade ore: large

amounts of minerals– Low-grade ore: low

amounts of minerals.

SPECIFIC CHEM. COMP.

SOLID

NATURALLY OCCURRING

DEF. CRYSTAL STRUCTURE

INORGANIC

Distribution & Formation• Widely distributed worldwide (see next slide)• Some countries have a lot, some have a little.===============================================

1. Magmatic Concentration• Magma cools & separates into layers• Heavy (Fe, Mg) on bottom, Light (SiO2) on top

2. Hydrothermal Processes• Hot groundwater dissolves minerals & react with S, making sulfides• Sulfides aren’t soluble, so they settle out.

3. Sedimentation• Water transports weathered particles and deposits them as sediment

4. Evaporation• Salts & minerals are left behind when water evaporates.

How is mining done?

STEP 1:DISCOVER THEM!

STEP 2:EXTRACT THEM!

STEP 3:PROCESS & REFINE THEM!

STEP 4:MAKE THEM INTO A PRODUCT!

Step 1: DISCOVERY

Aerial or Satellite photography

Measure Earth’s magnetic field & gravity

Geological knowledge of how minerals form

Drill for samples & analyze composition

Sea floor?? Detailed 3D maps!

Step 2: EXTRACTION• 2 ways: Surface & Subsurface Mining!

• Surface Mining (less $$, less danger)– Overburden must be removed

– 4 Kinds:• Open-pit mining = dig a big hole to make a quarry.

• Strip Mining = dig parallel trenches and create a spoil bank (dump new trench’s overburden in old trench)

• Mountaintop Removal = BAD!!!

• Dredging = chain buckets & draglines scrape underwater minerals

• Subsurface Mining (more $$, more danger)

Open-Pit Mine:

Bingham Canyon, UT

Largest man-made hole in the world

2.5 miles wide, 0.5 miles deep

Material removed = 7X amount moved to

create the Panama Canal

Strip Mine:

http://www.coal.ca/content/images/stories/stripmine.htm

TRENCH SPOIL BANK

Mountaintop Removal

(MTR)

“Strip Mining on Steroids”

• Widespread in WV, KY, TN, VA, PA

• Boston.com, 3/16/08: • “Short of a nationwide shift away from coal and toward

renewable sources, the Appalachia activists would like to see Congress pass the Clean Water Protection Act. This bill would reverse one of the Bush administration's most damaging concessions to industry on the environmental front. The Environmental Protection Agency decided in 2002 that mountaintop-removal miners' practice of dumping their waste into stream beds did not violate the Clean Water Act of 1970. The EPA decided the material was "fill," not waste.”

Step 2: EXTRACTION

• Surface Mining (less $$, less danger)

• Subsurface Mining (more $$, more danger)– Less damage to the environment (@ surface)

– Can cause subsidence & even miners’ deaths.

– 4 Kinds:

• Shaft Mine = direct vertical shaft, hauled out in buckets.

• Slope Mine = slanting passage, hauled out in cars.

• Room-and-pillar = some coal left in place as pillars to prevent collapse.

• Longwall = narrow tunnel supported by movable metal roof supports. Allowed to collapse after mining is completed.

Step 3: PROCESSING• Smelting

• Melting ore at high temperatures

to help separate impurities from

the molten metal.

• Uses a Blast Furnace

• Ore, coke, and limestone react

with heat to create:

– Purified molten iron (denser)

• Iron Ore + Coke = molten iron

+ carbon dioxide

– Impurities (“Slag”) (less dense)

• Limestone + Impurities = slag

• Exhaust gases are dangerous!

Step 4: CREATE PRODUCT

… that means…

Create a Product!!

Duh!

Environmental Implicationsp.336-340

• Get in groups of 6.

• Choose a partner within your group.

• Each pair summarizes one of the following:– 1 – Mining & the Environment (& c-b analysis)

– 2 – Environmental Impacts of Refining Minerals– 3 – Restoration of Mining Lands (& creative approaches)

• Vocab is key!!! …8min total!

• Teach your Home Group! …3min each!

Increasing our Mineral Suppliesp.340-344

• Locating & Mining New Deposits

• Minerals in Antarctica

• Minerals from the Ocean

• Advanced Mining Techniques

Increasing our Supplies…

Locating and Mining New Deposits

• Sometimes we know there are resources out

there… but they’re inaccessible.

