In coal mining, (1) the weight of the rocks above a narrow roadway is transferred to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway; and (2) the weight of the rocks over a longwall face is transferred to the front abutment, that is, the solid coal ahead of the face and the back abutment, that is, the settled packs behind the face.
Acid deposition or acid rain
Refers loosely to a mixture of wet and dry "deposition" (deposited material) from the atmosphere containing higher than "normal" amount of nitric and sulfuric acids. The precursors or chemical forerunners of acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulfur and nitrogen oxides resulting from fossil fuel combustion.
Run-off water from a mine generally with a pH between 2.0 and 4.5 produced by the oxidation of sulfide minerals within mine rock or tailings piles. Tailings ponds are designed to prevent acid mine drainage by submerging waste rock and thus preventing oxidation.
Mine water that contains free sulfuric acid, mainly due to the weathering of iron pyrites.
A somewhat outdated term for igneous rocks containing a high proportion of silica. Formal definitions have varied over the years, including "rock with greater than 66% silica" and "rock with 10% or more free quartz". Now often used loosely to refer to any igneous rock composed mainly of light-colored minerals. Similar to "felsic" and opposite of "basic".
Any place in a mine where miners are normally required to work or travel and which are ventilated and inspected regularly.
Entrance to a mine, generally a horizontal tunnel.
Mining in the same direction, or order of sequence; first mining as distinguished from retreat.
Aircraft-borne device used to measure the strength of the Earth's magnetic field. Mineral explorationists use this tool to look for magnetic anomalies caused by subsurface ore deposits. Metallic ores and basaltic rocks generally cause an increase in local magnetism, while granites and sedimentary rocks tend to produce reduced magnetic fields.
Geophysical survey conducted with an aerial magnetometer.
Generally, a rock composed of large, angular fragments of volcanic material. The term has had various formal definitions over the years. Also known as volcanic breccia.
Concentrating valuable minerals or coal based on their adhesion properties. Includes sintering, pelletizing, and briquetting.
Mechanical stirring or shaking. In metallurgy, agitation promotes the dissolution of ore minerals during processing.
Extraction of gold from mined rock accomplished by agitation in a cyanide solution.
The division of a current of air into two or more parts.
Exploration work conducted from an aircraft. Includes aerial photographic surveys and geophysical surveys to measure magnetism or radioactivity.
Any passage through which air is carried. Also known as an air course.
A mixture of two or more metals, often in combination with non-metals such as carbon. Common alloys include brass (copper and zinc) and bronze (copper and tin).
Clay, silt, sand, and gravel deposited by a body of running water during relatively recent geologic time. Includes flood plains, lake beds, and river deltas. Such deposits can contain heavy ores like gold, platinum, diamonds, and tin, which have been eroded and subsequently concentrated by the action of the river or stream.
A device used by explorationists to measure positively charged particles given off by radioactive elements such as uranium and thorium.
Positively charged particle given off by radioactive elements. Also known as an alpha particle.
Change in a rock's mineralogic composition caused by heat, pressure, mechanical weathering by wind or water, or exposure to chemicals in hydrothermal solutions. Milder and more localized than metamorphism. Certain types of alteration can be indicative of nearby ore mineralization; for example, chlorite and sericite alteration often surround porphyry copper and gold deposits.
Describes rocks or minerals that lack crystalline structure or have an extremely irregular internal arrangement of atoms, such as amorphous silica.
The gradual repayment of a liability -- such as loans for a mine start-up -- in regular installments over a specified period of time.
Metamorphic rock composed mainly of the minerals amphibole and plagioclase with little or no quartz.
Instrument for measuring air velocity.
Acronym for ammonium nitrate/fuel oil, an explosive mixture used as a blasting agent at many mines because of its ability to be pumped as a slurry.
The angle at which strata or mineral deposits are inclined to the horizontal plane. Shallow-dipping mineralized horizons (i.e., those nearer to horizontal) are more favorable for mining, requiring less removal of overburden.
In coal mine subsidence, this angle is assumed to bisect the angle between the vertical and the angle of repose of the material and is 20¡ for flat seams. For dipping seams, the angle of break increases, being 35.8¡ from the vertical for a 40¡ dip. The main break occurs over the seam at an angle from the vertical equal to half the dip.
The maximum angle from horizontal at which a given material will rest on a given surface without sliding or rolling.
A document issued by corporations each fiscal year to fulfill disclosure obligations to shareholders. Such reports contain information on company finances, operations, and future directions.
A rectangular plate made of partially-refined metal such as blister copper. In electrolytic metallurgy, the anode is dissolved in an acidic solution, with atoms of the desired metal being recaptured at a cathode.
An observed or measured deviation from normal geologic conditions, generally used to describe features that may suggest an ore deposit. Geochemical anomalies such as high arsenic content, or geophysical anomalies such as high magnetism, may signal the presence of mineralization.
Coal of the highest metamorphic grade, containing 92-98% fixed carbon. Anthracite has the highest energy content of any coal.
An upward fold or arch of rock strata. Petroleum or mineralized fluids can become trapped underneath anticlines.
The highest point of a vein relative to the surface. Under U.S. mining law, the holder of a claim containing the apex of a vein can mine the vein downdip, even if the mineralization eventually passes underneath an adjacent claim.
A water-bearing bed of porous rock, often sandstone. Often used to provide drinking water or process water for industrial operations.
The second oldest geologic era, lasting from 3.8 to 2.5 billion years ago. Most of the world's stable continental interiors, or shields, formed during the Archean, and these contain some of the largest known ore deposits. The Archean was also a time of prolific development of greenstone belts, which today are important targets for gold mineralization.
Fracture processes around a mine opening, leading to stabilization by an arching effect.
Average width multiplied by average height of airway, expressed in square feet.
Mill, consisting of one or more large stones dragged around on a circular bed, used to grind ore.
Inorganic residue left after coal is burned. Also, volcanic particles less than 2 millimeters in diameter.
A measure of the amount of an economic metal within an ore sample. The act of collecting such a measure.
Assay foot (meter, inch, centimeter)
Value obtained by multiplying an assay grade by the number of feet, meters, inches, centimeters across which the assayed sample was taken.
Schematic of an exploration property showing sampling locations and assay grades.
Approved activities that must be completed to retain the rights to claimed land. Generally refers to exploration mapping, sampling, or drilling. Mining laws often call for companies to spend a certain dollar amount yearly on assessment work.
A screw-shaped rotary drill used to penetrate, break, and then transport drilled material to surface. Suitable for soft materials such as coal or clay.
An ore processing method where large pieces of mined rock are placed in a rotating cylinder, being crushed and ground as they contact each other. In the case of softer ores, steel balls must often be added to the cylinder, making the process semi-autogenous.
All activities supportive of but not contributing directly to mining.
Portion of main ventilating current directed to face of dead end entry by means of an auxiliary fan and tubing.
A surveying term that references the angle measured clockwise from any meridian (the established line of reference). The bearing is used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line.
Rock taken for assay from the roof, or "back", of a mine opening.
Waste rock or soil used to fill a void created by mining. Mine waste or rock used to support the roof of a mine chamber after coal removal. Also, the act of placing such material.
The natural level of some physical property in the environment. Particularly, small-scale radioactivity present in almost all rocks on Earth.
Market condition where the futures price of a metal is lower in distant delivery months than in nearer delivery months. Opposite of contango.
A formal summary of a company's assets, liabilities, and net worth at a particular point in time. Also called a statement of condition.
Ore grinding device consisting of a rotating cylinder filled with steel balls. Crushed ore is placed in the cylinder and eventually ground as fine as sand-size.
