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Glossary of Mining Terms

a b c d e f g h i j k l m n o p q r s t u v w x y z

A

  • Abutment - A coal mining term to describe the weight of the rocks above a narrow roadway transfering to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway.
  • Angle of dip - The angle at which strata or mineral deposits are inclined to the horizontal plane.
  • Anorthosite - A plutonic rock composed almost entirely of plagioclase, which is usually labradorite.
  • Anticline - An upward fold or arch of rock strata
  • Antiform - An anticline-like structure.
  • API - Gravity of crude oil or other liquid hydrocarbons measured by a system developed by the American Petroleum Institute
  • Aquifer - A water-bearing bed of porous rock, often sandstone.
  • Archean - The oldest rocks of the Precambrian era, older than about 2,500 million years.
  • Auger - A rotary drill used in coal mining that uses a screw device to penetrate, break, and then transport the drilled material
  • Azimuth - A surveying term that references the angle measured clockwise from any meridian

B

  • Backfill – Mine waste or rock used to support the roof after coal removal.
  • Barrel - A unit of measure for crude oil and oil products equal to 42 U.S. Gallons (aroud 160 litres)
  • Basalt - A dark, fine grained extrusive igneous rock, composed of feldspar and iron and magnesium rich minerals.
  • Base metal - A non-precious metal.
  • Batholith - A large, domed, intrusive igneous body.
  • Bearing plate - A plate used to distribute a given load. In roof bolting, the plate used between the bolt head and the roof.
  • Beneficiation - The treatment of mined material, making it more concentrated or richer.
  • Bit - The hardened and strengthened device at the end of a drill rod that transmits the energy of breakage to the rock. The size of the bit determines the size of the hole. A bit may be either detachable from or integral with its supporting drill rod.
  • Biotite - A dark brown to green, magnesium-iron mica commonly found in igneous and metamorphic rocks.
  • Blasting cap - A detonator containing a charge of detonating compound, which is ignited by electric current or the spark of a fuse. Used for detonating explosives.
  • Borehole - Any deep or long drill-hole, usually associated with a diamond drill.

C

  • Cambrian - The oldest of the systems into which the Paleozoic stratified rocks are divided.
  • Chalcopyrite - An ore of copper (CuFeS2)
  • Chrome Spinel - Another name for the mineral picotite, a member of the spinel group.
  • Clinopyroxene - Pyroxene group mineral common in mafic rocks, with a monoclinic crystal form.
  • Coke – A hard, dry carbon substance produced by heating coal to a very high temperature in the absence of air.
  • Collar - The term applied to the timbering or concrete around the mouth or top of a shaft. The beginning point of a shaft or drill hole at the surface.
  • Comminution - The breaking, crushing, or grinding of coal, ore, or rock.
  • Concentrate - The concentrated mineral product resulting from preliminary processing.
  • Conformable - The relationship of stratigraphic units, emplaced in an uninterrupted succession.
  • Cordierite - A silicate of magnesium and aluminum, Mg2Al3(AlSi5O18), found as an accessory mineral in granite, gneiss (cordierite gneiss), schists, and in contact metamorphic zones.
  • Costean - A trench cut across the conjectured line of outcrop of a seam or ore body to expose the full width.

D

  • Dextral - Lateral movement on a fault whereby the far side block moves to the right, relative to the near side.
  • Diamonddrilling - Method of obtaining cylindrical core of rock by drilling with a diamond set or diamond impregnated bit.
  • Dip - The angle at which a stratum is inclined from the horizontal.
  • Dyke - A tabular body of intrusive igneous rock, crosscutting the host strata at an oblique angle.

E

  • Electrowinning - Recovery of a metal from an ore by means of electrochemical processes.

F

  • Fabric - The spatial and geometrical configuration of all those components that make up a deformed rock.
  • Fault - A fracture in a rock along which there has been relative movement either vertically or horizontally.
  • Feasibility Study - A study undertaken to determine the economic viability of a mineral deposit.
  • Felsic - Light coloured igneous rocks containing an abundance of feldspars, feldspathoids and silica.
  • Ferrogabbro - A gabbro in which the pyroxene or olivine minerals, or both, are exceptionally high in iron.
  • Ferromagnesian minerals - Minerals containing iron and magnesium, usually in the form of amphibole, pyroxene, biotite and olivine.
  • Flotation - The method of mineral separation in which a froth, created in water by a variety of reagents, floats some finely crushed minerals, whereas other minerals sink.
  • Fractionated - The progressive crystallisation of successive minerals from a silicate magma in response to falling temperature.

G

  • Gabbro - A coarse grained intrusive rock, which is low in silica and has relatively high levels of iron and magnesium minerals.
  • Gangue - Undesired minerals associated with ore, mostly nonmetallic.
  • Garnet - A brown-red silicate mineral.
  • Geochronology - The study of time in relationship to the history of the earth, or a system of dating developed for this purpose.
  • Geotechnical - Rock quality and structural investigations of rock masses.
  • Goethite - A hydrous oxide of iron.
  • Gossan - A ferruginous deposit remaining after the oxidation of the original sulphide minerals in a vein or ore zone.
  • Granitoid - A field term for a coarse grained felsic igneous rock, resembling granite.
  • Granulite Facies - A mineral and textural assemblage formed by very high temperatures and pressures during regional metamorphism.
  • Granulites - Metamorphic rocks formed by high temperature and/or pressure metamorphism.

