Environmental Geology: Minerals, Mining, and Plate Tectonics

Vocabulary flashcards covering environmental geology topics from Chapter 14, including mineral definitions, mining types, environmental impacts, plate tectonics, geological hazards, and mass wasting.

Mineral

A naturally occurring, inorganic solid that possesses a definite chemical structure (crystal in structure), has a unique set of physical properties, is made of one or more elements, and serves as a building block of rocks.

Rock

A solid combination of one or more minerals.

Ore

A rock containing a large enough concentration of minerals to be mined profitably.

Nonrenewable Mineral Resources

Mineral resources that exist in a fixed quantity on the human time scale.

Mineral Reserves

Estimated deposits from which a usable nonrenewable mineral can be extracted profitably at current prices and technology.

Economically Depleted Mineral Reserves

Mineral deposits where the cost to find, extract, transport, and process the material exceeds what the mineral is worth.

Open Pit Mining

A surface mining method where minerals (such as sand, gravel, and metal ores like iron and copper) are extracted by digging them out of the Earth's surface, leaving an open pit behind.

Area Strip Mining

A surface mining technique used in relatively flat areas where an earthmover strips away overburden, a power shovel removes mineral deposits, and the resulting trench is filled with overburden before making a parallel cut.

Contour Strip Mining

A surface mining method used in hilly or mountainous terrain where power shovels carve a series of terraces into a hillside to extract coal, dumping the overburden from each new terrace onto the one below.

Mountain Top Removal

A surface mining method where explosives, massive shovels, and draglines are used to remove the top of a mountain and expose seams of coal.

Subsurface Mining

The extraction of metal or coal from deep underground deposits using shafts and tunnels.

Spoils

Unwanted soil and rock (overburden) piled up when material is excavated from the Earth's surface or subsurface during mining.

Acid Mine Drainage

The outflow of acidic water formed when spoils containing pyrites and sulfides are exposed to air and rainwater, which then leaches into streams or infiltrates groundwater supplies.

Tailings

Piles of toxic, radioactive waste mineral material left behind after the unused portion (gangue) is separated from uranium ore.

Cyanide Heap Leaching

A gold-extraction technique in which large piles of crushed low-grade ore sitting on plastic tarps are sprayed with a cyanide solution to dissolve and separate the gold.

Smelting

A process that uses toxic chemicals to separate desired metals from other elements in an ore, releasing air pollutants such as $SO_2$, $NO_x$, lead, radioactivity, and mercury.

U.S. General Mining Law of 1872

A federal law permitting mining entities to purchase public lands at 1872 rates ($120$ per 20 acres per year) and pay a $2.3\%$ royalty on minerals extracted to the government.

Industrial Ecology

An industrial design strategy that mimics natural ecological systems by ensuring all waste from one industry becomes a valued raw material for another.

Environmental Justice

The fair treatment and meaningful involvement of all individuals regardless of race, color, sex, national origin, or income in the development, implementation, and enforcement of environmental regulations, laws, and policies.

Tectonic Plates

Massive, rigid pieces of Earth's lithosphere consisting of less dense continental material, denser oceanic material, or both, which slowly drift atop the asthenosphere.

Asthenosphere

The ductile, flowing portion of the Earth's upper mantle directly below the lithosphere on which tectonic plates glide.

Divergent Boundaries

Plate boundaries where tectonic plates pull apart from one another, allowing mantle magma to well up and solidify into new crust, producing volcanoes, mountains, earthquakes, and geysers.

Convergent Boundaries

Plate boundaries where tectonic plates collide, resulting in one plate subducting beneath the other into the mantle or both colliding upward to form mountains.

Transform Boundaries

Plate boundaries where tectonic plates slide horizontally past one another without generating or consuming lithosphere, generating earthquakes, mountains, and volcanoes.

Volcano

A vent or fissure in the surface of the Earth that allows magma, liquid lava, and gases to escape into the environment.

Earthquake

The release of energy through seismic waves radiating outward from subsurface rock fracturing along a fault plane, causing displacement.

Focus

The specific subsurface location where rock fractures and displacement initiates during an earthquake.

Epicenter

The point on Earth's surface situated directly above the subterranean focus of an earthquake.

Tsunami

A series of massive water waves caused by the abrupt vertical elevation or dropping of the seafloor.

Mass Wasting

The downslope movement of soil and rock debris under the direct pull of gravity.

Angle of Repose

The maximum, steepest angle relative to the horizontal at which loose granular material remains structurally stable without slumping.