Sedimentary deposits consisting of thin layers of iron minerals alternated with beds of silica. The most important worldwide sources of mined iron. Most banded iron formations (or BIFs) formed during the Proterozoic era, from 2.5 to 1.8 billion years ago, the layering being controlled by fluctuations in atmospheric oxygen. Various classes are recognized, distinguished mainly by the mineralogical form of iron - sulfide, oxide, carbonate, or silicate.
Said of rock or vein material containing no minerals of value, and of strata without coal, or containing coal in seams too thin to be workable.
Enclosing part of a mine to prevent inflow of noxious gasses from a mine fire or an explosion.
Solid blocks of coal left between two mines or sections of a mine to prevent accidents due to inrushes of water, gas, or from explosions or a mine fire.
A clay-rich deposit formed of material dragged along at the base of a glacier.
Dark-colored, silica-poor volcanic rock composed primarily of plagioclase and pyroxene, sometimes with olivine and quartz. Produced at ocean island volcanoes such as Hawaii's Kilauea, and various locations on the continents. Massive outpourings of basalt, known as flood basalts, have occurred periodically throughout geologic time, producing features such as the Deccan Traps in India and the Columbia Plateau in the northwestern U.S. Basalt horizons occasionally host economic deposits of gold, copper, chromite, and other metals.
Center from which exploration activity is conducted, usually in a remote location.
Non-precious metals such as copper, lead, zinc, aluminum, and nickel valued mainly for use in industrial applications. Base metals tend to be more chemically reactive than precious metals.
The underlying or older stratigraphy within a given area. Often refers to igneous or metamorphic rocks of Precambrian age which may be covered by younger sedimentary or volcanic rocks. Sometimes called the crystalline basement. The contact between basement and overlying rocks can be an important exploration target, particularly for uranium.
Somewhat outdated term for igneous rocks relatively low in silica, composed mostly of dark-colored minerals, such as basalt. Similar to "mafic" and opposite of "acidic".
A dome-like mass of igneous rock, often granitic, with a lateral extent generally more than 40 square miles, and no observable bottom. Batholiths are formed almost exclusively along margins between colliding tectonic plates, by numerous pulses of rising magma. Tin and tungsten deposits can be associated with such granitic bodies.
Rock composed of hydrous aluminum oxides and aluminum hydroxides. A residual deposit, formed by the transport and concentration of soil aluminum by rainwater in tropical and subtropical areas. Bauxite is the world's principal source of commercial aluminum, with large resources found in Australia, Brazil, Guinea, and Jamaica. A type of laterite deposit.
A bar or straight girder used to support a span of roof between two support props or walls.
The creation of a strong, inflexible beam by bolting or otherwise fastening together several weaker layers. In coal mining this is the intended basis for roof bolting.
A prolonged period of declining prices for shares, goods, or other financial instruments.
A surveying term used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line. The meridian is an established line of reference. Azimuths are angles measured clockwise from any meridian.
A plate used to distribute a given load. In roof bolting, the plate used between the bolt head and the roof.
A stratum of coal or other sedimentary deposit.
The arrangement of sedimentary rock layers, or beds. The physical and structural characteristics of a package of rock beds and the contacts between them. Also, stratification or layering.
A looped belt on which coal or other materials can be carried and which is generally constructed of flame-resistant material or of reinforced rubber or rubber-like substance.
A roller, usually of cylindrical shape, which is supported on a frame and which, in turn, supports or guides a conveyor belt. Idlers are not powered but turn by contact with the moving belt.
A belt pulley, generally under a conveyor belt and inby the drive pulley, kept under strong tension parallel to the belt line. Its purpose is to automatically compensate for any slack in the belting created by start-up, etc.
One of two or more divisions of a coal seam separated by slate or formed by the process of cutting the coal.
Small scale assaying set up.
The treatment of mined material, making it more concentrated or enriched.
A clay formed by chemical alteration of volcanic ash deposits, with great capacity for absorbing water. Bentonite is used as a thickening agent in oilwell drilling muds because of its ability to swell eight times in size when hydrated.
A pile or mound of material capable of restraining a vehicle.
An iron ore with phosphorus content lower than 0.045%.
A streak of impurity in a coal seam.
An ore-treatment process using bacteria to aid the dissolution and subsequent recovery of metals. Bioleaching can be accomplished both in-situ and within a treatment plant ("stirred tank leaching").
A potassium-magnesium-iron mica. Common in igneous, metamorphic, and sedimentary rocks.
The cutting end of a drill frequently made of an extremely hard material such as industrial diamonds or tungsten carbide.
A middle rank coal (between subbituminous and anthracite) formed by additional pressure and heat on lignite. Usually has a high Btu value and may be referred to as "soft coal."
A term generally applied to carbon dioxide. Strictly speaking, it is a mixture of carbon dioxide and nitrogen. It is also applied to an atmosphere depleted of oxygen, rather than having an excess of carbon dioxide.
Seafloor vent expelling hydrothermal fluids at temperatures over 350 degrees centigrade, found in areas of active ocean floor spreading and subduction. The name refers to black precipitates formed when the hot, sulfide-laden fluids come in contact with cold seawater. Ancient black smokers may have played a role in forming VMS-type massive sulfide ore deposits.
A term used by miners to describe sphalerite (zinc sulfide), especially darker varieties, which used to be considered a nuisance component of lead ores. Also used in Arkansas to describe dark, carbonaceous clay or earth associated with coal seams.
A cylindrical reaction vessel lined with heat-resistant bricks, into which "blasts" of high-pressure hot air and other gases are blown in order to produce metal from ore. Most commonly used in creating iron for steel-making, but also used to process lead, copper, tin, and other metals.
A mine employee who loads, primes, and detonates blasting materials.
A drillhole filled with explosives in order to blast rock loose.
Any material consisting of a mixture of a fuel and an oxidizer.
A detonator containing a charge of detonating compound, which is ignited by electric current or the spark of a fuse. Used for detonating explosives.
Electric circuits used to fire electric detonators or to ignite an igniter cord by means of an electric starter.
Bleeder or bleeder entries
Special air courses developed and maintained as part of the mine ventilation system and designed to continuously move air-methane mixtures emitted by the gob or at the active face away from the active workings and into mine-return air courses. Alt: Exhaust ventilation lateral.
Bulk Leach Extractable Gold, more commonly shortened to BLEG, is a geochemical sampling and analysis tool. It was developed in the early 1980s to address concerns relating to the accurate measuring of fine grained gold, and involves cyanide leaching relatively large (two to five kilos) samples for gold.>> (Bulk Leach Extractable Gold) samples on the west side. The first target they identified was Acrobat, currently in our West Pequop property JVed with Agnico Eagle. They did some early drilling there, which we followed up on with IPO money in the fall of 2005.
Intermediate product in the copper refining process, containing about 99% copper. Produced by oxidizing copper matte (mixture of copper and iron sulfides) to remove iron and reduce copper to its elemental form. So-named because the process forms bubbles of sulfur dioxide on the surface of the copper. Blister copper must be further refined before use in industrial applications.
A low-cost method of bulk mining in which large blocks of ore are undercut and the supporting pillars are blasted away, causing the ore to cave under its own weight.
A standard-sized block of shares, usually purchased by investors at a discount. In most cases a board lot is 100 shares, although some exchanges, such as Toronto, offer 500- and 1,000-share board lots.
The turning force in foot-pounds applied to a roof bolt to achieve an installed tension.
Note issued by a corporation or government as an agreement to pay the holder a certain amount of interest over a given period of time.
A powered steel arm used to support drifters, manbaskets, and hydraulic hammers.
Any deep or long drill-hole, usually associated with a diamond drill.
Any member of the managerial ranks who is directly in charge of miners (e.g., "shift-boss," "face-boss," "fire-boss," etc.).
Floor or underlying surface of an underground excavation.
