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MASTER GLOSSARY
AAS
Atomic Absorption Spectrometry, a method of analysis.
Acid digestion
Refers to an assay technique in which the sample is dissolved in strong
acid prior to analysis of its metal content.
Acid
Adamellite
Can be used as a general description of rock mineralogy and chemistry
– similar to felsic.
An intrusive igneous rock.
Adit
A horizontal opening into a mine, started from a hillside.
Aeromagnetic
Refers to measurement of magnetic qualities of rocks using a
aeroplane-mounted instrument.
Agglomerate
A rock composed of coarse angular fragments usually of volcanic origin.
Airleg
A hand held compressed air operated rock drill. When used in
conjunction with mining method terms, refers to that type of mining
using air leg equipment.
Airleg stoping
Method of breaking ore using a hand-held rockdrill.
Albite
A variety of plagioclase (felspar).
Alluvial, alluvium
Usually unconsolidated, transported sediment.
Alluvial gold
Gold transported and deposited by river action, and mined from the river
sediments.
Altered, alteration
Referring to physical or chemical change in a rock or mineral
subsequent to its formation.
Alunite
A hydrated sulphate of aluminium and potassium.
Amalgamation
A process of gold recovery in which finely divided ore is passed over
mercury to form a gold amalgam.
Amphibolite
A rock of medium metamorphic grade rich in the iron and magnesium
silicate minerals called amphibole.
Amygdaloidal
Volcanic rock containing cavities formed from gases in the lavas.
Andesite
A volcanic rock of intermediate chemical composition.
Anhydrite
Calcium sulphate.
Ankerite
A calcium magnesium iron carbonate mineral.
Anomaly
Zone or point in the soil or underlying rock determined by exploration
methods to be different from its general surroundings.
Anticline, antiformal
A part of a fold system forming an arch i.e. convex upwards.
Antimony
A metallic element, often a pathfinder element for gold.
Aranaceous
Describes detrital sedimentary rocks, particularly sandstones, with a
particle size from 1/16 mm to 2 mm.
Archaean
A geological time era, older than 2400 million years.
Arenites
Sandstone like sedimentary rocks.
Argillic (alteration)
Refers to the conversion of pre-existing minerals to clay minerals (see
hydrothermal alteration).
Argillite
Sedimentary rock with a sandy texture.
Arkose
A sandstone dominated by grains of feldspar.
Arsenopyrite
An arsenic iron sulphide mineral.
Assay
Test to determine the content of various chemical elements in a sample.
Assymetric fold
A fold in which the axial plane is inclined.
Auger drilling
An exploration drill which recovers samples using a screw-like action.
Aureole
Zone around body of intrusive rock where country rocks have been
altered by heating.
Auriferous
Gold bearing.
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Autogenous Mill
A mill in which the rock is broken by the interaction of fragments of that
rock; no external media is used.
Autunite
Hydrous phosphate of uranium and calcium mineral.
Axial plane
A plane which intersects a fold such that both sides of the fold are more
or less symmetrical with reference to the plane.
Axial trace
Projection of the fold axis to the surface.
Azurite
Copper carbonate mineral.
Backfill
Material used to fill mined-out stope voids.
Bacterial leaching
See bio oxidation
Ball Mill
A rotating cylindrical mill using iron balls to reduce broken ore to powder
to assist the release of constituent minerals.
Banded Iron Formation
("bif")
A chemical sediment with alternating iron rich and silica rich layers.
Basalt
A fine-grained basic volcanic rock.
Base Metal
Non precious metal, usually refers to copper, lead, zinc.
Basement
Generally refers to the older cratonic rocks below the sedimentary
basins.
Basic
Used to describe igneous rocks of low silica content (usually 45-55%
SiO2) whose dominant mineral constituents are iron and magnesium
silicates. See also mafic.
Batholith
A large, generally discordant plutonic mass that has more than 40sq mi
of surface exposure and no know floor.
Batter & berms
Technical terms for the components of a final pit wall. The slope batters
are typically 10-20m high vertically and have slopes between 40o and
70o. The horizontal berms between the batters are typically 5-10m wide.
Bed
Refers to a layer of sedimentary rock.
Bedding
A surface in sedimentary or volcanic rocks that was a depositional
surface when the sediments or volcanics were deposited.
Bedding plane fault
A fault along a surface parallel to the surface of deposition.
Bedrock
General term for the solid rock. underlying superficial weathered rock or
soil.
Bentonite
A clay mineral used for its swelling quality.
Bi-modal
Two distinct populations in one group.
Bio-oxidation (Bacterial
oxidation)
A process utilising thiobacillus ferroxidans or similar bacteria to oxidise
pyritic sulphides in acidic conditions.
Blind
Refers to an orebody that has no surface expression.
Blindboring
Drilling of a shaft from the top down.
Block model
The term applied to the final output of a computer-based process to
reflect the likely configuration of the mineralisation and the surrounding
material.
Bond work index
Result of a standard grinding work energy test, developed by Mr F C
Bond, usually expressed in kW-hours/tonne.
Bornite
Copper-iron sulphide mineral.
Bottle roll cyanide
leaching
A metallurgical test involving the mixing of a reagent (cyanide) with
water and a selected portion of ore, and agitating the mixture within a
bottle placed on rollers.
Boxworks
Refers to the texture of iron oxides residual from weathering of
sulphides.
Breakaway
A geomorphological term to describe an erosional cliff-like feature
typical of the West Australian interior.
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Breakeven grade
The estimated lowest grade of ore that can be mined and treated
profitably in a mining operation.
Breccia
A rock composed of angular fragments of rock embedded in a matrix.
Brecciated
Describes rocks which have been broken into angular fragments by
sedimentary or igneous action.
Bulk Cyanide Leach
(BCL)
An analytical method for gold geochemical samples
Bulk density
The in situ mass of a unit volume of material, normally expressed as
tonnes per cubic metre.
