Unit 2 Flashcards
what are minerals?
minerals are solid inorganic substances made by natural geological processes.
what are the 2 ways minerals can form?
- by the cooling of molten materials
2. formed by solutions -> as water evaporates from solutions, minerals are left behind.
what boundaries can minerals be found at?
destructive and constructive.
how do minerals form at a destructive boundary?
when the oceanic plate slips below the continental plate, it drags down sea water and oceanic sediment which is know as subduction. The sea water and oceanic sediment lowers the melting point and causes explosive volcanic eruptions. The magma carries metallic minerals which are deposited near the volcano after the eruption.
what are the examples of metals found at a destructive boundary?
copper, nickel and zinc
how do minerals form at a constructive boundary?
cracks in the sea bed can be found where oceanic plates move apart. cold sea water flows down the cracks and is heated through contact with magma. The heated water returns to the surface through hydrothermal vents. The water cools and dissolved minerals found in the water are deposited on the sea floor.
what are examples of minerals found at a constructive boundary?
copper, zinc, tin and iron ore
what is an ore?
an ore is a rock or other material (E.g. gravel) from which a metal can be economically extracted. It is usually composed of valuable ore minerals and usually worthless gangue minerals
What is aluminium extracted from?
Bauxite ore
what are the properties of aluminium?
- relatively soft
- light weight
- non-magnetic
- very good conductors of heat and electricity
- ductile- can be drawn into a wire
- highly reflective-mirrors
- resistant to corrosion
- easily recycled
what is aluminium used in?
transport, construction, packaging and electrical sectors
where is bauxite typically found?
found in countries with high rainfall and high temperatures.
why is bauxite found in these ares?
when vegetation decomposes, it produces organic acids. The high rainfall mixes with the acids and the underlying rock is chemically weathered to reveal the ore.
explain the formation of bauxite
as water percolates down the soil, nutrients are leached downwards through the soil. The acidic rainfall percolates through the soil and strips the top soil of its nutrients. Soil left behind is known as laterite soils (the soils contain bauxite)
what are the issues with extracting bauxite?
- when mining produces a lot of dust which could cause health problems for locals.
- noise pollution
- visual pollution
- gets into water systems and cause health problems
- land less sturdy - could cause mudslides
- effect on biodiversity
what are the issues converting bauxite into aluminium?
- a lot of energy required to extract
- extraction plants are typically in developed countries so bauxite needs to be transported thousands of miles causing pollution.
what is the hydrological system?
the hydrological system describes the distribution and movement of water between the earth and its atmosphere. This is an example of a closed system as the total amount of volume remains the same.
what is evaporation
evaporation is the conversion of water from a liquid to a gas by using solar energy.
what is condensation
condensation is the conversion of vapour/ gas to liqiuid.
what is precipitation and give examples
precipitation is the term for moisture that falls from the air to the ground. Examples include rain, sleet, snow, hail, fog, mist, drizzle.
what is evapotranspiration
evapotranspiration is the water lost to the atmosphere by evaporation from land surfaces
what is sublimation
sublimation is the process by which ice or snow goes from a solid to a gas without becoming a liquid.
what is inflitration
infiltration is the physical movement of water through soil.
what is groundwater flow
groundwater flow is water that occupies pore spaces in soil, sediment, and rock.
what is collection of groundwater known as?
an aquifer (underwater reservoir)
what is transpiration
transpiration is the water loss from plants
what is advection
movement of clouds.
what is percolation
the movement of water through soil by gravity and capillary action
what are the types of water storages?
surface storage and subterranean
give examples of surface storage
- water courses - rivers, lakes, streams
- soil moisture
- vapour - clouds
- ice and snow
give examples of subterranean storage
- groundwater
- aquifer
what is soil parent material derived from?
- weathered bedrock
- sediment/materials carried by flooded rivers or glaciers
what transforms parent material into soil?
weather such as wind, rain, sand, ice, sand and living things
what are provisional ecosystem services than soils provide?
- grow food in soils
- grow cotton for clothes
- produce lumbar bricks for houses
what are regulation ecosystem benefits?
- filters water
- stores carbon
what does soil consist of?
- mineral matter 45%
- organic matter 5%
- water 25%
- air 25%
what does the mineral matter consist of?
consists of minerals derived from parent material by physical and chemical weathering.
what does the organic matter consist of?
consists of decaying roots, leaves, needles and remains of dead organisms.
what does air and water do?
air and water co-exist in everchanging volumes and occupy spaces in the soil.
what is stage 1 in soil formation?
