Resources Flashcards
What are Fossil Fuels?
Fossil fuels refer to any organically derived sedimentary rock, or a product from an organic sedimentary rock that can be burned for fuel.
What are the principle types of fossil fuels?
- petroleum
-natural gas
-coal
Secondary peat, oil shales and oil sands.
How are fossil fuels formed?
-organic matter that is trapped in sedimentary rocks.
- biochemical alteration near the surface
- gradual burial of the sedimentary material drives off water increasing the heat and pressure on the organic material
What is coal?
A sedimentary rock occuring in beds
How is coal formed?
-Plants and trees die accumulating on land or under water
- Increases in pressure, temperature, and time eventually converts plants and trees to coal
What is Petroleum?
Liquid hydrocarbons found in rocks
What is Natural Gas?
A simple hydrocarbon that occurs in a gaseous state at the earth’s surface. Primarily consists of methane.
how are petroleum and natural gas formed?
1) a source rock that contains marine organic material,
2) formation of hydrocarbon molecules by increases in temperature and pressure associated with burial in a sedimentary basin (maturation stage)
3) migration of the hydrocarbon molecules away from the source rock, and,
4) trapping of the molecules in a suitable reservoir rock.
What are typical sources of rocks for the formation of petroleum and natural gas
Sedimentary. However fine grained, low energy rocks such as marine shales and
organic sedimentary rocks such as limestones typically contain the highest amount organic
material and are the best sources of hydrocarbon molecules
What is a sedimentary basin?
is a region where sediments accumulate over a long period of time resulting
in the formation of a thick sequence of sedimentary rocks
What is Maturation?
As a sedimentary basin develops, trapped organic material is subjected to increasing heat and pressure.
What is Migration?
As pressure increases in a sedimentary basen liquids and gases are expelled out and migrate upwards.
What is Accumulation and Trapping?
Areas where migrating hydrocarbons accumulate
What are the two general types of hydrocarbon traps:
stratigraphic traps and structural traps
what are stratigraphic traps?
This occurs when porous and permeably rocks are sealed off by an overlying impermeable bed.
What are structural traps?
this occurs where structures such as folds and faults serve to trap hydrocarbons.
What is a mineral resource?
any rock or mineral that is extracted (mined) for the benefit of society
What is a mineral deposit?
a naturally occurring concentration of minerals that may be extracted at a profit
What is an ore deposit?
A naturally occurring concentration of minerals in amounts sufficient to permit economic and profitable recovery
What are the primary groups of mineral deposits?
- Precious and Base Metal Deposits: gold, silver, platinum, copper, zinc, lead and aluminium.
- Ferrous metal deposits: iron, nickel, molybdenum, cobalt, tungsten (traditionally used to denote those metals that are used in the manufacturing of steel)
- Mineral fuels: coal, uranium, tar sands
- Industrial Minerals: a wide variety of minerals and rocks with industrial uses. It
includes aggregates, clays, limestone, silica and building stone
What geological processes are responsible for forming mineral deposits
1) Hydrothermal
2) Magmatic
3) Sedimentary
Hydrothermal Processes
Hydrothermal processes involve the circulation of hot aqueous solutions through rocks of the Earth’s crust
Magmatic Processes
Magmatic mineral deposits are those that form directly out of a magma due to a variety of processes that occur when a magma intrudes into the Earth’s crust and cools
Sedimentary Processes
Mineral deposists formed through the process of sedimentation