Bulk leach extractable
gold (BLEG) sampling
Geochemical technique in which samples are analysed for the amount
of gold extractable in cyanide solution.
Bulk mineable
Refers to orebodies that can be mined using large-scale mining
equipment.
Bulk sampling
Large scale sampling of rock or soil aimed at obtaining the most reliable
analytical result.
Cable bolting
A means of supporting a rock mass by grouting steel cables in drilled
holes.
Calcareous
Containing calcium carbonate minerals.
Calcine
The product of roasting sulphide concentrates.
Calcrete
A superficial rock containing a high proportion of calcium and/or
magnesium carbonate and formed by weathering of calcareous
bedrock.
Cambrian
A geological time period from 530 to 460 million years ago.
Carat
A unit of weight for diamonds and other gems. The metric carat or
international carat (“ct” ) equals 0.2 grams or 200 milligrams.
Carbonaceous
Term given to a rock containing carbon.
Carbonaceous
mudstone or shale
A fine grained, dark coloured sedimentary rock containing organic
material.
Carbonate
Minerals containing calcium and/or magnesium carbonate.
Carboniferous
A geological time period from 345 to 285 million years ago.
Carbon-in-leach (CIL)
A process of recovering gold from ores by crushing, grinding, leaching
with cyanide and adsorption on to activated carbon. Carbon is added to
the leaching tanks.
Carbon-in-pulp (CIP)
A process of recovering gold from ores by crushing, grinding, leaching
with cyanide and absorption on to activated carbon. Carbon is not
added to the leaching tanks.
Cassiterite
A tin oxide mineral.
Cathode
The negatively charged component of an electrowinning cell, where
valuable metals are deposited.
Chalcedony
An extremely fine-grained form of silica.
Chalcocite
A copper sulphide mineral, usually found in enriched zones.
Chalcopyrite
A copper iron sulphide mineral
Channel sampling
Chip samples taken in a representative channel across the
mineralisation.
Chert
A cryptocrystalline siliceous rock usually of sedimentary origin.
Chlorite
A green platey iron-magnesium rich silicate mineral.
Chromite
A chromium oxide mineral.
Cleavage
A preferred plane of breakage in a rock caused by the alignment of
micaceous minerals.
Coffinite
A uranium silicate mineral.
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Colluvial
Refers to broken rock, usually around hills or mountains that moves
downslope mainly under the influence of gravity.
Column leach tests
A metallurgical test involving the leaching of ore in a cylinder.
Competent Person
Defined in the 2004 JORC Code as a a person who is a Member or
Fellow of The Australasian Institute of Mining and Metallurgy, or of the
Australian Institute of Geoscientists, or of a ‘Recognised Overseas
Professional Organisation’ (‘ROPO’) included in a list promulgated from
time to time. A ‘Competent Person’ must have a minimum of five years
experience which is relevant to the style of mineralisation and type of
deposit under consideration and to the activity which that person is
undertaking. If the Competent Person is preparing a report on
Exploration Results, the relevant experience must be in exploration. If
the Competent Person is estimating, or supervising the estimation of
Mineral Resources, the relevant experience must be in the estimation,
assessment and evaluation of Mineral Resources. If the Competent
Person is estimating, or supervising the estimation of Ore Reserves, the
relevant experience must be in the estimation, assessment, evaluation
and economic extraction of Ore Reserves.
Co-magmatic
Formed during the same igneous event.
Concentrates
The product of a treatment plant in which the abundance of specific
mineral species is higher than in the ore.
Conductors
Geological structures or units able to conduct induced electromagnetic
currents.
Conglomerate
A coarse-grained sedimentary rock containing rounded or sub-rounded
rock and mineral fragments.
Contact zone (aureole)
A zone surrounding an igneous intrusion in which contact
metamorphism of the country rock has taken place.
Core recovery
The proportion of the drilled rock column recovered as core in core
drilling.
Core
Cylinder of rock recovered from diamond drilling.
Costeaning
Exploration technique involving digging of trenches to expose rock.
Covellite
A copper sulphide mineral.
Crack Seal
Process during rock deformation where open fractures are sealed by
later mineralisation.
Crackle zones/crackling
Open-spaced joints produced during deformation of rocks.
Craton
A large stable mass of rock, usually igneous and/or metamorphic, which
forms a major structural unit of the earth's crust.
Cretaceous
A geological period from 100 to 70 million years ago.
Crosscut
An underground opening generally driven to cut across a mineralised
vein or structure.
Cross-bedding
Cross stratification in which the cross-beds are more than 1cm in
thickness.
Cross-folding
A later fold structure that intersects a pre-existing fold of different
orientation.
Crushing
The reduction in size of ore from the mine to a size suitable for grinding
in a mill-usually minus 12 mm size.
Crust
That portion of the earth from surface to a depth of 35 km.
Cultural
Refers to a magnetic anomaly due to man-made structure (e.g. metal
shed).
Cumulate
A layered igneous rock formed by the accumulation of crystals of
minerals precipitating from magma.
Cuprite
A copper oxide mineral.
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Cut and fill
A stoping method in which the ore is excavated by successive flat or
inclined slices working upward. Ore is extracted and the stope void is
backfilled progressively to provide a working floor.
Cut or top cut
The statistical process of reducing all higher-grade assay values to an
acceptable level for the purposes of determining the average grade of a
mineral deposit or drill intersection.
Cut-off grade
The grade at or above which material is treated as ore, and below which
it is treated as waste.
Cyanide leach,
cyanidation
A method of extracting gold and silver from an ore by dissolving them in
a weak solution of sodium cyanide.
Cyclone
Equipment for separating course and fine particles by centrifugal force.
Dacite
The extrusive equivalent of quartz diorite.
Decline
A tunnel access to an orebody, inclined downward from the surface.
