Environmental Science PowerPoint Lecture

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Environmental Science PowerPoint Lecture
Principles of Environmental Science - Inquiry and
Applications, 2nd Edition by William and Mary Ann
Cunningham
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Chapter 11 familiarize you with

• Understand some basic geologic principles,
  including how plate-tectonic movements affect
  conditions for life on earth
• Explain how the three major rock types form and
  how the rock cycle works
• Summarize economic mineralogy, strategic minerals
• Discuss environmental effects of mining and
  mineral processing
• Recognize geologic hazards earthquakes,
  volcanoes, floods, and erosions

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Key Terms Chapter 11

• Metamorphic rocks
• Midocean ridges
• Mineral
• Rock
• Rock cycle
• Sedimentary rocks
• Sedimentation
• Smelting
• Strategic metals minerals
• Tectonic plates
• Volcanoes
• Weathering

• Barrier islands
• Core
• Crust
• Earthquakes
• Flood
• Floodplains
• Heap-leach extraction
• Igneous rocks
• Landslides
• Magma
• Mantle

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Chapter 11 - Topics

• A Dynamic Planet
• Minerals and Rocks
• Economic Geology and Mineralogy
• Environmental Effects of Resource Extraction
• Conserving Geologic Resources
• Geologic Hazards

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Part 3 Economic Geology and Mineralogy

• Economic mineralogy the study of minerals that
  are valuable for manufacturing and trade (most
  metal ores) need economically recoverable
  levels(non-metal geologic resources graphite,
  feldspar, quartz crystals, diamonds)
• Public policy in the U.S. has encouraged mining
  on public lands as a way of boosting the economy
  and utilizing natural resources

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Living things C, N, O, H
Atmosphere C, N, O, Ar, Ne, He
Earth, rocks O, Al, Fe, Ni, Si, Mg, Ca, Na
Economic metals Al, Fe, Ni, Cr, Cu, Pb, Mn
Primary toxins Ni, Pb, Hg, Se, Br, Cd, Be, Rn, As
O
Fe used most followed by Al
What common - living things, atmosphere, earth,
rocks?
NO
Are any economic metals important for living
things?
What elements are common between atmospheric
element economic metals?
Al Fe Ni
None
What elements common between earth economic
metals?
Pb, Ni
What common elements for economic metals
primary toxins?
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Metals consumed in highest quantity globally

• Iron (most consumed) gt aluminum gt manganese gt
  copper gt chromium gt nickelearths crust 8.2
  Al, 5.8 Fe
• Most metals consumed in the following order of
  highest consumption US gt Japan gt Europe
• Most metals produced primarily in South America,
  South Africa, Russia

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Sources of Minerals
Extensive marine evaporite deposits in US
deposits left after water evaporates (large
inland lake with no outlet)
E.A. Keller. 1992. Environmental Geology
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Major deposits of mercury in red, small deposits
in green, bulk of productive deposits highlighted
in blue global occurrence mercury deposits
along subduction zones, with volcanic systems
Tectonic plate boundaries related to origin of
ore deposits such as iron, gold, copper, mercury
E.A. Keller. 1992. Environmental Geology
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US deposits of copper, beryllium, zinc, gold
not all deposits along tectonic boundaries
E.A. Keller. 1992. Environmental Geology
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(No Transcript)
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Global Metal Trade






Suppliers
Consumers US, Japan, Europe
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Nonmetal Mineral Resources

• Silicate minerals (gemstones, mica, talc,
  asbestos)Sand and gravel (for road and building
  construction)SaltsLimestone (like sand, gravel
  mined and quarried for concrete, crushed for road
  rock)greatest volume and dollar value of all
  nonmetal mineral resources
• Evaporites halite (rock salt deice roads in
  winter table salt),gypsum (plaster board wall
  covering Egyptians 5,000 yrs ago), potash (make
  fertilizers)
• Sulfur deposits mined mainly for sulfuric acid
  production (industry, car batteries, some
  medicinal products)
• Graphite, feldspar, quartz crystals, diamonds
  useful or demand for beauty

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• World industry dependent on 80 minerals /
  metals18 short supply (i.e. tin, platinum,
  gold, silver, lead) 1/3 to ½ strategic metals
  minerals
• Strategic metals and minerals - those a country
  uses but cannot produce itself
• Wealthy industrial nations often stockpile
  strategic resources, especially metals

U.S.
Stock piles of strategic metals
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E.A. Keller. 1992. Environmental Geology

• Much of cycle connected to waste
• Environmental impacts related to wastes
• Not recycle enormous economic burden
  environmental impact
• Metal recycling important difficult to find
  concentrated sources

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Percent of US consumption recycled aluminum,
copper, lead
Pb short supply, is strategic metal
Al - more energy to extract from ore than
recycle is strategic metal
E.A. Keller. 1992. Environmental Geology
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Part 4 Environmental Effects of Resource
Extraction