A short raise or opening driven upward from a drift in order to mine overlying ore or permit access.
A small, portable magazine used to store limited quantities of explosives or detonators for short periods of time at locations in the mine which are convenient to the blasting sites at which they will be used.
Brattice or brattice cloth
Fire-resistant fabric or plastic partition used in a mine passage to confine the air and force it into the working place. Also termed "line brattice," "line canvas," or "line curtain."
An abrupt geologic discontinuity such as a fault, fracture, or unconformity.
The line that roughly follows the rear edges of coal pillars that are being mined. The line along which the roof of a coal mine is expected to break.
A passage for ventilation that is cut through the pillars between rooms.
A surface, or face, being worked within a mine. "Before breast" refers to material still ahead to be mined.
Coarse-grained sedimentary deposit made of angular fragments of rock surrounded by finer material. Breccias form when rock is broken and then redeposited by hydrothermal activity, faulting, or volcanism. Such rocks sometimes indicate a nearby mineralized system.
The process of forming a breccia.
A short conveyor hung from the boom of mining or lading machine or haulage system with the other end attached to a receiving bin that dollies along a frame supported by the room or entry conveyor, tailpiece. Thus, as the machine boom moves, the bridge conveyor keeps it in constant connection with the tailpiece. Also known as a bridge carrier.
Mine ore broken by blasting but not yet brought to surface.
A low place in the roof of a mine, giving insufficient headroom.
A pocket compass used for sighting lines as well as measuring strike and dip of geologic horizons.
Digging up the bottom or taking down the top to give more headroom in roadways.
British thermal unit. A measure of the energy required to raise the temperature of one pound of water one degree Fahrenheit.
The fine particles of coal or other material resulting form the boring or cutting of the coal face by drill or machine.
Large-scale extraction of many thousands of tonnes of ore per day.
A large rock sample, often hundreds of tons, selected to be representative of a potential orebody. Used to determine metallurgical characteristics.
A prolonged period of increasing prices for shares, goods, or other financial instruments.
Prospector's term for white, coarse-grained quartz bearing little or no mineralization.
Bars or ingots formed of metal. Usually refers to precious metals, such as gold bullion.
A violent dislocation of the mine workings which is attributed to severe stresses in the rock surrounding the workings.
A short, poorly defined vertical cleavage plane in a coal seam, usually at right angles to the long face cleat.
A coal mining term that has different meanings in different locations. It can be synonymous with panel entry, submain entry, or in its older sense it refers to an entry that is "butt" onto the coal cleavage (that is, at right angles to the face).
An accessory metal or mineral product recovered during processing of ore. Silver is often a byproduct of lead, zinc, copper, and gold treatment. Gold can yield nuisance byproducts such as arsenic and mercury.
A steel cable cemented into a drillhole to help support blocky ground.
The conveyance used to transport men and equipment between the surface and the mine levels.
Ore concentrate that has been prepared for smelting by heating, oxidation, or reduction to drive off unwanted components such as sulfur and water.
An option contract allowing the holder to buy shares at a specified price. Also, the act of exercising such a contract. The opposite of a "put".
A massive, non-caking block coal composed dominantly of spores, with a fine, even grain and a conchoidal fracture which has a high percentage of hydrogen, burns with a long, yellow flame, and is extremely easy to ignite.
A miner's safety helmet. Also, a highly sensitive, encapsulated explosive that is used to detonate larger but less sensitive explosives.
A flat piece of wood inserted between the top of the prop and the roof to provide bearing support.
The total number of shares authorized for issuance under a company's charter. Includes common stock and preferred stock. Also, the book value of a corporation's outstanding shares.
Total value of securities issued by a corporation, including stocks, bonds, and debentures, often taken as a measure of a company's market value. Calculated by multiplying the number of outstanding securities by the current price. Sometimes called the cap or market cap. Generally, companies are said to have a "large cap" if they have a capitalization over $5 billion, "medium cap" if $1 billion to $5 billion, "small cap" if $250 million to $1 billion, and "micro cap" if less than $250 million.
A stope accessible only through a manway.
A railway wagon, especially any of the wagons adapted to carrying coal, ore, and waste underground.
The mechanism for unloading a car.
More correctly, cemented tungsten carbide. A cutting or drilling bit for rock or coal, made by fusing an insert of molded tungsten carbide to the cutting edge of a steel bit shank.
A process very similar to carbon-in-pulp. In the carbon-in-leach process, the leaching and absorbing of gold onto carbon take place in the same tank
Process to recover gold from a cyanide leach slurry. Coarse, activated carbon particles are moved counter-current to the slurry, absorbing the gold. Loaded carbon is removed by screening, and the gold is recovered from the carbon by stripping in a caustic cyanide solution followed by electrolysis or by zinc precipitation.
Includes production costs, royalties, marketing and refining charges, together with all administration expenses.
Most generally, gross earnings minus payments made. An approximation of a company's profits. May or may not take into account other costs such as depreciation.
A directed throw; in strip-mining, the overburden is cast from the coal to the previously mined area.
The negatively charged electrode in an eletrolytic cell. In electrolytic refining of copper, anodes of impure blister copper and cathodes of pure copper are placed in an electrified solution of copper sulphate and sulphuric acid. Copper dissolves from the anode and is redeposited at the cathode, leaving behind impurities. The result is a rectangular plate of copper, usually 99.99% pure, referred to as a copper cathode or simply cathode.
Describes a person who has passed an examination to do a required job.
A geophysical instrument that measures the strength of the Earth's magnetic field. See "magnetic survey".
A conveyor on which the material is moved along solid pans (troughs) by the action of scraper crossbars attached to powered chains.
A copper sulfide mineral, more copper-enriched than others such as chalcopyrite. Often occurs in the supergene zone of an ore deposit when primary copper minerals in the upper section of the orebody are oxidized, creating a copper solution that percolates downward and redeposits. A "chalcocite blanket" zone of mineralization often occurs at or near the water table in such settings.
A copper and iron sulfide mineral. Less enriched in copper than minerals such as chalcocite and bornite. The primary form of copper mineralization in most deposits, although this is often oxidized and redeposited to form more-enriched copper minerals.
Building where mine workers change into work clothes; also called the "dry".
Rock pieces taken from a vein or mineral deposit by way of a small trench or channel, generally about 10 cm wide and 2 cm deep. Often taken at regular intervals across a geologic outcrop using a portable circular saw.
A document that creates, or incorporates, a company or other institution.
A financial institution regulated by government.
Sheet of brattice cloth hung across an airway to control the passage of the air current.
Machine, somewhat like the arrastra, in which heavy stone wheels turn about a central shaft and crush ore.
Small pieces of rock taken from across a geologic outcrop, often for assay.
Large hydraulic jacks used to support roof in longwall and shortwall mining systems.
An iron-chromium oxide mineral. The main source of mined chromium. Generally associated with ultramafic igneous rocks, as at South Africa's Bushveld complex, Zimbabwe's Great Dike, and Montana's Stillwater complex.
An opening used to pass ore into mine cars.
A mercury sulfide mineral, recognized for its distinctive red color.
Mineral processing system using a closed circuit that returns below-criteria material to the head of the treatment loop for further processing prior to release. Also, the material returned to the head for further processing.
Land held by a prospector or mining company for the purpose of mineral exploration. The holder of a claim is generally granted rights to the land in exchange for an agreement to spend a given amount of money on exploratory work.
The removal or settling of suspended material from dirty water.
A machine that separates minerals on the basis of given criteria, often size and density.
A mineral particle less than 1/256th of a millimeter in size, or a sedimentary rock composed primarily of such particles. Most clays are made up of hydrous silicate minerals such as kaolinite, illite, or montmorillonite, formed mainly by weathering of primary silicate minerals.
