A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | V | W
Snow and rain that have a low pH, caused by sulphur dioxide and nitric oxide gases from industrial activity released into the atmosphere.
Igneous rock carrying a high (greater than 65%) proportion of silica.
Acid mine drainage
Acidic run-off water from mine waste dumps and mill tailings ponds containing sulphide minerals. Also refers to ground water pumped to surface from mines.
An opening driven horizontally into the side of a mountain or hill for providing access to a mineral deposit.
An instrument used to measure magnetic field strength from an airplane.
A geophysical survey using a magnetometer aboard, or towed behind, an aircraft.
A breccia composed largely or entirely of fragments of volcanic rocks.
A method of concentrating valuable minerals based on their adhesion properties.
In metallurgy, the act or state of being stirred or shaken mechanically, sometimes accomplished by the introduction of compressed air.
A survey made from an aircraft to obtain photographs, or measure magnetic properties, radioactivity, etc.
A compound of two or more metals.
Relatively recent deposits of sedimentary material laid down in riverbeds, flood plains, and lakes or at the base of mountain slopes. (Adj. alluvial)
An instrument used to measure positively charged particles emitted by radioactive materials.
Any physical or chemical change in a rock or mineral subsequent to its formation. Milder and more localized than metamorphism.
A term applied to rocks or minerals that possess no definite crystal structure or form, such as amorphous carbon.
The gradual and systematic writing off of a balance in an account over an appropriate period.
A gneiss or schist largely made up of amphibole and plagioclase minerals.
A volcanic rock common in island arcs and mountain ranges.
Acronym for ammonium nitrate and fuel oil, a mixture used as a blasting agent in many mines.
The formal financial statements and report on operations issued by a corporation to its shareholders after its fiscal year-end.
A rectangular plate of metal cast in a shape suitable for refining by electrolytic process.
Any departure from the norm, which may indicate the presence of mineralization in the underlying bedrock.
A hard, black coal containing a high percentage of fixed carbon and a low percentage of volatile matter.
An arch or fold in layers of rock shaped like the crest of a wave.
The top or terminal edge of a vein on surface or its nearest point to the surface.
The inorganic residue remaining after ignition of coal.
A chemical test performed on a sample of ores or minerals to determine the amount of valuable metals contained.
Assay foot (metre, inch, centimetre)
The assay value multiplied by the number of feet, metres, inches, centimetres across which the sample is taken.
Plan view of an area indicating assay values and locations of all samples taken on the property.
The amount of work, specified by mining law, that must be performed each year in order to retain legal control of mining claims.
See capital stock.
The process of grinding ore in a rotating cylinder using large pieces of the ore instead of conventional steel balls or rods.
The ceiling or roof of an underground opening.
Waste material used to fill the void created by mining an ore body.
Normal amount of metal in soil or rock, where there is no presence of mineralization.
Rock chips collected from the roof or back of an underground opening for the purpose of determining grade.
A situation when the cash or spot price of a metal stands at a premium over the price of the metal for delivery at a forward date.
A formal statement of the financial position of a company on a particular day, normally presented to shareholders once a year.
A steel cylinder filled with steel balls into which crushed ore is fed. The ball mill is rotated, causing the balls to cascade and grind the ore.
Banded iron formation
A bedded deposit of iron minerals.
An extrusive volcanic rock composed primarily of plagioclase, pyroxene and some olivine.
Unsorted glacial debris at the base of the soil column where it comes into contact with the bedrock below.
The underlying or older rock mass. Often refers to rocks of Precambrian age, which may be covered, by younger rocks.
Centre of operations from which exploration activity is conducted.
Any non-precious metal (e.g. Copper, lead, zinc, nickel, etc.).
Igneous rocks that are relatively low silica
A large mass of igneous rocks extending to great depth with its upper portion dome-like in shape. Similar, smaller masses of igneous rocks are known as bosses or plugs.
A rock made up of hydrous aluminum oxides; the most common aluminum ore.
Term used to describe market conditions when share prices are declining.
The arrangement of sedimentary rocks in layers.
To concentrate or enrich; often applied to the preparation of iron ore for smelting.
A clay with great ability to absorb water and which swells accordingly.
An iron ore with a very low phosphorus content.
A process for recovering metals from low-grade ores by dissolving them in solution, the dissolution being aided by bacterial action.
A platy magnesium-iron mica, common in igneous rocks.
