| acanthite |
a silver sulphide mineral (Ag2S) which contains 87% silver |
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| acid volcanic |
a volcanic igneous rock containing 66% or more of free or combined silica |
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| adamellite |
a quartz-bearing coarse grained intrusive igneous rock similar to granite |
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| andesite |
a dark-coloured basic volcanic igneous rock |
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| anomaly |
a distinctive local variation in value or grade |
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| aplite |
a pale coloured igneous dyke-rock of granitic composition but finer grained |
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| arenite |
a consolidated sedimentary rock having the texture of sand |
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| arsenopyrite |
a tin-white sulphide of arsenic and iron, FeAsS |
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| azimuth |
direction - eg to which a non-vertical drill hole is inclined |
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| base metals |
any of the non-precious metals |
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| bornite |
sulphide of copper and iron (Cu5FeS4) - a valuable copper ore |
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| bournonite |
a sulphide of lead, antimony and copper |
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| bulk-tonnage |
ore deposits whose relatively low grade is compensated by large tonnages |
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| calcite |
calcium carbonate - a common gangue mineral |
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| carbonate |
a compound containing the acid radical of carbonic acid (CO3) - eg calcite |
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| cerussite |
a lead carbonate mineral (PbCO3) |
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| chalcopyrite |
a sulphide of copper and iron (CuFeS2) - an important ore of copper |
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| clastic |
a rock composed of fragments of other rocks |
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| country rock |
the barren rock traversed by or adjacent to an ore deposit |
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| diamond drilling |
core drilling using a diamond-encrusted bit |
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| DIGS |
database system (Digital Imaging of Geologic System) by which the NSW Department of Primary Industries (Mineral Resources) delivers exploration and geoscience information |
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| dip |
the angle at which a feature is inclined from the horizontal; strike (q.v.) is a horizontal line at right angles to the dip |
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| DPI |
The NSW Department of Primary Industries which now incorporates the former Department of Mineral Resources (Mines Department) |
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| drag fold |
any fold that is a subsidiary part of a larger fold |
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| dyke |
a discordant body of igneous rock injected into a fissure when molten, and which cross-cuts the structure of the host country rock |
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| en echelon |
parallel but offset structural features (eg like roof tiles when viewed from the side) |
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| ferruginised |
enriched in iron |
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| fold belt |
a regionally large zone of folded rocks |
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| galena |
sulphide of lead which may also contain up to 1% silver as the isomorphous silver sulphide, argentite |
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| gangue |
unwanted minerals - usually non-metallic such as quartz or calcite - associated with ore |
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| gm/cc |
grams per cubic centimetre - a measure of density or specific gravity |
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| gossan(ous) |
an iron-rich deposit or capping on rocks that are pyrite-rich granite a quartz-rich coarse grained intrusive igneous rock |
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| granitoid |
a rock having the texture of a granite; a granite-like rock |
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| host-rock |
the rock containing a mineral deposit (wallrock, country rock) |
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| hydrothermal |
pertaining to hot, water-rich solutions emanating from molten igneous material |
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| induced |
an electrical geophysical procedure polarisation (IP) |
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| intrusive |
molten igneous rocks injected below (as opposed to intrusion at) the earth's surface |
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| jamesonite |
a lead-iron-antimony sulphide, sometimes with a small amount of copper and zinc |
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| JORC code |
a set of guidelines for the reporting of mineral resources and reserves |
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| leucogranite |
pale-coloured granite typified by white mica |
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| limonite |
a yellowish oxide of iron |
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| lode |
a fissure in country rock filled with mineral; usually applied to metalliferous deposits |
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| Mesozoic |
an era of geological time from 245 to 65 million years ago ' literally "middle life" |
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| metasediments |
a partially metamorphosed (altered) sedimentary rock |
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| metasomatism |
a replacement process by which one mineral is replaced by another of different chemical composition |
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| multispectral |
comprising a range of wavelengths of electromagnetic energy |
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| one-minute units |
the area defined by one minute of latitude by one minute of longitude - approximately 3 square kilometres in NSW, becoming smaller to the south |
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| orogen |
orogeny is the geological process of mountain building resulting from plate-tectonic motions; an orogen is the body of rocks that comprise a suture zone resulting from this process |
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| pelite |
a general term for clastic sedimentary rocks composed of clay-sized (very fine) particles |
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| percussion |
originally a drilling method employing a string of drilling |
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| drilling |
tools raised and lowered by a cable, but now also applying to air-hammer drilling |
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| Permian |
a period in geological history from about 286 to 248 million years from the present |
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| plane table |
a simple surveying procedure used for mapping |
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| plunge |
also called pitch or rake when applied to ore bodies, this is the angle between a horizontal plane and the line of maximum elongation of the body |
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| porphyry |
an igneous rock in which coarser crystals are scattered though a finer groundmass |
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| ppm |
parts per million (equivalent to one gram per tonne) |
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| precious metal |
the relatively scarce and valuable metals such as gold, silver and the platinum group metals |
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| pyrite |
sulphide of iron (FeS2), also known as "fools gold" |
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| pyrrhotite |
a magnetic sulphide of iron |
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| radiometric |
elating to the measurement of nuclear decay of naturally occurring radioactive isotopes; airborne radiometric surveys measure gamma radiation from potassium, thorium and uranium, and are useful for geological mapping |
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| RC drilling |
reverse-circulation drilling - the circulation of the drilling fluid down the outside of the drillrods, and upwards inside the rods |
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| reef |
a lode or vein, particularly applying to quartz outcrops |
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| rhyodacite |
an intermediate igneous rock, the extrusive equivalent of a granodiorite |
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| scorodite |
a green to brownish iron-arsenic mineral |
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| sericite |
a white mica similar (or identical) to muscovite |
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| shear(s) |
a zone of failure in rocks caused by a shearing motion |
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| shoot (ore) |
an elongated body of ore |
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| sphalerite |
zinc sulphide (ZnS) - an important ore of zinc |
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| spontaneous |
an electrical geophysical procedure (also called self potential (SP) potential) |
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| stannite |
a copper-iron-tin (and sometimes zinc) mineral associated with tin-bearing veins |
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| stibnite |
antimony sulphide (Sb2S3), a lead-grey mineral sometimes containing silver and gold |
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| stope |
an excavation from which ore has been extracted |
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| strike |
a horizontal line at right angles to the dip (q.v.) |
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| submeridional |
approximately paralleling meridians of longitude - i.e. more or less north-south |
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| sulphide(s) |
a compound of sulphur with a range of elements; in the context of mining, the term usually applied to metallic sulphides |
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| tetrahedrite |
a copper-antimony-arsenic sulphide mineral which may also contain silver, zinc, iron or mercury as part-replacement for the copper |
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| Trassic |
the first period of the Mesozoic Era (q.v.), from 248 to 206 million years ago |
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Turam geophysical
survey |
a geophysical survey comprising electromagnetic methods |
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| underlay |
a shaft sunk in the footwall (lower side) of an ore body, and following its dip |
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| wallrock |
country rock (q.v.) immediately adjacent to an orebody |
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| water table |
the upper limit, or surface of groundwater; the level below which rocks are permanently saturated with water |
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| winze |
a vertical or inclined opening connecting two levels in a mine, constructed from the top down; when constructed from the bottom up, the opening is known as a raise |