– Malaria in Indonesia, Ice in Antarctica, High sedimentation

in Amazon Basin

• Create new technologies

– Dig 10km below surface, go through ice sheets, etc.

• Possible to find new resources?? USGS: sure!

Increasing our Supplies…

Minerals in Antarctica• To date, no substantial mineral deposits have been

found in Antarctica.– But we might find some!– FYI – nobody owns Antarctica… so the rules can get

sticky when people want to exploit resources.• ANTARCTIC TREATY – 1961

– Limits activity in Antarctica to peaceful uses such as scientific studies.

• Environmental Protection Protocol to the Antarctic Treaty (Madrid Protocol) – 1990 – Moratorium on mineral exploration and development for

>50yrs

• People are already ruining Antarctica’s fragile ecosystem… science, tourism, noise, pollution…

Increasing our Supplies…

Minerals from the Ocean• What’s there?

– Minerals from the seawater (evaporation) – NaCl, Br– Manganese Nodules! (p.344 in book) – Pacific has lots!

• How do we get them?– Dredging mostly. $$$$$$$$$

• Problems?– BAAAAD for the marine life.– Who has the rights? It’s in international waters!– Controversy:

• Some: it’s inevitable… Let’s mine it.• Others: so much ecological damage… Let’s declare it off-limits.

China denies reports on halting export of rare earth

Increasing our Supplies…

Advanced Mining Technologies• Use more low-grade mineral deposits.

– $$$$$$$$$$$$$$$– Causes greater land disruption– Produces far more pollution than high-grade ores

• In arid regions, lots of water needs to be pumped in to help with the mining process.

• Biomining– Microorganisms can extract minerals from low-grade ores– Copper mining uses it.– They help!!

• 90% recovery of gold with them• 75% recovery without them.

Expanding our Supplies by Substitution and Conservation

• Finding Mineral Substitutes– Use inexpensive, abundant materials instead!– Old=Tin. New=plastic, glass, aluminum.– Old=Copper wires. New=fiber optics (glass).

• Mineral Conservation – important!! (they’re nonrenewable!)

– Reuse & Recycle– Changing our Mineral Requirements

• Become a low-waste society!• Sustainable manufacturing (minimize waste in industry)

– Dematerialization• Decrease weight of products.

“Throwaway” Mentality

Sustainable Manufacturing

Traditional Flow of Minerals

Low-Waste Society Flow of Minerals

RELEVANT LEGISLATION• General Mining Law (1872)

– Allowed people to “stake claims” & make profit

• Surface Mining Control and Reclamation Act (1977)– Required reclamation of previously mined areas– Only from coal mining!!

• Antarctic Treaty (1961)– Limits activity in Antarctica to peaceful uses such as scientific studies– Convention on the Regulation of Antarctic Mineral Resource Activities

(1980s)• Never ratified – would have permitted exploitation of Ant. minerals

• Environmental Protection Protocol to the Antarctic Treaty (Madrid Protocol) (1990)– Moratorium on mineral exploration & development for >50 years– Designated Antarctica & its marine ecosystem as a “natural reserve

dedicated to peace and society”

Chapter 17

LAND RESOURCES LAND RESOURCES & &

CONSERVATIONCONSERVATION

Role of Rural Lands• Ecosystem services

– Wildlife habitat, flood/erosion control, ground water recharge

– Breaks down pollutants & recycles waste

– Provide habitat for organism

• Recreational/spiritual uses– Hiking, boating, sport hunting, fishing

• Used as bench marks for scientists to determine the impact of human activity

Land ownership in US55% owned privately

3% owned by Native Americans

~35% owned by the Federal Govt.Includes ecosystems from tundra to desertContains important resources such as minerals, fossil fuels, historical significance or critical habitatMostly in Alaska and 11 western states

Managed by:

1. US Department of the Interior Bureau of Land Management (BLM) Fish and Wildlife Service (FWS) National Park Service (NPS)

2. Department of Agriculture U.S. Forest Service (USFS)

~7% owned by state/local Govt.

