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The various theories of ore genesis explain how the various types of mineral deposits form within the Earth's crust. Ore genesis theories are very dependent on the mineral or commodity. Earth cutaway from core to exosphere. ...
Minerals are natural compounds formed through geological processes. ...
Ore genesis theories generally involve three components: source, transport or conduit, and trap. This also applies to the petroleum industry, which was first to use this methodology. Pumpjack pumping an oil well near Sarnia, Ontario Petroleum (from Greek petra – rock and elaion – oil or Latin oleum – oil ), crude oil, sometimes colloquially called black gold or Texas Tea, is a thick, dark brown or greenish liquid. ...
- Source is required because metal must come from somewhere, and be liberated by some process
- Transport is required first to move the metal bearing fluids or solid minerals into the right position, and refers to the act of physically moving the metal, as well as chemical or physical phenomenon which encourage movement
- Trapping is required to concentrate the metal via some physical, chemical or geological mechanism into a concentration which forms mineable ore
The biggest deposits are formed when the source is large, the transport mechanism is efficient, and the trap is active and ready at the right time. Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a volume of rock containing components or minerals in a mode of occurrence which renders it valuable for mining. ...
Ore genesis processes Evans (1993) divides ore genesis into the following main categories based on physical process. These are internal processes, hydrothermal processes, metamorphic processes and surficial processes.
Internal processes These processes are integral physical phenomena and chemical reactions internal to magmas, generally in plutonic or volcanic rocks. These include; Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ...
Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ...
- Fractional crystallization, either creating monominerallic cumulate ores or contributing to the enrichment of ore minerals and metals
- Liquation, or liquid immiscibility between melts of differing composition, usually sulfide segregations of nickel-copper-platinoid sulfides and silicates.
In chemistry, Fractional Crystallization is a method of refining substances based on differences in soluability. ...
In geology a cumulate is an igneous rock formed by the accumulation of crystals from a magma. ...
Miscibility is the ability of two or more substances to mix, and form a single homogeneous phase. ...
Hydrothermal processes These processes are the physico-chemical phenomena and reactions caused by movement of hydrothermal waters within the crust, often as a consequence of magmatic intrusion or tectonic upheavals. The foundations of hydrothermal processes are the source-transport-trap mechanism. Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ...
Sources of hydrothermal solutions include seawater, formational brines (water trapped within sediments at deposition) and metamorphic fluids created by dehydration of hydrous minerals during metamorphism. Brine is water saturated or nearly saturated with salt. ...
Metamorphism can be defined as the mineralogical, chemical and crystallographic changes in a solid-state rock, i. ...
Metal sources may include a plethora of rocks. However most metals of economic importance are carried as trace elements within rock-forming minerals, and so may be liberated by hydrothermal processes. This happens because of
- incompatibility of the metal with its host mineral, for example zinc in calcite, which favours aqueous fluids in contact with the host mineral under diagenesis.
- solubility of the host mineral within nascent hydrothermal solutions in the source rocks, for example mineral salts (halite), carbonates (cerussite), phosphates (monazite and thorianite) and sulfates (barite)
- elevated temperatures causing decomposition reactions of minerals
Transport by hydrothermal solutons usually requires a salt or other soluble species which can form a metal-bearing complex. These metal-bearing complexes facilitate transport of metals within aqueous solutions, generally as hydroxides, but also by processes similar to chelation.
This process is especially well understood in gold metallogeny where various thiosulfate, chloride and other gold-carrying chemical complexes (notably tellurium-chloride/sulfate or antimony-chloride/sulfate). The majority of metal deposits formed by hydrothermal processes include sulfide minerals, indicating sulfur is an important metal-carrying complex. General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ...
SAM WAS HERE!!!!!!!!!! Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ...
In geology, diagenesis refers to all the chemical, physical, and biological changes undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration (weathering). ...
Halite is the mineral form of sodium chloride, NaCl, commonly known as rock salt. ...
Sample of cerussite-bearing quartzite Cerussite (also known as Horn silver, Lead carbonate, White lead ore) is a mineral consisting of lead carbonate (PbCO3), and an important ore of lead. ...
Monazite powder In geology, the mineral monazite is a reddish-brown phosphate containing rare earth metals and an important source of thorium, lanthanum, and cerium. ...
Thorianite is a rare mineral, discovered by W. D. Holland, and found in the gem-gravels of Sri Lanka, where it occurs as small, heavy, black, cubic crystals, usually much water-worn. ...
Baryte with Cerussite from Morocco Baryte with Galena and Hematite from Poland Barite (BaSO4) is a mineral consisting of barium sulfate. ...
Chelation (from Greek, claw like) describes the reversible binding of an organic ligand, the chelator or chelating agent, to a metal ion, forming a metal complex, the chelate. ...
General Name, Symbol, Number tellurium, Te, 52 Chemical series metalloids Group, Period, Block 16, 5, p Appearance silvery lustrous gray Atomic mass 127. ...
The term sulfide (sulphide in British) refers to several types of chemical compounds containing sulfur in its lowest oxidation number of -2. ...
