anomaly
An anomaly is a spot where a measurement — such as the strength of a magnetic field or the amount of a metal in soil — is noticeably different from the surroundings, suggesting something unusual might lie underground.
技术层面: In exploration geology, an anomaly is a statistically significant departure from the local or regional background value of a measured parameter, whether geochemical, geophysical, or remote-sensing derived, and it forms the basis for prioritising drill targets. Not all anomalies reflect economic mineralisation; many result from barren lithological contrasts, instrument artefacts, or surficial contamination, which is why anomaly follow-up always involves additional lines of evidence before drilling is committed. The term should be qualified by its type and the method that detected it — for example, a soil geochemical anomaly differs fundamentally in its implications from a magnetic anomaly even if both occur in the same area.
Geology
assay
An assay is a chemical test that measures exactly how much of a valuable mineral or metal is present in a piece of rock, the way a cook might weigh out exactly how much sugar is in a recipe.
技术层面: An assay is a quantitative analytical procedure applied to a rock, soil, or water sample to determine the concentration of one or more elements or minerals, reported in units such as grams per tonne or percentage by mass. In resource estimation, assay results are the primary input to grade calculations and must be traceable to certified reference materials and blanks to be defensible. Assay is sometimes loosely used to mean the result itself rather than the procedure; technical reports treat these as distinct.
Geology
banded iron formation
A very ancient layered rock made of alternating stripes of iron-rich minerals and silica, laid down on ancient seafloors long before there was much oxygen in the atmosphere.
技术层面: A banded iron formation (BIF) is a chemically precipitated sedimentary rock characterised by alternating iron-rich layers (typically magnetite or hematite) and silica-rich layers (chert), deposited predominantly in Precambrian marine basins. The banding is thought to reflect periodic changes in ocean chemistry or oxygen availability rather than clastic input. BIFs are the principal source rock for most of the world's iron ore, with economic deposits typically requiring secondary enrichment to raise iron grades to commercially workable levels.
Geology
brine
Water with a very high concentration of dissolved salts — much saltier than seawater. Underground brines in certain deserts contain lithium, potassium, and other elements that can be extracted commercially.
技术层面: Brine is an aqueous solution with a total dissolved solids concentration substantially above that of seawater, typically formed by the dissolution of evaporite minerals or by long-term evaporative concentration of meteoric or volcanic waters in closed basins. In the context of mineral resources, the term refers specifically to subsurface or surface-ponded waters exploited for their content of lithium, potassium, boron, magnesium, or bromine. Brine differs from seawater not only in concentration but often in ionic ratios, which determine the processing route required; a high magnesium-to-lithium ratio, for instance, significantly complicates selective lithium recovery.
Geology
brownfield
A brownfield project is one carried out near or around an existing or former mine, where some rock has already been studied and some infrastructure already exists, giving explorers a head start.
技术层面: A brownfield exploration or development project operates in the proximity of an existing or previously mined deposit, benefiting from existing geological data, drill results, metallurgical knowledge, and often surface infrastructure such as roads, power, or processing facilities. Targeting in brownfield settings typically focuses on extensions of known mineralisation or satellite deposits within established geological corridors, which reduces some categories of exploration risk while introducing others, such as sterilised ground, legacy contamination, and tenure complications. Brownfield should not be confused with the environmental planning term of the same name, which refers to previously developed urban land; the mining usage is geological and logistical in scope.
Geology
carbonatite
A rare type of volcanic rock made mostly of carbonate minerals — the same family as limestone — rather than the silicate minerals found in ordinary igneous rocks. Some carbonatites are important sources of rare-earth elements and niobium.
技术层面: Carbonatite is an igneous rock, intrusive or extrusive, containing more than fifty percent carbonate minerals by volume, typically calcite, dolomite, or ankerite. It is genetically distinct from carbonate sedimentary rocks and from carbonated hydrothermal veins. Carbonatites are economically significant as hosts for niobium, rare-earth elements, phosphate, fluorite, and occasionally copper, and they are often associated with alkaline silicate intrusions in continental rift settings. The distinction from a marble or a hydrothermal carbonate vein rests on demonstrating an igneous origin through geochemistry and field relationships.
