Mining

What we mine… Ore : Ore : any material that mined –is mined (not grown) demand –is in demand (there is a need) profit –can be sold for a profit –Do NOT need to be minerals EconomicallyEconomically dependent Types of Ores –Metallic –Non-Metallic –Fuel

Metallic Ores Possess metallic properties Often good conductors of electricity Examples: –Gold –Copper –Hematite/Magnitite –Silver

Non-metallic Ores Possess non-metallic properties Examples: –Aggregate –Limestone –Halite –Sulfur –Gypsum

Fuel Ores Used to supply energy Many considered “Fossil fuels” Examples: –Crude Oil –Natural Gas –Coal –Uranium

Michigan Mining Metallic Ores  Copper  Iron Non-Metallic Ores  Aggregate  Rock Salt  Brine

Michigan’s Ores: Copper & Iron Pre-Cambrian BILLIONS of years ago Volcanic environment Cooling magma/lava

Underground Mine: UP Michigan

World’s Largest Copper Calumet, MI (UP)

Empire Mine (UP, Michigan)

Taconite (Iron/Silica) Pellets

Michigan’s Ores: Halite/Gypsum Paleozoic Era: millions years ago Coastal, tropical, saltwater environment Mineral deposits after evaporation Buried by recent (10,000yrs) glacial activity

Salina Formation

Rock Salt Mining

Halite Layer

Michigan’s Ores: Aggregate Cenozoic Era: millions years ago Ice Ages: Repeated glaciers in MI Retreats leave layers of sand and gravel (1000’)

Brine Salt Mining Pump freshwater down into salt beds Salt deposits dissolve Saltwater (brine) pumped out to surface Re-crystallizes as salt

Steps to Mining: Pre-Mining Buy the Land ( 1872 General Mining Law) Design the Reclamation Plan ( 1977 Reclamation Act) Post Reclamation Bond During Mining Preserve Topsoil Begin Reclamation

How we mine… Post-Mining: “Reclamation” ~ to return to its natural state –Preserve Original Slope –Re-vegetate –Recover Original Bond

How we mine: Surface Mining –Advantages –Disadvantages Underground Mining –Advantages –Disadvantages