AS The Lithosphere

Question 1

Alluvial deposits

Answer 1

a sedimentary process which produces deposits of valuable materials formed due to being carried and separated to to flowing water, deposition depends on the density of the solids and the velocity of the water, eg gold, diamonds, tin

Question 2

Bioleaching

Answer 2

A method of using bacteria to dissolve metals from low grade ores.

Question 3

Biological sediments

Answer 3

a sedimentary process which produces mineral deposits formed from living organisms eg coal, limestone

Question 4

Cradle to Cradle design

Answer 4

designing products so that materials can be reused at the end of the life of the product.

Question 5

Cut-off ore grade

Answer 5

The lowest purity of a mineral that can be exploited economically.

Question 6

Evaporites

Answer 6

a sedimentary process which produces valuable deposits formed from the evaporation of water leaving crystallised salts, eg sodium chloride

Question 7

Gravimetry

Answer 7

A geological exploration technique that detects changes in the force of gravity. Used in mineral exploitation to identify dense deposits

Question 8

Hydrothermal deposition

Answer 8

the igneous process which produces valuable deposits. Valuable metals are deposited from hot mineral-rich solutions when intrusions of magma heat ground water, minerals are deposited at different temperatures as the water moves away from the hot magma (fractional crystallisation) along veins. Eg silver, gold, lead, tin

Question 9

Iron displacement

Answer 9

A method used to process metal ores by using a more reactive metal (iron) to reduce (remove oxygen) from the valuable metal such as copper which will the come out of solution an can be collected

Question 10

Lasky’s principle

Answer 10

The theoretical model stating that, as the purity of available mineral deposits declines in a linear fashion, there is a logarithmic increase in the amount of the material present.

Question 11

Lithosphere

Answer 11

The relatively hard outer layer of the Earth comprising the crust and upper layer of the mantle. It is the source of mineral resources such as metal ores and affects soil formation and properties.

Question 12

Magnetometry

Answer 12

A method of detecting mineral deposits based on their magnetism.

Question 13

Metamorphic processes

Answer 13

Geological processes that change the form of a rock with heat and/or pressure, but without melting it. Eg slate from shale, marble from limestone

Question 14

Overburden

Answer 14

The soil and rock above a mineral deposit that must be removed to provide access.

Question 15

Phytomining

Answer 15

A method used to extract metals that have been absorbed and concentrated by plants. It can be used as a method to exploit low purity metal deposits or decontaminate polluted areas.

Question 16

Bioleaching

Answer 16

the use of living organisms to extract metals from their ores

Question 17

Polymetallic nodules or manganese nodules

Answer 17

metal rich nodules found on the seabed approx 5-10 cm in diameter. They contain manganese, iron, nickel, copper, cobalt and titanium. Exploitation may become viable in the future if the value of these materials rises or the mining methods become cheaper.

Question 18

Proterozoic marine sediments

Answer 18

a sedimentary process which includes the iron oxide deposits produced by the reaction of dissolved iron minerals with the oxygen produced by photosynthesis. This occurred in the early Proterozoic era and delayed the build-up of oxygen in the atmosphere.

Question 19

Trial drilling

Answer 19

an expensive method of surveying where samples can actually be obtained and undergo chemical analysis to determine chemical composition and purity

Question 20

IR spectroscopy

Answer 20

a survey technique which identifies different minerals by the different wavelengths that infrared is emitted from them

Question 21

Reserve

Answer 21

the amount of the resources that can be exploited now, economically using existing technology

Question 22

Resistivity

Answer 22

A method of predicting the mineral composition of mineral deposits underground using the ease with which they conduct electricity.

Question 23

Resource

Answer 23

includes all of the material that could be theoretically exploited, includes the reserve and the material that could be obtained but not at profit. If value rises or extraction costs fall, some of the resource may become the reserve in the future

Question 24

Secondary enrichment

Answer 24

a sedimentary process which produces deposits of metals that oxidise at the surface, percolate down through the ground and are precipitated below the water table when they reduce (lose oxygen) in anaerobic conditions and come out of solution

Question 25

Seismic surveys

Answer 25

These use sound waves produced at the surface that reflect off underground geological structures to determine the depth and shape of the rock structures. The reflected sound waves are detected by geophones at the surface.

Question 26

Stock

Answer 26

this includes all of the resource that exist in the lithosphere including the reserve, the resource and the material that we know exists but cannot ever be extracted.

Question 27

What would decrease the cut off ore grade?

Answer 27

decreased cost of extraction, increased market value

Question 28

What would increase the cut off ore grade?

Answer 28

increased cost of extraction, decreased market value

Question 29

Impacts of mining

Answer 29

Habitat loss, Dust, Increased turbidity, Noise, Spoil disposal, Acid mine drainage

Question 30

Barriers to recycling

Answer 30

Transport costs, labour costs, difficulty identifying and separating materials, public cooperation

Question 31

Factors affecting mine viability

Answer 31

Ore purity, Overburden, Hydrology (eg above or below the water table), Depth, Transport costs, Labour costs, Energy costs, Market demand and value