Geology
core sample
A core sample is a long cylinder of rock drilled out of the ground whole, like using a hollow cookie-cutter through layers of cake, so geologists can see the rock exactly as it sits underground.
技术层面: A core sample is a continuous cylindrical section of rock recovered by a diamond or other rotary drill bit fitted with an annular cutting face, which preserves the original stratigraphy, structure, and mineralisation relationships along the drill path. Core recovery percentage — the proportion of the drilled interval actually retrieved — is recorded because incomplete recovery can bias grade estimates, particularly in friable or broken ground. Core differs from drill chips or reverse-circulation cuttings in that it retains orientation and intact fabric, making it the preferred sample type for structural logging and geometallurgical testwork.
Geology
cut-off grade
The lowest grade of rock that is still worth processing. Rock above the cut-off goes to the mill; rock below it is left behind or sent to the waste dump.
技术层面: Cut-off grade is the minimum grade at which a unit of rock — a block, bench, or development heading — generates sufficient revenue to cover the cost of mining, processing, and selling. It determines the boundary between ore and waste and therefore controls both the size and the average grade of the reported resource or reserve. Because it is derived from cost and price assumptions, cut-off grade changes with commodity prices, exchange rates, and processing recoveries, which means the economic boundary of an orebody is not fixed.
Geology
drill hole
A drill hole is a narrow hole bored into the ground by a drilling machine, used to bring up samples of rock from deep underground so geologists can study what is there.
技术层面: A drill hole is a borehole created by a drilling rig for the purpose of geological investigation, resource definition, geotechnical assessment, or hydrogeological testing; it is defined by its collar coordinates, azimuth, dip, and total depth, all of which must be surveyed to enable accurate three-dimensional plotting. In resource reporting, each drill hole is assigned a unique identifier, and its downhole survey data are used to reconstruct the actual path of the hole, which deviates from a straight line in most cases. Drill hole is the preferred term in technical reporting over the informal borehole when the context is mineral exploration, though the two are sometimes used interchangeably.
Geology
evaporite
An evaporite is a rock made from minerals that were left behind when a body of salty water dried up, the way a ring of white salt forms around the edge of a puddle as it evaporates.
技术层面: An evaporite is a sedimentary rock composed predominantly of minerals precipitated by the progressive concentration and eventual evaporation of saline water, either in marine basins or continental lake settings; common evaporite minerals include halite, gypsum, anhydrite, sylvite, and various borates and lithium salts. The sequence in which minerals precipitate follows solubility order, so the stratigraphic position within an evaporite succession indicates the degree of concentration the original brine reached and the depositional environment. Evaporites are economically significant both as ore themselves — potash and lithium brine deposits are evaporitic — and as host rocks or seals for other commodities, and their physical properties, particularly plasticity and low density, have important consequences for the structural geology of any basin in which they occur.
Geology
gangue
The useless rock mixed in with the valuable mineral. It has to be separated and discarded during processing.
技术层面: Gangue comprises the minerals in an ore that have no commercial value in the context of the operation and must be separated from the target mineral during beneficiation. Its composition matters practically because certain gangue minerals — clays, talc, pyrrhotite — complicate flotation, leaching or smelting. The term is specific to the unwanted mineral fraction; the broader term for all displaced non-ore material is waste rock.
Geology
geophysics
Geophysics is the science of using physical measurements — such as gravity, magnetism, or electrical signals — to work out what kinds of rock or minerals lie underground without having to dig there first.
技术层面: Applied geophysics in mineral exploration encompasses a range of techniques — including magnetics, gravity, seismic reflection, induced polarisation, electromagnetic, and radiometric surveys — that detect contrasts in physical rock properties such as density, magnetic susceptibility, electrical resistivity, and radioactive emission. Results are interpreted as anomalies relative to background, which then guide drill targeting rather than directly confirming the presence of ore. Geophysics is distinct from geochemistry, which measures elemental concentrations; the two disciplines are complementary and are routinely integrated in exploration programmes.