Important Land Laws

1. Wilderness Act (1964)

Preserves (natural & unchanged) federally owned land that: retains its primeval character lacks permanent improvements or human dev’t

Given the highest protection of any federal land

Mostly in the west or Alaska

Restrict # of people allowed in these areas to decrease erosion, pollution & human impact

2. The Wild & Scenic Rivers Act (1968)

Protects rivers with outstanding beauty, recreational value, unique geologic features, important wildlife

National Parks Service Protect land & biological diversity

in an unimpaired condition

385 sites (57 of them are National Parks)

Many parks are threatened Human Activities- littering, graffiti, pollution, development

around parks Large mammal population decrease (Bears) Large mammal population increase (Elk)

Parks are now managed using Natural Regulation Populations are allowed to fluctuate naturally due to

weather or predators Fires are not suppressed unless they threaten people Park managers DO control exotic species invasion

FORESTS• Occupy less than 1/3 of Earth’s surface• Supply: Fuel, timber, paper products,

nuts, mushrooms, fruits, medicines• Provide many ecosystem services

– Influence local climate - Transpiration– Regulating global biogeochemical cycles

– Act as “sinks” for CO2

– Hold soil in place reducing erosion/mudslides– Watersheds:

• Absorb, hold and slowly release water • Controls flooding & droughts

– Animal habitat

FOREST MANAGMENT

• Most “managed” forests are monocultures where trees are planted in rows and are of one variety– All trees are the same age &

size– More prone to insects and

diseases– Insecticides & fungicides are

used– Monocultures can’t support

large food webs

Sustainable Forestry

• Seeks to:– Conserve forests for long-term

commercial timber harvest– Sustain biodiversity by…

• Provide improved habitat for many species

• Decrease soil erosion• Preserve watersheds

• COOPERATION is crucial!– environmentalists– government officials

– loggers– farmers

• Sustainable Logging Practices:– Unlogged areas are saved as sanctuaries– Wildlife corridors are created

• (zones that connect isolated unlogged areas)

Provide escape routes so

animals can interbreed

(help reduce extinction)

Large animals can

maintain large territories.

wildlife corridor

Harvesting Trees• 5 Countries harvest the most trees

– US, Canada, Russia, China, Brazil

• What happens to harvested trees?• 55% are burned

– Fuel wood or made into charcoal (partially burn w/o O2)

– Very important for developing nations

• 45% used for paper/wood products in highly developed nations

• Harvesting Methods 1. Selective cutting

2. Shelter wood cutting

3. Seed tree cutting

4. Clearcutting

1. Selective Cutting• Mature trees are cut individually or

in small clusters while the rest of the forest remains intact.

• Remaining trees fill in with saplings

• Animals don’t lose habitat

2. Shelterwood Cutting• Some mature trees are harvested,

leaving some to provide protection/shade for young trees and seedlings.

• The remaining mature trees are harvested once regeneration is well established.

• Little soil erosion

3. Seed Tree Cutting

• Almost all trees are harvested from an area

• A few desirable trees are left to provide seeds for the regeneration of the forest.

4. Clearcutting• Removal of all trees from an area• Area is allowed to reseed and

regenerate naturally or is planted• Timber companies prefer because it is

cost effective.• Destroys habitat & causes fragmentation• Massive soil erosion issues

LOGGING ROAD

MUDSLIDE

Deforestation

• Temporary or permanent clearance of large expanses of forest for agriculture/other uses– World decrease of 37 Million acres yearly– Causes: Drought, land clearing, expansion of

agriculture, construction of roads, tree harvests, insects, disease

– Threatens indigenous people– Results in decreased soil fertility through rapid leaching– Uncontrolled soil erosion – Sedimentation of waterways (harms fisheries)– Extinction of species– Global Temp Increase from more carbon/CO2 released– Regional/global climate changes – less transpiration

• “If there isn’t a rainforest, there isn’t rain and then there is no river” Sean Connery in Medicine Man

Only write these facts if you don’t know them

Why are Tropical Forest Disappearing?

• More people need more food… …agricultural expansion!!– Economic, social and governmental factors– Amazonian Deforestation

1. Subsistence Agriculture: (~60% of deforestation) – Slash & Burn Agriculture- high yield at first, then very

poor

2. Commercial Logging: for exports (~20%)

3. Cattle Ranching: Provide rangeland (~12%)

• Tropical Dry Forests– Tropical areas with a wet &

dry season– Disappearing primarily for fuel

• Wood is used to make charcoal – important for developing countries

• Boreal Forests– Coniferous evergreen trees– Alaska, Canada, Scandinavia &

N. Russia– Cover 11% of Earth (world’s largest biome)– Primary source of world’s industrial wood and

wood fiber– Estimated annual loss: Area 2x the size of the

Amazonian Rainforests of Brazil – Logging in Canada seems to be

unsustainable.