Clean Air Act Amendments of 1990
A comprehensive set of amendments to the federal law governing the nation's air quality. The Clean Air Act was originally passed in 1970 to address significant air pollution problems in our cities. The 1990 amendments broadened and strengthened the original law to address specific problems such as acid deposition, urban smog, hazardous air pollutants and stratospheric ozone depletion.
The breaking of a mineral along crystallographic planes, defined by the mineral's internal arrangement of atoms. Cleavage gives a mineral its characteristic crystal structure. Also, the formation of regular, planar structures within a rock body by fracturing or metamorphism.
Type of ore processing where below-criteria product is returned to the head of a loop for further treatment to bring it to required specifications before release.
Generally, any carbon-rich material formed by the compaction and alteration of plant matter. More specifically, a rock containing more than 50% carbonaceous material by weight, and more than 70% by volume. A number of coal "ranks" or classes are recognized, based on the amount of heating and compaction undergone by the rock. These are (from least altered to most altered): peat, lignite (brown coal), sub-bituminous, bituminous, sub-anthracite, and anthracite. Coals can also be classified by "grade", based on the amount of impurities (such as sulfur) present. High rank coals are often used to produce coke for steel-making, while mid- to low rank coals are generally used in heating and power generation.
Heating, compaction, or other geochemical alteration of plant material, leading to the formation of coal.
The mouth or upper end of a mine shaft. Also, timber or concrete placed around such an opening for re-enforcement.
Ore processing technique where crushed rock is placed in a tall, cylindrical column filled with chemicals that cause valuable minerals to separate from gangue minerals by either floating or sinking.
Production for accounting purposes.
The breaking, crushing, or grinding of coal, ore, or rock.
A unit of ownership in a company, also called a share. Entitles the holder to vote on corporate policy and receive dividend payments. Common stock holders are paid dividends only after holders of "preferred shares" are given such payments.
Rock which, because of its physical and geological characteristics, is capable of sustaining openings without any structural support except pillars and walls left during mining (stalls, light props, and roof bolts are not considered structural support).
Ore containing more than one economic mineral. Complex ores are more difficult to process due to the varying chemical properties of the target minerals. For example, some copper minerals interfere with the cyanidation of gold by absorbing excess amounts of cyanide.
The valuable portion of an ore, mostly stripped of gangue minerals, obtained by processing.
A facility that produces a mineral concentrate which is subsequently smelted or otherwise purified.
In the oil and gas industry, a concession generally means a government or a government agency has granted a plot of land to a company or group of companies to conduct hydrocarbon exploration, development, or production activities. A concession generally implies that the country is using a royalty-tax system in its fiscal systems. A production-sharing contract or a service contract system would not grant concessions.
Ore crushing machine that uses a gyrating cone or "crushing head" inside of an inverted cone known as a "bowl".
In business, a written statement acknowledging a sales or purchasing agreement.
A sedimentary rock composed of rounded rock fragments, greater than 2 millimeters in size, held together by a matrix of sand or silt. Similar to a breccia, but distinguished by a greater degree of rounding in the clasts. Often formed in river or delta settings.
The place or surface where two different kinds of rocks meet. For example, the contact between a limestone and a sandstone. Also, between an igneous intrusion and the host rock that surrounds it. Contacts can be important zones for mineralization because metal-bearing fluids often flow along this plane of weakness. Contacts between older basement rocks and overlying sedimentary rocks (also called "unconformities") host many of the world's uranium deposits.
Metamorphism caused when a body of magma heats the rock around it. A high temperature, low pressure form of metamorphism, that generally creates a geologic pattern known as a "hornfels facies", characterized by the minerals hornblende, pyroxene, albite, and epidote.
Market condition where prices for future delivery are higher than the cash or spot price. Opposite of backwardation.
Machine that continually produces ore from a working face.
An imaginary line that connects all points on a surface having the same elevation.
Explosives discharges designed to accomplish a particular objective.
A furnace used to smelt pure copper metal from matte.
Roughly north-south trending chain of mountain ranges extending along the western margins of North and South America. Created by subduction of tectonic plates underlying the Pacific Ocean underneath these continents. Tectonics and volcanic activity in this region have formed a wide variety of ore deposits including numerous copper-gold-molybdenum porphyries.
A cylindrical piece of rock, 5-10 centimeters in diameter and up to several meters in length, taken as a sample of a subsurface geologic interval and brought to surface by drilling. Cores are used to ascertain the nature of local geology and can be assayed to provide information about ore grade.
The part of a drill string used to collect a core sample. Consists of two nested tubes, the outer rotating with the drill bit and the inner being the location where the core sample is stored for return to surface.
Type of pump developed in Cornwall, England, and commonly used in deep mines of the nineteenth century to raise underground water.
Barren rock surrounding an orebody. Also called host rock.
The overburden of any deposit.
The forcing of pillars into soft bottom by the weight of a strong roof. In surface mining, a very slow movement of slopes downhill.
A roof support of prop timbers or ties, laid in alternate cross-layers, log-cabin style. It may or may not be filled with debris. Also may be called a chock or cog.
The horizontal member of a roof timber set supported by props located either on roadways or at the face.
A horizontal opening driven from a shaft and (or near) right angles to the strike of a vein or other orebody.
A machine for crushing rock or other materials. Among the various types of crushers are the ball mill, gyratory crusher, Handsel mill, hammer mill, jaw crusher, rod mill, rolls, stamp mill, and tube mill.
The Earth's outermost layer -- a veneer of solid rock floating atop the partially-molten mantle or inner Earth. The crust is broken into several tectonic plates, which move with respect to each other. Continental crust has a geologic composition similar to granite and averages 40 kilometers in thickness, while crust underlying oceans is mainly composed of basalt and other mafic/ultramafic rocks averaging about 8 kilometers in thickness.
Share-purchase structure where a buyer is entitled to receive a dividend payment on the shares they own.
A figure representing the total of a company's cash, marketable securities, accounts receivable, and all other assets likely to be converted to cash within a year.
Debts that a company must repay within one year. Generally includes accounts payable and short-term loans.
A smelter which processes concentrates from independent mines. Concentrates may be purchased or the smelter may be contracted to do the processing for the independent company.
Applies to assays that have been reduced to some arbitrary maximum to prevent erratic high values from inflating the average.
A method of stoping in which ore is removed in slices, or lifts, and then the excavation is filled with rock or other waste material (backfill), before the subsequent slice is extracted.
The lowest grade of mineralized material considered economic; used in the calculation of the ore reserves in a given deposit
Method of extracting gold grains from crushed or ground ore by dissolving them in a weak solution of sodium or calcium cyanide: also known as leaching
A chemical species containing carbon and nitrogen used to dissolve gold and silver from ore.
An order to buy or sell shares, good only on the day the order was entered.
Method of raising capital whereby companies borrow money from a lending institution.
An effort to raise funds in which a company borrows an amount of money from a financial institution or accredited investors for project development purposes and/or general working capital. This is in contrast to an equity financing, in which companies raise funds by offering a certain number of shares (sometimes lower than the market) to institutions and accredited investors to purchase.
The area around the shaft collar where men and materials enter the cage to be lowered underground.
A sloping underground opening for machine access from level to level or from surface; also called a ramp.
Expenses incurred but not charged against the current year's operation.
An accounting device, used primarily in tax computations. It recognizes the consumption of an ore deposit, a mine's principal asset.
Means a mineralized body which has been physically delineated by sufficient drilling, trenching, and/or underground work, and found to contain a sufficient average grade of metal or metals to warrant further exploration and/or development expenditures. Such a deposit does not qualify as a commercially mineable ore body or as containing ore reserves, until final legal, technical, and economic factors have been resolved.