Sulfide deposition:
Sulfide deposition within the trap zone occurs when metal-carrying sulfate, sulfide or other complexes become chemically unstable due to one or more of the following processes;
- falling temperature, which renders the complex unstable or metal insoluble
- loss of pressure, which has the same effect
- reaction with chemically reactive wall rocks, usually of reduced oxidation state, such as iron bearing rocks, mafic or ultramafic rocks or carbonate rocks
- degassing of the hydrothermal fluid into a gas and water system, or boiling, which alters the metal carrying capacity of the solution and even destroys metal-carrying chemical complexes
Metal can also become precipitated when temperature and pressure or oxidation state favour different ionic complexes in the water, for instance the change from sulfide to sulfate, oxygen fugacity, exchange of metals between sulfide and chloride complexes, etcetera. In ring theory, a ring R is said to be reduced if it has no non-zero nilpotent elements. ...
In chemistry, the oxidation state is a measure of the degree of oxidation of an atom in a chemical compound. ...
In geology, mafic minerals and rocks are silicate minerals, magmas, and volcanic and intrusive igneous rocks that have relatively high concentrations of the heavier elements. ...
Ultramafic (or ultrabasic) rocks are igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content). ...
In inorganic chemistry, a carbonate is a salt of carbonic acid. ...
In thermodynamics, the fugacity is a state function of any isothermal system. ...
Metamorphic processes Lateral secretion:
Ore deposits formed by lateral secretion are formed by metamorphic reactions during shearing, which liberate mineral constituents such as quartz, sulfides, gold, carbonates and oxides from deforming rocks and focus these constituents into zones of reduced pressure or dilation such as faults. This may occur without much hydrothermal fluid flow, and this is typical of podiform chromite deposits. Study of geological shear is related to the study of structural geology, rock microstructure or rock texture and fault mechanics. ...
Old fault exposed by roadcut near Harrisburg, Pennsylvania. ...
Metamorphic processes also control many physical processes which form the source of hydrothermal fluids, outlined above.
Surficial processes Surficial processes are the physical and chemical phenomena which cause concentration of ore material within the regolith, generally by the action of the environment. This includes placer deposits, laterite deposits and residual or eluvial deposits. The physical processes of ore deposit formation in the surficial realm include; Regolith (Greek: blanket rock) is a layer of loose, heterogeneous material covering solid rock. ...
A sluice box used in placer mining Placer mining (pronounced plass-er) is a open-pit or open-cast form of mining by which certain valuable minerals are extracted from the earth without tunneling. ...
Laterite is a red-colored clay rich soil found in the tropics and subtropics. ...
Eluvium or eluvial deposits are those geological deposits and soils that are derived by in situ weathering or weathering plus gravitational movement or accumulation. ...
- erosion
- deposition by sedimentary processes, including winnowing, density separation (eg; gold placers)
- weathering via oxidation or chemical attack of a rock, either liberating rock fragments or creating chemically deposited clays, laterites or manto deposits
- Deposition in low-energy environments in beach environments
Severe soil erosion in a wheat field near Washington State University, USA. Erosion is the displacement of solids (soil, mud, rock, and other particles) by the agents of wind, water, ice, movement in response to gravity, or living organisms (in the case of bioerosion). ...
Wind winnowing is a method developed by ancient cultures for agricultural purposes. ...
Weathering is the process of disintegration of rocks, soils and their minerals through natural, chemical, and biological processes. ...
Orebody mantos are irregular to rod shaped ore occurrences usually horizontal or near horizontal in attitude and commonly restricted to some stratigraphic layer. ...
90 mile beach Australia A beach or strand is a geological formation consisting of loose rock particles such as sand, shingle, cobble, or even shell along the shoreline of a body of water. ...
Classification of ore deposits Ore deposits are usually classified by ore formation processes and geological setting. For example, SEDEX deposits, literally meaning "sedimentary exhalative" are a class of ore deposit formed on the sea floor (sedimentary) by exhalation of brines into seawater (exhalative), causing chemical precipitation of ore minerals when the brine cools, mixes with sea water and loses its metal carrying capacity.
Ore deposits rarely fit snugly into the boxes in which geologists wish to place them. Many may be formed by one or more of the basic genesis processes above, creating ambiguous classifications and much argument and conjecture. Often ore deposits are classified after examples of their type, for instance Broken Hill Type lead-zinc-silver deposits or Carlin-type Gold deposits. Broken Hill is an isolated mining city and Local Government Area in the far west of outback New South Wales, Australia, with a population of 21,000. ...
Carlin can refer to: George Carlin The dog breed also known as Pug This is a disambiguation page: a list of articles associated with the same title. ...
Classification of hydrothermal ore deposits is also achieved by classifying according to the temperature of formation, which roughly also correlates with particular mineralising fluids, mneral associations and structural styles. This scheme, proposed by Lindgren (1933) classified hydrothermal deposits as hypothermal, mesothermal, epithermal and telethermal. In climatology, the term mesothermal is used to refer to certain forms of climate found typically in the Earths Temperate Zones. ...