The cutting end of a drill frequently made of an extremely hard material such as industrial diamonds or tungsten carbide.
A miner's term for sphalerite (zinc sulphide).
Volcanic vent found in areas of active ocean floor spreading, through which sulphide-laden fluids escape.
A mine employee responsible for loading, priming and detonating blast holes.
A reaction vessel in which mixed charges of oxide ores, fluxes and fuels are blown with a continuous blast of hot air and oxygen-enriched air for the chemical reduction of metals to their metallic state.
A drill hole in a mine that is filled with explosives in order to blast loose a quantity of rock.
A crude form of copper (assaying about 99%) produced in a smelter, which requires further refining before being used for industrial purposes.
An expensive method of mining in which large blocks of ore is undercut, causing the ore to break or cave under its own weight.
One hundred shares.
An agreement to pay a certain amount of interest over a given period of time.
A telescoping, hydraulically powered steel arm on which drifters, man baskets and hydraulic hammers are mounted.
A short raise or opening driven above a drift for the purpose of drawing ore from a stope, or to permit access.
Loosely used to describe a large-scale regional shear zone or structural fault.
A working face in a mine usually restricted to a slope.
A rock in which angular fragments are surrounded by a mass of fine-grained minerals.
The ore in a mine which has been broken by blasting but which has not yet been transported to surface.
A pocket compass equipped with sights and a reflector, used for sighting lines, measuring dip and carrying out preliminary surveys.
A large-scale, mechanized method of mining involving many thousands of tonnes of ore being brought to surface per day
A large sample of mineralized rock, frequently hundreds of tonnes, selected in such a manner as to be representative of the potential ore body being sampled. Used to determine metallurgical characteristics.
Metal formed into bars or ingots.
Term used to describe financial market conditions when share prices are going up.
A prospector's term for white, coarse-grained, barren quartz.
A secondary metal or mineral product recovered in the milling process.
A steel cable, capable of withstanding tens of tonnes, cemented into a drill hole to lend support in blocky ground.
The conveyance used to transport men and equipment between the surface and the mine levels.
Calcium carbonate, a mineral often introduced by mineralizing solutions.
A financial term used to describe the value financial markets put on a company. Determined by multiplying the number of outstanding shares of a company by the current stock price.
A group of minerals, all containing the carbonate radical (CO3), common in veins and in altered rocks.
A sample composed of pieces of vein or mineral deposit that have been cut out of a small trench or channel, usually about 10 cm wide and 2 cm deep.
A method of sampling a rock exposure whereby a regular series of small chips of rock is broken off along a line across the face.
A vermillion-colored ore mineral of mercury.
The term applied to the timbering or concrete around the mouth of a shaft; also used to describe the top of a drill hole.
A material produced in metallurgical processes, containing the greater part of the valuable mineral in an ore.
A geological term used to describe the line or plane along which two different rock formations meet.
Metamorphism of country rocks adjacent to an intrusion, caused by heat from the intrusion.
The long cylindrical piece of rock, about an inch in diameter, brought to surface by diamond drilling.
That part of a string of tools in a diamond drill hole in which the core specimen is collected.
Loosely used to describe the general mass of rock adjacent to an ore body or to a body of intrusive rock.
The outermost layer of the Earth; includes both continental and oceanic crust.
Applies to assays that have been reduced to some arbitrary maximum to prevent erratic high values from inflating the average.
A method of extracting exposed gold or silver grains from crushed or ground ore by dissolving it in a weak cyanide solution. May be carried out in tanks inside a mill or in heaps of ore out of doors.
A chemical species containing carbon and nitrogen used to dissolve gold and silver from ore.
A volcanic rock similar to andesite, but normally containing more quartz.
An order to buy or sell shares good only on the day the order was entered.
Method of raising capital whereby a company borrows money from a lending institution.
Underground work carried out for the purpose of opening up a mineral deposit. Includes shaft sinking, crosscutting, drifting and raising.
Drilling that establishes accurate estimates of mineral reserves.
A rotary type of rock drill that cuts a core of rock that is recovered in long cylindrical sections, two centimeters or more in diameter.
Rock that is, by necessity, removed along with the ore in the mining process, subsequently lowering the grade of the ore.
Dilution (of shares)
A decrease in the value of a company's shares caused by the issue of treasury shares.
The angle at which a vein, structure or rock bed is inclined from the horizontal as measured at right angles to the strike, also, the angle at which a drill hole is inclined, measured from the horizontal.
