1. Chapter 18-19 September 8, 2015

2. Minerals –Inorganic –Naturally occurring –Solid material with a definite composition –Atoms arranged in a specific pattern

3. Single Elements or Compounds Can be single elements: –Gold (Au), silver (Ag), copper (Cu), iron (Fe) Can be compounds : –Quartz (SiO 2 ) Can be metals: –Fe, Al, Au, Ag, Cu Can be nonmetals –Sulfur, Gypsum

4. Examples

5. Metals and Nonmetals d

6. Metals Vs. Non Metals d

7. Smelting The process of heating and refining an ore to separate the valuable metals.

8. Some minerals and their uses

9. Metals in International Trade Industry and agriculture rely on metals for machinery and building materials Unequal distribution of metals in the environment creates an interdependence between countries. Nations that depend on resources from unstable regions are vulnerable to the changes in those regions.

10. d

11. Three types of Mining Surface Mining Subsurface Mining Dredging

12. Surface Mining –Removes minerals at or near the surface. –Layers of rock, soil, and vegetation are removed to uncover mineral deposits.

13. Open Pit Mining is an example of Surface Mining Uses large machines to dig ore from huge holes in the ground.

14. Hazards of Surface Mining Tailings: –Large deposits of discarded material are left near the mines. –Often contain toxic substances in the form of heavy metals such as lead and copper.

15. Environmental Hazards of Tailings Heavy metals are poisonous to living things Wind may carry these metals to new habitats Rainwater may leach through tailings and pollute groundwater, or carry toxic materials into fields or streams. Open pits eventually fill with water, which leaches into the ground and pollutes ground water.

16. Tailings

17. Subsurface Mining s

18. A shaft is dug into the crust. Explosives are used to expose the minerals Machinery is then lowered into the shaft to retrieve the mineral deposits.

19. Hazards of Subsurface Mining Less environmental damage More dangerous to the workers –Walls, ceilings, and underground tunnels can collapse –Explosions of natural gas and dust –Dust inhalation causes lung diseases.

20. Dredging Scraping or vacuuming minerals from the bottoms of bodies of water. –Ocean floors, lake bottoms, stream beds.

21. Hazards of Dredging Removes organisms and nutrients, potentially altering aquatic ecosystems.

22. Other Hazards from Mineral Mining Smelting –Emits sulfur dioxide, arsenic, and lead into atmosphere. –Create areas where plant and animal life cannot live. Heap Leaching –Liquid cyanide is sprayed over gold ores. –The cyanide dissolves gold and leaches it from the ore. –Gold is then collected from the cyanide liquid.

23. Soil Results from the weathering of solid bedrock.

24. 2 ways that exposed rock can be weathered? 1.Mechanically: a. processes that cause physical disintegration of exposed rock without any change in the chemical composition of the rock 1.Chemical b. Chemical breakdown of rock.

25. Mechanical Weathering d

26. Chemical Weathering

27. What is bedrock? Why is it important to soil formation? Bedrock: igneous, metamorphic, and sedimentary rock of lithosphere. As bedrock weathers, it supplies material needed to build soil Parent rock: –Bedrock source for an area of soil.

28. Soil Formation s

29. Soil Formation. Soil: mixture of mineral particles, air, H 2 O, & living and decaying organisms 1.Outer layer of bedrock weathers (cracks and holes) 2.Cracks reach deeper & outer layer becomes broken into small particles –Burrowing animals & plant roots break down bedrock & aerate soil

30. 4 distinct layers form. Soil profile: a vertical cross section of soil from the ground surface down to the bedrock A Horizon: topsoil B Horizon: subsoil C Horizon: weathered parent bedrock R Horizon: bedrock

31. Soil Profile d

32. 3 major soil textures. 1.Sandy: largest mineral size. 2.Silt: Medium sized mineral grains. 3. Clay: flat and traps H 2 O, preventing H 2 O drainage; smallest mineral size

33. Soil Textures (cont) d

34. Characteristics of soil Sandy soil – drains well, good aeration, but dries out quickly. –Not good for plants Clay soils –Hold water very well, but does not drain well –Not good aeration, so not good for plants.