Geology
grade
How much of the valuable substance is in the rock, usually expressed as a small fraction — for example, grams of gold per tonne of rock, or a percentage of copper.
技术层面: Grade is the concentration of a target commodity within a sample, block, or orebody, expressed in units appropriate to the commodity — mass percent for base metals, grams per tonne for gold and platinum-group elements, parts per million for trace elements, and carats per hundred tonnes for diamonds. Average grade must always be qualified by the volume or mass it represents, because a high-grade but small intersection and a low-grade but large one can carry identical contained metal. Grade as reported in a resource statement is a block-averaged figure, not a point measurement.
Geology
greenfield
A greenfield project is an exploration effort in a place where no mining has ever taken place before, so the company is starting completely from scratch with no existing information about what lies underground.
技术层面: A greenfield exploration project is one conducted in an area with no prior mining or significant modern exploration history, meaning there is no inherited infrastructure, no historical drill database, and no existing resource to guide targeting. Risk at the greenfield stage is highest because the geological model is largely unvalidated, but so is the potential for a discovery that has no historical discount applied to its scale. The term is routinely contrasted with brownfield, and in practice the boundary between the two is not always sharp: an area near a historical mine but geologically untested may be treated as greenfield for modelling purposes.
Geology
host rock
The body of ordinary rock that surrounds or contains a mineral deposit — the background rock that the ore or veins sit inside.
技术层面: Host rock is the pre-existing rock body within which mineralisation has been emplaced, precipitated, or formed, irrespective of whether that rock was chemically altered in the process. The term is descriptive and spatial rather than genetic: it identifies what the deposit is hosted in without implying a particular origin for the mineralisation. In metasomatic systems such as skarns, the host rock is substantially modified, while in many vein systems it may be largely unchanged; both usages are correct, and care is needed not to conflate 'host rock' with 'unaltered country rock'.
Geology
hydrothermal
Anything to do with hot water moving through cracks in the Earth's crust, often carrying dissolved metals that crystallise out when the water cools.
技术层面: In economic geology, 'hydrothermal' describes processes, fluids, and deposits formed by the circulation of heated aqueous solutions through fractures and permeable zones in the crust. These fluids may derive from magmatic, metamorphic, or meteoric sources, and deposit minerals as temperature, pressure, or chemistry changes along the flow path. The term covers a wide range of deposit styles — from high-temperature porphyry systems to low-temperature epithermal veins — so it should always be qualified by temperature regime or deposit type in technical usage.
Geology
ion-adsorption clay
An ion-adsorption clay is a type of weathered rock in which rare earth elements are not locked tightly inside mineral crystals but instead cling loosely to the surface of clay particles, a bit like static-charged dust sticking to a screen, making them relatively easy to recover.
技术层面: Ion-adsorption clay deposits, also called in-situ leach rare earth deposits or weathered crust elution-deposited rare earth deposits, form by deep tropical or subtropical weathering of granitic or volcanic parent rocks, during which rare earth elements are released from primary minerals and adsorbed onto the surface of secondary clay minerals — principally halloysite, kaolinite, and smectite — rather than forming discrete rare earth minerals. Because the elements are electrostatically bound rather than structurally incorporated, they can be displaced into solution by treatment with ammonium sulfate or other electrolyte solutions at relatively low temperatures, which gives these deposits a processing advantage over hard-rock rare earth ores despite their typically low total rare earth oxide grades. They are the principal global source of heavy rare earth elements, which are preferentially enriched in them relative to the light rare earth elements that dominate most hard-rock deposits such as carbonatites.
Geology
kimberlite
A rare type of rock that erupts violently from very deep in the Earth and sometimes brings diamonds with it, forming carrot-shaped pipes in the crust.
