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Glossary

A B C D E F G H I J K L M O P Q R S T U V W X Y Z

A

“ADR” adsorption desorption recovery

“adsorption” part of a method for gold extraction in a processing plant

“agglomeration” the act of binding fine particles together to create coarse particles as part of a mineral processing activity

“alluvial” pertaining to material deposited by rivers

“alteration” alteration of a rock/mineral by geological forces

“alteration halo” zone of alteration that surrounds the principal source of alteration. Often observed as a warning of alteration with distance from a source

“amphibolite” a metamorphic rock type. In this case, it defines specific temperature and pressure conditions

“anatomising” relating to veins that split and rejoin in a braided fashion

“anomalous” value of a given element that is deemed to be above the background or normal value

“apatitic” relating to a concentration of calcium phosphate mineral

“Archaean” period of geological time, before é,500 million years ago

“arsenic” a chemical element often associated with gold deposits

“arsenopyrite” arsenic-iron sulphide mineral

“artisanal miners” local miners that generally operate on a pick and shovel basis or small scale mechanical production. In many cases these are unofficial miners and are ignored by local governments

“Au” gold

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B

“bacterial oxidation” a metallurgical process that uses certain bacteria to break down sulphide minerals in order to release the contained metals

“Birimian” era of geological time between 2,200 and 1,800 million years ago. Typified by deposition of rocks similar to those of the Birim Valley, Ghana

“BLEG” bulk leach extractable gold, an assaying technique

“brittle” action when rock or mineral under pressure breaks rather than bends (see ductile)

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C

“carbonate” relating to rocks rich in calcium and or magnesium

“carbonatite” an intrusive rock rich in carbonates

“chalcopyrite” copper sulphide mineral

“clastic” formed from fragments of pre-existing rock transported and deposited

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D

“deposit” an anomalous occurrence of a specific mineral or minerals within the Earth’s crust

“destral” right sided displacement along a fault

“dilution” mixing of economic grade material with non-economic grade or waste material in the mining process

“dip” inclination of a geological feature/rock from the horizontal

“dolomite” magnesium limestone, a type of rock

“dykes” intrusive rocks that are discordant to host rocks. Often thin and tabular

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E

“EIS” environmental impact study

“elution” the removal of adsorbed gold from activated carbon through processes of washing with specific liquors under controlled conditions

“Environmental Baseline study” study of the local environmental conditions prior to mine construction

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F

“facies” unit defined by its geological features

“feasibility study” a detailed study of the economics of a project based on technical calculations and specific mine designs undertaken to a sufficiently high degree of confidence to justify a decision on construction

“ferricrete” see laterite

“flotation” chemical process as part of gold extraction from crusher ore

“foliation” orientation of minerals in a rock due to deformational process

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G

“GeoBiotics” a proprietary process for cost effective bio-oxidation of sulphidic material using heap leach system prior to conventional metal recovery. This system has yet to be utilised on a commercial basis

“gochemical soil sampling” prospecting technique using samples of soil and laboratory analysis

“GIS” Geographical Information System, a computer database utilising world coordinates estimation of the mean grade of a deposit based on sample date population

“gneiss” metamorphic rock displaying banding

“granite” igneous rock type

“granitoids” group of rock types related to granite

“greenschist” a particular level of metamorphism defined by a particular mineral assemblage and specific pressure and temperature conditions

“greenstone” a field term for altered basic igneous rocks

“g/t” grammes per tonne

“global parametric statistical analysis of the estimating” estimation of the mean grade of a deposit based on sample data population

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H

“halo” area immediately surrounding a specific point, mineral or occurrence

“HDPE” high density polyethylene

“heap leaching” a low cost technique for extracting metals from ore by percolating leaching solutions through heaps of ore placed on impervious pads. Generally used for low grade ores

“hydrothermal” process involving super heated magmatic waters

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I

“indicated mineral resource” 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 though 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

“indicator kriging” a kriging methodology which is used to a database in which all grades have been converted to either 0 or 1 depending on whether they are less than, or greater than, a specified threshold or cut off grade

“inferred mineral resource” 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

“intrusive” derived from molten material that originated and solidified beneath the Earth’s surface

“inverse distance modelling” a method of block grade estimation which uses as a weighting factor the inverse of distance ‘raised to a specified power) of each sample from the block under evaluation

“isoclinal fold” tight folding of a rock band or strata whereby the limbs are parallel

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J

“JORC code” Australasian code for reporting of mineral resources and ore reserves

“JV” joint venture

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K

“kaolinisation” process by which minerals are degraded to form kaolin

“Karstic” type of weathering specific to carbonate rock types

“km/km2” kilometre(s)/square kilometre(s)