Common classification groupings - Magmatic nickel-copper-iron-PGE deposits including
- Carbonatite - alkaline igneous related deposits including,
Olympic Dam (30°27′ S 136°53′ E) is a Australian mining centre in South Australia - located some 550km NNW of Adelaide the capital city of South Australia. ...
In climatology, the term mesothermal is used to refer to certain forms of climate found typically in the Earths Temperate Zones. ...
A lode is the metalliferous ore that fills a fissure in a rock or a vein of ore deposited between layers of rock. ...
Kalgoorlie is a Western Australian city located about 600 km east of Perth. ...
Kalgoorlie may refer to the following geographically related places: Kalgoorlie, Western Australia, a city and council in Western Australia; Division of Kalgoorlie, a federal division of the Australian House of Representatives located around the geographical area; Electoral district of Kalgoorlie, an electoral district of the Western Australian Legislative Assembly. ...
Witwatersrand is a low mountain range which runs through Gauteng in South Africa. ...
Carlin can refer to: George Carlin The dog breed also known as Pug This is a disambiguation page: a list of articles associated with the same title. ...
Jasperoid is a rare, peculiar type of metasomatic alteration and occurs in two main forms; sulfidic jasperoids and hematitic jasperoids. ...
A stockwork is a complex system of randomly oriented veins. ...
porphyry copper ...
Tombstone most commonly means a headstone marking the grave of a deceased person. ...
Official language(s) English Capital Juneau Largest city Anchorage Area - Total - Width - Length - % water - Latitude - Longitude Ranked 1st 663,267 sq mi 1,717,854 km² 808 miles 1,300 km 1,479 miles 2,380 km 13. ...
Broken Hill is an isolated mining city and Local Government Area in the far west of outback New South Wales, Australia, with a population of 21,000. ...
Sedimentary exhalative deposits (abbreviated as SEDEX from SEDimentary EXhalative) are ore deposits which are interpreted to have been formed by release of ore-bearing hydrothermal fluids into a water reservoir (usually the ocean), resulting in the precipitation of stratiform ore. ...
This article is about the chemical element. ...
General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ...
General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...
Red Dog, also known as Yablon, Ace-deuce, In between or Between the sheets, is a game of chance played with cards. ...
Mount Isa, Queensland, Australia Mount Isa is a city located in north western Queensland, Australia. ...
General Name, Symbol, Number tungsten, W, 74 Chemical series transition metals Group, Period, Block 6, 6, d Appearance grayish white, lustrous Atomic mass 183. ...
In the 19th century the Erzgebirge mountains were a centre for lace making. ...
Chert Chert is a fine-grained silica-rich cryptocrystalline sedimentary rock that may contain small fossils. ...
Official language(s) English Capital Jackson Largest city Jackson Area - Total - Width - Length - % water - Latitude - Longitude Ranked 32nd 125,443 km² 275 km 545 km 3 30°13N to 35°N 88°7W to 91°41W Population - Total (2000) - Density Ranked 31st 2,697,243 23. ...
In geology a cumulate is an igneous rock formed by the accumulation of crystals from a magma. ...
Vanadium is a chemical element in the periodic table that has the symbol V and atomic number 23. ...
Magnetite is a ferromagnetic mineral form of iron(II,III) oxide, with chemical formula , one of several iron oxides and a member of the spinel group. ...
Chromite, iron magnesium chromium oxide: (Fe,Mg)Cr2O4, is an oxide mineral belonging to the spinel group. ...
Ilmenite (FeTiO3) is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and plutonic igneous rocks. ...
Norilsk downtown was designed in a typical Stalinist style. ...
Sudbury Basin is the oval structure, next to the much younger lake-filled Wanapitei crater The Sudbury Basin is the second largest impact crater on earth, and a major geologic structure in Ontario, Canada. ...
Laterite is a red-colored clay rich soil found in the tropics and subtropics. ...
Volcanogenic massive sulfide ore deposits or VMS are a type of metal sulfide ore deposit, mainly Cu-Zn, associated with certain types of volcanism. ...
Iron oxide pigment There are a number of iron oxides: Iron oxides Iron(II) oxide or ferrous oxide (FeO) The black-coloured powder in particular can cause explosions as it readily ignites. ...
Chromite, iron magnesium chromium oxide: (Fe,Mg)Cr2O4, is an oxide mineral belonging to the spinel group. ...
The Savage River is located in Garrett County, Maryland and is the first large tributary of the North Branch of the Potomac River. ...
2. ...
This heap of iron ore pellets will be used in steel production. ...
Carbonatites are intrusive igneous rock structures with more than 50% carbonate content, many of which contain distinctive abundances of apatite, magnetite, barite, and fluorite, that may contain economic or anomalous concentrations of rare earth elements, phosphorus, niobium, uranium, thorium, copper, iron, titanium, barium, fluorine, zirconium, and other rare or incompatible...
Tantalite is a mineral that is close to columbite. ...
Vermiculite is a natural mineral which expands with the application of heat. ...
Phalaborwa is a large town situated at half way up along the length of the Kruger National Park in Limpopo Province of South Africa. ...
de;Metalle der Seltenen Erden Categories: Stub | Chemical element groups ...
