Area where earth's lithospheric plates are pushed together

• divergent plate boundary
• transform plate boundary
• convergent plate boundary
• earthquake

The time it takes to use a certain fraction, usually 80%, of the known or estimated supply of a nonrenewable resource

• country time
• depletion time
• reduction time
• exclusion time

Type of surface mining that uses explosives, massive shovels, and even larger machinery called drag lines to expose seams of coal underneath

• mountaintop removal
• area strip mining
• contour strip mining
• open-pit mining

Part of a metal-yielding material that can be economically and legally extracted at a given time

• geology
• mineral
• lithosphere
• ore

Layer of soil and rock overlying a mineral deposit

• underburden
• overburden
• lithosphere
• asthenosphere

Process in which a desired metal is separated from the other elements

• high-grade ore
• spoils
• ore
• smelting

Area in which oceanic lithosphere is carried downward under a continent at a plate boundary

• convergent plate boundary
• divergent plate boundary
• transform boundary
• subduction zone

Extraction of a metal ore or fuel resource such as coal from a deep underground deposit

• open-pit mining
• contour strip mining
• surface mining
• subsurface mining

Tailings are

• minerals found in metamorphic rock
• magma ore resulting from seafloor spreading
• the remaining supply of metals on Earth
• the waste material from mining

Which type of mining is usually most directly harmful to miners?

• sub-surface mining
• open pit mining
• placer mining
• strip mining