Crustal Composition and Reserves
Which single element is the most abundant in the Earth’s crust, making up 46 percent of its composition?
Oxygen
Which mining technique involves the removal of "strips" of soil and rock to expose the underlying ore?
Strip mining
What type of mining is required when a desired resource is more than 100 meters (328 feet) below the Earth's surface?
Subsurface mining
What is the primary air pollutant produced by the earth-moving equipment used in surface mining?
Dust and particulate matter
What respiratory disease is a common risk for coal miners due to the chronic inhalation of mine dust?
Black lung disease
What are concentrated accumulations of minerals from which economically valuable materials can be extracted?
Ores
What is the name of the overlying vegetation, soil, and rock that must be removed to reach an ore deposit?
Which controversial method uses explosives to remove the entire top of a mountain to reach coal deposits?
Mountaintop removal
This phenomenon occurs when water passing through mine tailings becomes highly acidic, lowering the pH of nearby soil and streams
Acid mine drainage
Aside from respiratory issues, what are the three primary physical hazards faced by subsurface miners?
Accidental burial, explosions, and fires
What is the term for elements with properties that allow them to conduct electricity and heat energy?
Metals
Which technique is used when a resource is close to the surface but extends both horizontally and vertically, creating a large visible hole?
Open-pit mining
What is the process of looking for metals and precious stones in river sediments using water to separate heavier items?
Placer mining
During mountaintop removal, where are the resulting mine tailings typically deposited?
In adjacent valleys or lower-elevation regions
Why is recycling a critical solution to the challenges of mining?
It increases the reserves of materials and reduces the energy and environmental impact of new mining
What specific term describes the known quantity of a resource that can be economically recovered?
Reserve
What are the chemical compounds and rock residues called that are left behind after the desired metal is removed from the ore?
Mine tailings
What highly volatile and toxic metal is often used in placer mining and can damage the central nervous system?
Mercury
Why does the extraction of lower-grade ores lead to more environmental damage than high-grade ores?
It requires more energy and results in more waste, air pollution, and soil disturbance
400: According to the "Approximate supplies" table, which metal has a U.S. reserve of only 2 years?
Aluminum
Which four elements constitute over 88 percent of the Earth's crust?
Oxygen, silicon, aluminum, and iron
Located in Utah, what is the name of the largest open-pit mine in the world?
Kennecott Bingham Canyon mine
According to the sources, how deep are the deepest mines on Earth?
Up to 3.5 km (2.2 miles) deep
Which greenhouse gas is often released from coal beds during subsurface mining, posing both a danger to miners and the climate?
Methane
Why do mining efforts naturally become more expensive over time?
Because the most accessible/highest-concentration ores are mined first, forcing companies to move to harder-to-reach deposits