Ore carrying small particles of valuable minerals spread more or less uniformly through the host rock.
Indicated reserves- The size and quality of a potential ore body as suggested by widely spaced drill holes, more work is required before reserves can be classified as probable or proven.
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 long and relatively thin body of igneous rock that, while in the molten state, intruded a fissure in older rocks.
A geophysical survey employing the generation of electromagnetic waves at the earth’s surface. These waves penetrate the earth and impinge on a conducting ore body, which in turn produce induced currents, which can be detected by instruments at the surface.
Ore bodies formed by hydrothermal fluids and gases that were introduced into host rocks from elsewhere, filling cavities in the host rock.
The provision of funds by buying shares.
The breaking down and subsequent removal of either rock or surface material by wind, rain, wave action, freezing and thawing and other processes.
Prospecting, sampling, mapping, diamond drilling, and other work involved in searching for ore.
A break in the Earth's crust caused by tectonic forces, which have moved the rock on one side with respect to the other.
Term used to describe light-colored rocks containing feldspar, feldspathoids and silica.
A pattern of drill holes along a line.
Fineness is the proportion of pure gold or silver in jewellery or bullion expressed in parts per thousand. Thus, 925 fine gold indicates 925 parts out of 1,000, or 92.5% is pure gold.
An extensive crack, breaks, or fractures in the rocks.
Pieces of rock that have been broken off and moved from their original location by natural forces such as frost or glacial action.
A milling process in which valuable mineral particles are induced to become attached to bubbles and float, and others sink.
Shares in an exploration company that allows the tax deduction or credits for mineral exploration to be passed to the investor.
Any bending or wrinkling of rock strata.
The rock on the underside of a vein or ore structure.
A break in the rock, the opening of which allows mineral-bearing solutions to enter. A "cross-fracture" is a minor break extending at more-or-less right angles to the direction of the principal fractures.
Ores of gold or silver from which the precious metals can be recovered by concentration methods without resort to pressure leaching or other chemical treatment.
Lead sulphide, the most common ore mineral of lead.
The worthless minerals in an ore deposit.
Geochemical, geochemistry, geochemical anomaly
A concentration of one or more elements in rock, soil, sediment, vegetation or water markedly different from the normal concentration in the surroundings. A survey involving the chemical analysis of systematically collected samples of rocks, soil, plants or water. A prospecting method, which seeks to locate mineral, deposits by the detection, in the overlying soil, of very small quantities or traces of the metals concerned.
The science of the earth with respect to its structure, composition and development. Relating to the physics of the earth, such as magnetism, electrical conductivity, gravity and seismic. Prospecting for minerals, mineral fuels or the nature of earth materials by measuring the various physical properties of the rocks and interpreting the results in terms of geologic feature or the economic deposits sought. Physical measurements are taken at the surface of differences in electrical resistance or magnetic properties of the rocks.
A small open pit or surface excavation from which high grade ore has been mined.
The rust-colored capping or staining of a mineral deposit, generally formed by the oxidation or alteration of iron sulphides.
A sample from a rock outcrop that is assayed to determine if valuable elements are contained in the rock. A grab sample is not intended to be representative of the deposit, and usually the best-looking material is selected.
A coarse-grained intrusive igneous rock consisting of quartz, feldspar and mica.
Financing furnished to a prospector in return for an interest in any discoveries made.
The rock on the upper side of a vein or ore deposit.
The average grade of ore fed into a mill or metallurgical process.
Rich ore. As a verb, selective mining of the best ore in a deposit or theft of ore from a mine.
The rock surrounding an ore deposit or intrusion.
Relating to hot fluids circulating in the Earth's crust.
Rocks formed by the solidification of molten material from far below the Earth's surface.
Induced polarization (IP)
When an electric current passing into the earth through ground electrodes is suddenly interrupted, a potential can be measured between these or nearby electrodes for some time after the current stops. This potential can leave a charge in conductive particles such as disseminated sulphides, which act as condensers and who decay of retained electrical charges can be measured by instruments on the surface. All sulphides, with the exception of the zinc mineral sphalerite, can be detected by IP. Graphite, which is a strong conductor, can also give an IP anomaly.
Pension funds and mutual funds managing money for a large number of individual investors.
A body of igneous rock formed by the consolidation of magma intruded into other rocks, in contrast to lava, which are extruded upon the surface.
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.
A variety of peridotite; the most common host rock of diamonds.
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.