The periodic, systematic charging to expense of plant assets reflecting the decline in economic potential of the assets.
The word alone generally denotes vertical depth below the surface. In the case of incline shafts and boreholes it may mean the distance reached from the beginning of the shaft or hole, the borehole depth, or the inclined depth.
An instrument whose price is "derived" from its underlying asset. This can include futures, options, forwards, and swaps.
Specialized chemical or electronic instruments used to detect mine gases.
A device containing a small detonating charge that is used for detonating an explosive, including, but not limited to, blasting caps, exploders, electric detonators, and delay electric blasting caps.
Underground work carried out for the purpose of opening up a mineral deposit. Includes shaft sinking, crosscutting, drifting and raising.
Drilling to establish accurate estimates of mineral reserves.
A common basic igneous rock usually occurring in dykes or sills.
The hardest known mineral, composed of pure carbon; low-quality diamonds are used to make bits for diamond drilling in rock.
A rotary type of rock drill that cuts a core of rock that is recovered in long cylindrical sections, two cm or more in diameter.
A person who operates a diamond drill.
Blending of a gas and air, resulting in a homogeneous mixture. Blending of two or more gases.
To lower the concentration of a mixture; in this case the concentration of any hazardous gas in mine air by addition of fresh intake air.
The contamination of ore with barren wall rock in stopping.
Volcanic vent found in areas of active ocean floor spreading, through which sulfide-laden fluids escape.
A decrease in the value of a company's shares caused by the issue of treasury shares.
An intrusive igneous rock composed chiefly of sodic plagioclase, hornblende, biotite or pyroxene.
The inclination of a geologic structure (bed, vein, fault, etc.) from the horizontal; dip is always measured downwards at right angles to the strike.
A compass with the needle mounted so as to swing in a vertical plane, used for prospecting to determine the magnetic attraction of rocks.
A method of drilling involving the use of stabilizers and wedges to direct the orientation of the hole.
The minimum price below the par value at which treasury shares may legally be sold.
Roughly linear deposit of material left behind by a moving geologic body. In diamond exploration, the term generally refers to tracks of "indicator" minerals such as garnet, ilmenite, and chromite, eroded from a kimberlite by glaciers. As the glaciers move the melting of the ice releases these minerals into the underlying sediment, forming the train. In some cases, kimberlites can be located by following the train back to its "head" or source. Dispersion trains of gold can also be formed when glaciers move overtop an ore body. Dispersion train also refers to the trail of debris left by a volcanic eruption or meteorite impact.
Ore carrying small particles of valuable minerals, spread more or less uniformly through the gangue matter; distinct from massive ore, wherein the valuable minerals occur in almost solid form with very little waste mineral included
Cash or stock awarded to preferred and common shareholders at the discretion of the company's board of directors.
Made when a dividend has been paid to the previous holder because stock has not yet been transferred to the name of the new owner.
The final saleable product of a gold mine. Usually consisting of gold and silver.
The result of the plastic deformation of a rock unit where it has been folded or bent back on itself.
The process of removing surplus ground or surface water either by artificial means or by gravity flow.
An underground opening at the bottom of a stope through which broken ore from the stope is extracted.
A horizontal underground opening that follows along the length of a vein or rock formation as opposed to a crosscut which crosses the rock formation.
A hydraulic rock drill used to drill small-diameter holes for blasting or for installing rock bolts.
A machine utilizing rotation, percussion (hammering), or a combination of both to make holes. If the hole is much over 0.4m in diameter, the machine is called a borer.
The size and quality of a potential orebody as suggested by widely spaced drillholes; more work is required before reserves can be classified as probable or proven.
The use of such a machine to create holes for exploration or for loading with explosives.
A building where the miner changes into working clothes.
The degree of care and caution required before making a decision; loosely, a financial and technical investigation to determine whether an investment is sound.
A bag filled with sand, clay, etc., used for stemming a charged hole.
To unload; specifically, a load of coal or waste; the mechanism for unloading, e.g. a car dump (sometimes called tipple); or, the pile created by such unloading, e.g. a waste dump (also called heap, pile, tip, spoil pike, etc.).
A long and relatively thin body of igneous rock that, while in the molten state, intruded a fissure in older rocks.
To connect with the ground to make the earth part of the circuit.
An electric current is passed through a solution containing dissolved metals, causing the metals to be deposited onto a cathode.
The process of purifying metal ingots that are suspended as anodes in an electrolytic bath, alternated with refined sheets of the same metal which act as starters or cathodes.
A geophysical survey method which measures the electromagnetic properties of rocks.
Roughly parallel but staggered structures.
An underground horizontal or near-horizontal passage used for haulage, ventilation, or as a mainway; a coal heading; a working place where the coal is extracted from the seam in the initial mining; same as "gate" and "roadway," both British terms.
Environmental impact study
A written report, compiled prior to a production decision, that examines the effects proposed mining activities will have on the natural surroundings.
Orebodies formed by hydrothermal fluids and gases that were introduced into the host rocks from elsewhere, filling cavities in the host rock.
Hydrothermal deposits formed at low temperatures and low pressure. These are associated with large vein systems (Epithermal Veins) found in volcanic rock. The epithermal veins are always located over an intrusive rock structure whch has extruded to the surface in feeder stocks and and dykes. The vent areas are centers of intense fracturing and hydrothermal activitity. The veins normally contain base metal sulphides such as chalcopyrite, galena and sphalerite but are most important as sources for silver and gold which occur as native elements or in cpounds or as impurities in other minerals. The veins can be mined as high grade, low tonnage deposits, often called "bonanza" veins. In some places, the whole shooting match - country rock and veins are mined together in a bult, low grade, large tonnage operation.
A mineral deposit consisting of veins and replacement bodies, usually in volcanic or sedimentary rocks, containing precious metals or, more rarely, base metals.
A device that companies use to raise money for exploration, development, or general working capital purposes. The company offers a certain number of shares at a price (sometimes lower than the
market) to institutions and accredited investors. This is in contrast to a debt financing, in which a company borrows an amount of money from a financial institution or accredited investors for project development purposes and/or general working capital.
A large division of geologic time - the Precambrian era, for example.
The breaking down and subsequent removal of either rock or surface material by wind, rain, wave action, freezing and thawing and other processes.
Either a piece of visible gold or a large glacial boulder.
Shares deposited in trust pending fulfilment of certain conditions, and not ordinarily available to trading until released.
On stocks selling "ex-dividend", the seller retains the right to a pending dividend payment.
Prospecting, sampling, mapping, diamond drilling and other work involved in searching for ore.
Any rapidly combustive or expanding substance. The energy released during this rapid combustion or expansion can be used to break rock.
The process of mining and removal of coal or ore from a mine.
Lava and other forms of magma that have flowed out onto the earth's crust - thus not allowing for a lengthy (crystal creating) cooling process. The resulting rock is, as a result, typically fine grained. Also called "volcanics".
The end of a drift, crosscut or stope in which work is taking place.
The ratio of the ultimate breaking strength of the material to the force exerted against it. If a rope will break under a load of 6000 lbs., and it is carrying a load of 2000 lbs., its factor of safety is 6000 divided by 2000 which equals 3
A mass of roof rock or coal which has fallen in any part of a mine.
Automation device designed to give alarm if the main fan slows down or stops.
A small, portable fan used to supplement the ventilation of an individual working place.
A large fan installed in the main air current, and thus in tandem with the main fan.
A break in the Earth's crust caused by tectonic forces which have moved the rock on one side with respect to the other.
A fault, instead of being a single clean fracture, may be a zone hundreds or thousands of feet wide. The fault zone consists of numerous interlacing small faults or a confused zone of gouge, breccia, or mylonite.