技术层面: Kimberlite is a volatile-rich, ultramafic to potassic igneous rock emplaced from depths in excess of roughly 150 km, typically forming sub-vertical, roughly cylindrical bodies called pipes, dykes, and sills. It is the principal primary host for diamond, carrying xenoliths of mantle material including diamond-bearing peridotite. Kimberlite is often confused with lamproite, which can also be diamond-bearing; the distinction matters in exploration because the two rock types have different indicator-mineral suites and eruption styles.
Geology
laterite
A layer of deeply weathered soil or rock found in tropical regions, where heavy rainfall over millions of years has dissolved away most minerals and left iron and aluminium compounds behind. Some laterites are mined for nickel or bauxite.
技术层面: Laterite is a residual weathering product formed by intense and prolonged tropical or subtropical weathering that leaches silica and soluble cations from parent rock, leaving a material enriched in iron oxides, aluminium oxyhydroxides, and sometimes nickel, cobalt, or manganese. The term encompasses a spectrum from soft, clayey saprolite at depth to a hard, indurated ferruginous crust or duricrust at the surface. In the mining context, lateritic nickel deposits are distinct from magmatic sulfide nickel deposits in both mineralogy and processing requirements: the nickel is hosted in oxide and silicate minerals rather than sulfides, making pyrometallurgical and hydrometallurgical treatment substantially different.
Geology
mineralisation
The presence of useful or interesting minerals concentrated in rock, not necessarily enough to mine but enough to be worth studying.
技术层面: Mineralisation is the occurrence of one or more minerals of economic or potential economic interest within a rock body, introduced or concentrated by geological processes. The term is intentionally non-committal about grade or quantity, and its use in technical reporting deliberately avoids the implication that the material qualifies as a mineral resource under any reporting code. It is often used in early exploration to describe anomalous concentrations before sufficient data exist to classify the occurrence formally; once adequate drilling and sampling have been completed, the material may be reclassified as a mineral resource or found to fall below economic thresholds.
Geology
ore
Rock that contains enough of a useful mineral to be worth digging up and processing. Rock with the same mineral but too little of it is just rock.
技术层面: Ore is rock or sediment from which one or more commodities can be extracted at a profit under the prevailing economic and technical conditions. The classification is economic, not purely geological: the same material can be ore at one metal price and waste at another. It is often confused with 'mineral', which refers to a specific chemical compound regardless of whether its occurrence is economically exploitable.
Geology
orebody
A distinct mass of ore in the ground with a recognisable shape — like a thick underground blob or sheet of valuable rock that has been mapped out.
技术层面: An orebody is a continuous, three-dimensionally defined volume of rock that meets the criteria for ore and is sufficiently coherent in geometry and grade to be treated as a discrete extraction target. The term implies that the boundaries have been established by drilling or sampling, distinguishing it from a mere mineralised occurrence or prospect. A single deposit may contain several separate orebodies if high-grade zones are separated by material that does not meet cut-off grade.
Geology
outcrop
A place where solid bedrock is exposed at the surface, not covered by soil, loose sediment, or vegetation — the rock you can walk up to and touch.
技术层面: An outcrop is any exposure of in-situ bedrock or mineralisation at the Earth's surface, whether natural (erosion, cliff face, stream cut) or artificial (road cut, quarry face). In field mapping and early-stage exploration, outcrop is significant because it allows direct sampling and observation without drilling or trenching. The extent of outcrop should not be equated with the extent of the underlying unit, since the same rock body may extend considerable distances beneath cover; conversely, an apparently continuous outcrop may be interrupted by faulting that is invisible from the surface.
Geology
overburden
All the soil, loose rock, and waste material sitting on top of a mineral deposit that has to be moved out of the way before mining can begin.
技术层面: Overburden refers to the mass of rock, regolith, and soil overlying an orebody or target stratum that must be stripped or excavated to gain access to the material of interest, particularly in surface mining. The ratio of overburden volume to ore volume (the strip ratio) is a primary determinant of the economics of open-pit and strip mining. In some technical contexts, particularly in sedimentary basin studies, the term is used more broadly to denote any overlying rock sequence regardless of mining context, which can cause ambiguity; the intended meaning should be clear from context.