Genesis of common ores This page has been organised by metal commodity; it is also possible to organise theories according to geological criteria of formation, as well as by metal association. Often ores of the same metal can be formed by multiple processes, and this is described by commodity. Hot metal work from a blacksmith Look up Metal in Wiktionary, the free dictionary In chemistry, a metal (Greek: Metallon) is an element that readily forms ions (cations) and has metallic bonds, and metals are sometimes described as a lattice of positive ions (cations) surrounded by a sea of delocolised...
The word commodity is a term with distinct meanings in business and in Marxian political economy. ...
Geology (from Greek γη- (ge-, the earth) and λογος (logos, word, reason)) is the science and study of the Earth, its composition, structure, physical properties, history, and the processes that shape it. ...
Iron Iron ores are overwhelmingly derived from ancient sediments known as banded iron formations (BIFs). These sediments are composed of iron oxide minerals deposited on the sea floor. Particular environmental conditions are needed to transport enough iron in sea water to form these deposits, such as acidic and oxygen-poor atmospheres within the Proterozoic Era. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ...
2. ...
Iron oxide pigment There are a number of iron oxides: Iron oxides Iron(II) oxide or ferrous oxide (FeO) The black-coloured powder in particular can cause explosions as it readily ignites. ...
In geology, the Proterozoic is an eon prior to the first abundant complex life on earth. ...
Often, more recent weathering during the Tertiary or Eocene is required to convert the usual magnetite minerals into more easily processed hematite. Some iron deposits within the Pilbara of West Australia are placer deposits, formed by accumulation of hematite gravels called pisolites. These are preferred because they are cheap to mine. Weathering is the process of disintegration of rocks, soils and their minerals through natural, chemical, and biological processes. ...
The Tertiary period was previously one of the major divisions of the geologic timescale, from the end of the Cretaceous period about 65 million years ago to the start of the Quaternary period about 1. ...
The Eocene epoch (56-34 Ma) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. ...
Magnetite is a ferromagnetic mineral form of iron(II,III) oxide, with chemical formula , one of several iron oxides and a member of the spinel group. ...
Hematite (AE) or haematite (BE) is the mineral form of Iron (III) oxide, (Fe2O3), one of several iron oxides. ...
The Pilbara is one of the nine regions of Western Australia. ...
Motto: Cygnis Insignis (Distinguished by its swans) Nickname: Wildflower State Other Australian states and territories Capital Perth Government Governor Premier Const. ...
Lead zinc silver Lead-zinc deposits are generally accompanied by silver, hosted within the lead sulfide galena or within the zinc sulfide sphalerite. This article is about the chemical element. ...
General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ...
General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...
Galena is a lead ore. ...
Sphalerite sample Another sphalerite sample Sphalerite (ZnS) is a mineral that is the chief ore of zinc. ...
Lead and zinc deposits are formed by discharge of deep sedimentary brine onto the sea floor (termed sedimentary exhalative or SEDEX), or by replacement of limestone, in skarn deposits, some associated with submarine volcanoes (called volcanic-hosted massive sulfide or VHMS) or in the aureole of subvolcanic intrusions of granite. The vast majority of lead and zinc deposits are Proterozoic in age. The immense Broken Hill, Century Zinc, Lady Loretta, and Mt Isa deposits in Australia, the sullivan, Red Dog and Jason deposits of North America and the Hindustan zinc belt in India are all SEDEX type deposits. Brine is water saturated or nearly saturated with salt. ...
Sedimentary exhalative deposits (abbreviated as SEDEX from SEDimentary EXhalative) are ore deposits which are interpreted to have been formed by release of ore-bearing hydrothermal fluids into a water reservoir (usually the ocean), resulting in the precipitation of stratiform ore. ...
Limey shale overlaid by limestone. ...
Skarn is a fine grained metamorphic rock that is usually variably colored green or red, occasionally grey, black, brown or white. ...
Images of Mary, mother of Jesus are often surrounded by an aureole, as in this image of Our Lady of Guadalupe. ...
In geology, the Proterozoic is an eon prior to the first abundant complex life on earth. ...
Broken Hill is an isolated mining city and Local Government Area in the far west of outback New South Wales, Australia, with a population of 21,000. ...
Mount Isa, Queensland, Australia Mount Isa is a city located in north western Queensland, Australia. ...
Hindustan (Hindi: हिनà¥à¤¦à¥à¤¸à¥à¤¤à¤¾à¤¨ [HindustÄn], Urdu: [HindostÄn], from the (Sanskrit) HindÅ« + -stÄn, archaic Hindoostan) and the adjective Hindustani may relate to various aspects of four geographic areas: Hindustan: Land of the Hindus. ...
The limestone replacement type of deposit exemplifies the Mississippi Valley Type (MVT). Some of these occur by replacement and degradation of hydrocarbons, which are thought important for transporting lead. Hydrocarbons are refined at oil refineries and processed at chemical plants In chemistry, a hydrocarbon is any chemical compound that consists only of the elements carbon (C) and hydrogen (H). ...