35. Loam Soils Mixture of sand, silt, and clay Are ideal for plants because loam holds water and air.

36. Soil & Climate Deserts and Tundra –Thin profile because there is less water to break down the bedrock Grasslands –More precipitation and more plants/animals increase rate of weathering bedrock –Thicker profile Temperate and tropical soils –Thickest profiles –Abundant precipitation increases weathering.

37. Soil Mismanagement Vegetation removal Overgrazing Deforestation Pesticides Fertilizers Irrigation

38. Abiotic Agents of Soil Erosion 2.5 billion tons lost to water 1.5 billion tons lost to wind TOTAL=4 billion metric tons!

39. 4 types of soil conservation 1.Strip-farming: plowed strips separated by planted strips 2.Contour Farming: plowing along a slope instead of across it; furrows collect H 2 O which reduces erosion

40. 3.Terracing: series of platforms (terraces) are built into the slope; separated by vertical steps 4.Shelter belts: rows of trees planted along outer edges of field

42. How do we define solid wastes? All garbage, refuse, & sludge products from agriculture, forestry, mining, and municipalities –Examples: garbage trashjunk sewage scrap refuse

43. Describe how garbage disposal has changed over the years. Hunter-gatherers: left it and moved on Athens, Greece 500BC: trashed dumped outside of city walls –Rest of Europe dumped in the streets NYC/NJ 1892-1900: garbage loaded onto ships and dumped in Atlantic Ocean Now we use landfills

46. What is a landfill? How much garbage is dumped there? Site where wastes are disposed of by burying them 70%

47. Why are open landfills no longer allowed in the US? It supported large populations of rats, insects, etc. Foul odor and disease

48. Describe what a sanitary landfill is & identify 2 problems. Wastes are spread in layers ~3m deep & compacted by bulldozers Soil spread on top of refuse & compacted Repeated until garbage reaches certain heights 1.Methane produced 2.Leaching of toxic substances

50. What are hazardous wastes? Solid, liquid, or gaseous wastes that are potentially harmful to humans and environment Love Canal, NY: Town built next to old chemical plant –Steel containers holding waste leaked –Birth defects and cancer affected the people –Government relocated them ($190 million)

51. Name 6 types of hazardous waste. 1.Reactive Waste: can explode 2.Corrosive Waste: can eat through steel, clothing, and burn skin 3.Ignitable Waste: can burn at low temp; toxic fumes when lit 4.Toxic Waste: chemicals that are poisonous to people 5.Radioactive Waste: gives off radiation (given off when mining Uranium) 6.Medical Waste: old medicine, medicine containers, lab equipment and specimens

52. Identify & explain 4 methods for reducing volume of waste. 1.Recycle: paper, plastic, aluminum, glass, etc. 2.Reuse: cloth diapers 3.Biodegradable: leaves, grass clippings, food waste*, composting 4.Repair: old appliances, shoes, cars

53. Name 6 ways of disposing of hazardous waste. 1.Waste exchange: use haz. waste in production of other materials 2.Deep Well Injection: inject waste into porous rock under water table; LIQUID 3.Secure Chem. Landfill: waste is stored on nonporous bedrock pipes to monitor and collect leaks; cover with clay

54. 4.Controlled Incineration: burn waste at high temp Expensive 5.Biological and Chemical Treatment Plants: turn harmful things into harmless 6.Radioactive Waste Disposal: put in H 2 O or bury underground

55. What does EPA stand for? EPA = Environmental Protection Agency Established in 1970

56. Briefly describe Superfund. Law designed to protect communities from dangers of hazardous wastes CERCLA (1980): got $9 billion dollars to implement

57. What are some countries doing to combat high cost of disposal? Ship waste to developing nations and leave it there –Examples: West Africa and Zimbabwe