“kriging” an interpolation method that minimises the estimation error in the determination of mineral resources

“KW” kilowatt(s)

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L

“Landsat TM imagery” satellite imagery of the earth’s surface

“laterite” residual deposits of iron oxide formed as a result of weathering under specific climatic conditions

“lava” igneous rock flow at surface in both molten and cooled form

“limb” a geological term for one side/part of a fold

“logging” recording geological, geotechnical and other information from dill core metre(s)

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M

“m” metre(s)

“mm” millimetre(s)

“m3” cubic metre(s)

“m3/hr” cubic metre(s) per hour

“Ma” abbreviated term for million years

“magnetics” geophysical prospecting technique using variations in the earth’s magnetic field

“measured mineral resource” that portion 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 workings and drill holes. The locations are spaced closely enough to confirm geological and/or grade continuity

“metallurgical” studies pertaining to the metal content of the rock and the extraction of such metals

“metamorphism” process by which rocks are changed by the agencies of heat and pressure

“metasediment” sedimentary rocks that have undergone varying levels of metamorphism but are still recognisable as original sediments

“metavolcanic” a volcanic rock that has undergone metamorphism

“migmatite” high grade metamporphic rock type

“MIK” multiple indicator kriging, variant of indicator kriging which uses multiple thresholds

“mineral resource” a concentration or occurrence of material of intrinsic economic interest in or on the Earth’s crust in such form 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

“mineralised” rock that contains ore minerals

“mylonite” rock type found in fault zones

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O

“occluded” relates to an element or mineral enclosed by or within another mineral

“ordinary kriging” a kriging methodology which estimates grade weighting factors in such a way that the sum of these factors equals one

“ore reserve” the economically mineable part of a measured or indicated mineral resource. It includes diluting materials and allowances for losses which may occur when the material is mined. Appropriate assessments, which may include feasibility 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 proven ore reserves

“orebody” the volume of rock containing the mineral resource

“ounce” troy ounce

“oxide” soft, weathered rock, formed by the processes of weathering near surface

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P & Q

“PGM” platinum group metals

“proscorite” apatite rich carbonatite

“pre-feasibility study” a study approaching feasibility level based on assumptions and comparisons with like deposits and where variables have moderate degree of confidence

“probable ore reserve” the economically mineable part of an indicated, and in some circumstances measured mineral resource. It includes diluting materials and allowances for losses which may occur when the material is mined. Appropriate assessments, which may include feasibility 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

“proven ore reserve” The economically mineable part of a measured mineral resource. It includes diluting material and allowances for losses which may occur when the material is minded. Appropriate assessments, which may include feasibility 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

“pyrite” iron sulphide mineral, FeS2

“quartzite” a rock type formed predominantly of recrystalised quartz

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R

“RAB drilling” rotary air blast drilling technique

“radiometric” geophysical prospecting technique using radiation

“RC drilling” reverse circulation drilling technique

“reserves” that of a mineral resource which has been demonstrated to be economically exploitable

“resistivity” geophysical exploration technique using electrical conductivity of rocks

“resources” that part of mineral deposit which has the potential to be exploited

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S

“saprolite” weathered rock depleted as part of the lateritisation process but with some distinguishable features/minerals of the original rock

“schist” metamorphic rock type with a characteristic fabric

“sedimentary” rock type formed from fragments of other rocks

“shale” a type of sedimentary rock

“shear zone” fault zone, often associated with fluid movement and mineralisation

“siltstone” type of fine grained sedimentary rock

“stope” underground void created by mining

“strike” general trend or direction of a geological feature in a horizontal plane

“sulphide” iron and sulphide based metalliferous minerals

“syn” contemporaneous

“synformal” rocks folded in the shape of a basin

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T

“tailings” finely ground waste rock from which valuable minerals or metals have been extracted

“tectonic” relating to a major structural event

“tholiitic” type of basic igneous rock

“thrust” low angle reverse fault

“twin” process by which drill holes are verified with a new hole in close proximity

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U–Z

“ultra mafic” igneous rock type defined by its dark mineral content

“un-oxidised” that portion of a deposit that has not been weathered or oxidised

“variography” the process by which a semi-variogram is produced and modelled. A semivariogram expresses the rate of change of the differences of grade (and other variables) as the separation between samples increases and is used in the kriging process

“vein/veinlet” small conduit within larger rock mass

“VLF” geophysical exploration technique using very low frequency waveforms

“volcano:sedimentary” package of rock comprising intercalated volcanic and sedimentary rocks

“weathering” degradation of rocks at the Earth’s surface by climatic forces

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