• Geologic resource extraction involves1) the
  physical processes of mining,2) the physical or
  chemical processes of separating minerals,
  metals, and other geologic resources from ores or
  other materials.
• Ore - a rock in which a valuable or useful metal
  occurs at a concentration high enough to make
  mining it economically attractive

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Mining and Air, Water Pollution

• EPA lists gt 100 toxic air pollutants released
  from US mines every year
• Gold and other metals often found in sulfide ores
  found in hydrothermal deposits- sulfur-bearing
  minerals exposed to air produce highly mobile and
  strong acids- vast quantities of ores crushed
  and washed to extract metals, uses lots of water
  (Nevada 60 million gallons/day) that gets
  contaminated

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Mining

• Placer mining
• Strip-mining or open-pit mining most common
• Underground mining tunneling deep
• Tailings - surface waste deposits
• Groundwater contamination
• Spoil banks - acid and sediment runoff
• Surface Mining Control and Reclamation Act (1977)
• By 2000, cumulative land used for mining was less
  than 1 percent (0.2) globally

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Hydraulic miners, 1910, in PNW
Since CA gold rush of 1849, placer miners used
water cannons to blast away hillsides Placer
mining ancient method of accumulating gold,
diamonds, coal
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Montana drainage into Blackfoot River
Bingham Canyon, Utah
2.5 mi wide
HOW RECLAIM, RESTORE? No soil or biological
legacyGround water in pits toxic (technology to
detoxify not known
2,640 feet deep
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Metals extracted from ores by heating (smelting)
or chemical solvents these more negative than
mining
Smelting roasting ore to release metals using
heat or chemical solvents
Ducktown, Tennessee most ecological devastating
smelting operations created wastelands
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Heap-Leach Extraction chemical extraction to
dissolve pulverized ore (GOLD)
Process for low-grade ores Uses cyanide trickling
through crushed ore to extract gold, other
precious metals
Thick clay pad plastic liner
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Kola peninsula arctic border of Russia, Finland
and Norway has biggest air polluting industries
in Europe

• Ni and Cu mines, rich in S
• Around 1985, about 700 thousand tons of SO2/year
• In 1994, about 350 thousand tons of SO2/yr (more
  than the total emissions of Norway, Sweden and
  Finland combined)

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Kola peninsula all forests gone close to
source, soil eroding, effects of nickel smelters
extending from Russia into Finland and Norway,
air pollution reaches critical limits
Chemical legacy hard to restore back to natural
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High in sulfur, copper, zinc, gold, iron
Ocean mining of rich mineral deposits a
technological challenge
700 F
Hydrothermal vents or black smokers
Mid-ocean ridges
http//www.pbs.org/wnet/savageearth/hellscrust/htm
l/sidebar2.html
http//www.pmel.noaa.gov/vents/geology/MOR.html
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E.A. Keller. 1992. Environmental Geology

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Geologic Hazards, Climate and Human Health
Volcanic eruption in Indonesia in 1963 lt air
temperatures by 0.2 C for 2 years
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Hekla eruption 1991
Natural volcanic eruptions result in similar Air
Pollution and Human Health problems as mining
causes

• Snow on North and Eastern Iceland pH 3
• Water close to Hekla was very toxic when it
  melted.
• Gas movement from underground sources polluted
  groundwater (e.g.SO4).

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Lakagígar 1783-1784 eruptions
Ash from eruption in Iceland fell in mainland
Europe
Gas aerosols released caused cooling in Northern
Hemisphere (by 1 degree C).
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Lakagígar eruption 1780s

• More than 50 million tons of SO2 emitted (more
  than the current total annual emission of Europe)
• Thick carpet of particulate and gaseous pollution
  over Iceland.
• Pollution probably very acidic

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Lakagígar eruption consequences in Iceland
(1780s eruptions)

• Grass and other vegetation withered
• Birds fell dead from the sky
• Fish disappeared from the rivers
• Large part of livestock died due to eating
  fluorine contaminated grass (poisoned)
• crop failure (by acid rain)
• People experienced respiratory problems, death of
  9,000 people (1/4 of residents of Iceland) due to
  famine

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Geology and Human Health
Released during volcanic eruptions SO2 sulfur
dioxide HCl hydrochloric acid HF hydrogen
fluoride aluminum smelters next biggest
sources very toxic to grazing animals
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Asbestos
Asbestos ferromagnesium silicate, used brake
lining insulation, very heat resistant so
prevents overheating of machinery prevents
fires LUNG DISEASE can result in lung cancer
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Iodine deficiency in drinking water correlated to
goiter frequency
Lithium naturally in water in southwest results
in less depressed people
Keller 1992 Environmental Geology
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Heart Disease and the Geochemical Environment
Correlation between chemistry of drinking water
(esp. hardness of water) and heart disease
mortality
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Occurrence of heart attack death correlated to
sulfate-rich and bicarbonate rich surface water,
Ohio
Cause-effect relationship -soft water acidic
corrodes pipes releases trace elements into water
that cause heart disease -hard water dissolves
trace elements into water may prevent heart
disease. Some trace elements in soil manganese,
chromium, vanadium, and copper, have been found
to prevent heart disease