Feasibility Study: (“Bankable Feasibility Study”)
According to NI 43-101, a feasibility study is a "comprehensive study of a mineral deposit in which all geological, engineering, legal, operating, economic, social, environmental and other relevant factors are considered in sufficient detail that it could reasonably serve as the basis for a final decision by a financial institution to finance the development of the deposit for mineral production”
A group of common rock-forming minerals that includes microcline, orthoclase, plagioclase and others.
Term used to describe light-colored rocks containing feldspar, feldspathoids and silica.
Any material that is put back in place of the extracted ore to provide ground support.
A vehicle for companies to raise money for exploration, development, or general working capital. See entries for "equity financing" and "debt financing" for two different kinds.
Fineness is the proportion of pure gold or silver in jewelry or bullion expressed in parts per thousand. Thus, 925 fine gold indicates 925 parts out of 1,000, or 92.5% is pure gold.
The combustible gas, methane, CH4. Also, the explosive methane-air mixtures with between 5% and 15% methane. A combustible gas formed in mines by decomposition of coal or other carbonaceous matter, and that consists chiefly of methane.
An extensive crack, break, or fracture in the rocks.
Possessions such as buildings, machinery and land which, as opposed to current assets, are unlikely to be converted into cash during the normal business cycle.
The metal strap or crossbar attached to the drag chain-and-flight conveyor.
Pieces of rock that have been broken off and moved from their original location by natural forces such as frost or glacial action.
That part of any underground working upon which a person walks or upon which haulage equipment travels; simply the bottom or underlying surface of an underground excavation.
Process for concentrating materials based on the selective adhesion of certain minerals to air bubbles in a mixture of water and ground-up ore. When the right chemicals are added to a frothy water bath of ore that has been ground to the consistency of talcum powder, the minerals will float to the surface. The metal-rich flotation concentrate is then skimmed off the surface
Shares in an exploration company that allow the tax deduction or credits for mineral exploration to be passed to the investor.
An illustration showing the sequence of operations, step by step, by which ore is treated in a milling, concentration or smelting process.
A chemical substance that reacts with gangue minerals to form slags, which are liquid at furnace temperature and low enough in density to float on the molten bath of metal or matte.
An instrument used in geophysics to measure total magnetic field.
The finely divided particles of ash suspended in gases resulting from the combustion of fuel. Electrostatic precipitators are used to remove fly ash from the gases prior to the release from a power plant's smokestack.
Any bending or wrinkling of rock strata.
The mass of rock beneath a geological structure such as an orebody or fault
Any assemblage of rocks which have some character in common, whether of origin, age, or composition. Often, the word is loosely used to indicate anything that has been formed or brought into its present shape.
The sale or purchase of a commodity for delivery at a specified future date.
A general term to include any kind of discontinuity in a body of rock if produced by mechanical failure, whether by shear stress or tensile stress. Fractures include faults, shears, joints, and planes of fracture cleavage.
Ores of gold or silver from which the precious metals can be recovered by concentrating methods without resorting to pressure leaching or other chemical treatment.
Easy to break, or crumbling naturally. Descriptive of certain rocks and minerals.
A cord-like substance used in the ignition of explosives. Black powder is entrained in the cord and, when lit, burns along the cord at a set rate. A fuse can be safely used to ignite a cap, which is the primer for an explosive.
A financial obligation for the buyer to purchase the underlying asset at a point in time in the future called the expiry date, and for the seller to deliver the underlying asset at its expiry date. At the expiry date, the goods can be delivered or settled in cash (in a process called "netting"). This differs from options because the buyer of an option has the "option" to buy, whereas the buyer of a future has the "obligation" to buy.
A dark, coarse-grained igneous rock.
Lead sulfide, the most common ore mineral of lead.
A horizontal or a nearly horizontal underground passage, either natural or artificial.
A unit of measurement of magnetic intensity.
The worthless rock in a vein which holds valuable metals.
An instrument used to measure the radioactivity that emanates from certain minerals by means of a Geiger-Mueller tube.
The study of the chemical properties of rocks.
One who studies the constitution, structure, and history of the earth's crust, conducting research into the formation and dissolution of rock layers, analyzing fossil and mineral content of layers, and endeavoring to fix historical sequence of development by relating characteristics to known geological influences (historical geology).
The science concerned with the study of the rocks which compose the Earth.
A scientific method of prospecting that measures the physical properties of rock formations. Common properties investigated include magnetism, specific gravity, electrical conductivity and radioactivity.
The study of the physical properties of rocks and minerals.
Pertains to the heat of the Earth's interior.
Sedimentary material that has been transported by glaciers.
Lines or scratches on a smooth rock surface caused by glacial abrasion.
An open pit from which ore is extracted, especially where broken ore is passed to underground workings before being hoisted.
A layered or banded crystalline metamorphic rock, the grains of which are aligned or elongated into a roughly parallel arrangement.
A form of debt financing whereby a potential gold producer borrows gold from a lending institution, sells the gold on the open market, uses the cash for mine development, then pays back the gold from actual mine production.
Gold particles found within material deposited by a glacier. Gold-in-till is formed when a glacier overrides a gold-bearing deposit, eroding gold and entraining it into the ice. When the glacier melts, the gold is laid down along with sand, silt, clay, and other material to form a deposit known as a till. Gold-in-till sampling is sometimes used to determine the general location of a gold-bearing ore body.
An area of rusty staining on the rocks that is formed when sulphide minerals are oxidized. Often an important indicator to geologists that minerals of interest may be present. Iron most usually leaves the rusty stains, nickel a light green, and secondary uranium minerals can leave an orangish stain.
Fine, putty-like material composed of ground-up rock found along a fault.
A sample from a rock outcrop that is assayed to determine if valuable elements are contained in the rock. Literally walking the ground and grabbing prospective looking rock samples, mapping the location of each. The samples are then assayed to begin forming a map of where further investigation may be warranted. A grab sample is not intended to be representative of the deposit, and usually the best-looking material is selected.
A downfaulted block of rock.
In petrology, that factor of the texture of a rock composed of distinct particles or crystals which depends upon their absolute size.
A coarse-grained intrusive igneous rock consisting of quartz, feldspar and mica.
Gravity meter, gravimeter
An instrument for measuring the gravitational attraction of the earth; gravitational attraction varies with the density of the rocks in the vicinity.
Recovery of gold from crushed rock or gravel using gold's high specific gravity to separate it from lighter material
An area underlain by metamorphosed volcanic and sedimentary rocks, usually in a continental shield.
Material used to finely grind ore material to a size which allows recovery of the desired contained material
A grating, usually constructed of steel rails, placed over the top of a chute or ore pass for the purpose of stopping large pieces of rock or ore that may hang up in the pass.
The total number of acres that a company holds on a project.
This term is in contrast to net acres, the number of acres the company actually owns, given its ownership percentage of the property.
The theoretical value of ore determined simply by multiplying the assay of metal or metals and the current market price. It must be used only with caution and severe qualification because gross value completely ignores all the costs that have to go into extracting and processing the metals, including the time value of money. Also, transporting the ore, smelting costs - including dealing with any negative by products (mercury or arsenic), etc.
A share of gross revenue from the sale of minerals from a mine.
The regulation and final arresting of the closure of the walls of a mined area. The term generally refers to measures taken to prevent roof falls or coal bursts.
The pressure to which a rock formation is subjected by the weight of the superimposed rock and rock material or by diastrophic forces created by movements in the rocks forming the earth's crust. Such pressures may be great enough to cause rocks having a low compressional strength to deform and be squeezed into and close a borehole or other underground opening not adequately strengthened by an artificial support, such as casing or timber.
The process of sealing off a water flow in rocks by forcing a thin slurry of cement or other chemicals into the crevices; usually done through a diamond drill hole.