A mineral deposit in solid rock, as distinguished from a placer.
To examine drill core and record observations.
Low mag response
Refers to magnetic intensity, usually measured in units called “gammas” or under metric terms as “nano-teslas”. A low magnetic response refers to the strength of the measurable magnetism. A “low” means there is a lack of magnetic minerals, such as would be found in rocks having been altered by hydrothermal fluids, wherein the magnetic minerals have lost their magnetism. A high mag response would indicate that little or no alteration has taken place and the original magnetic minerals still retain their original intensity. Areas of low mag response could indicate the presence of host rocks favourable to ore deposition. Butte is an area of low mag response, which harbors ore mineralization.
The molten material deep in the Earth from which rocks are formed.
A geophysical prospecting method, which maps variations in the magnetic field of the earth, which are attributable to, changes of magnetic susceptibility in near surface rocks or their contained mineralization. Only two minerals are strongly magnetic, magnetite, an iron oxide and pyrrhotite, an iron sulphide, which is commonly associated with nickel and platinum group
An iron sulphide mineral, a low-temperature relative of pyrite.
Ore reserves that are known to be extractable using a given mining plan.
Mobile Metal Ions Process (MMI)
The MMI is a new type of geochemical survey that measures concentrations of metals in soils, directly above the mineralized zones. The results are quoted as being so many times above “normal”. Normal content is considered to be the average or expected amount of metal in a soil sample when mineralization is absent.
A metal occurring in nature in pure form, uncombined with other elements.
Net profit interest
A portion of the profit remaining after all charges, including taxes and bookkeeping charges (such as depreciation) have been deducted.
Net smelter return
A share of the net revenues generated from the sale of metal produced by a mine.
A small mass of precious metal, found free in nature.
A mine that is entirely on surface. Also referred to as open-cut or open cast mine.
An agreement to purchase a property reached between the property vendor and some other party who wishes to explore the property further.
A mixture of valuable minerals and gangue from which at least one of the metals can be extracted at a profit.
The calculated tonnage and grade of mineralization which can be extracted profitably; classified as possible, probable and proven according to the level of confidence that can be placed in the data.
The portion, or length, of a vein or other structure, that carries sufficient valuable mineral to be extracted profitably.
An exposure of rock or mineral deposit that can be seen on surface, i.e. that is not covered by soil or water.
A chemical reaction caused by exposure to oxygen that results in a change in the chemical composition of a mineral.
To wash gravel, sand or crushed rock samples in order to isolate gold or other valuable metals by their higher density.
A company's interest in a mine, which entitles it to a certain percentage of profits in return for putting up an equal percentage of the capital cost of the project.
- Unusually high-grade strips in a placer mineral deposit.
- A deposit of valuable minerals, in particular gold in alluvial sand or gravel.
- A small body of intrusive rock, typically cylindrical or pipe-like in shape. Often a remnant "feeder" for a volcano.
The vertical angle a linear geological feature makes with the horizontal plane.
Refers to rocks of igneous origin that have come from great depth.
Any igneous rock in which relatively large crystals, called phenocrysts, are set in a fine-grained ground mass.
A deposit of disseminated copper minerals in or around a large body of intrusive rock. Commonly also contains gold, molybdenum, or tungsten.
Valuable mineralization not sampled enough to accurately estimate its tonnage and grade, or even verify its existence. Also called "inferred resources."
Valuable minerals deposited during the original period or periods of mineralization as opposed to those deposited as a result of alteration or weathering.
The sale of shares to individuals or corporations outside the normal market at a negotiated price. Often used to raise capital for a junior exploration company.
Valuable mineralization not sampled enough to accurately estimate the terms of tonnage and grade. Also called "indicated resources."
A mining property, the value of which has not been determined by exploration.
A document filed with the appropriate securities commission detailing the activities and financial condition of a company seeking funds from the public by issuing shares in the company.
Mineralization that has been sampled extensively by closely spaced diamond drill holes in enough detail to give an accurate estimation of grade and tonnage. Also called "measured resources."
Pulverized or ground ore in a solution.
A yellow iron sulphide mineral, normally of little value. It is sometimes referred to as "fool's gold".
A bronzed-colored, magnetic iron sulphide mineral, a high- temperature relative of pyrite.
Common rock-forming mineral consisting of silicon and oxygen.
A preliminary survey of ground.
The percentage of valuable metal in the ore that is recovered by metallurgical treatment.