Deep lead
Auriferous alluvials buried by younger rocks.
Development
Mining carried out to gain access to ore.
Devonian
A geological time period from 395 to 345 million years ago.
Diamond drilling
Method of obtaining a cylindrical core of rock by drilling with a diamond
impregnated bit.
Diamondiferous
Refers to rock or unconsolidated material that contains diamonds.
Differentiated
A body of igneous rock or metamorphic which has separated into zones
or layers of different textural and chemical composition during the
magmatic or metamorphic process.
Digenite
A copper sulphide mineral.
Dilation zone
Open spaces or fractures in rocks caused by structural deformation.
Dilation
Process whereby open space results from structural deformation of a
rock mass.
Dilution
Reduction of ore grade by contamination with waste material.
Diopside
A calcium-magnesium silicate mineral found in igneous and
metamorphic rocks.
Diorite
A group of igneous rocks intermediate in composition between acid and
basic.
Dip
The angle at which layered rocks, foliation, a fault, or other planar
structures, are inclined from the horizontal.
Discordant
Cutting pre-existing structures.
Disseminated
Mineralisation distributed throughout a rock.
Dolerite
A medium grained basic igneous rock.
Dolomite
A calcium magnesium carbonate mineral.
Dome
A form of anticlinal folding about more than one axis so that its form is
dome like rather than arch like.
Dragfold
Any fold that is a subsidiary part of a large fold.
Drilling and blasting
The process required in most mines to fragment the material so it can
be excavated efficiently.
Ductile
The stress response of certain minerals which undergo permanent
deformation without fracturing.
Dunite
A usually medium grained ultramafic igneous rock containing the
mineral olivene.
Duricrust
A layer of strongly cemented material occurring near the surface in
unconsolidated sediments.
Dyke
A discordant tabular body of igneous rock that was injected into a
fissure when molten.
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Electrolyte
An ionised chemical, or its solution in water, which conducts an electric
current.
Electromagnetic
Refers to a geophysical exploration method which measures responses
to induced electromagnetic currents in rocks.
Electrowinning
Deposition of metal on an electrode from electrolysis.
Eluvial
Weathered material near to its source
EM geophysical survey
Survey in which electromagnetic pulses are induced into the earth.
En Echelon
Linear geological formations or features displaced sideways but with the
same general strike.
Eocene
A geological time division part of the Tertiary period.
Epidote
Calcium aluminium silicate mineral.
Epigenetic
Distant from the source.
Epithermal
Low temperature hydrothermal processes.
Evaporites
Rocks formed by the evaporation of saturated solutions e.g. salt and
potash deposits.
Excavator
Open pit mining machine that mines by digging, lifting and dumping
bucket loads of material into a truck; generally articulated by hydraulics.
Facies
The aspect, appearance and characteristics of a rock unit, usually
reflecting the conditions of its origin.
Fault
A fracture in rocks along which rocks on one side have been moved
relative to the rocks on the other.
Feasibility study
(bankable)
A comprehensive technical and economic study of a project of sufficient
accuracy to provide the basis for a decision concerning financing.
Feldspar (felspar)
A very abundant group of rock-forming silicate minerals in which
calcium, sodium and potassium are in combination with aluminium.
Felsic
Used to describe rocks whose dominant constituents are the lightcoloured silicate minerals such as quartz and feldspar.
Ferronickel
A nickel-iron alloy.
Fire assay
A method for assaying in which gold in a pulverised sample is
amalgamated with lead, the latter subsequently being fumed off to leave
the gold.
Flatmake
A historic term used by miners in parts of Victoria to describe essentially
flat-lying orebodies.
Flexure
A warp or fold in the rocks.
Flitch
Mining level in an open pit.
Flood basalt
Basic volcanic rock of extensive areal distribution.
Flotation
A wet mineral extraction process by which articles containing certain
minerals are induced to become attached to bubbles and float, whilst
others sink.
Flow
Short for lava flow.
Fluviatile
Deposited by rivers.
Fluvioglacial
Sedimentary rocks formed from the accumulation of glacially eroded
material.
FOB
Free on board - at point of shipment
Fold belt (Orogenic belt)
A linear or arcuate region that has been subjected to folding and other
deformation during an orogenic cycle.
Footwall
The underlying side of a geological feature or mine opening.
Fractionation
Controlled precipitation from a saline solution of salts of different
solubilities, as affected by varying temperatures or by the presence of
other salts in solution.
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Free milling
(Non-refractory) mineralisation from which gold is able to be recovered
by conventional means.
Fumarolic activity
A late stage of volcanic activity characterised by the emission of water
vapour and other volatiles from a vent (fumarole).
Gabbro
A coarse-grained igneous rock, low in silica and high in magnesium and
calcium.
Galena
Lead sulphide mineral.
Gallery Stoping
A method of hand-held underground mining of narrow orebodies. The
ore is accessed by closely spaced sub-levels developed off vertical
openings or rises.
Gangue
Waste.
Garnet
A hard aluminium silicate mineral usually found in metamorphic rocks
but also in kimberlite and related rocks.
Geochemical
Prospecting techniques which measure the content of certain metals in
soils and rocks and define anomalies for further testing.
Geomechanical
Pertaining to the mechanical behaviour of rocks during excavation.
Geomorphic
Pertaining to the past, present and future land forms.
Geophysical
Prospecting techniques which measure the physical properties
(magnetism, conductivity, density etc) of rocks and define anomalies for
further testing.
Geostatistical resource
estimation method
A computer based methodology wherein particular mathematical
relationships between sample points are established and employed to
project the influence of the sample points.
Geosyncline
A thick succession of stratified sediments and volcanics deposited in a
basin or trough.
Geotechnical
Referring to the physical behaviour of rock under stress.
Geothermal gradient
Rate at which the temperature of the earth's crust increases with depth.
