Introduction to Resources Flashcards
What is the main purpose of the Haber Bosch process?
Convert atmospheric nitrogen to ammonia
Which type of rock is primarily subject to chemical weathering via carbonation reactions?
Limestone
What is the main cause of saline intrusion in coastal aquifers?
Over-pumping of groundwater
Why is the availability of earth’s resources considered a critical challenge for future generations?
Many resources are non-renewable and unevenly distributed
What is the primary difference between a mineral resource and a reserve?
A reserve is fully evaluated and economically viable, while a resource is only potentially useful
What is the primary source of phosphorus in fertilisers?
Apatite
What process best describes the breakdown of primary minerals in rocks and formation of secondary minerals?
Chemical weathering
What are the 6 primary factors in soil formation?
Vegetation, parent material, climate, organisms, topography and time
Which types of soil are considered the most productive?
Mollisol, alfisols and spodosols
What percentage of Earth’s water is freshwater?
2.97%
Where do resources come from?
Vast majority are derived from minerals or sea water, some come from atmospheric or biological systems
What are the macro-nutrients (elements) required for fertile soil?
Nitrogen, phosphorus and potassium
What are the micro-nutrients (elements) required for fertile soil?
Iron, boron, zinc, copper, manganese and molybdenum
What are the secondary nutrients (elements) required for fertile soil?
Calcium, magnesium and sulphur
What are minerals?
Naturally occurring, solid, crystalline substance, which are the building blocks of rocks, the form from crystallisation of fluids (magma or water) or changes in heat or pressure acting on existing minerals.
What are the methods of physical weathering?
Mechanical breakdown of rocks by frost, wind or water and the differential expansion and contractions during rapid heating and cooling
What is chemical weathering?
Breakdown of primary minerals in the rock and formation of new secondary minerals. Water is an essential reagent as it reacts with minerals and transports dissolved species that can react.
What are some of the different reactions that can occur in chemical weathering?
Hydrolysis, hydration, carbonation, oxidation, ion exchange and chelation (formation of two or more separate co-ordinate bonds)
What factors affect chemical weathering?
Particle size, composition, type and amount of vegetation and climate
What do black or red soils indicate?
Black= rich in organic matter
Red= rich in Fe oxides
What are the particle size of the different soil textures?
Clay: <0.002mm
Silt: 0.05-0.002mm
Sand: 2-0.05mm
What are soil horizons?
Distinctive horizontal layers with different chemistry and structure exposed in a soil profile. R=bedrock and O=organic matter then labelled A-Z when mineral composition or structure changes
How does clay affect soil?
Atoms are arranged in layers, water and ions become weakly bonded due to the electrostatic charge on the particles, so they store minerals and retain water well, they allow ions exchange so are really fertile soils
What are some less productive soils?
Entisols, aridosols and oxisols
What is potash?
Potassium from wood ash
What is the crustal abundance of phosphorus and where are the deposits found?
0.23%, deposits found in igneous and marine sedimentary rocks
How abundant is potassium and what tend to be the economic deposits?
8th most abundant on Earth and evaporites are most viable
What are some sources of potassium?
Sylvite (KCl), Langbeinite (2MgSO4.K2SO4), Kainite (KCl.MgSO4.3H2O) and carnallite (KCl.MgCl2.6H2O)
What are some of the environmental concerns around mining?
Groundwater pumped out of mines can release toxic and radioactive metals, large amounts of gypsum by-product of sulphuric acid treatment, strip mining with no ecological remediation and eutrophication
What’s the maximum percentage of dissolved salt safe for human consumption in water?
0.05%
What is porosity and permeability?
Porosity: void space within a rock that can be filled with fluids (water, oil or gas)
Permeability: the ease of movement of fluid through rock strata
What factors affect permeability and how is it measured?
Number of conduits, size of conduits and straightness of conduits
Measured in Darcy (D)
How is the water table affected with water mining?
Forms cone of depression around well
What is saline intrusion?
The incursion of salt water into an aquifer by osmosis, due to over-pumping, which contaminates fresh water
What are some of the sources of groundwater contamination?
Unlined landfill, septic tank cesspool discharge, waste lagoon, fertiliser, pesticides, factory waste and sewer leakage
What are the methods and concerns with desalination of salt water for drinking?
Distillation: expensive
Reverse osmosis: expensive, only 50% yield
Both dumping salt back into ocean too
