Chapter 9 - The Lithosphere

Question 0

Define: Crust

Answer 0

The solid surface layer of the Earth, made up of plates of the crust that form the continents or the ocean floor.

Question 1

Define: Resource

Answer 1

The name of a material or the total amount of a material that could theoretically be exploited.

Question 2

Define: Mantle

Answer 2

The molten and semi-molten layer of the Earth between the core and crust.

Question 3

Define: Ore

Answer 3

A body of rock that contains minerals that can be exploited.

Question 4

Define: In Situ

Answer 4

In the place where it is found.

Question 5

Define: Igneous

Answer 5

Rocks or processes involving molten rock.

Question 6

Define: Batholith

Answer 6

A large underground mass of solidified molten magma.

Question 7

Define: Hydrothermal

Answer 7

Processes or deposits associated with hot water.

Question 8

Define: Regolith

Answer 8

The solid rock particles left after weathering.

Question 9

Define: Solute

Answer 9

A dissolved substance.

Question 10

Define: Alluvial

Answer 10

Materials such as soil or weathered rock particles deposited by a river or other flowing water.

Question 11

Define: Placer Deposits

Answer 11

Deposits of dense minerals carried by water e.g. Tin and gold.

Question 12

Define: Metamorphic

Answer 12

Rocks changed by intense heat and pressure, but without fully melting.

Question 13

Define: Sedimentary

Answer 13

Materials or processes that involve material being carried by air or water then deposited.

Question 14

Define: Reserve

Answer 14

The proportion of a resource that can be economically exploited with existing technology.

Question 15

Define: Overburden

Answer 15

The unwanted material on top of the mineral deposit that is to be exploited.

Question 16

Define: Cut-off Ore Grade

Answer 16

The lowest purity of ore that can be exploited economically.

Question 17

Define: Turbidity

Answer 17

A measure of the cloudiness of water caused by suspended solid particles.

Question 18

Define: Leachate

Answer 18

Liquids and dissolved materials such as fertilisers washed through the ground, usually downwards.

Question 19

Define: Core

Answer 19

The solid and molten inner layers of the Earth.

Question 20

Define: Eutrophication

Answer 20

The natural nutrient enrichment of water body. it can be accelerated by human actions such as the release of sewage effluent or the use of fertilisers that are leached into water bodies.

Question 21

Define: Homeostasis

Answer 21

The combined processes that maintain balance in a living organism or the environment

Question 22

Define: Gaia Hypothesis

Answer 22

A theory that considers the Earth to be a single, self-regulating system.

Question 23

Define: Absorption

Answer 23

The attachment of a material onto a surface.

Question 24

Define: Detritivores

Answer 24

Organisms that feed on dead organic matter, often in or on the soil, e.g. Earthworms, millipedes and woodlice. They break down dead organic matter that can be further digested by decomposers.

Question 25

Define: Decomposers

Answer 25

Micro-organisms, including many bacteria and fungi, which break down and digest dead organic matter.

Question 26

Define: Soil Structure

Answer 26

The characteristics of a soil based on the aggregation of soil particles into peds.

Question 27

Define: Ped

Answer 27

The basic unit of soil structure where particles of sand, silt, clay and human form aggregates.

Question 28

Define: Soil Texture

Answer 28

The characteristics of a soil based on proportions of the mineral particles that are sand, silt and clay.

Question 29

What services and resources does the Lithosphere provide?

Answer 29

- Human exploitable physical resources (fossil fuels, metal ores) - Biogeochemical cycles (recycle carbon, nitrogen and phosphorous) - Soil (plant growth medium, habitat for organisms)

Question 30

What are the environmental impacts of mineral exploitation?

Answer 30

- Exploration (marine seismic surveys cause loud vibrations) - Land Take (associated buildings, access routes, dumping) - Habitat Loss (destruction, restoration must be carried out) > Loss of Amenity (aesthetic problems for local communities) - Pollution > Dust (blasting/vehicle movements) > Noise (Mine vehicles/rock blasting) > Turbid Drainage Water (blocks sunlight, chokes filter-feeding animals) > Toxic Leachate (kill aquatic life) > Spoil Disposal (landslides/erosion) - Flooding (collapse of poorly constructed dams) - Subsidence (poor spoil compaction) - Traffic Congestion (road traffic and car accidents)

Question 31

How can the pollution impacts of mineral exploitation be reduced?