Gneiss
Banded rocks formed during high-grade metamorphism.
Goethite
A hydrated iron oxide mineral.
Gossan
Weathered or oxidised upper portion of a mineral deposit generally
formed by the decomposition of metallic sulphides.
Gouge
Crushed rock usually associated with a fault.
Graben zone
Downthrown area between two faults.
Grade control
A general term which describes the many measures required to
maximise mining recovery of the valuable mineral whilst minimising
dilution.
Grade
Quantity of metal per unit weight of host rock.
Graded bedding
A type of bedding in which each layer displays a gradual change in
particle size.
Granite
A coarse grained igneous rock consisting largely of quartz and feldspar.
Granitoid
A granite like intrusive rock.
Granodiorite
A coarse grained intermediate igneous rock.
Gravity (shaking) table
A slightly inclined table provided with riffles which separates heavy
minerals by a lateral shaking motion.
Gravity concentration
Separating grains of minerals by virtue of their differing densities.
Gravity, gravimetric
survey
A geophysical exploration technique which measures contrasts in
density of the underlying rocks.
Greenschist
A rock of low metamorphic grade characterised by parallel arrangement
of chlorite and micas in basic volcanic rocks.
Greenschist facies
A set of metamorphic mineral assemblages produced by metamorphism
of a wide range of rock types.
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Greenstone
A general descriptive term commonly in use in Western Australia for a
suite of weakly metamorphosed, mainly basic igneous rocks with
associated sediments.
Greywacke
Sedimentary rock composed of fine to coarse, angular to sub-angular
particles which are mainly rock fragments.
Grid
Rectangular pattern marked on ground, usually with wooden pegs, to
provide reference points for exploration observations and
measurements.
Grinding
Size reduction to relatively fine particles.
Grit
A quartz rich sediment, coarser grained than sandstone.
Haematite
An iron oxide mineral.
Half Graben
Down faulted younger sediments against older rocks.
Hangingwall
The wall or rock on the topside of a geological feature or mine opening.
Hard rock deposits
Used here to describe non-alluvial gold deposits.
Head grades
A general term referring to the grade of ore delivered to the processing
plant.
Headframe
The structure above a shaft that supports the hoisting cables and
facilitates the movement of men and materials.
Heap leaching
Method of extracting metals from ore dumped on a prepared pad by
applying a solution, usually by irrigation via sprinkling or by dripping.
Heterolithic
A mixture of rock types.
Hornfels
A fine to medium grained rock formed by thermal metamorphism.
Hydrogeochemical
Refers to a geochemical exploration technique where ground water is
sampled and analysed.
Hydrometallurgical
Recovery of metal from ore using water-based solution of reagent.
Hydromorphic
Movement in groundwater.
Hydrothermal
A process related to the introduction of heated or superheated waters
associated with igneous activity.
Igneous
A rock formed by the solidification of a mineral-rich molten liquid.
Ignimbrite
A volcanic rock formed by solidification from flows comprising a mixture
of very hot rock fragments and hot gases.
Indicated Mineral
Resource
Defined in the 2004 JORC Code as that part of a Mineral Resource for
which tonnage, densities, shape, physical characteristics, grade and
mineral content can be estimated with a reasonable level of confidence.
It is based on exploration, sampling and testing information gathered
through appropriate techniques from locations such as outcrops,
trenches, pits, workings and drill holes. The locations are too widely or
inappropriately spaced to confirm geological and/or grade continuity but
are spaced closely enough for continuity to be assumed.
Induced polarisation (IP)
Method of ground geophysical surveying which employs the passing of
an electrical current into the ground to test for indications of metallic
sulphides.
Inferred Mineral
Resource
Defined in the 2004 JORC Code as that part of a Mineral Resource for
which tonnage, grade and mineral content can be estimated with a low
level of confidence. It is inferred from geological evidence and assumed
but not verified geological and/or grade continuity. It is based on
information gathered through appropriate techniques from locations
such as outcrops, trenches, pits, workings and drill holes which may be
limited or of uncertain quality and reliability.
Inlier
A body of older rocks completely surrounded by younger rocks.
Intrusion
A body of igneous rock that invades older rocks.
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Inverse distance
squared
(cubed)
A method of projecting grades into a block model in which the weighting
of any nearby sample is inversely proportional to the square (cube) of
its distance from the block being estimated.
Ion exchange resin
A hydrocarbon-based material which allows a reversible exchange of
ions with a solution.
Ironstone
A broad term for a rock consisting mainly of iron oxides.
Isoclinal Folding
Tight folding of rock strata such that the fold limbs are nearly parallel.
Jarosite
An iron sulphate mineral often formed as zinc smelter waste.
Jaw crush
Refers to a process used to crush rocks.
Jig
Appliance which separates particles of different density using a pulsed
column of water.
JORC, JORC Code
Joint Ore Reserves Committee, common reference to the Australasian
Code for Reporting of Exploration Results, Mineral Resources and Ore
Reserves, 2004.
Jurassic
A geological time period from 195-135 million years ago.
Kaolin
Clay mineral derived from alteration of aluminium silicate minerals.
Kimberlite
A hybrid volatile-rich potassic ultrabasic igneous rock intruded from the
mantle and occurring at or near the surface as a cone-shaped volcanic
pipe or as sheet-like dykes or sills.
Knelson concentrator
Device for separating gold particles by centrifugal force.
Komatiite
A magnesium rich volcanic rock.
Kriging
A geostatistical means of projecting grades into resource blocks from a
range of sample points.
Lacustrine
Deposited in a lake.
Laminated Reef
A sequence of narrow quartz veins emplaced closely together along
bedding planes.
Lamproite
Ultramafic intrusive rock with a very deep source usually found in
marginal areas to cratons.
Lamprophyre
Medium grained, often porphyritic, intrusive rock of intermediate
composition rich in iron and magnesium minerals.
