ESS103 WEEK 5 ENERGY & GEOLOGICAL RESOURCES

sediment

loose particles produced by weathering/erosion, chemical precipitation, or biological activity.

lithification

The process that turns loose sediment into sedimentary rock.

porosity

The amount of empty/pore space within a rock or sediment.

permeability

The ability of fluids to move through connected pore spaces.

hy are porosity and permeability important for petroleum?

Porosity allows a reservoir to hold oil/gas, while permeability allows fluids to move through the rock.

Can a rock have high porosity but poor permeability?

Yes. It may have lots of pore space, but if the pores aren't well connected, fluids can't move easily.

renewable energy

replenished on human timescales

non renewable energy

sources are finite & take extremely long period to form

non renewable energy sources

coal, oil, natural gas & nuclear fuel

examples of renewable energy sources

wind, hydro, solar, geothermal & biomass

installed energy capacity

The amount of electricity-generating power that a system is capable of producing.

actual energy output

The amount of electricity that is actually produced.

Why aren't installed capacity and actual output necessarily the same?

A power source may have a large capacity but not operate continuously or at full capacity.

Does finding a valuable mineral automatically mean you have an economically viable ore deposit?

No. Extraction must be economically feasible.

What factors can affect whether a deposit is economically viable?

Deposit size/grade, depth, extraction costs, technology, infrastructure, environmental requirements, and commodity prices.

basic sequence of mineral processing?

Mine → crush/grind → concentrate → refine.

tailings

Waste material left over after valuable minerals have been separated from the ore.

acid rock drainage (ARD)

Acidic drainage produced when sulfide-bearing rocks are exposed to oxygen and water.

Why can mining cause ARD?

Mining exposes sulfide minerals that were previously isolated underground to oxygen and water.

What mineral is commonly associated with ARD?

Pyrite (FeS₂).

Why is ARD environmentally dangerous?

Acidic water can increase the mobility/solubility of metals, allowing them to enter surrounding water systems.

What is coal made primarily from?

Ancient terrestrial plant material that accumulated and was buried.

Where does coal formation commonly begin?

In wet, swampy, oxygen-poor environments where plant material accumulates.

what is peat

Accumulated, partially decomposed plant material that can eventually become coal.

sequence of coal formation/rank

Peat → lignite → bituminous → anthracite.

What happens to carbon concentration as coal rank increases?

Carbon concentration increases.

What happens to energy content as coal rank increases?

increases

Which has the highest rank: lignite, bituminous, or anthracite?

anthracite

What is the basic formation process for oil and gas?

Organic matter → burial → heat + pressure → hydrocarbons.

source rock

Rock containing organic material from which hydrocarbons are generated.

reservoir rock

Rock that stores hydrocarbons within its pore spaces

What two properties are especially important for a petroleum reservoir?

porosity & permeability

petroleum trap

A geological structure that prevents hydrocarbons from continuing to migrate upward, allowing them to accumulate.

Why do oil and gas tend to migrate upward?

They are generally less dense than the surrounding formation water.

Typical arrangement of fluids in a petroleum reservoir

Gas on top → oil → water at the bottom.

What makes oil sands difficult to extract?

The petroleum/bitumen is extremely viscous and does not flow easily.

in-situ oil sands method

Steam is injected underground to heat the bitumen and reduce its viscosity so it can flow more easily.

Where do diamonds form?

Deep within Earth's mantle under extremely high pressure and temperature.

Why are indicator minerals useful?

They're more common than diamonds and can provide clues about the location of a diamond-bearing kimberlite source.

What are diamond indicator minerals?

Minerals associated with kimberlite that can help geologists locate potential diamond deposits.