The subvolcanic intrusion type of deposit is renowned for high silver grades, and typifies the deposits of Argentina, Bolivia and Peru. These deposits are essentially Cenozoic in age and are known as the Andean silver belt, the most recent example being San Cristobal with 450 million ounces of silver. These deposits form by discharge of fluids bearing incompatible elements from the cooling granite mass, and have low lead grades but exceptional silver enrichment. The Cenozoic Era (sen-oh-ZOH-ik; sometimes Caenozoic Era in the United Kingdom) meaning new life (Greek kainos = new + zoe = life) is the most recent of the three classic geological eras. ...
Gold Gold deposits are formed via a very wide variety of geological processes. Deposits are classified as primary, alluvial or placer deposits, or residual or laterite deposits. Often a deposit will contain a mixture of all three types of ore. Geology (from Greek γη- (ge-, the earth) and λογος (logos, word, reason)) is the science and study of the Earth, its composition, structure, physical properties, history, and the processes that shape it. ...
A sluice box used in placer mining Placer mining (pronounced plass-er) is a open-pit or open-cast form of mining by which certain valuable minerals are extracted from the earth without tunneling. ...
Laterite is a red-colored clay rich soil found in the tropics and subtropics. ...
Plate tectonics is the underlying mechanism for generating gold deposits. The majority of primary gold deposits fall into two main categories: lode gold deposits or intrusion-related deposits. It has been suggested that Tectonic plate be merged into this article or section. ...
A lode is the metalliferous ore that fills a fissure in a rock or a vein of ore deposited between layers of rock. ...
Pluton redirects here. ...
Lode gold deposits are generally high-grade, thin, vein and fault hosted. They are comprised primarily of quartz veins also known as lodes or reefs, which contain either native gold or gold sulfides and tellurides. Lode gold deposits are usually hosted in basalt or in sediments known as turbidite, although when in faults, may occupy intrusive igenous rocks such as granite. Quartz is amongst one of the most common minerals in the Earths continental crust. ...
In chemistry, a sulfide (sulphide in British and Canadian English) is a combination of sulfur with an oxidation number of -2, with another chemical element or a radical thereof. ...
Telluride is either: A compound of a metal with the element Tellurium. ...
Basalt Basalt is a common gray to black volcanic rock. ...
USGS image Turbidite geological formations have their origins in turbidity current deposits, deposits from a form of underwater avalanche that are responsible for distributing vast amounts of clastic sediment into the deep ocean. ...
Old fault exposed by roadcut near Harrisburg, Pennsylvania. ...
Quarrying granite for the Mormon Temple, Utah Territory. ...
Lode-gold deposits are intimately associated with orogeny and other plate collision events within geologic history. Most lode gold deposits sourced from metamorphic rocks because it is thought that the majority are formed by dehydration of basalt during metamorphism. The gold is transported up faults by hydrothermal waters and deposited when the water cools too much to retain gold in solution. Orogeny is the process of mountain building, and as such is both a tectonic structural event, a geographical event and a chronological event, in that orogenic events happen within a time frame, affect certain regions of rocks and crust, and cause distinctive structural phenomena and related tectonic activity. ...
Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means change in form, derived from the Greek words meta, change, and morphe, form. The protolith is subjected to extreme heat (>150 degrees Celsius) and pressure causing profound...
Dehydration is the removal of water (hydor in ancient Greek) from an object. ...
Basalt Basalt is a common gray to black volcanic rock. ...
Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ...
Intrusive related gold (Lang & Baker, 2001) is generally hosted in granites, porphyry or rarely dikes. Intrusive related gold usually also contains copper, and is often associated with tin and tungsten, and rarely molybdenum, antimony and uranium. Intrusive-related gold deposits rely on gold existing in the fluids associated with the magma (White, 2001), and the inevitable discharge of these hydrothermal fluids into the wall-rocks (Lowenstern, 2001). Skarn deposits are another manifestation of intrusive-related deposits. (For other meanings of Porphyr, see Porphyry) A slab of imperial porphyry from Egypt, about 15 cm across. ...
A dike in geology refers to a tabular intrusive igneous body. ...
General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ...
General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ...
General Name, Symbol, Number tungsten, W, 74 Chemical series transition metals Group, Period, Block 6, 6, d Appearance grayish white, lustrous Atomic mass 183. ...
General Name, Symbol, Number molybdenum, Mo, 42 Chemical series transition metals Group, Period, Block 6, 5, d Appearance gray metallic Atomic mass 95. ...
General Name, Symbol, Number antimony, Sb, 51 Chemical series metalloids Group, Period, Block 15, 5, p Appearance silvery lustrous grey Atomic mass 121. ...
General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ...
Magma is molten rock located beneath the surface of the Earth (or any other rocky planet), and which often collects in a magma chamber. ...
Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ...
Skarn is a fine grained metamorphic rock that is usually variably colored green or red, occasionally grey, black, brown or white. ...
Placer deposits are sourced from pre-existing gold deposits and are secondary deposits. Placer deposits are formed by alluvial processes within rivers, streams and on beaches. Placer gold deposits form via gravity, with the density of gold causing it to sink into trap sites within the river bed, or where water velocity drops, such as bends in rivers and behind boulders. Often placer deposits are found within sedimentary rocks and can be billions of years old, for instance the Witwatersrand deposits in South Africa. Sedimentary placer deposits are known ad 'leads' or 'deep leads'. Examples include the gold deposits of Bendigo and Ballarat in Australia. Alluvium is soil land deposited by a river or other running water. ...