Landsat TM
Mapping based on satellite recorded multi-spectral imagery of the
Earth's surface.
Lapilli
Shards or fragments of volcanic rock.
Laterite, lateritised
A near surface concretionary deposit or crust formed by leaching of
silica and aluminium and enrichment in iron.
Lattice
The unit cell in the crystal structure of a mineral.
Leach pad
A levelled and compacted surface, prepared for the purpose of heap
leaching with an impervious layer to direct the liquor to the collection
point. May be reusable or non-reusable.
Leatherjackets
Historic term, used initially at Ballarat for gold bearing quartz reefs
generally located on the east side of anticlinal structures.
Lenses
Geological features bounded by converging surfaces.
Lerchs-Grossmann
Modelling technique used to determine the optimum open pit design for
a given set of parameters.
Leucite
A potassium aluminium silicate mineral.
Level
A main underground roadway or passage.
Limestone
A sedimentary rock consisting chiefly of calcium carbonate mainly as
calcite.
Lineament
A linear feature, generally recognisable in the topography, of regional
extent; commonly detected by satellite imagery.
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Lithostratigraphic unit
A body of rock that consists dominantly of a certain lithologic type of
combination of types, or has other unifying lithologic features.
Lithology
General descriptive term referring to the composition and texture of
rocks present in any area.
Loam sample
Surface sample of residual or transported lag material.
Lode
Tabular body of mineralisation or ore.
Macrodiamond
A diamond whose dimensions of at least two sides are larger than 0.4
mm diameter.
Mafic or basic
Used to describe igneous rocks of low silica content (usually 45-55%
SiO2, or silicon dioxide) whose dominant mineral constituents are iron
and magnesium silicates.
Magma (magmatic)
Molten rock material.
Magnesite
Magnesium carbonate mineral.
Magnetic survey
A geophysical technique which measures variations in the earth's
magnetic field.
Magnetite
An iron oxide mineral.
Malachite
A green hydrated, copper carbonate mineral.
Mantle
The portion of the earth's interior below the crust from a depth of 35 km
to 2,900 km.
Marcasite
An iron sulphide mineral.
Massive
Homogenous structure with no bedding, lamination or orientation of
mineral grains.
Massive sulphide
Body of mineralisation comprised mainly of sulphide minerals.
Measured Mineral
Resource
Defined in the 2004 JORC Code as that part of a Mineral Resource for
which tonnage, densities, shape, physical characteristics, grade and
mineral content can be estimated with a high level of confidence. It 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. The locations
are spaced closely enough to confirm geological and grade continuity.
Mechanised cutting
The use of a continuous mining machine such as a road-header for excavating a tunnel.
Merill Crowe
A process in which gold is recovered from cyanide solution by
precipitation on zinc shavings.
Mesothermal
A hydrothermal deposit formed at intermediate temperatures and
depths.
Mesozoic
A geological era ranging in time from 225 my to 70 my.
Metabasalts
A metamorphosed basalt.
Metakimberlite
A kimberlitic rock altered by metamorphism.
Metamorphism,
Metamorphic
Term applied to pre-existing sedimentary and igneous rocks which have
been altered in composition, texture, or internal structure by processes
involving pressure, heat and/or the introduction of new chemical
substances.
Metasedimentary
General term used to describe sedimentary rocks which have been
metamorphosed.
Metasomatism
A metamorphic change which involves the introduction (usually as fluid)
of material from an external source.
Microdiamond
A diamond that passes through a sieve with a mesh opening of 0.4 mm
diameter.
Migmatite
A rock consisting of mixed igneous and metamorphic materials.
Mill
A rotating machine used for reducing the size of ore particles.
Mineragraphic
Study of polished section of rock.
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Mineral Resource
Defined in the 2004 JORC Code as a concentration or occurrence of
material of intrinsic economic interest in or on the Earth’s crust in such
form, quality and quantity that there are reasonable prospects for
eventual economic extraction. The location, quantity, grade, geological
characteristics and continuity of a Mineral Resource are known,
estimated or interpreted from specific geological evidence and
knowledge. Mineral Resources are sub-divided, in order of increasing
geological confidence, into Inferred, Indicated and Measured categories.
Mineralisation
The process by which minerals are introduced into a rock. More
generally a term applied to accumulations of economic or related
minerals in quantities ranging from anomalous to economically
recoverable.
Mineralised zone
A volume of rock which contains anomalous to economically
recoverable quantities of mineral.
Miocene
A geological time division, part of the Tertiary period.
Mudstone
A fine, more or less sandy, clayey rock.
Mullock
Waste rock produced during mining operations.
Mylonite
A laminated milled rock formed by movement on fault surfaces.
Nugget
Refers to a particle of gold or other precious metal, usually a few
millimetres in size or larger.
Oligocene
A geological time division, part of the Tertiary period.
Olivine
A silicate mineral of magnesium and iron.
Open cut
Mine excavation produced by quarrying or other surface earthmoving
equipment.
Open pit
Mine excavation produced by removing all material overlying and
including the extracted ore. No underground caverns are created.
Ordovician
A geological time period from 460 to 435 million years ago.
Ore
Mineral bearing rock which can be mined and treated profitably under
current or immediately foreseeable economic conditions.
Ore Reserve
Defined in the 2004 JORC Code as the economically mineable part of a
Measured and/or Indicated Mineral Resource. It includes diluting
materials and allowances for losses, which may occur when the material
is mined. Appropriate assessments and studies have been carried out,
and include consideration of and modification by realistically assumed
mining, metallurgical, economic, marketing, legal, environmental, social
and governmental factors. These assessments demonstrate at the time
of reporting that extraction could reasonably be justified. Ore Reserves
are sub-divided in order of increasing confidence into Probable Ore
Reserves and Proved Ore Reserves.
Orebody
A physically discrete body of rock comprising ore.