Answer 31

- Dust (water sprays) - Noise ('baffle mounds' deflect noise, set blasting times) - Turbid Drainage Water (holding lagoon where solid settle out) - Toxic Leachate (filter bed immobilises metal) - Spoil Disposal (spoil compaction reduce instability)

Question 32

What are the methods that may be used to extend the lifespan of mineral reserves?

Answer 32

- Mining unexploited reserves - Increased Exploration - Better Exploratory Techniques > Remote Sensing (collecting information without direct contact) > Gravimetry (strength of gravity, igneous rocks) > Magnetometry (strength of magnetism, iron ore) > Seismic Surveys (echoes of surface vibrations) > Core Sampling (drilling into ground) - Mechanised Mining Techniques (rapid extraction) - Low Grade Ore Exploitation - Recycling - Substitution (abundant material swapped with a rarer material)

Question 33

What are the major processes in the carbon cycle?

Answer 33

- Photosynthesis (converts low-energy substances into high-energy carbohydrates) - Respiration (releases energy to drive metabolic processes) > Aerobic (break down organic compounds) > Anaerobic (organisms survive in oxygen-deficient environments) - Food Chains (pass organic compounds) - Fossilisation (incomplete decomposition of organisms) - Combustion (releases carbon dioxide) - Volcanoes release carbon dioxide

Question 34

What are the human impacts on the carbon cycle?

Answer 34

- Combustion of fossil fuels (carbon dioxide increase) - Coal mines (release methane) - Combustion of wood (reduces carbon store) - Anaerobic gut bacteria (release methane) - Anaerobic bacteria in rice padi fields (release methane) - Soil disturbance by ploughing (decomposition rates increase) - Global climate change (decomposition rates increase)

Question 35

What are the major processes in the nitrogen cycle?

Answer 35

- Ionising phenomena (provide energy for nitrogen and oxygen to react) - Chemical reduction to ammonia (carried out by micro-organism during nitrogen fixation) - Food chains (pass nitrogen between organisms) - Nitrification (oxidation of ammonium ions to nitrites then to nitrates) - Denitrification (chemical reduction of nitrates) - Leaching (loss of soluble substances when carried away by water) - Plant roots absorb nitrogen

Question 36

What are the effects of human activities on the nitrogen cycle?

Answer 36

- Haber process (industrial fixation of atmospheric nitrogen) - Nitrate fertilisers use (increase leaching problems) - Drainage (increases aerobic nitrifying bacteria and reduces aerobic denitrifying bacteria) - Soil disturbance by ploughing (increases decomposition rates) - Legumes (increase nitrogen compounds in soil) - Combustion processes release NOx (increase nitrates washed into soil by rain)

Question 37

What are the components of soil?

Answer 37

- Mineral skeleton of soil (produced by weathering of rocks, Regolith) - Air in soil (provides gases for aerobic organisms) - Soil water (used for physiological functions) - Living organisms (decomposition, nutrient recycling and aiding drainage) - Dead organic matter (source of food for soil organisms)

Question 38

What type of living organisms are found in soil?

Answer 38

- Plants (roots hold soil together) - Detritivores (break up dead organic matter) - Decomposers (digest dead organic matter) - Nitrogen cycle bacteria (nitrogen fixation, nitrification, denitrification) - Mycorrhizal fungi (provides plant roots with nutrients)

Question 39

What are the effects of soil properties on soil fertility and productivity?

Answer 39

- Aeration (enables rapid aerobic processes) - Water drainage/retention (enable nutrient absorption) - Thermal capacity (retain heat) - Soil structure (particles aggregate together to form peds) - pH (ideal soil acidity 5.5 - 6.5) - Soil texture (affects drainage, nutrient retention and root penetration)