UNITED STATES FORESTS

• 57% privately owned; 20% US Gov.; 15% Corporations; 8% State & local Gov.– Privately owned forests can be protected

through the Forest Legacy Program• Landowner grants a conservation easement • US Gov. buys the land, agreeing not to develop it

for a certain number of years

• National Forests have multiple uses.– timber, livestock, water & watershed

protection, mining, recreation & habitat• Issues

– confrontations over multiple uses– building of logging roads with tax revenues– clear cutting

Rangelands• Temperate & Tropical Grasslands

– Predominant vegetation includes grasses, forbs, and shrubs

– Provide fodder for livestock

• Animals eat the leafy shoots of the grass and the fibrous roots continue to develop, allowing the plant to recover and re-grow– Can actually encourage greater plant diversity– Cannot exceed carrying capacity

• Overgrazed land BAD!!!!• Can lead to Desertification: rangeland converted to

desert due to drought and or overgrazing

– Desertification is result of overuse of the land leaving it dry and erosion removes the little topsoil present and the sand left behind forms dunes.

• Reduces agricultural productivity, forces organisms out and threatens endangered species

– About 135 Million people are in danger of displacement due to desertification

The fence is the line of demarcation between an overgrazed private property and ungrazed nature reserve. The impact of grazing here is

obvious and dramatic.

US RANGELANDS

• Approximately 30% of US– Governed by the BLM which is guided by:

• Taylor Grazing Act (1934)• Federal Land Policy & Management Act (1976)• Public Rangeland Improvement Act (1978)

• Conditions have improved since the Dust Bowl of the 1930’s– Fewer livestock permitted to graze on it– Rangeland management

• Seed places that are sparse• Conduct controlled burns to suppress shrubs• Build fencing to allow rotational grazing• Control exotic weeds

Issues with US Rangelands

• Private livestock operators buy permits from the federal gov’t to use public rangelands for grazing

• Environmental groups want to reduce the number of animals allowed– They want to be able to buy some of

those permits to minimize grazing…• Want lands to be used for habitat, recreation

and scenic value rather than livestock grazing

– Conservative economists agree…• taxpayers paid $53 M more than the grazing

fees collected

Wetlands• Transitional zones between aquatic and

terrestrial ecosystems• ~ 75% are privately owned• Ecosystem Services:

• Threatened by:

•Recharge groundwater

•Reduce flooding

•Filter water pollution

•Habitat

•Produce commercially important products

•Recreation

•Drainage for agriculture

•Drainage for pest control

•Dredging for navigation

•Dam construction

•Flood control dykes & dams

•Used for waste disposal

•Development / building

•Conversion to aquaculture

• Emergency Wetlands Resource Act (1986)

– Authorized FWS to inventory and map US wetlands

– Confusion about• Definition of a wetland• Question of who owns wetlands

– Private landowners resent the government restricting what they can do with their lands

• Wetland Reserve Program (WRP)– Voluntary program, seeks to restore &

protect privately-owned freshwater wetlands

• Participants are offered financial incentives and they can establish conservation easements

• Permanent easement WRP pays all restoration costs

COASTLINES• Include tidal marshes & coastal wetlands• Ecosystem services:

– Nurseries for wildlife species– Protect from coastal erosion & storms

• Historically drained & filled in or dredged out to turn them into “productive” areas

• Many coastal areas are over-developed, highly polluted and over-fished

• About 2/3 of the world population lives within 150 miles of a coastline

• There are massive erosional forces acting on our beaches. Natural beaches are better at stopping erosion than seawalls

Seawalls

National Marine Sanctuaries

• To protect natural resources and historical sites along US coasts– National marine Sanctuary Program

administers the sanctuaries• 12 sites

– Kelp Forests off California– Coral Reefs in the Florida Keys– Fishing grounds along the continental shelf– Deep submarine Canyons– Shipwrecks & other historical sites

• Managed for multiple purposes– Conservation, recreation, education, mining,

scientific research, ship salvage

AGRICULTURE• Former forests or grasslands that

have been plowed for cultivation• Prime Farmland:

– has the soil type, growing conditions and available water to produce food, forage, fiber and oilseed crops.

• Prime farmland is being threatened by development or “urbanized” and lost to food/crop production

• Farming involves large tracts of land by agribusiness conglomerates, not family farms.