Geology
pegmatite
An igneous rock with exceptionally large crystals — sometimes as long as your arm. Pegmatites often contain unusual elements like lithium, caesium, and rare-earth metals that got concentrated into the last fluids as a magma cooled.
技术层面: Pegmatite is an intrusive igneous rock characterised by an extremely coarse crystal size, conventionally with a median grain size exceeding a few centimetres, formed from volatile-enriched residual melts or fluxed crystallisation in the final stages of magmatic cooling. The high concentrations of water, fluorine, boron, and lithium in these residual melts allow rare and large-ion-lithophile elements — lithium, caesium, rubidium, beryllium, tantalum, niobium, tin, and rare earths — to reach exploitable concentrations. Lithium-caesium-tantalum (LCT) pegmatites are the principal hard-rock source of lithium globally and are distinguished from the niobium-yttrium-fluorine (NYF) family by their geochemical affinity and tectonic setting.
Geology
placer deposit
A natural concentration of heavy or tough minerals that have been washed out of older rocks and settled in a riverbed, beach, or ancient valley floor, much like gold settling to the bottom of a prospector's pan.
技术层面: A placer deposit forms when weathering liberates resistant, dense minerals from their source rocks and flowing water, wind, or wave action sorts and concentrates them by specific gravity. Economically significant placers include alluvial (river), eluvial (hillslope), and marine shoreline varieties. The term is sometimes loosely applied to aeolian concentrations, but strictly these require separate qualification because the sorting mechanism differs from hydraulic settling.
Geology
porphyry
A type of igneous rock that has large crystals scattered through a finer-grained background, like chocolate chips in a biscuit. Several of the world's biggest copper and gold mines are found in porphyry rock.
技术层面: In economic geology, porphyry refers both to the igneous rock texture — phenocrysts set in an aphanitic or fine-grained groundmass — and to a class of large, low-grade, disseminated metal deposits genetically linked to shallow intrusions of porphyritic composition. Porphyry copper deposits, which may also carry molybdenum, gold, or silver, are typically of low grade but very large tonnage, with mineralisation distributed through a network of stockwork veins and fractures rather than in discrete high-grade shoots. They are distinguished from skarn and epithermal deposits by their intrusion-centred, stockwork-controlled geometry and broadly calc-alkaline host magmatism.
Geology
prospect
A prospect is a place where geologists have found enough signs of valuable minerals to investigate further, but where no one yet knows whether there is enough to mine.
技术层面: A prospect is an area of mineralisation interest that has been identified by surface sampling, mapping, or geophysical surveys and has received some exploratory attention, but which has not yet been sufficiently drilled or tested to support a mineral resource estimate under any recognised reporting code. It sits between a raw anomaly, which is merely a measurement departure, and a deposit, which has defined mineralisation geometry and grade continuity. The term carries no implication of economic viability; conflating prospect with deposit or resource is a common and consequential error in non-technical communication.
Geology
salar
A vast, flat salt flat found in the high deserts of South America. Beneath the salt crust lies salty water — called brine — which in some salars contains lithium at concentrations high enough to be mined.
技术层面: A salar is an endorheic salt flat occupying a closed basin in an arid to hyper-arid environment, characterised by an evaporite surface crust — predominantly halite, with variable sulfates and carbonates — and a subsurface porous horizon saturated with concentrated brine. The term is used most precisely for the high-altitude basins of the central Andean Puna plateau, though analogous features occur elsewhere. In the lithium industry, salars are significant because the brines beneath the crust of certain basins carry elevated lithium concentrations derived from volcanic inputs and long-term evaporative concentration; the geometry and hydrogeology of the brine aquifer govern the economics of extraction.
Geology
skarn
A rock formed when hot fluids from a cooling magma bake and chemically change the surrounding limestone, often leaving behind concentrations of metal minerals in the process.