Beaches is a 1988 movie adapted by Mary Agnes Donoghue from the novel Beaches by Iris Rainer Dart. ...
Gravity is a force of attraction that acts between bodies that have mass. ...
Density (symbol: Ï - Greek: rho) is a measure of mass per unit of volume. ...
Witwatersrand is a low mountain range which runs through Gauteng in South Africa. ...
Bendigo () is a regional city in central Victoria, located in the City of Greater Bendigo. ...
Location of Ballarat in Victoria (red) Ballarat Base Hospital For the electoral division in the Australian House of Representatives, see Division of Ballarat. ...
Placer deposits are often worked by fossicking, and panning for gold is a popular pastime. Fossicking is searching for gold by sifting through prospective area. ...
Laterite gold deposits are formed from pre-existing gold deposits (including some placer deposits) during prolonged weathering of the bedrock. Gold is deposited within iron oxides in the weathered rock or regolith, and may be further enriched by reworking by erosion. Some laterite deposits are formed by wind erosion of the bedrock leaving a residuum of native gold metal at surface. Laterite is a red-colored clay rich soil found in the tropics and subtropics. ...
Iron oxide pigment There are a number of iron oxides: Iron oxides Iron(II) oxide or ferrous oxide (FeO) The black-coloured powder in particular can cause explosions as it readily ignites. ...
Regolith (Greek: blanket rock) is a layer of loose, heterogeneous material covering solid rock. ...
Platinum Platinum and palladium are precious metals generally found in ultramafic rocks. The source of platinum and palladium deposits is ultramafic rocks which have enough sulfur to form a sulfide mineral while the magma is still liquid. This sulfide mineral (usually pentlandite, pyrite, chalcopyrite or pyrrhotite) gains platinum by mixing with the bulk of the magma because platinum is chalcophile and is concentrated in sulfides. Alternatively, platinum occurs in association with chromite either within the chromite mineral itself or within sulfides associated with it. Ultramafic (or ultrabasic) rocks are igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content). ...
General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ...
The term sulfide (sulphide in British) refers to several types of chemical compounds containing sulfur in its lowest oxidation number of -2. ...
Pentlandite is a iron-nickel sulfide, (Fe,Ni)9S8. ...
The mineral pyrite, or iron pyrite, is iron disulfide, FeS2. ...
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. ...
Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: Fe(1-x)S (x = 0 to 0. ...
The Goldschmidt Classification, developed by Victor Goldschmidt, is a geochemical classification which groups the chemical elements according to their preferred host phases into siderophile (iron loving), lithophile (silicate loving), chalcophile (sulphur loving), and atmophile (gas loving). ...
Chromite, iron magnesium chromium oxide: (Fe,Mg)Cr2O4, is an oxide mineral belonging to the spinel group. ...
Sulfide phases only form in ultramafic magmas when the magma reaches sulfur saturation. This is generally thought to be nearly impossible by pure fractional crystallisation, so other processes are usually required in ore genesis models to explain sulfur saturation. These include contamination of the magma with crustal material, especially sulfur-rich wall-rocks or sediments; magma mixing; volatile gain or loss.
Often platinum is associated with nickel, copper, chromium, and cobalt deposits. General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Atomic mass 195. ...
General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ...
General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ...
General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ...
General Name, Symbol, Number cobalt, Co, 27 Chemical series transition metals Group, Period, Block 9, 4, d Appearance metallic with gray tinge Atomic mass 58. ...
Nickel Nickel deposits are generally found in two forms, either as sulfide or laterite.
Sulfide type nickel deposits are formed in essentially the same manner as platinum deposits. Nickel is a chalcophile element which prefers sulfides, so an ultramafic or mafic rock which has a sulfide phase in the magma may form nickel deposits. The best nickel deposits are formed where sulfide accumulates, much like in a placer gold deposit, in the base of lava tubes or volcanic flows — especially komatiite lavas. General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Atomic mass 195. ...
Thurston Lava Tube in Hawaii_Volcanoes_National_Park Lava tubes are natural conduits through which lava travels beneath the surface of a lava flow. ...
This article is about volcanoes in geology. ...
Komatiites are ultramafic mantle-derived volcanic rocks. ...
Komatiitic nikel-copper sulfide deposits are considered to be formed by a mixture of sulfide segregation, immiscibility, and thermal erosion of sulfidic sediments. The sediments are considered to be necessary to promote sulfur saturation.
Some subvolcanic sills in the Thompson Belt of Canada host nickel sulfide deposits formed by deposition of sulfides near the feeder vent. Sulfide was accumulated near the vent due to the loss of magma velocity at the vent interface. The massive Voisey's Bay nickel deposit is considered to have formed via a similar process.
The process of forming nickel laterite deposits is essentially similar to the formation of gold laterite deposits, except that ultramafic or mafic rocks are required. Generally nickel laterites require very large olivine-bearing ultramafic intrusions. Minerals formed in laterite nickel deposits include gibbsite. Ultramafic (or ultrabasic) rocks are igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content). ...
