1. Plate Tectonics, Minerals, Rocks & Mining
Terrestrial Earth
Plate Tectonics, Minerals, Rocks & Mining

2. Plate tectonics shapes the Earth
Plate tectonics = process that underlies earthquakes and volcanoes and that determines the geography of the Earth’s surface
Crust = lightweight thin component of Earth’s surface
Mantle = malleable layer on which the crust floats
Core = molten heavy center of Earth made mostly of iron 2

3. Pangaea: the supercontinent
Pangaea = at least twice in Earth’s history, all landmasses were joined in one supercontinent 3

4. Earth’s crust is constantly created and destroyed
Divergent plate boundaries = magma surging upward to the surface divides plates and pushes them apart, creating new crust as it cools and spreads
Transform plate boundary = two plates meet, slipping and grinding alongside one another
Friction spawns earthquakes along slip-strike faults

5. Tectonic plates can collide
Convergent plate boundaries = where plates collide
Subduction = one plate of crust may slide beneath another
Magma erupts through the surface in volcanoes
Two colliding plates of continental crust may lift material from both plates
Resulted in the Himalaya and Appalachian mountains
Boundary Interactive
Boundary Animations 5

6. The Earth has 15 major tectonic plates
Movement of these plates influences climate and evolution

7. Minerals and Rocks What is a mineral?
naturally occurring, inorganic, solid element or compound with a definite chemical composition and a regular internal crystal structure
What is rock?
solid, cohesive, aggregate of one or more minerals
Each rock type has a characteristic mixture of minerals
What is an Ore?
Rock with large concentration of a particular maineral to make it profitable
High and low grade ores
NON- Metalic Mineral
Sand, gravel, limestone
Metalic
Aluminum, Steel, manganese, cobalt, chromium, Copper, Gold

8. Minerals

10. Rock Cycle Sedimentary Rock Heat, Pressure Heat, Igneous Rock
Shale, Sandstone,
Limestone
Deposition
Transport
Erosion
Rock Cycle
Heat,
Pressure
Weathering
Heat,
Pressure
Igneous Rock
Granite, Pumice,
Basalt
Metamorphic Rock
Slate, Quartzite,
Marble
Magma
(Molten Rock)
Fig p. 339

12. Mining: Extract Ore from Ground
Types of Mining:
Surface Mining: Scoop ore off surface or earth.
cheap.
safe for miners.
large environmental destruction.
Sub-Surface or Underground Mining: Use of shafts to reach deeply buried ores.
expensive.
hazardous for miners.
less environmental damage.

13. Surface Mining open pit mining:
circular hole in ground, with ramp circling down along sides, allows deeper ore to be reached.

14. Surface Mining- Strip Mining
strip-mining: scoop off rock overburden, and then scoop off ore material.
Economics of strip mining depend on stripping ratio
Large land area can be involved, especially for coal and bauxite.
Results of Mining utube

15. Bauxite Mine
In the Earth's Crust, in every million atoms, around of them are Aluminum, ( ppm1), by weight. This is around 8 % or almost one in every 12 atoms. This places aluminum amongst the world's most abundant elements.
Despite being present of Earth in such incredibly vast quantities on Earth, the metal never occurs on it's own in nature. Instead of existing free like Gold and Silver, due to its higher level of reactivity, it is always chemically bonded in compounds when it normally occurs. The most common of these compounds is Bauxite, or Aluminum Ore which contains large quantities of Aluminum Oxide.

16. Mountain Top Removal
Removing Overburden

17. spoils Overburden Coal seem bedrock Appalachian Voices

18. Gold in Quartz
A large quartz boulder with a lot of visible gold. Usually, the gold is much finer and hard to see.

19. Placer Deposition Panning for gold in a placer deposit
Weathering liberates particles of heavy metal containing minerals
Minerals and gangue (waste) are transported by water
As water velocity decreases, heavy metals sink first, accumulating in protected parts of a stream bed
Much of the early gold removed from the Sierra Nevada was found in placer deposits
RESISTANT PLACERS Minerals resistant to weathering and erosion may also accumulate in this manner
Examples include diamonds, sapphires and rubies (varieties of corundum), and emeralds
Photo Source:

20. Aeolian Placers
The "diamond crawl" in a deflation basin, Diamond Area No 1, Namibia
Diamond concentrations were increased by wind erosion

21. Environmental Impact of Mining

22. Waste water/sludge dams

24. Underground Mining A technology originating in antiquity.
A variety of configurations, depending upon conditions

25. Acid Mine Drainage
AMD results from the oxidation of sulfide minerals at the earth’s surface.
This form of chemical weathering generates sulfuric acid, a very powerful acid.
The sulfuric acid quickly reacts, dissolving other minerals and often releasing poisonous metal cations into surface waters.

