Mining of natural resources from the earth….. ….how did these resources get here? See Chapter 16, Living in the Environment, G.T. Miller Gold Mine

Minerals, rocks and fossil fuels are mined out of the earth The earth’s crust is composed of rocks and minerals (see p for some basic geology) Element composition: astr.gsu.edu/Hbase/tables/elabund.htmlhttp://hyperphysics.phy- astr.gsu.edu/Hbase/tables/elabund.html mineral = solid element or non C containing compound, with regular, internal crystalline structure & specific chemical composition…Ag, Au, C, S, NaCl, quartz…. mica is a mineral…. Micas.html Micas.html

Rocks are solid combinations of 1 or more minerals Limestone = CaCO 3 (sedimentary) Quartzite = SiO 2 (metamorphic) 8&sa=N&tab=wi 8&sa=N&tab=wi Granite =SiO 2, TiO 2, Al 2 O 3, Fe 2 O 3, etc. (igneous) ch+Images&aq=f&oqhttp://images.google.com/images?hl=en&um=1&sa=1&q=granite&btnG=Sear ch+Images&aq=f&oq=

What else do we mine out of the ground? Salt, clay, phosphates, sand, soil, bauxite Coal, oil, natural gas, U Renewable or nonrenewable? What else?

How do we know where to mine? Exploratory Wells Aerial photos Satellite images Radiation monitoring Magnetometer Seismic surveys (use explosives, detect shock waves) Chemical analysis of rock and water

Depending on where the resource is…

Surface mining Indiana Illinois Most mining in U.S. “Overburden” is stripped away Wastes are “spoils” or “tailings”.

Strip Mining “Since the mid-1970s, strip-miners in Montana, as well as in other states, are required by law to remove overburden in an orderly manner, to refill the pits after mining the coal, restoring the overburden as nearly as possible to its original condition, and to replant it with the original types of vegetation. "The art and science of mine reclamation are now so highly developed," say geologists David Alt and Donald Hyndman, "that the recently worked sites are visible only to a knowing and practiced eye."1 Some of the lignite mined here at Colstrip is used to generate electricity at the plant in the upper center. The rest is shipped to coal-fired generators in other parts of the country, via 100-car "unit" trains.”

Mountain top removal At least two sides to every issue….. rules-in-favor-of-m_n_ html id.php?id=288&category_id=4 id.php?id=288&category_id=4

Subsurface mining Kentucky coal mine: longwall mining More pixs: ml What’s good about subsurface mining? What’s bad about it?

Subsurface Mining Advantages Only way to access some resources Disturbs less than 1/10 th as much land as surface mining Usually produces less waste material Disadvantages Dangerous Collapse of roofs & walls Explosions of dust & natural gas Lung diseases from mining dust Leaves much of the resource in the ground Subsidence (sinking of earth that is not slope related)

Cyanide heap leaching At Wind Mountain More on ZL al.html al.html Read about Zortman- Landusky Read about Zortman- Landusky mine

Why do these problems persist? Public Land in US is cheap! U.S. General Mining Law of 1872… see text; case study Resource developers want to use U.S. land Government subsidies ?

What can we do? Reduce consumption Reuse stuff Recycle Enforce environmental protection Look for substitutes Biomining (use bacteria to “grab” the metal) Mining seawater (high cost, who owns resource?) Nanotechnologies (research to build at atomic & molecular level)