- physical and chemical weathering attack the rock and weaken it
- chemicals are released from the weathered rock surface which provides nutrients for plant life.
- pioneer species such as mosses and lichens are present.
what is stage 2 in soil formation?
- roots in plants cause cracks in the rocks and help weather it
- the plants add nutrients to the soil when they die (humus)
- this makes it easier for the next generation of plants to survive - grasses and shrubs.
what is stage 3 in soil formation?`
- as more plants start to die, nutrients (humus) in soil increases
- continued weathering breaks the rock down into smaller fragments
- the soil develops into 4 horizons
what are the 6 main factors affecting soil formation?
- parent material
- organisms
- climate
- relief
- time
- human activity
what does the Ao horizon consist of?
- L (litter) which consists of leaves and pineneedles/cones
- F (fermentation) where organic materials start to decompose
- H (humus) the decomposed remains of vegetation, animals and bacteria which provide the soil with nutrients.
what is humus?
humus is a jelly like substance made of decomposed organic matter which provides the soil with nutrients.
what does the A horizon consist of?
- main top layer
- topped with organic debris e.g. twigs, cones
- it is here that organic material is introduced from the Ao horizon
- dark in colour
- it is usually nutrient rich and fine in texture
what does the B horizon consist of?
- This is a subsoil which contains less organic material and is coarser in texture
- minerals and nutrients may be leached out of horizon A and into horizon B.
- lack of organisms due to lack of air
what is leaching?
leaching is the removal of soluble materials and humus by water
what does the C horizon consist of?
- zone of regolith whose larger particle sit upon the underlying bedrock
- physical and chemical weathering of parent material is a further source of nutrients
Where is podsol soil found?
- northern boreal coniferous forests
- cold and wet climates where precipitation is greater than evaporation
why does podsol have distinct layers
there is a lack of organisms due to low temperatures so there is less mixing of the soils
what does the Ao horizon of podsol consist of?
- leaf litter consists of pine needles, cones and twigs from coniferous forests
- due to cold climate, organic matter decays very slowly and forms a acidic mor humus
- cold climate and acidity means there is less organisms and soil bacteria present.
- pH < 4.5 meaning there are few nutrients
- because of this there is a thin layer of dark humus
what does the A horizon of podsol consist of?
- ash - grey in colour due to the leaching of minerals.
- minerals are washed down the soils (eluviated) due to high levels of rainfall
- the rainfall mixes with the acidic humus this causes the acidic rainfall to strip minerals and nutrients away
- this results in minerals (iron, aluminium, clay) and nutrients leaving the A horizon and deposited in the B horizon which leaves behind silica and sand particles causing the grey colour.
what does eluviation mean?
eluviation is the movement of suspended or dissolved compounds by percolating water from an upper into a lower horizon.
what does illuviation mean?
illuviation is the process of deposition of soil materials moved from upper horizon to lower horizon.
what does the B horizon of podsol consist of?
- aluminium, iron, clay and minerals are washed in (illuviated)and deposited here causing the reddish, brownish colour.
- contains iron pan. Iron pan prevents drainage of soil and causes waterlogging.
what does the C horizon of podsol consist of?
- forms weathered parent rock
- the rock is less broken up.
give examples of the uses of podsol.
podsol soils are not fertile soils and crop yields rapidly decrease. Lime is added to counteract the acidity and add manure to boots the quality of humus.
where is brown earth soil located?
brown earth soil is located beneath temperate deciduous forests of Europe and North America. Found in mild and wet climates.
why do brown earth soils have less distinct layers?
organisms like earthworm and woodlice are present and mix up the soil.
what does the Ao horizon of brown earth soil consist of?
- rich of nutrients
- litter decomposes rapidly due to mild wet climate producing only slightly acidic mull humus
what does the A horizon of brown earth soil consist of?
- dark brown in colour because humus replaces minerals as they are leached out
- leaching is less because precipitation is slightly greater than evaporation so there is slow movement of moisture through soil
What does the B horizon of Brown Earth soil consist of
- less distinct but is usually lighter in colour as humus becomes less abundant.
What does the C horizon of Brown Earth soil consist of?
- less acidic parent material
- Chemical and Biological weathering is rapid which helps to form a deep soils.
- plant roots extract minerals and replace those lost by leaching
What are some land uses of brown earth soil?
Agriculture
What are Biofuels?
Biofuels are fuels that are produced from renewable resources. They are derived from biological processes. The fuels are made from biomass - plant, vegetable oil and treated waste. They are an alternative to fuels.
What are first generation biofuels?
First generation biofuels are derived from sources which include starch, sugar, animal fats and vegetable oil.