In geology, mafic minerals and rocks are silicate minerals, magmas, and volcanic and intrusive igneous rocks that have relatively high concentrations of the heavier elements. ...
Olivine The mineral olivine is a magnesium iron silicate with the formula (Mg,Fe)2SiO4 in which the ratio of magnesium and iron varies between the two endmembers of the series: forsterite (Mg-rich) and fayalite (Fe-rich). ...
Gibbsite, Al(OH)3, is an important ore of aluminium and is one of three minerals that make up the rock bauxite. ...
Copper Copper is found in association with many other metals and deposit styles. Commonly, copper is either formed within sedimentary rocks, or associated with igneous rocks. Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ...
The world's major copper deposits are formed within the granitic porphyry copper style. The source of the copper is generally considered to be the lower crust or mantle where the granite melt forms. The copper is enriched by processes during crystallisation of the granite and forms as chalcopyrite — a sulfide mineral, which is carried up with the granite. porphyry copper ...
Earth cutaway from core to exosphere. ...
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. ...
Sometimes granites erupt to suface as volcanoes, and copper mineralisation forms during this phase when the granite and volcanic rocks cool via hydrothermal circulation. This article is about volcanoes in geology. ...
Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ...
Sedimentary copper forms within ocean basins in sedimentary rocks. Generally this forms by brine from deeply buried sediments discharging into the deep sea, and precipitating copper and often lead and zinc sulfides directly onto the sea floor. This is then buried by further sediment. Brine is water saturated or nearly saturated with salt. ...
This article is about the chemical element. ...
General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ...
Often copper is associated with gold, lead, zinc and nickel deposits. General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ...
This article is about the chemical element. ...
General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ...
General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ...
Uranium Uranium deposits are usually sourced from radioactive granites, where certain minerals such as monazite are leached during hydrothermal activity or during circulation of groundwater. The uranium is brought into solution by acidic conditions and is deposited when this acidity is neutralised. Generally this occurs in certain carbon-bearing sediments, within an unconformity in sedimentary strata. The majority of the world's nuclear power is sourced from uranium in such deposits. Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ...
Monazite powder In geology, the mineral monazite is a reddish-brown phosphate containing rare earth metals and an important source of thorium, lanthanum, and cerium. ...
Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ...
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of geologic formations. ...
There is a billion year gap in the geologic record where this 500 million year old dolomite lies on 1. ...
A nuclear power station. ...
Uranium is also found in nearly all coal at several parts per million, and in all granites. Certain granites are so radioactive that it is unhealthy to live atop them. Radon is a common problem during mining of uranium as it is a radioactive gas. Coal is a fossil fuel extracted from the ground by underground mining or open-pit mining (surface mining). ...
Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ...
General Name, Symbol, Number radon, Rn, 86 Chemical series noble gases Group, Period, Block 18, 6, p Appearance colorless Atomic mass (222) g/mol Electron configuration [Xe] 4f14 5d10 6s2 6p6 Electrons per shell 2, 8, 18, 32, 18, 8 Physical properties Phase gas Melting point 202 K (-71 °C...
Uranium is also found associated with certain igenous rocks, such as granite and porphyry. The Olympic Dam deposit in Australia is an example of this type of uranium deposit. It contains 70% of Australia's share of 40% of the global low-cost recoverable uranium inventory. Quarrying granite for the Mormon Temple, Utah Territory. ...
(For other meanings of Porphyr, see Porphyry) A slab of imperial porphyry from Egypt, about 15 cm across. ...
Olympic Dam (30°27′ S 136°53′ E) is a Australian mining centre in South Australia - located some 550km NNW of Adelaide the capital city of South Australia. ...
Geoscience Australia Uranium Infosheet
Titanium Titanium ore is formed as placer deposits - literally 'mineral sands' - or as layers within ultramafic layered intrusions. Titanium within layered intrusions forms as ilmenite, a titanium oxide mineral, via the process of crystallisation as the intrusion cools. Sufficently thick ilmenite layers will form ore. These layers can form considerable tonnages and lengths. This type of ore is known as 'hard rock titanium'. Hard rock titanium mineralisation may contain vanadium as a second ore metal, as a contaminant within the ilmenite. Most sand on beaches consists of grains of the mineral quartz (SiO2). ...
Ultramafic (or ultrabasic) rocks are igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content). ...
Ilmenite (FeTiO3) is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and plutonic igneous rocks. ...
Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a volume of rock containing components or minerals in a mode of occurrence which renders it valuable for mining. ...
Vanadium is a chemical element in the periodic table that has the symbol V and atomic number 23. ...
Mineral sands Mineral sands are the predominant type of titanium, zirconium and thorium deposit. They are formed by accumulation of such heavy minerals within beach systems, and are a type of placer deposits. The minerals which contain titanium are ilmenite and leucoxene, zirconium is contained within zircon, and thorium is generally contained within monazite. These minerals are sourced from primarily granite bedrock by erosion and transported to the sea by rivers where they accumulate within beach sands. Rarely, but importantly, gold, tin and platinum deposits can form in beach placer deposits. General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ...