Orogeny
The process of formation of mountains.
Orthocumulate
A layered igneous rock formed by the accumulation of crystals of
minerals precipitating from magma where the intercumulus liquid has
crystallised into one or more minerals which enclose the original
cumulate crystals.
Orthopyroxenite
A basic to ultramafic intrusive rock or differentiate.
Ounce
Troy ounce of 31.1 grams.
Outcrop
Expression of rock unit at surface.
Overbreak
Refers to the adjoining waste necessarily broken when mining ore.
Oxidation
The process by which minerals are altered by the addition of oxygen in
the crystal structures.
Oxide mineralisation
Derived from alteration of primary sulphide minerals by oxidation in the
weathered zone.
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Oxide ore
Ore that has been oxidised by exposure to air and circulating
groundwaters. During this process, sulphide minerals break down to
iron and other metal oxide minerals.
Palaeocene
A geological time division, part of the Tertiary period.
Palaeo-divide
Ancient drainage divide.
Palaeogravels
Gravels occupying a palaeochannel.
Palaeo-valley
Ancient river valley.
Palaeozoic
A geological era from 570 to 225 million years ago.
Paleodrainage,
palaeochannel
Fossil drainage system related to pre-existing topography.
Paragenetic (models)
Relates to mode of origin of a rock or mineral.
Parakimberlite
A rock having some chemical and textural similarities to a kimberlite.
Parasitic fold
A subsidiary fold in the limbs or closure of a larger fold.
Pathfinder element
Refers to elements which can be used in the search for metals (e.g.
arsenic in the search for gold).
Pedogenic
Formed as part of soil-making process.
Pegmatite
A very coarse grained igneous rock.
Pelitic
Descriptive term for fine-grained sediments such as shale and siltstone.
Peneplaination
Process of weathering rocks in which the end result is a plain.
Pentlandite
A nickel iron sulphide.
Percussion drilling
Drilling method which utilises a hammering action under rotation to
penetrate rock while the cuttings are forced to the surface by
compressed air.
Peridotite
An ultramafic intrusive rock.
Period
Reporting time division for a mining operation; usually 4 weeks.
Permian
A geological time period from 280 to 225 million years ago.
Petrography
The description and systematic classification of rocks by means of
microscopic examination of thin-sections.
pH
A measure of relative acidity.
Phenocryst
Refers to a relatively large mineral grain in a finer-grained ground mass.
Photogeological
Refers to a geological map based on interpretation of aerial
photographs.
Photolineament
Refers to a linear feature on the surface of the earth as seen on an
aerial photograph.
Phreatomagmatic
A volcanic eruption resulting from the contact of ground water and a
heat source.
Phyllite
A cleaved metamorphic rock with affinities with both slates and schists.
Picroilmenite
A titanium mineral associated with kimberlite rocks, hence an "indicator
mineral".
Pitchblende
Also called Uraninite. Uranium oxide mineral.
Planar cross-bedding
Cross-bedding in which the lower bounding surfaces are planar
surfaces of erosion.
Platinoids
The platinum group metals.
Pliocene
A geological time division, part of the Tertiary period.
Plunge
The angle from the horizontal of a geological feature viewed in a vertical
plane parallel to its strike.
Pluton
An igneous intrusion; a body of consolidated magma.
Polygons, polygonal
The derived shape of the mineralisation on a particular cross-section
which provides the basis for projecting the mineralisation to the next
section and thus establishing the tonnage.
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Porphyry, porphyritic
A rock composed of relatively large mineral grains (phenocrysts) in a
fine-grained groundmass.
Portal
The entrance to a tunnel or decline.
Potassic
Of, pertaining to, or containing potassium.
Powder factor
The explosives per unit of volume or tonne of material required to effect
fragmentation.
Precious metals
Generally refers to gold and silver.
Pre-Cambrian
A geological time period incorporating the Archaean (older than 2,400
million years) and Proterozoic (2,400 million years to 570 million years).
Pre-feasibility study
A relatively comprehensive analysis which is qualified by the availability
and accuracy of fundamental criteria and assumptions to the degree
that it cannot be the basis for final decisions.
Pregnant solution
Solution, containing dissolved metals, after percolation through a heap.
Pressure oxidation
The use of elevated temperature and pressure to promote the oxidation
of sulphides.
Pre-stripping
Removal of waste rock before mining of ore in an open pit.
Primary
In this context the original mineralisation before it has been subject to
secondary processes.
Probable Ore Reserve
Defined in the 2004 JORC Code as the economically mineable part of
an Indicated, and in some circumstances, a Measured Mineral
Resource. It includes diluting materials and allowances for losses which
may occur when the material is mined. Appropriate assessments and
studies have been carried out, and include consideration of and
modification by realistically assumed mining, metallurgical, economic,
marketing, legal, environmental, social and governmental factors These
assessments demonstrate at the time of reporting that extraction could
reasonably be justified.
Prograde
E.g. prograding shoreline A shoreline that is being built forward or
outward into a sea or lake by deposition and accumulation.
Propylitic
A style of hydrothermal alteration dominated by a characteristic mineral
assemblage (e.g. epidote, calcite, chlorite, pyrite).
Proterozoic
A geological era from 2,400 million years to 570 million years.
Proved Ore Reserve
Defined in the 2004 JORC Code as the economically mineable part of a Measured
Mineral Resource. It includes diluting materials and allowances for losses which may
occur when the material is mined. Appropriate assessments and studies have been
carried out, and include consideration of and modification by realistically assumed mining,
metallurgical, economic, marketing, legal, environmental, social and governmental factors.
These assessments demonstrate at the time of reporting that extraction could reasonably
be justified.
Psammitic
Term used to describe a metamorphised sandstone, arkose or quartzite
rich in the mineral quartz.
Pyrite
An iron sulphide mineral.