技术层面: A skarn is a metasomatic rock produced by the reaction of high-temperature hydrothermal or magmatic fluids with carbonate-bearing country rocks, typically limestone or dolomite, resulting in a mineral assemblage dominated by calcium, magnesium, iron, and aluminium silicates such as garnet, pyroxene, and wollastonite. Economically, skarns host deposits of iron, copper, tungsten, zinc, lead, and other metals precipitated during the metasomatic process. The term is sometimes misapplied to any contact-metamorphic rock; strictly, skarn requires evidence of significant chemical exchange with an external fluid, not simply recrystallisation by heat alone.
Geology
stratabound
A mineral deposit that is confined to a particular layer or set of layers in the rock, running roughly parallel to the surrounding beds rather than cutting across them.
技术层面: A stratabound deposit is one whose mineralisation is largely or entirely contained within a specific stratigraphic unit or set of units, following bedding rather than cutting across it. The term does not necessarily imply that the deposit formed at the same time as the enclosing sediments (syndiagenetic); it may have been introduced later but was controlled by the permeability or chemistry of the host stratum. Stratabound is sometimes conflated with 'stratiform', but the latter implies a planar, layer-parallel geometry of the mineralisation itself, whereas stratabound refers only to stratigraphic confinement regardless of internal geometry.
Geology
strip ratio
In an open-pit mine, the strip ratio tells you how many tonnes of useless rock must be moved to reach each tonne of ore. A high strip ratio means a lot of digging for a little ore.
技术层面: Strip ratio, expressed as tonnes of waste per tonne of ore, is the primary measure of mining dilution in open-pit operations and a principal determinant of operating cost. As a pit deepens or extends laterally, the strip ratio typically rises, eventually reaching a point at which mining the marginal increment of ore is uneconomic and the pit limit is defined. Strip ratio should not be confused with dilution, which refers to the blending of waste or low-grade material into the ore stream, though both affect the effective grade processed.
Geology
supergene enrichment
A natural process where rainwater seeping into a mineral deposit dissolves metals near the surface and carries them downward, leaving behind a richer, concentrated zone deeper in the ground.
技术层面: Supergene enrichment occurs when oxidising meteoric water descends through a primary sulphide deposit, dissolves metals such as copper, and reprecipitates them at or below the water table as secondary sulphide or native-metal minerals, forming a zone of elevated grade above the unaltered primary ore. The overlying oxidised zone, from which metals have been leached, is termed the oxide cap or gossan. Supergene enrichment is frequently confused with secondary mineralisation in general; the specific distinction is that supergene processes are driven by downward-percolating surface water operating at low temperature, in contrast to hypogene (primary) mineralisation introduced from depth by hydrothermal fluids.
Geology
unconformity
An unconformity is a buried surface where a gap in time exists between two layers of rock — older rocks were worn away before new ones formed on top, leaving a kind of missing chapter in the rock record.
技术层面: An unconformity is a surface of contact between rock units that represents a significant hiatus in geological time, caused by erosion, non-deposition, or tectonic uplift of the older sequence before deposition of the younger one resumed. In mineral exploration, unconformities are structurally and chemically significant because they can act as pathways for hydrothermal fluids and as chemical or permeability traps that localise ore; the Athabasca Basin unconformity-type uranium deposits are the canonical example. Three main varieties are recognised — angular unconformity, disconformity, and nonconformity — distinguished by whether bedding above and below is parallel and whether the lower unit is sedimentary or crystalline.
Geology
vein
A sheet-like filling of minerals occupying a crack in older rock, like a seam of material running through a block of stone.
技术层面: In geology, a vein is a tabular body of minerals deposited by fluids that have crystallised within a fracture or fault in the host rock, typically under hydrothermal conditions. Veins are distinguished from dykes by their mineral (not igneous) fill, and from sedimentary layers by their cross-cutting or discordant relationship to surrounding strata. In economic geology, the term carries the specific implication that the mineralised fill is spatially discrete and bounded, which has direct consequences for how tonnage and grade are estimated during resource definition.
Geology