Ch. 15 Flashcards
Acid mine drainage
Rainwater seepage through a mine or mine wastes carries sulfuric acid to nearby streams and groundwater.
Area strip mining
Used when terrain is flat, a big machine removed the top mineral deposit.
Asthenosphere
Lower mantle of partly melted rock that flows and moves like plastic.
Biological weathering
Lichens break down rock with chemicals and tree roots physically break rocks.
Biomining
Using bacteria to remove a metal from ores while leaving environment undisturbed.
Buckyballs
Small molecular spheres that have a variety of applications like medicine and cosmetics, part of nanotechnology revolution
Chemical weathering
Rock reacts with oxygen carbon dioxide moisture and acids to break it down.
Contour strip mining
Used on mountainous terrain, cuts terraces into sides of hills and is highly erodible afterwards.
Frost wedging
Water collects in pores and cracks of rocks and expands, breaking it off.
Gangue
Waste material left behind by ore.
Highwall
Highly erodible bank of soil and rock left behind by contour strip mining.
Igneous rock
Forms below or on earth’s surface when molten rock wells up from the upper mantle or deep crust, cools, and hardens. Like granite, and lava rock
Lithosphere
Tectonic plates and the rigid part of the mantle.
Manganese nodules
Potato sized, cover about half of Pacific ocean floor.
Mass wasting
When rock and soil masses become detached and move downhill under gravity, like rockslides, but can be slower.
Materials revolution
Silicon, ceramics, plastics, and others, are replacing metals.
Metamorphic rock
Preexisting rock is subjected to high temperatures, high pressure, chemical fluids, or a combination of these. Like anthracite, slate, and marble.
Mountaintop removal
Dragline machinery and explosives destroy mountains, leaving behind waste and toxic substances like selenium, arsenic, and mercury.
Oceanic ridges
Form at divergent plate boundary and have higher peaks and deeper canyons than the tallest mountains.
Convection cells / currents
Move rocks in loops in the mantle like conveyor belts.
Convergent plate boundary
Continental rises over the oceanic plate, or continental plates both rise and create mountains.
Cyanide heap extraction
Cyanide makes the gold leave the mountain and is harvested at the bottom, but is toxic and is often left behind.
Depletion time
How long it takes to use up a certain proportion of the reserves of a mineral at a given rate of use.
Divergent plate boundary
When ocean plates move away from one another.
External changes
Geologic changes based on energy from the sun and on gravity. Build landforms and the environment.
Open-pit mining
Machined dig holes and remove ores, sand, gravel, and stone.
Overburden
Rock or soil over a mineral deposit.
Physical / mechanical weathering
Physically break by frost wedging, wind, and rain.
Resource exchange webs
Wastes of one manufacturer become raw materials for the other.
Sedimentary rock
When rocks are eroded and the sediments are bound together by pressure and dissolved minerals. Like sandstone, shale, dolomite, limestone, lignite, and bituminous coal.
Smelting
Roasts ores to release metals, releasing air pollutants that acidify soil, cause water pollution, and produce solid hazardous waste.
Spoils
Overburden waste material.
Spoil banks
Highly erodible hills left behind by area strip mining.
Subduction
When a convergent plate boundary forces an oceanic plate to go under a continental plate.
Surface Mining Control and Reclamation Act of 1977
Mining companies must restore surface mined land by grading and replanting it.
Tailings
Large piles of solid waste that can contaminate nearby water.
Transform fault
Plates slide and grind past each other, most of which are in the ocean.
Trench
Forms at converging ocean plates