Pyroclastic
Produced by explosive or aerial ejection of material from a volcanic vent
Pyrometallurgical
Processes for wining and refining metals using heat, as in roasting and
smelting.
Pyrope
A form of garnet.
Pyrophyllite
A talc-like mineral.
Pyrrhotite
Magnetic iron sulphide mineral.
Quartz
Mineral species composed of crystalline silica (SiO2).
Quartzite
A metasedimentary rock derived from sandstone.
Quaternary
A geological period from two million years ago to the present.
Radiometric
Measurement of radioactivity useful in mapping rock formation.
Raffinate
Acid generated in the solvent extraction process.
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Raise boring
Method of underground excavation by drilling upwards.
Reagents
Chemicals used in the treatment of ores to recover metals.
Recent
Youngest time division of the Quaternary.
Recovery
The percentage of metal in an ore extracted by the metallurgical
process.
Reduced fluid
A fluid with limited or no dissolved oxygen.
Reef
A lode or vein.
Refractory
Ore from which it is difficult or expensive to recover the valuable
constituent related minerals in quantities ranging from anomalous to
economically recoverable.
Regolith
The altered, unconsolidated or recemented cover that overlies coherent
bed rock.
Relict
Said of a topographic feature that remains after other parts have
disappeared.
Reserve
See “Ore Reserve”
Resource
See “Mineral Resource”
Retrograde
metamorphism
A type of polymetamorphism by which minerals of a lower grade are
formed at the expense of minerals characteristic of a higher grade.
Reverse circulation (RC)
drilling
Variant of percussion drilling in which cuttings are raised to surface by a
stream of compressed air inside a metal tube.
Reverse fault
A fault in which one block moves in a relative sense over the other.
Rhyodacite
Fine grained acid to intermediate volcanic rock.
Rhyolite
Fine grained acid volcanic rock.
Rift
A zone of the Earth's crust which ruptures under extensional forces.
Rising main
A main pump line to carry water being pumped in an underground mine
either to the surface or a higher pumping station.
Roasting
A process of burning sulphides to liberate the contained metals.
Rock chip sampling
Refers to collecting a representative sample comprising numerous small
chips of rock.
Rod mill
A mill for fine grinding of ore which uses long steel rods instead of balls.
ROM stockpile
Stockpile of "run of mine" ore which provides a buffer, for various
reasons, between the mining and crushing operations.
Rotary air blast (RAB)
drilling
A shallow rotary drilling method used to penetrate soil and the upper
weathered part of the bedrock.
Saddle reef
A particular form of quartz reef occurrence in the crest of an anticline,
common in the Central Victorian goldfields.
SAG mill
Semi-autogenous grinding ball mill in which the rock being ground
assists in the grinding process.
Sandstone
A medium grained sedimentary rock with a high content of quartz.
Sapphire
A flawless crystal of corundum.
Saprolite
A soft, clay rich near surface horizon in the weathering profile in which
certain minerals and metals can be enriched, others depleted.
Schist
Fine grained micaceous metamorphic rock with laminated fabric.
Screened fire assay
Fire assaying of a sample after it has been divided into separate size
fractions, aimed at ensuring a representative proportion of the coarser
metal (usually gold) grains in the assay sample.
Sedimentary
Rocks formed of particles deposited from suspension in water, wind or
ice.
Sericite
A member of the mica mineral group; an aluminium silicate often
derived from alteration.
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Serpentinite
A metamorphic rock derived from ultramafic rocks.
Shaft
A nearly vertical passage from the surface by which a mine is entered
and through which ore is transported.
Shale
A sedimentary rock of silt to clay grain size with well marked bedding
plane fissility.
Shear
Zone in which rocks have been deformed by lateral movement along
parallel planes.
Shearing
Deformation by lateral movement along parallel planes.
Sheeted vein
Quartz veins occurring in close-spaced parallel sheets.
Shoot
A general term describing lens-like bodies of mineralisation defined by
grade/thickness parameters.
Shrinkage, shrink
stoping
Method of ore extraction whereby the ore is broken in successive flat or
inclined slices working upward. The broken ore forms the working
surface, with enough drawn off from below to provide a working space.
Silicified
Referring to rocks in which a significant proportion of the original
constituent minerals have been replaced by silica.
Sill
An intrusion which is parallel to (conformable with) the stratigraphy of
the enclosing rocks.
Sill pillar
A horizontal block left unmined to support ongoing mining.
Siltstone
A fine-grained sedimentary rock.
Silurian
A geological time period from 435 to 395 million years ago.
Sinter
Silica deposited by hot springs.
Sirotem
A method of geophysical exploration relying on the use of transient
electromagnetic fields.
Size reduction
Refers to the process of crushing a sample and then splitting off a
representative sub-sample for assaying.
Slate
A fine-grained fissile metamorphic rock derived from shales and similar
sediments.
Smelting
Chemical reduction of a metal from its ore by fusion.
Soil anomaly
A zone or point determined by geochemical sampling and assaying of
the soil to be different from the general surrounds.
Solid solution
An inter-mixing of minerals without defined grain boundaries.
Solution mining
The extraction of metals by dissolving them in solution pumped into and
recovered from the host rock through bore holes.
Solvent extraction
A means of selectively separating a metal in a solution from other
elements by its affinity for a particular solvent.
Sphalerite
A zinc sulphide mineral.
Spinel
A group of iron and aluminium oxide minerals usually found in
metamorphic rocks of which magnetite and chromite are most common.
Spirals
A sluice formed in 5 or 6 tight spirals in which centrifugal force aids the
separating effect.
Splay
A fracture which is subsidiary to a major fault and usually oblique to it.
Spurry
The irregular development of quartz veining in dilation zones.
Stibnite
An antimony sulphide mineral.
Stockwork
A set of veins in a number of different orientations.
Stope
An underground opening from which ore is extracted.
