chapter 16

From whom must mining companies obtain permits before mining a site?

a bonding company

two or more metals combined

alloy

Gangue minerals

are valued for their rarity and durability

Which of the following is not one of the ways that ore minerals may form?

circulation of hydrothermal solutions through rocks

The process by which land sinks with little or no horizontal movement is known as

compounding

what hot, subsurface waters must contain in order to be considered hydrothermal solutions

dissolved minerals

salts left behind after evaporation

evaporites

Minerals are arranged in a regular, repeating geometric pattern of

evaporites.

material that bonds with impurities and separates them from molten metal during smelting

flux

a mining method used to recover gold from ancient riverbeds

hydraulic mining

a process used by mining companies to identify areas where there may be valuable mineral resources

mineral exploration

a mining method used for large ore deposits near the surface that are mined downward

open-pit mining

Reclamation is the process of

removing coal from a subsurface seam

Which of the following is not a method of subsurface mining

room-and-pillar mining

Which of the following would not be considered an aggregate

sand

Crushed ore is melted at high temperatures to separate impurities from molten metal during

smelting

a water contaminant that can cause acid mine drainage

sulfuric acid

the mining method used when shallow ore deposits are located close to Earth's surface

surface mining

one of the most serious consequences of coal mining

underground mine fires

Stream placers often occur

where rivers meet lakes