Finances or supplies of food, etc., furnished to a prospector in return for an interest in any discoveries made.
The timber rails installed along the walls of a shaft for steadying, or guiding, the cage or conveyance.
A cement applied by spraying to the roof and sides of a mine passage.
A sedimentary rock consisting of hydrated calcium sulfate.
A machine that crushes ore between an eccentrically mounted crushing cone and a fixed crushing throat. Typically has a higher capacity than a jaw crusher.
The wall or rock on the upper or topside of an ore deposit.
Any underground entry or passageway that is designed for transport of mined material, personnel, or equipment, usually by the installation of track or belt conveyor.
The average grade of ore fed into a mill.
A term used in both belt and chain conveyor work to designate that portion of the conveyor used for discharging material.
The structure surmounting the shaft which supports the hoist rope pulley, and often the hoist itself.
A vein above a drift. An interior level or airway driven in a mine. In longwall workings, a narrow passage driven upward from a gangway in starting a working in order to give a loose end.
A process whereby valuable metals, usually gold and silver, are leached from a heap, or pad, of crushed ore by leaching solutions percolating down through the heap and collected from a sloping, impermeable liner below the pad.
An area of land equivalent to 10,000 square meters or 2.47 acres.
Taking a buy or sell position in a futures market opposite to a position held in the cash market to minimize the risk of financial loss from an adverse price change.
An oxide of iron, and one of that metal's most common ore minerals.
Rich ore. As a verb, it refers to selective mining of the best ore in a deposit.
One who steals rich ore, especially gold, from a mine.
A sharp rise in the floor of a seam.
The machine used for raising and lowering the cage or other conveyance in a shaft.
The vertical transport coal or material.
A corporation engaged principally in holding a controlling interest in one or more other companies.
In geology, any given definite position or interval in the stratigraphic column or the scheme of stratigraphic classification; generally used in a relative sense.
A fine-grained contact metamorphic rock.
A mass of waste rock lying within a vein or orebody.
A mass of material with a slippery surface in the roof; shaped like a horse's back.
An upfaulted block of rock.
The rock surrounding an ore deposit.
Of or pertaining to fluids in motion. Hydraulic cement has a composition which permits it to set quickly under water. Hydraulic jacks lift through the force transmitted to the movable part of the jack by a liquid. Hydraulic control refers to the mechanical control of various parts of machines, such as coal cutters, loaders, etc., through the operation or action of hydraulic cylinders.
The treatment of ore by wet processes, such as leaching, resulting in the solution of a metal and its subsequent recovery.
A process where water heated by pressure and magma to high degrees interacts with the country rock to either precipitate (leach) minerals into deposits, or even cause metamorphic reactions leading to concentrations of mineralization.
Rocks formed by the solidification of molten material from far below the earth's surface.
An ore mineral of titanium, being an iron-titanium oxide.
In the natural or original position. Applied to a rock, soil, or fossil when occurring in the situation in which it was originally formed or deposited.
Any entry to a mine that is not vertical (shaft) or horizontal (adit). Often incline is reserved for those entries that are too steep for a belt conveyor (+17 degrees -18 degrees), in which case a hoist and guide rails are employed. A belt conveyor incline is termed a slope. Alt: Secondary inclined opening, driven upward to connect levels, sometimes on the dip of a deposit; also called "inclined shaft".
Applied to strata, a formation, a rock, or a rock structure not combining sufficient firmness and flexibility to transmit a thrust and to lift a load by bending.
Indicated Mineral Resource
An 'Indicated Mineral Resource' is that part of a Mineral Resource for which quantity,
grade or quality, densities, shape and physical characteristics, can be estimated with a level
of confidence sufficient to allow the appropriate application of technical and economic
parameters, to support mine planning and evaluation of the economic viability of the
deposit. The estimate is based on detailed and reliable exploration and testing information
gathered through appropriate techniques from locations such as outcrops, trenches, pits,
workings and drill holes that are spaced closely enough for geological and grade continuity
to be reasonably assumed.
Induced Polarization - discovered in the early days of resistivity surveying (i.e. shooting electrical charges through the ground and mapping the varying levels of conducivity). IP is based on the finding that certain types of mineral deposits can be "charged" and will hold an electrical charge passed through them. When the charge is turned off, it does not "switch off" but instead drains off over time. Resistivity and IP are usually done at the same time. This is particularly useful in detecting sulphide minerals which may be economic in themselves, or which can serve as pathfinders to other mineral deposits.
Non-metallic, non-fuel minerals used in the chemical and manufacturing industries. Examples are asbestos, gypsum, salt, graphite, mica, gravel, building stone and talc.
Inferred Mineral Resource
An 'Inferred Mineral Resource' is that part of a Mineral Resource for which quantity and
grade or quality can be estimated on the basis of geological evidence and limited sampling
and reasonably assumed, but not verified, geological and grade continuity. The estimate is
based on limited information and sampling gathered through appropriate techniques from
locations such as outcrops, trenches, pits, workings and drill holes.
The first sale of shares to the public, usually by subscription from a group of investment dealers.
Pension funds and mutual funds, managing money for a large number of individual investors.
The passage through which fresh air is drawn or forced into a mine or to a section of a mine.
An igneous rock containing 52% to 66% quartz.
A term used in belt and chain conveyor network to designate a section of the conveyor frame occupying a position between the head and foot sections.
Refers to mineral deposits that are formed by the upward movement of magma toward the earth's crust. The intrusive rock itself can host a large porphry type deposit (low grade, large tonnage), or important concentrations of minerals can be found around the edges where the intrusive rock has interacted with country rock. Also, because of the different mineral properties of intrusive rock, mineralization can concentrate in skarns situated to either side of the mineral "cap" or top of the deposit having "pooled" there through hydrothermal processes or leaching from the crust.
An exchange of ions in a crystal with irons in a solution. Used as a method for recovering valuable metals, such as uranium, from solution.
A line, on a map, drawn through points of equal thickness of a designated unit. Synonym for isopachous line; isopachyte.
A percussion drill used for drifting or stopping that is mounted on a telescopic leg which has an extension of about 2.5 m. The leg and machine are hinged so that the drill need not be in the same direction as the leg.
A caltrop or other object manufactured with one or more rounded or sharpened points, which when placed or thrown present at least one point at such an angle that it is peculiar to and designed for use in puncturing or damaging vehicle tires. Jackrocks are commonly used during labor disputes.
A dense, usually gray, chertlike siliceous rock, in which chalcedony or cryptocrystalline quartz has replaced the carbonate minerals of limestone or dolomite; a silicified limestone.
A machine in which rock is broken by the action of steel plates.
A piece of milling equipment used to concentrate ore on a screen submerged in water, either by the reciprocating motion of the screen or by the pulsation of water through it.
Job Safety Analysis (J.S.A.)
A job breakdown that gives a safe, efficient job procedure.
A divisional plane or surface that divides a rock and along which there has been no visible movement parallel to the plane or surface.
A smooth, rounded piece of rock, cylindrical in shape, which may drop out of the roof of a mine without warning. The origin of this feature is thought to be the remains of the stump of a tree that has been replaced by sediments so that the original form has been rather well preserved.
Iron Cornish bucket used to hoist ore and miners to the surface.
2.205 pounds. When describing percentages of minerals in bulk tonnage, kgs are often used. To wit, a company might report 4% copperÉ which is to say 4 kg of copper per tonne of rock.
A variety of peridotite; the most common host rock of diamonds.
Planks or small timbers placed between steel ribs along the roof of a stope or drift to prevent rocks from falling, rather than to support the main weight of the overlying rocks.
The electric cap lamp worn for visibility. Also, the flame safety lamp used in coal mines to detect methane gas concentrations and oxygen deficiency.
