Earth Materials and Natural Resources

Question 1

Define Open Cast Mine

Answer 1

Takes place from quarries of ‘open pits’ at the surface. Overburden is removed

Question 2

Define Deep Mine

Answer 2

Mining deep within the earth. Drill vertically down with the overburden in place

Question 3

What are the three types of deep mine?

Answer 3

Longwall, Pillar and stall, Bell pit

Question 4

What are four geological hazards associated with coal extraction?

Answer 4

Mass movements, Gases, Subsidence, Acid Mine Drainage (AMD)

Question 5

What are six environmental issues associated with coal extraction?

Answer 5

Change in water table and water quality, Noise, Loss of habitat, Visual impact, Air quality, Transportation of material out of the mine/quarry

Question 6

What are five factors affecting the accuracy of estimation in the size of the coal deposit?

Answer 6

Bed geometries, Folds, Erosional features, Faulting, Previous mining

Question 7

Define Source Rock

Answer 7

Sediment that contained the plankton - where the hydrocarbon is made/comes from

Question 8

Define Reservoir Rock

Answer 8

Permeable and porous rock which the hydrocarbons collect in e.g. sandstone

Question 9

Define Cap Rock

Answer 9

Impermeable rock on top of reservoir rock which stops upwards migration of oil and gas

Question 10

Define Trap

Answer 10

Geological structure which stops the oil from migrating

Question 11

Define Oil Window

Answer 11

The right conditions for the organism to break down into petroleum

Question 12

Why is Darcy’s Law useful to oil and gas extraction?

Answer 12

It calculates the flow rate of the hydrocarbons in the reservoir rock

Question 13

What are the four types of hydrocarbon trap?

Answer 13

Anticline, Fault, Salt dome, Stratigraphic

Question 14

What are two potential problems associated with fracking?

Answer 14

Linked to low magnitude earthquakes, Ground water pollution

Question 15

What are four surveys used to prospect for hydrocarbons and coal?

Answer 15

Seismic methods, Magnetic methods, Gravity methods, Fossil identification

Question 16

What are the two types of microfossil?

Answer 16

Calcareous (foraminifera and coccolithophores) and palynomorphs (pollen, dinoflagellates and spores)

Question 17

Define Average Crustal Abundance

Answer 17

The amount of metal in ‘average’ continental crust

Question 18

Define Concentration Factor

Answer 18

The amount by which the metal is concentrated to make an ore deposit

Question 19

Concentration Factor =

Answer 19

Concentration of metal in ore/Average crustal abundance

Question 20

Define Grade

Answer 20

The concentration of valuable mineral within an ore

Question 21

Define Cut-Off Grade

Answer 21

The grade below which it is uneconomical to mine

Question 22

Define Ore Deposit

Answer 22

An accumulation of metal that may be economic to mine

Question 23

Define Ore Reserve

Answer 23

The rock containing valuable metal which is economic to mine

Question 24

Define Metallic Ore

Answer 24

Rock containing metallic ores which is economic to mine e.g. galena

Question 25

Define Native Metal

Answer 25

Pure metal - hasn't been bound with anything else e.g. gold

Question 26

Define Gangue Metal

Answer 26

A low-value waste mineral

Question 27

Define Mineral Vein

Answer 27

A layer/sheet of material that contains minerals

Question 28

Define Syngenetic

Answer 28

Deposits formed at the same time as the country rock

Question 29

Define Epigenetic

Answer 29

Deposit formed after the country rock

Question 30

Define Total Reserves

Answer 30

Can be worked at a profit

Question 31

Define Conditional Resources

Answer 31

There but not profitable at present

Question 32

Define Hypothetical Resources

Answer 32

Undiscovered or discovered but not assessed

Question 33

What are five factors which can change whether a resource becomes profitable/unprofitable?

Answer 33

Increase in demand or price increases globally, Decrease in mining cost due to technological advances, Positive political will for the extraction of the resource, Environmental restrictions, Alternate energy resource of product

Question 34

Define Magmatic Segregation

Answer 34

Separation of ore minerals by fractional crystallisation and related processes during magmatic differentiation

Question 35

What deposits are formed by magmatic segregation?

Answer 35

Chromite and platinum

Question 36

Define Volcanic Exhalative

Answer 36

The emission of hydrothermal solutions at the surface, usually under marine conditions and generally producing stratiform orebodies

Question 37

What deposits are formed by massive sulphide deposits (VMS)?

Answer 37

Copper and zinc

Question 38

Define Magmatic Crystallisation

Answer 38

Precipitation of ore minerals as major or minor constituents of igneous rocks in the form of disseminated grains or segregations

Question 39

What is formed by magmatic segregation?

Answer 39

Pegmatites

Question 40

Define Hydrothermal Veins

Answer 40

Deposition from hot aqueous solutions

Question 41

What are the two sources of the fluids for hydrothermal veins?

Answer 41

Magmatic waters and Meteoric ground water

Question 42

What deposits are formed by hydrothermal veins?

Answer 42

Tin, Tungsten, Copper, Lead, Iron

Question 43

Define Secondary Enrichment

Answer 43

Leaching of valuable elements from the upper parts of mineral deposits and their precipitation at depth to produce higher concentrations

Question 44

What deposits are formed by secondary enrichment?

Answer 44

Porphyry deposits e.g. copper

Question 45

Define Mechanical Accumulation

Answer 45

Concentration of heavy, durable minerals into placer deposits (surface deposits formed by weathering, erosion, transportation and deposition)

Question 46

What are five main requirements for placer deposits?

Answer 46

Pre-existing mineral veins at the surface, Dense and resistant ore minerals, Erosion and transportation, Suitable sites of deposition, Chemically unreactive ore minerals

Question 47

What deposits are formed by mechanical accumulation?

Answer 47

Placer deposits e.g. gold

Question 48

Define Residual Processes

Answer 48

Leaching from rocks of soluble elements leaving concentrations of insoluble elements in the remaining material

Question 49

What deposits is formed by residual processes?

Answer 49

Residual deposits e.g. bauxite

Question 50

Define Bauxite

Answer 50

A mixture of hydrated aluminium oxides and hydroxides

Question 51

What are three conditions needed to form bauxite?

Answer 51

A hot and humid tropical environment causing intense chemical weathering, Aluminium rich and iron poor rock e.g. granite or limestone, Groundwater between pH4 and pH10

Question 52

Define Sedimentary Precipitates

Answer 52

Precipitation of particular elements in suitable environments, with or without the intervention of biological organisms

Question 53

What deposits are formed by sedimentary precipitates?

Answer 53

Precipitated deposits e.g. iron or gypsum

Question 54

What are seven geophysical and geochemical techniques to prospect for metallic ore deposits?

Answer 54

Magnetic methods, Gravity methods, Electrical methods, Electromagnetic methods, Geochemical surveys, Remote sensing, Drilling

Question 55

How is china clay formed?

Answer 55

Hydrolysis of orthoclase feldspar in quartz to make clay minerals (kaolin)

Question 56

Define Quarrying

Answer 56

At or near the surface used for sandstone, limestone, chalk and aggregates

Question 57

Define Open Cast Mining

Answer 57

Initial removal of shallow surface layers (overburden) followed by extraction of the mineral such as coal and bauxite

Question 58

Define Mining Underground

Answer 58

Removal of minerals from below the surface such as coal, rock salt, iron sulphides, gold

Question 59

Define Dredging

Answer 59

Removal of material from sea, lakes or rivers to extract minerals such as sand and gravel, tin and gold