Ore that resists the action of chemical reagents in the normal treatment processes and which may require pressure leaching or other means to affect the full recovery of the valuable minerals.
In assaying, crushed or ground material in excess of what is needed for assaying; usually stored or returned to the client.
Ore formed by a process during which certain minerals have passed into solution and have been carried away, while valuable minerals from the solution have been deposited in the place of those removed.
The calculated amount of material that can be mined from a mineral deposit, based on dense drilling and sampling and on technical assessments of minability
The calculated amount of material in a mineral deposit, based on limited drill information. A less precise figure than a "reserve," giving no assurance that all the material is minable.
Refers to the nature of alteration that has come as a consequence of hydrothermal solutions. The composition of certain pre-existing minerals is chemically and physically changed from what they were originally. Ability to identify various types of alteration can be useful in determining sequences of events related to ore formation.
A fine-grained, extrusive igneous rock, which has the same chemical composition as granite.
An amount of money paid at regular intervals by the lessee or operator of an exploration or mining property to the owner of the ground. Generally based on a certain amount per ton or a percentage of the total production or profits. Also, the fee paid for the right to use a patented process.
The act of introducing metals or minerals into a deposit or samples, resulting in false assays- done either by accident or with the intent of defrauding the public.
A small portion of rock or a mineral deposit, taken so that the metal content can be determined by assaying.
Selecting a fractional but representative part of a mineral deposit for analysis.
An instrument used to detect and measure radioactivity by detecting gamma rays; also called a "scintillometer."
Enrichment of a vein or mineral deposit by minerals that have been taken into solution from one part of the vein or adjacent rocks and redeposited into another.
Secondary rocks formed from material derived from other rocks and laid down under water. Examples are limestone, shale and sandstone.
Shear or shearing
The deformation of rocks by lateral movement along innumerable parallel planes, generally resulting from pressure and producing such metamorphic structures as cleavage and schistosity. - A zone in which shearing has occurred on a large scale.
Shear zone Shoot
A concentration of mineral values; that part of a vein or zone carrying values of ore grade.
Silicon dioxide. (Quartz is a common example).
A rock containing an abundance of quartz.
Name for the metamorphic rocks surrounding an igneous intrusive where it comes in contact with a limestone or dolostone formation.
Rock cuttings from a diamond drill hole, sometimes used for assaying.
A chemical used in the mill of gold ores to dissolve gold and silver.
A zinc sulphide mineral; the most common ore mineral of zinc.
To divide a sample into portions, taking care that the portions, whether equal or unequal, are identical in composition.
Holes drilled to intersect a mineralization horizon or structure along strike or down dip.
Strictly, the description of bedded rock sequences; used loosely, the sequence of bedded rocks in a particular area.
The direction, or bearing from true north, of a vein or rock formation measured on a horizontal surface.
A narrow vein or irregular filament of a mineral or minerals traversing a rock mass.
To remove the overburden or waste rock overlying an ore body in preparation for mining by open pit methods.
An excavation from which ore has been excavated as a series of steps. The outlines of the ore body determine the outlines of the stope. A chamber or room from which ore has been extracted.
The ratio of tonnes removed as waste relative to the number of tonnes or ore removed from an open pit mine.
A compound of sulphur and some other element.
A down-arching fold in bedded rocks.
Waste material from a metallurgical process after the recoverable minerals have been extracted.
The direction, in the horizontal plane, of a linear geological feature (for example, an ore zone), measured from true north.
Rock composed of fine volcanic ash.
A fissure, fault or crack in a rock filled by minerals that have travelled upwards from some deep source.
Very long frequency (VLP)
Nuclear powered submarines use very long frequency transmissions as a means of underwater navigation. These frequencies are transmitted from a number of stations around the earth and they have the property of being able to penetrate directly through the earth in a straight line. When a conductive ore body is in line with these transmissions, an induced current is set up within this ore body so as to generate a separate electromagnetic field, which can be detected by an instrument on the surface.
Native gold, which is discernable, in a hand specimen, to the unaided eye.
Igneous rocks formed from magma that has flowed out or has been violently ejected from a volcano.
A small cavity in a rock, frequently lined with well-formed crystals.
Rock units on either side or an ore body. The hangingwall and footwall rocks of an ore body.
Unmineralized rock, or sometimes mineralized rock that is not minable at a profit.
The liquid resources a company has to meet day-to-day expenses of operation; defined as the excess of current assets over current liabilities.