Zusammenfassung der Ressource
Last minute geology
- Rock examples
- Igneous
- Intrusive- granite, quartz
- Extrusive- Pumice, basalt
- Sedimentary
- conglomerate
- sandstone
- mudstone
- Metamorphic
- limestone=marble
- siltstone=slate
- Exploration methods
- The search for the rocks
containing the minerals, oil or coal
- Aerial methods
- Magnetic surveys
- Iron, nickel, cobalt
change magnetic field
- Magnetometers- detect change
- 'magnetic anomaly'
- Gravity surveys
- Gravimeters- detect
changes in gravitational pull
- Dense r&m affect pull
- Electromagnetic surveys
- detects good electric conductors
- Magnetic field sent from transmitter(plane)
- MF makes tiny eddy currents in minerals
- Eddies make own magnetic
field(secondary field)
- Receiver detects SF
- copper sulfide, lead sulfide, zinc sulfide, gold, silver
- On-site methods
- Seismic survey
- Shock wave into ground
- record reflecting sound waves
- geophones, detect sound waves
- structure of Earth's crust 35-60km deep
- help understand how minerals form
- help predict where minerals are
- Geochemical surveys
- Geochemistry
- samples from surface/drill holes in rock-
see amount of mineral
- core sample- rock removed
- water above/below indicator of minerals
- groundwater dissolves minerals
- detects diamonds, gold, uranium, copper
- Satellite images
- make images using light rays we can't see
- sensors detect radiation-
near-infrared,
shortwave-infrared,
thermal-infrared
- help see features images
with normal light don't show
- Geological maps
- show ore bodies
from above&side
- side view- 'cross-section'
- help us decide how to best mine the ore
- Mining
- type of mineral
geology of the area
cost & mineral value
- Surface Mining
- cheapest if near surface
- open-cut mine/ large pit
- ore removed by machines with
large shovels, giant drills called
augers and drag lines
- Underground mining
- ore is deep, fairly
concentrated, small
space/narrow veins
- Vertical shafts
- horizontal shaft into ore
- hoist lifts it to surface
- Steady slope/decline
- ore driven out by vehicle
- 15 degrees
- inside mountain- adit-
horizontal tunnels
- Dredging
- minerals heavier than sand
- dig pit- fill with water= lake
- boat sucks up sand using hoses
- separated then sand & water piped back in
- Leach mining
- minerals dissolved in fluid injected
- holes drilled into rock
- 'leach solution' is pumped into the ore
- dissolved ore solution pumped to the surface
- solution which will dissolve
the ore= 'leach solution'
- Petroleum wells
- Petroleum- liquide & gas-
trapped within sedimentary rock
layers
- bore narrow holes into rock
- Derrick- steel tower to
support drilling equipment
- hole drilled until oil/gas found or give up
- clay, chemicals, water
pumped through drill
pipe- keep cool
- When found
- drill & pipe removed
- metal casing (hollow tube
lowered into hole and cemented
in place
- System of pipes and valves
-'wellhead'- separates into
storage tanks
- pumps, water/steam/gas
injected to increase
pressure/oil flow
- Rigs
- rest on seafloor, float wires attached, boats
- pumped through pipelines on seafloor to factories
- floating ships link to well,
onboard treatment/storage
- flammable- disaster risk high