26. Environmental Impact of Mining
Scaring the land surface- result spoils banks
Soil poor, windblown .. Primary succession slow
Toxic wastewater stored in sludge dams.
Toxins include slenium, arsenic, and mercury

27. Cassiterite
tin oxide ore mineral, SnO2. It is generally opaque but is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite has been the chief tin ore throughout ancient history and remains the most important source of tin today
TinSoldiers

28. Non-renewable Mineral Resource Depletion Curves
Source: Miller, G. Tyler, Living In The Environment. (2000) Wadsworth Publishing. New York.

29. Non-renewable Mineral Resource Depletion Curves
Source: Miller, G. Tyler, Living In The Environment. (2000) Wadsworth Publishing. New York.

30. US Non-renewable Resource Reserves
Source: Miller, G. Tyler, Living In The Environment. (2000) Wadsworth Publishing. New York.

31. Mining is an Economic Activity
The decision to mine (or not to mine) a particular ore deposit depends upon:
an analysis of costs, benefits and risks
tangible (i.e. dollar profit)
intangible (i.e. hopes of stimulating the economy, fears of environmental damage)

32. Gradual shift toward surface mining

33. Mining around the world Hungary’s disaster China’s rare earth minerals
Minining Law
Mining around the world
Hungary’s disaster
China’s rare earth minerals
US rare earth mineral info ad
Proposal for New Massive Mine in Romania
Goldmining
Mining ore
Bauxite mining
Mountaintop removal

35. Mining Issues surface Mine Safety:
In U.S., stringent mining regulations have lead to a reduction in fatalities, both in terms of total deaths per year, deaths per person-hour worked, and deaths per ton mined.
surface

36. Acid Mine Drainage
AMD results from the oxidation of sulfide minerals at the earth’s surface.
This form of chemical weathering generates sulfuric acid, a very powerful acid.
The sulfuric acid quickly reacts, dissolving other minerals and often releasing poisonous metal cations into surface waters.

37. Health Problems collapse of mine. fire (methane, coal dust, etc.).
asphyxiation (methane, carbon monoxide, etc.).
pneumoconiosis (from inhaling coal dust).
asbestosis (from inhaling asbestos fibers).
silicosis (from inhaling silicate dust).
heavy metal poisoning (e.g. mercury).
radiation exposure (in uranium mining).

38. Environmental Damage 4FeS2 + 14H2O = 4Fe(OH)3 + 8H2SO4
Gaping holes in ground (old open pit mines).
Piles of mine tailings (non-ore removed from mines).
Accidental draining of rivers and lakes.
Disruption of ground water flow patterns.
Loss of topsoil in strip-mined regions (350 to 2,700 km2 in US alone).
Contamination from sulfuric acid (H2SO4) produced through weathering of iron sulfide (FeS2, pyrite) in tailings.
4FeS2 + 14H2O = 4Fe(OH)3 + 8H2SO4
Contamination from heavy metals (e.g. arsenic, mercury) in mine tailings.

39. Smelting and Refining: Environmental Problems
Production of huge piles of slag.
Emission of CO2, a greenhouse gas, into the atmosphere.
Pollution associated with the generation of electricity needed in anode furnaces (especially aluminum).
Sulfur dioxide emissions from the refining of sulfide ores are a major source of air pollution. The sulfur dioxide combines with water to produce sulfuric acid.
Release of heavy metals (As, Cd, Hg), present in trace quantities in sulfide ores, into the atmosphere.

41. Cost Trends copper Cents per pound
Amount of commodities mined per year has generally increased.
Commodity prices can take big swings, but average prices during the last century often declined or remained constant.
Cents per pound
copper
Ore grades have all decreased as milling technology has improved