Glossary

Agglomerate: reform into lumps of suitable size (Encyclopedia Britannica, 2022b)

Base metal: a metal (e.g., zinc, lead) of comparatively low value compared to precious metals (e.g., gold, silver) (Merriam-Webster, 2022)

Breccia: sharp-angled fragmented rock (Merriam-Webster, 2022)

Cambrian: a geologic period that began approximately 542 million years ago and ended 488 million years ago (USGS, 2007a)

Commercial gold mining: higher-tech gold mining that occurs on a larger scale than small-scale gold mining

Comminution: the crushing and grinding of a material/ore to reduce it to smaller or finer particles (Multotec Group, 2019)

Criteria air pollutants: particulate matter, photochemical oxidants (including ozone), carbon monoxide, sulfur oxides, nitrogen oxides, and lead (EPA, 2022c)

Dip: the angle of inclination measured from horizontal of a planar geologic feature (Encyclopedia Britannica, 2022b)

Doré: recovered metal containing gold and silver (Encyclopedia Britannica, 2022b)

En echelon: parallel or subparallel, closely spaced, steplike minor structural features in rock (Davis et al., 2011)

Epithermal: deposited under conditions in the lower ranges of temperature and pressure (Merriam-Webster, 2022)

Fugitive dust: small particles emitted to the air from open air sources or opening that are not a stack, chimney, or vent. Fugitive dust may include particulate material of a range of sizes, including PM₁₀ (generally 10 microns in diameter or smaller) and PM_2.5 (generally 2.5 microns in diameter or smaller) (9VAC5-50-70)

Gabions: rectangular baskets filled with stone or dirt for support (Merriam-Webster, 2022)

Gangue: the economically worthless material that surrounds, or is closely mixed with, a desirable mineral in an ore deposit (Mindat, 2022a)

Geosynthetic: a planar product made from polymeric material used with soil, rock, or earth for construction (Idaho Transportation Department, 2011)

Geotextiles: a permeable geosynthetic comprised solely of textiles (Idaho Transportation Department, 2011)

Greenschist-facies: low to medium metamorphism corresponding to temperatures of about 300°C to 500°C and pressures of 3 to 20 kbar, which is typical of continental collision tectonics (Arndt, 2011)

Hydrometallurgy: the treatment of ores by wet processes such as leaching (Merriam-Webster, 2022)

Igneous rock: rock formed by magma or lava (Merriam-Webster, 2022)

Indicated mineral resource: that part of a mineral resource for which quantity and grade or quality are estimated on the basis of adequate geological evidence and sampling (17 CFR § 229.1300)

Intrusive: igneous rock formed within the crust

Island arc: a curved chain of volcanic islands that are found along tectonic plate margins (Merriam-Webster, 2022)

Lixiviant: a liquid medium used in hydrometallurgy to selectively extract the desired metal from the ore or mineral (AIME, 1917)

Lode: an ore body found within rock (Encyclopedia Britannica, 2022b)

Mafic: a rock rich in magnesium and iron and relatively depleted in silica (Merriam-Webster, 2022)

Measured mineral resource: that part of a mineral resource for which quantity and grade or quality are estimated on the basis of conclusive geological evidence and sampling (17 CFR § 229.1300)

Mesozoic: a geologic era that began 251 million years ago and ended 66 million years ago (USGS, 2007a)

Metaclastics: metamorphosed clastic sedimentary rocks, which is composed of detrital rock and mineral fragments (Mindat, 2022b)

Metalloid: an element with properties that are intermediate between those of metals and nonmetals (Merriam-Webster, 2022)

Metamorphic rock: formed under extreme heat and temperature (Merriam-Webster, 2022)

Metasedimentary rocks: sedimentary rocks that have been metamorphosed

Mineral: a crystalline inorganic substance (Merriam-Webster, 2022)

Ordovician: a geologic period started 488 million years ago and ended 444 million years ago (USGS, 2007a)

Ore: a naturally occurring accumulation of one or more valuable mineral resources (Merriam-Webster, 2022)

Orogenic gold deposits: Deposits that are formed from the remobilization of gold scavenged during metamorphism and redeposited elsewhere (Sillitoe, 2020)

Paleozoic: a geologic era that began 542 billion years ago and ended 251 million years ago (USGS, 2007a)

Placer: deposit that has been moved following river, marine, or glacial action (Merriam-Webster, 2022)

Plutonic: igneous rock formed deep underground

Precambrian: a geologic period that began approximately 4,600 million years ago and ended 542 million years ago (USGS, 2007a)

Processing: in this report, processing indicates both the physical processing sometimes called “beneficiation” along with chemical processing that is principally hydrometallurgical for gold, although the last steps are pyrometallurgical

Proterozoic: a geologic eon that began approximately 2.5 billion years ago and ended 542 million years ago (USGS, 2007a)

Pulp: is a freely flowing mixture of powdered ore and water (911 Metallurgist, 2016)

Pyrometallurgy: chemical metallurgy depending on heat action (such as roasting and smelting) (Merriam-Webster, 2022)

Recreational gold mining: mining, often by a few individuals, primarily for recreation. This is often limited to panning for alluvial gold in streams

Sedimentary rock: formed from sediment deposited by water or air (Merriam-Webster, 2022)

Shotcrete: pneumatically applied concrete consisting of cement, aggregates, water, and additives such as accelerators, silica fume, and steel fibers (USACE, 1993)

Slag: the material that is left when rocks that contain metal are heated to get the metal out (Encyclopedia Britannica, 2022b)

Small-scale mining: low-tech, labor-intensive mineral extraction and processing carried out mostly by local people (Hilson and Maconachie, 2020)

Stopes: excavation areas underground that are formed as the ore is mined in successive layers (Merriam-Webster, 2022)

Strike: the orientation of an imaginary horizontal line across the plan of a geologic feature (Encyclopedia Britannica, 2022b)

Surfactant: a surface-active substance that lowers the surface tension (or interfacial tension) (Merriam-Webster, 2022)

Tailings: the remaining waste following ore processing (Merriam-Webster, 2022)

Terranes: coherent units of Earth’s crust that have a distinct geologic history and that are bounded by faults (Encyclopedia Britannica, 2022b)

Triassic: a geologic period that began approximately 251 million years ago and ended 200 million years ago (USGS, 2007a)

Volcanic: igneous rock formed near the surface (Merriam-Webster, 2022)

Volcanogenic massive sulfide: accumulations of sulfide minerals that form due to hydrothermal action on the seafloor; ancient varieties may now be exposed on land (Jamieson et al., 2016)

Waste rock: bedrock that has been mined and transported out of the pit but does not have gold concentrations of economic interest