Resources & Energy

Chapter 7, Section 1 - Mineral Resources                                                                                                                                                              

Ore - A natural mineral deposit from which metals and nonmetals may be profitably removed.
  • Can be found either as native elements or in compounds.
  • Formed in various ways...
  1. By Cooling Magma
    • Dense metallic minerals sink as magma cools => form a layer at the bottom of the magma chamber.
    • ex. - ores of Cr, Ni, Pb
  2. By Contact Metamorphism
    • Heat & chemical reactions can change rock to form ores.
    • Hot fluids flowing through cracks (hydrothermal solutions) can dissolve away some minerals and leave others to form veins (narrow zones) of ores.
      • Lode - An ore deposit where many thick veins form in a relatively small area.
    • ex. - ores of Au, Ag, Sn, Pb, Cu
  3. By Moving Water
    • As rock is weathered, small fragments of native elements can be released.
    • The fragments are carried by water until the current grows too weak, and they are deposited.
      • Placer Deposit - A deposit that contains a valuable mineral that has been concentrated by mechanical sorting.
    • ex. - Au

Uses of Mineral Resources
  • Gemstone - A mineral, rock or organic material that can be cut and polished for use as jewelry.
  • Examples of common mineral uses...
 Metallic Minerals Uses
 Hematite & Magnetite (iron) for making steel
 Galena (lead) in car batteries, in solder 
 Gold, Silver, Platinum  in electronics and dental work; as coins, jewelry, eating utensils and bowls
 Chalcopyrite (copper) as wiring; in coins and jewelry; as building ornaments 
 Sphalerite (zinc) for making brass and galvanized steel 
 Nonmetallic MineralsUses 
 Diamond (carbon) in drill bits and saws (industrial grade); in jewelry (gemstone quality)
 Graphite (carbon) in pencils, paint, lubricants, and batteries
 Calcite in cement; as building stone 
 Halite (salt) for food preparation and preservation 
 Kaolinite (clay) in ceramics, paper, cement and bricks 
 Quartz (sand) in glass and computer chips 
 Sulfur  in gunpowder, medicines and rubber 
 Gypsum in plaster and wallboard 


Mineral Exploration & Mining
  • An area is considered for mining if it contains 100 to 1000 times the concentration of desired minerals found elsewhere.
  • Mineral deposits are located and identified by...
    • Studying local geology: patterns in magnetism, gravity, radioactivity, and rock color.
    • Testing rock samples for composition.
  • Types of Mining...
    • Subsurface Mining  [video]
      • Miners work underground to locate and recover minerals.
    • Surface Mining
      • Overlying material is stripped away to reveal mineral deposits.
    • Placer Mining
      • Floating barges dredge up sediments and separate out the denser minerals.
      • Remaining sediment is released into the water.
    • Undersea Mining
      • Nodules (lumps of Fe, Mn, Ni) form on the ocean floor.
      • Difficult to mine due to location.  (Minerals on land are less expensive to mine.)

Chapter 7, Section 2 - Nonrenewable Energy                                                                                                                                                         

Nonrenewable Resource - A resource that forms at a rate much slower than the rate at which it is consumed.

Fossil Fuel - A nonrenewable energy source formed from the remains of organisms that lived long ago.
  • Composed mainly of hydrocarbons (compounds of H and C), which store energy converted from sunlight.
  • Examples:
    • Coal
    • Petroleum (Oil)
    • Natural Gas
Coal
  • The remains of ancient plants that undergo the process of carbonization to form coal.
    • Partially decomposed plant matter is buried and compressed to form peat.
    • Methane (CH4) and carbon dioxide (CO2) are released until mainly carbon remains.  (In the absence of oxygen.)
    • As sediments are added on top, water and gases are squeezed out, peat is converted into lignite (brown coal).
    • With more heat and pressure, lignite changes into bituminous coal (soft coal), which is 80% carbon.
    • Folding of the crust creates enough heat and pressure to convert bituminous coal into anthracite coal (hard coal), which is 90% carbon.
  • All of these can be used as energy sources.
    • Bituminous is the most abundant.
    • Anthracite releases the most energy.
Petroleum & Natural Gas
  • Made up of hydrocarbons; petroleum (a.k.a.: oil) is in liquid form, natural gas is in gaseous form.
  • Formed from dead plants and microorganisms that were buried by sediments in oceans, lakes and seas.  Heat and pressure converted the remains into petroleum and natural gas.
  • Usually mined from permeable sedimentary rocks.  (Rock with spaces for fluids to flow through.)








Resources

Chapter Assignment
  Pg. 190-191 #5-24, 34-36.