Strata
Layers of rock.
Stratabound
Confined within a particular strata.
Stratiform
Parallel to sedimentary bedding.
Stratigraphy
Refers to the classification of a series of layered rock or strata.
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Stream-sediment survey
Systematic sampling of sediments within drainage channels.
Strike
The direction of bearing of a bed or layer of rock in the horizontal plane.
Stringer sulphides
A sulphide mineral occurrence where the sulphide minerals form thin
veins.
Stripping
Removal of metal from material on which it has precipitated or been
adsorbed e.g. gold from carbon or copper from cathodes.
Structural
corridor/zones/trends
Refers to processes of fracturing and folding of rocks.
Structural feature
Used in this report to refer to a significant fracture, fault or shear in
which mineralisation may be concentrated.
Structural targets
Zones of deformation interpreted to be favourable to the localisation of
mineralisation.
Structural
In this report refers to processes of fracturing and folding of rocks.
Subaerial
Formed on the land surface.
Sub-outcrop
Expression of rock unit near surface.
Sulphides
Minerals consisting of a chemical combination of sulphur with metals.
Sulphide concentrate
The product, usually of the flotation process, in which sulphide particles
are removed from the crushed rock, containing predominantly sulphide
minerals.
Supergene
Concentration of minerals by secondary processes.
Syenite
A plutonic igneous rock consisting principally of alkali feldspar with one
or more mafic minerals.
Syncline
A fold in rock strata which is concave upwards.
Tailings
Material rejected from a treatment plant after the recoverable valuable
minerals have been extracted.
Talc
A member of the mineral group, micas, usually occurring in
metamorphic rocks.
Tectonics
Forces in the Earth's crust which result in movements of sections of the
crust and produce deformation of rock bodies.
Tellurides
A mineral compound of tellurium, often rich in gold and silver.
Tension gash
An opening in rocks formed as a subsidiary fracture to a fault
movement.
Terrace
Refers to a sheet of alluvial sediments (usually sand or gravel) lying at
an elevation above the current river in a valley.
Terrane
An obsolescent term applied to a rock or group of rocks and to the area
in which they crop out. General term.
Tertiary
A geological time period from 70 to two million years ago.
Tetrahedrite
A copper and silver ore mineral.
Tholeiitic
A variant of basalt containing little or no olivine.
Thickener
Apparatus for reducing the proportion of water in a pulp.
Thiourea
An organic solvent sometimes used for separating precious metals.
Thrust
A low angle fault.
Toll treated
Usually refers to processing at a relatively adjacent treatment facility.
Top cut
An upper assay limit to which all abnormally high assays in a population
are reduced to restrict their influence on the average grade of the
resource.
Torbernite
Hydrated copper uranium phosphate mineral.
Trace elements
Minor elemental constituents often significant in geochemical
exploration.
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Transfer fault
A type of fault which represents the release of stress related to another
major fracture.
Trash screen
Protective screen for removing detritus from the pulp stream.
Triassic
A geological time period from 225 to 195 million years.
Tribute
Refers to a mine where the owner allows another party to operate in
return for a share of the product.
Trommel
A screen used in grading coarsely crushed ore.
True thickness
The thickness of a lens or shoot normal to its plane of maximum
elongation as opposed to the thickness indicated by a drill hole intercept
which may cut the lens obliquely giving a large apparent thickness.
Tuff
Rock which contains fragments of other rocks and minerals sourced
from eruptive volcanic action.
Tuffaceous sandstone
or siltstone
Indurated sedimentary rock composed of sand grains derived from
explosive volcanic activity.
Turbidite
A sediment formed from a slurry moving at high speeds down a basin
slope.
Ultrabasic or ultramafic
Used to describe igneous rocks of very low silica content (usually < 45%
SiO2,) consisting essentially of iron and magnesium silicates to the
virtual exclusion of quartz and feldspar.
Unconformity
A contact between rock units that represents a time break in rock
deposition or formation.
Unconstrained model
Refer also geostatistical methods. Means an interpreted geological
boundary has not been used finitely to limit the influence of statistically
projected sample grades.
Underground methods
Methods used for underground mining as opposed to open pit methods.
Uphole benching;
Uphole retreating
A method of mechanised open stope underground mining in which the
ore is drilled and blasted from below.
Vat leaching
Leaching of the ore within large tanks or vats, which involves flooding
the ore with the lixiviant, then draining the solution for further treatment.
Vein
A tabular form mineral filling of a rock fracture.
Ventilation raise
An opening drilled upwards to surface to provide mine ventilation.
Vertical
A historic mining term used in parts of the Victorian goldfields to
describe steeply dipping veins.
Violarite
A violet-grey sulphide mineral of nickel and iron.
Volcanic
Rocks formed from the solidification of lava extruded on or erupted at
the Earth's surface. Also includes pyroclastic rocks.
Volcanoclastic
Descriptive of a clastic sediment containing material of volcanic origin.
Volcanogenic
Refers to rocks of volcanic derivation.
Vuggy
Containing many cavities.
Waste to ore (stripping)
ratio
Tonnage/volume of waste material which must be removed to allow the
mining of one tonne/cubic metre of ore in an open cut.
Waste
Rock other than ore excavated during a mining operation.
Wavelength
In this report, refers to the distance between the crests of adjacent
anticlines.
Weathering
Near-surface alteration of minerals and rocks by exposure to the
atmosphere and groundwater.
Wedge
A section of diamond drill-hole mechanically deviated from the direction
of the primary hole.
Whittle 3D (4D)
optimisation
Computer program used for planning open-pit dimensions based on
technical and economic parameters relevant to resource under study.
Winder
An electrically driven winding engine for hoisting up a shaft.
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Winze
A vertical opening in an underground mine developed from the top
downwards.
Workings
Refers to pits, shafts and adits mark by prospectors in search of
minerals.
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