Final Stuff Flashcards
What are people using more of? What specifically?
Energy, Fossil fuels
How are most of our energy needs met?
Through things found and extracted from the Earth?
Is it getting harder or easier to extract resources from the Earth?
Harder. We have to go deeper to find what we are looking for
What are various forms of burned organic carbon initially produced by photosynthesis and chemically transformed by burial and heating?
Fossil fuels
What fossil fuel is derived from buried plant matter?
Coal
What fossil fuel is derived from buried algae?
Oil
What is the earliest fossil fuel to be used? What percentage of total energy consumption does it account for?
Coal, 26%
In what type of environment does coal form?
Humid, swampy environments
In what period did 60% of the world’s coal reserves form?
Carboniferous period
What are the three requirements for oil and gas formation?
1: An organic rich source rock that has entered the oil window
2: A permeable reservoir rock that can collect and hold the hydrocarbons generated
3: An impermeable trap that allows hydrocarbons to accumulate/concentrate
How do oil and gas form?
1: Organic rich shales form in nutrient rich and/or oxygen poor waters, where organic matter is buried before it can decompose
2: When burial produces high enough temperatures and pressures, organic molecules react to generate mobile hydrocarbons that then migrate into reservoirs, traps
What is a structure that allows hydrocarbons to accumulate in a reservoir beneath or against an impermeable seal
hydrocarbon traps
What is a known supply of oil and gas held underground?
A hydrocarbon reserve
What is the association of source rock, migration pathway, reservoir rock, seal and trap geometry that leads to the occurrence of hydrocarbon reserve?
A hydrocarbon system
Are oil reservoirs young or old?
In geological time, they are relatively young.
Are oil reservoirs young or old?
In geological time, they are relatively young.
Has the success rate of drilling changed over time? Why?
No. Although oil is deeper, we can use seismic waves to find oil reserves. Before, it was closer to the surface but was hit or miss. But it is difficult to keep up with increases in oil demand
Has the success rate of drilling changed over time? Why?
No. Although oil is deeper, we can use seismic waves to find oil reserves. Before, it was closer to the surface but was hit or miss. But it is difficult to keep up with increases in oil demand
What is an example of unconventional reserves?
Going straight to the rocks (fracking, tarsands)
What is an example of unconventional reserves?
Going straight to the rocks (fracking, tarsands)
What are the two major types of minerals?
Metallic and non-metallic
What does concentration mean for mineral resources?
A resource occurs where the material of interest occurs in a sufficient abundance and concentration to be economically extracted
What are some characteristics of metals?
- opaque, shiny, smooth, conductive solid
- metal properties derive from metallic chemical bonds
- conductive because of delocalized electrons move from atom to atom easily
- hard or soft
- ductile (Able to be drawn into thin wires)
- malleable (Able to be hammered into thin sheets)
How do native metals occur naturally?
In a pure form. They are essential in modern industrial society
What is an ore?
A rock composed of metal-rich minerals concentrated enough to be economic to mine
What does concentration determines?
An ore’s grade
What are magmatic ore deposits?
Formed in a cooling plutonic intrusion
-sulfide minerals crystalize early and sink in magma, forming massive sulfide deposits at the bottom of the chamber
What are hydrothermal ore deposits?
Circulation of hot, chemically active water near intruding magmatic body
- hot fluid leeches metal ions out of rock near plutons
- minerals precipitate in lower P and T locations
- often concentrated in veins
What is secondary ore enrichment?
Groundwater leaches and oxidizes primary sulfide ores
-when reprecipitated, concentration is higher
What is groundwater transport?
Referred to as Mississippi Valley Type (MVT) ores (From lead-zinc deposits in the Mississippi Valley)
- organic belts squeegee hot water through deep basins
- the hot water leaches minerals and carries them away
- where basin brines surface and cool, they deposit metals
What are sedimentary deposits?
- form under special conditions
- banded iron formations (layered gray iron oxides and red chert (jasper))
- manganese nodules (rich in trace elements, these grow slowly on the sea floor)
What are residual mineral deposits?
- form via extreme chemical weathering in wet tropics
- intense weathering strips almost everything out of soil
- the residual soil is enriched in Fe and Al oxide
What is bauxite?
Primary ore of aluminum
What are placer deposits?
Concentrations of metal grains in stream sediment that develop when rocks containing native minerals erode and create a mixture of sand grains and metal fragments; the moving water of teh stream carries away lighter mineral grains
Where are ore deposits formed?
- tectonic processes are a dominant control
- igneous/magmatic and hydrothermal activity occur (plate boundaries, rifts, hot spots)
- tectonic effects are overprinted by the hydrological cycle
What are nonmetallic resources called?
industrial minerals
How do mineral resources form?
Through timely geological processes
What does it mean if a system is stable?
Ball at the bottom of a hill, needs lots of energy
What does it mean if a system is unstable?
Ball at the top of the hill, needs hardly any energy at all
What does it mean if a system is quasi-stable?
Ball in a dip half-way down a hill, needs a little bit of energy
What are the two forms of equilibrium and what do they mean?
Static-nothing happens because forces are in balance
Dynamic-no overall change because processes are occurring at the same rates
What are positive/amplifying feedbacks?
Allow small initial changes to blow up into big ones (a mechanism that enhances the process that causes the mechanism in the first place)
What are negative/stabilizing feedbacks?
Try to return system to the status quo (feedback that slows a process down or reverses it)
What is the Earth system?
A set of interacting components which cycles energy and elements between various reservoirs
Is the Earth continuously evolving?
Yes
What kind of equilibrium is the Earth in?
Dynamic. Many different driving forces, changing one changes the earth (Add in the human race)
What does the geological timescale reflect?
Transitions between quasi-stable equilibrium states
What are unidirectional changes?
There is no going back
What are cyclic changes?
Switching between two states
What type of changes does Earth’s history consist of?
Unidirectional changes being modulated by cyclic ones
Greenhouse gases are transparent to incoming solar radiation but absorb infrared radiation from Earth’s surface
Just know this
What is the trapping of heat in the Earth’s atmosphere by carbon dioxide and other greenhouse gases, which absorb infrared radiation?
The greenhouse effect
Is the greenhouse effect entirely bad?
No, it helps maintain Earth’s warmth
Which greenhouse gas has the longest residence time and what does that mean?
CO2. It means it is easier to changes its long-term atmospheric concentration *triggers warming
How is humanity disrupting the carbon cycle?
By burning fossil fuels
What kind of equilibrium is atmospheric CO2 in?
Dynamic with other reservoirs (ocean, biosphere)
Is CO2 a part of the plate and tectonic rock cycles?
Yes. long-term changes in these processes can affect the atmospheric concentration
What are paleoclimates?
the past climates of the Earth
How are paleoclimates interpreted?
By datable Earth materials that are climate sensitive (depositional environments are often climate sensitive)
How do growth rings work?
wetter, warmer=thicker
drier, colder=thinner
What are humans doing to the climate?
Taking carbon from a geological reservoir and adding it to the atmosphere
What is a rock (organic rich shale) containing raw materials from which hydrocarbons eventually form?
Source rock
What is the narrow range of temperatures under which oil can form in a source rock?
Oil window
What is a rock with high porosity and permeability so it can contain an abundant amount of easily accessible oil?
Reservoir rock