H

  • Harzburgite - A variety of peridotite that consists essentially of olivine and enstatite or bronzite.
  • Hornblende - A rock forming amphibole group mineral which forms part of the mafic component of igneous rocks.
  • Hydrotherma - Pertaining to hot aqueous solutions, usually of magmatic origin, which may transport metals and minerals in solution.

I

  • Indicated Resources - In situ mineral resource calculated with a moderate confidence level to which economic parameters have not been applied.
  • Inferred Resources - In situ mineral resource calculated with a low confidence level to which economic parameters have not been applied.
  • (IP) Induced Polarisation - Electrical geophysical field technique, commonly used to detect disseminated mineralisation or alteration within a rock mass.
  • Inverse Distance Squared - A grade estimation technique in which the influence of assays is determined by the inverse of the square of the distance away from the point being estimated.
  • Iron Induration - Cemented by secondary (reprecipitated) iron oxides.

K

  • Komatiite - Magnesium-rich mafic to ultramafic extrusive rock.

L

  • Laccolith - A concordant intrusive body that has domed up the overlying rocks.
  • Leucocratic- A light coloured rock containing a low proportion (generally less than 30%) of dark ferromagnesian minerals.
  • Limonite - Hydrous oxide of iron, FeO(OH)-nH2O.

M

  • Mafic - Descriptive of igneous rocks composed dominantly of magnesium and iron rockforming silicates.
  • Magmatic - Related to bodies of molten rock within the earth.
  • Magnetic - Of or pertaining to a mineral, object, area or locale possessing the properties of a magnet.
  • Massive sulphides - Rock containing abundant sulphides that can form close to 100% of the mass.
  • Matte - A metallic sulphide mixture made by melting the roasted product in smelting sulphide ores of copper, lead and nickel.
  • Metallogenic - A group of metal ores which are peculiar to a particular area.
  • Metallurgy - The science of separating metals from their ores and preparing them for use, as by concentration, smelting and refining.
  • Metamorphic - Rocks which have been modified in composition or texture by heat and/or pressure.
  • Metasediment - A partly metamorphosed sedimentary rock.
  • Mobile Zone - An elongate belt in the earth's crust within which major deformation, igneous activity and metamorphism has occurred.
  • Monzonite - A granular plutonic rock containing approximately equal amounts of orthoclase and plagioclase and thus, intermediate between syenite and diorite.

N

  • Norite - A coarse grained igneous rock of basic composition consisting essentially of plagioclase (near labradorite in composition) and orthopyroxene.

O

  • Olivine - A magnesium-iron silicate occurring in mafic and ultramafic rocks.
  • Orthopyroxene - Any of several pyroxene minerals that crystallize in the orthorhombic system.

P

  • Paragneiss - A gneiss formed from a sedimentary rock by the intermediary action of an igneous magma to such an extent that a virtually new rock is formed.
  • Para-Migmatite - Lithology formed by partial melting of an igneous rock.
  • Pentlandite - A common sulphide ore of nickel, FeNiS.
  • Peridotite - A general term for intrusive ultramafic igneous rocks dominantly consisting of olivine and lacking feldspar.
  • Platinoid - A precious metal which belongs to the platinum group.
  • Plunge - The attitude of a line in a plane which is used to define the orientation of fold hinges, mineralised zones and other structures.
  • Pluton - A body of igneous rock that has formed beneath the surface of the earth by the consolidation of magma.
  • Pre-feasibility Study - An intermediate study to determine the likely economic viability of a project.
  • Proterozoic - An era of geological time spanning the period from 2,500 million years to 570 million years before present.
  • Pyrrhotite - A sulphide mineral of iron, FeS.

R

  • Rock Chip Sampling - The collection of representative samples of rock fragments within a limited area.

S

  • Shearing - The deformation and dislocation of rocks, primarily by ductile means, in response to applied stresses.
  • Sill - A sheet of igneous rock which is flat-lying or has intruded parallel to strata.
  • Sillimanite - A silicate of aluminium, Al2 SiO5, common in aluminous rocks of high metamorphic grade.
  • Soil Geochemistry - The determination of relative or absolute abundances of elements in soil.
  • Specific Gravity - The weight of a substance compared with the weight of an equal volume of pure water at 4°C.
  • Standard Deviation - A measure of accuracy or precision, calculated as the square root of the variance.
  • Strike Length - The horizontal distance along the long axis of a structural surface, rock unit, `mineral deposit or geochemical anomaly.
  • Strike Slip Fault - A fault in which the net slip is practically in the direction of the fault strike.
  • Supergene - Mineral enrichment produced by the chemical remobilisation of metals in an oxidised or transitional environment.

T

  • Tholeiitic Basalt- A term applied to basic or ultrabasic rocks composed predominantly of magnesium rich feldspar and pyroxene minerals.
  • Titaniferous Ilmenite - An oxide of iron and titanium, with a high relative abundance of the latter element.
  • Tonalite - A coarse grained granitic rock composed of quartz, sodium-calcium feldspar and a high proportion of iron-rich minerals.
  • Transient Electromagnetic (TEM) - A geophysical technique whereby transmitted electromagnetic fields are used to energise and detect conductive material beneath the earth's surface.
  • Troctolite - A variety of gabbro consisting essentially of labradorite and olivine with little or no pyroxene.

U

  • Ultramafic - Igneous rock consisting essentially of ferromagnesian minerals with trace quartz and feldspar.
  • Upper cut -The value, in a population of assays, to which higher values are reduced.

V

  • Violarite - A common sulphide ore of nickel, (Fe,Ni)3S4.

Links to Other Mining Glossaries