An igneous rock, composed of dark minerals, that occurs in dykes; sometimes contains diamonds.
Rocks in tropical climates weather to form laterite, a soft, deeply weathered mixture of oxide and hydroxide minerals and clays. Some metals may be leached by the weathering, but others - aluminum, iron and nickel - can stay behind as oxides or silicates. Laterites produce virtually all the world's aluminum ore and laterite nickel deposits are a significant source of the world's nickel.
A chute or trough for conveying pulp, water or powdered ore in a mill.
A general name for the molten rock ejected by volcanoes.
The design or pattern of the main roadways and workings. The proper layout of mine workings is the responsibility of the manager aided by the planning department.
Extractable by chemical solvents.
A chemical process for the extraction of valuable minerals from ore; also, a natural process by which ground waters dissolve minerals, thus leaving the rock with a smaller proportion of some of the minerals than it contained originally; see cyanidation
Generally used to describe a body of ore that is thick in the middle and tapers towards the ends.
A deposit having roughly the form of a double convex lens.
The horizontal openings on a working horizon in a mine; it is customary to work mines from a shaft, establishing levels at regular intervals, generally about 50 meters or more apart.
The use of borrowed money, also called "margin," to finance a corporation or a person's activities and trading. A mortgage, for example, is considered leverage.
There are many types of licenses, each of which dictates what can or cannot be done on a concession (see definition under C). For example, a company holding an oil exploration license cannot actually produce and market the oil until it has been switched to an exploitation or production license.
A soft, low-rank, brownish-black coal.
A bedded, sedimentary deposit consisting chiefly of calcium carbonate.
An order made by a client to a broker to buy or sell shares at a specified price or better.
A brown, hydrous iron oxide.
Straight clearings through the bush to permit sightings for geophysical and other surveys.
The character of a rock described in terms of its structure, color, mineral composition, grain size, and arrangement of its component parts; all those visible features that in the aggregate impart individuality of the rock. Lithology is the basis of correlation in coal mines and commonly is reliable over a distance of a few miles.
To place explosives in a drill hole. Also, to transfer broken material into a haulage device.
Transfer point at a shaft where bulk material is loaded by bin, hopper, and chute into a skip.
A mineral deposit in solid rock.
The process of recording geological observations of drill core either on paper or on computer disk.
The twice-daily bidding session held by five dealing companies to set the gold price. There are also daily London fixes to set the prices of other precious metals.
A major bidding market for base metals, which operates daily in London.
Securities owned outright or carried on margin.
2,240 lbs. avoirdupois (compared with a short ton, which is 2,000 lbs.).
Up to and including 660 volts by federal standards.
Igneous rocks composed mostly of dark, iron- and magnesium-rich minerals.
The molten material deep in the Earth from which rocks are formed.
An ore-forming process whereby valuable minerals are concentrated by settling out of a cooling magma.
A geophysical survey using a pair of magnetometers a fixed distance apart, to measure the difference in the magnetic field with height above the ground.
A process in which a magnetically susceptible mineral is separated from gangue minerals by applying a strong magnetic field; ores of iron are commonly treated in this way.
A geophysical survey that measures the intensity of the Earth's magnetic field.
A measure of the degree to which a rock is attracted to a magnet.
Black, magnetic iron ore, an iron oxide.
An instrument used to measure the magnetic attraction of underlying rocks.
A mechanical ventilator installed at the surface; operates by either exhausting or blowing to induce airflow through the mine roadways and workings.
A carrier of mine personnel, by rail or rubber tire, to and from the work area.
A safety hole constructed in the side of a gangway, tunnel, or slope in which miner can be safe from passing locomotives and car. Also called a refuge hole.
An entry used exclusively for personnel to travel form the shaft bottom or drift mouth to the working section; it is always on the intake air side in gassy mines. Also, a small passage at one side or both sides of a breast, used as a traveling way for the miner, and sometimes, as an airway, or chute, or both.
A form of claim-staking practised in some jurisdictions whereby claims are staked by drawing lines around the claim on claim maps at a government office.
A metamorphic rock derived from the recrystallization of limestone under intense heat and pressure.
Cash deposited with a broker as partial payment of the purchase price for any type of listed stock. The stock is held by the broker as security for the loan.
An orebody of minimal profitability.
The "worth" of a company's total shares outstanding, computed by multiplying the number of shares outstanding by the share price.
An order to buy or sell at the best price available. In absence of any specified price or limit, an order is considered to be "at the market".
A product of a smelter, containing metal and some sulfur, which must be refined further to obtain pure metal.
Measured Mineral Resource
A 'Measured Mineral Resource' is that part of a Mineral Resource for which quantity,
grade or quality, densities, shape, physical characteristics are so well established that they
can be estimated with confidence sufficient to allow the appropriate application of technical
and economic parameters, to support production planning and evaluation of the economic
viability of the deposit. The estimate is based on detailed and reliable exploration,
sampling and testing information gathered through appropriate techniques from locations
such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough to
confirm both geological and grade continuity.
A surveying term that establishes a line of reference. The bearing is used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line. Azimuths are angles measured clockwise from any meridian.
General classification for ore deposits formed at moderate depths (between 1 and 5 kilometers) and temperatures (between 200 and 300 degrees celsius). Usually occur in, or near to, igneous rocks, with mineralization present as replacement deposits or fracture filling.
Commonly-associated metals include gold, silver, copper, lead, and zinc.
The study of extracting metals from their ores.
Rocks which have undergone a change in texture or composition as the result of heat and/or pressure.
A pronounced change in the constitution of rock effected by pressure, heat, and water that results in a more compact and more highly crystalline condition.
Rock consisting of thin, alternating layers of granite and schist.
A plant in which ore is treated and metals are recovered or prepared for smelting; also a revolving drum used for the grinding of ores in preparation for treatment.
Ore that contains sufficient valuable mineral to be treated by milling process.
A measure of the voltage of an electric current, specifically, one-thousandth of a volt.
Ore reserves that are known to be extractable using a given mining plan.
The term employed to designate the operations involved in preparing a mine for ore extraction. These operations include tunneling, sinking, cross-cutting, drifting, and raising.
One who is engaged in the business or occupation of extracting ore, coal, precious substances, or other natural materials from the earth's crust.
An inorganic compound occurring naturally in the earth's crust, with a distinctive set of physical properties, and a definite chemical composition.
Any mass of host rock in which minerals of potential commercial value occur
A person qualified by education, training, and experience in mining engineering. A trained engineer with knowledge of the science, economics, and arts of mineral location, extraction, concentration and sale, and the administrative and financial problems of practical importance in connection with the profitable conduct of mining.
The complete or partial failure of a blasting charge to explode as planned.
Ore or rock that has been broken by blasting.
A representative piece of ore that is taken from a muck pile and then assayed to determine the grade of the pile.
A charge of high explosive fired in contact with the surface of a rock after being covered with a quantity of wet mud, wet earth, or sand, without any borehole being used. Also termed adobe, dobie, and sandblast (illegal in coal mining).
The international unit for measuring magnetic flux density.
A metal occurring in nature in pure form, uncombined with other elements.
Ventilation of a mine without the aid of fans or furnaces.
The number of acres the company actually owns, given its ownership percentage of the property. This term is in contrast to gross acres, the total number of acres that a company holds on a project.
A portion of the profit remaining after all charges, including taxes and bookkeeping charges, such as depreciation, have been deducted.
An interest in a mining property held by the vendor on the net revenue generated from the sale of metal produced by the mine
The difference between total assets and total liabilities.
Device at the end of the trailing cable of a mining machine used for connecting the trailing cable to the trolley wire and ground.
A coarse-grained igneous rock that is host to copper/nickel deposits in the Sudbury area of Ontario.
A small mass of precious metal, found free in nature.