GEOL-1021EL Lecture 12: earth resources lecture 12
16 Jun 2018
School
Department
Course
Professor
November 27, 2017
GEOL-1021
Earth Resources
“If it can’t be grown, it has to be mined.”
•this includes:
•base metals
•precious metals
•iron
•Uranium
•Aluminium
•coal and diamonds
•many other elements
•in a broader sense, also extraction of any non-renewable resources (petroleum, natural
gas, potash, limestone, gypsum, sand/gravel)
•Ore: rocks or minerals from which a valuable constituent (most commonly a metal, but not
exclusively) can be extracted at a profit
•the economic aspect is key and occurrences may become ore when demand/price
increases
•typically associated to specific geological processes
•e.g.) most important Cu deposits worldwide are associated with young and shallow
igneous rocks of intermediate composition
•Important Au vein systems are related to metamorphism in old rocks
•uranium deposits are associated with sedimentary rocks
•Rare earth elements, including elements like Nd, are more concentrated in very
igneous rocks (carbonatites)
•sulfide minerals are the most important group for metallic resources
•Relevant questions to mining:
•“how do we extract all the resources required to sustain civilization (and improve living
standards) in a responsible way?”
•
•“how to make more sensible used of those resources? (ex. minimize waste)”
•
Human Impact
•human population is immense and reserves are being consumed at an astounding rate
•Balancing resource usage VS environmental protection is challenging
•it remains to be seen if we can use our resources for sustainable development
•Civilization as a Global System
•Civilization exists at the thing interact between the climate, plate tectonic and
geodynamic systems
•human civilization has profoundly altered the planet, especially in the last 200 years
•Human population increase now doubles every 50 years
•humans now alter the global environment on a. Scale that is staggering compared to
the natural processes
•Ex) one third of the forests are cleared
•humans move more soil and rock than all natural processes
•dams and reservoirs now trap 30% of all river sediments
•coolants have damaged the critical ozone layer
•CO2 levels up by 40%
•Natural energy resources
•Renewable (biomass//burning wood)
•Non-renewable (fossil fuels//oil, gas, coal)
•USA Perspective
•before 1850, most US Energy was from wood burning
•after 1850 the rise of US fossil fuel economy
•1990: coal was approx 70%
•by 1950 fossil fuel was approx 90%
•Europe
•Vast forests throughout the earlier medieval centuries (energy source: wood)
•after 1250 AD widespread of deforestation
•on the edge of a fuel disaster by 1500 AD: running short of wood for heating and cooking
•turned to burning soft coal in the 16th century
•Beginning of petroleum use
•early 19th century: whale oil was the dominant form of lubrication and feel for lamps
•depletion of the whale stocks by mid century caused whale oil prices to skyrocket
•alternative to whale oil: petroleum (1st commercialized in Pennsylvania)