General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Atomic mass 91. ...
General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass 232. ...
Heavy mineral sands are a class of ore deposit which is an important source of zirconium, titanium, thorium, tungsten, rare earth elements, the industrial minerals diamond, sapphire, garnet and occasionally precious metals or gemstones. ...
90 mile beach Australia A beach or strand is a geological formation consisting of loose rock particles such as sand, shingle, cobble, or even shell along the shoreline of a body of water. ...
In geology, a placer deposit is a deposit of earth, sand, or gravel, containing valuable minerals in particles, especially by the side of a river, or in the bed of a mountain stream. ...
Leucoxene is a finely granular yellow to brown alteration product of titanium minerals. ...
Zircon is a mineral belonging to the group of nesosilicates. ...
Monazite powder In geology, the mineral monazite is a reddish-brown phosphate containing rare earth metals and an important source of thorium, lanthanum, and cerium. ...
Quarrying granite for the Mormon Temple, Utah Territory. ...
Severe soil erosion in a wheat field near Washington State University, USA. Erosion is the displacement of solids (soil, mud, rock, and other particles) by the agents of wind, water, ice, movement in response to gravity, or living organisms (in the case of bioerosion). ...
For the Second World War frigate class, see River class frigate The Murray River in Australia A waterfall on the Ova da Fedoz, Switzerland A river is a large natural waterway. ...
General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ...
General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ...
General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Atomic mass 195. ...
Tin, tungsten, and molybdenum These three metals generally form in a certain type of granite, via a similar mechanism to intrusive-related gold and copper. They are considered together because the process of forming these deposits is essentially the same. Skarn type mineralisation related to these granites is a very important type of tin, tungsten and molybdenum deposit. Skarn deposits form by reaction of mineralised fluids from the granite reacting with wall rocks such as limestone. Skarn mineralisation is also important in lead, zinc, copper, gold and occasionally uranium mineralisation. Quarrying granite for the Mormon Temple, Utah Territory. ...
Skarn is a fine grained metamorphic rock that is usually variably colored green or red, occasionally grey, black, brown or white. ...
Limey shale overlaid by limestone. ...
This article is about the chemical element. ...
General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ...
General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ...
General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ...
General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ...
Greisen granite is another related tin-molybdenum and topaz mineralisation style. Greisen is a highly altered granitic rock or pegmatite. ...
Rare earth elements, niobium, tantalum, lithium The overwhelming majority of rare earth elements, tantalum and lithium are found within pegmatite. Ore genesis theories for these ores are wide and varied, but most involve metamorphism and igneous activity. Lithium is present as spodumene or lepidolite within pegmatite. de;Metalle der Seltenen Erden Categories: Stub | Chemical element groups ...
General Name, Symbol, Number tantalum, Ta, 73 Chemical series transition metals Group, Period, Block 5, 6, d Appearance gray blue Atomic mass 180. ...
General Name, Symbol, Number lithium, Li, 3 Chemical series alkali metals Group, Period, Block 1, 2, s Appearance silvery white/gray Atomic mass 6. ...
Pegmatite is a very coarse-grained igneous rock that has a grain size of 20 mm or more; such rocks are referred to as pegmatitic. ...
Metamorphism can be defined as the mineralogical, chemical and crystallographic changes in a solid-state rock, i. ...
Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ...
Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate - LiAl(SiO3)2 - and is a source of lithium. ...
Lepidolite (KLi2Al(Al,Si)3O10(F,OH)2) is a lilac or rose-violet colored phyllosilicate mineral of the mica group that is a secondary source of lithium. ...
Carbonatite intrusions are an important source of these elements. Ore minerals are essentially part of the unusual carbonatite mineralogy. Carbonatites are intrusive igneous rock structures with more than 50% carbonate content, many of which contain distinctive abundances of apatite, magnetite, barite, and fluorite, that may contain economic or anomalous concentrations of rare earth elements, phosphorus, niobium, uranium, thorium, copper, iron, titanium, barium, fluorine, zirconium, and other rare or incompatible...
Phosphate Phosphate is used in fertilisers. Immense quantities of phosphate rock occur in older sedimentary basin, generally formed in the Proterozoic. Phosphate deposits are thought to be sourced from the skeletons of dead sea creatures which accumulated on the seafloor. Similar to iron ore deposits and oil, particular conditions in the ocean and environment are thought to have contributed to these deposits within the geological past. In inorganic chemistry, a phosphate is a salt of phosphoric acid. ...
In geology, the Proterozoic is an eon prior to the first abundant complex life on earth. ...
Phosphate deposits are also formed from alkaline igneous rocks such as nepheline syenites, carbonatites and associated rock types. The phosphate is, in this case, contained within magmatic apatite, monazite or other rare-earth phosphates. Nepheline syenite is a coarse crystalline igneous rock composed primarily of orthoclase alkali-feldspars, nepheline and mafic minerals such as the sodium rich pyroxenes and amphiboles. ...
Carbonatites are intrusive igneous rock structures with more than 50% carbonate content, many of which contain distinctive abundances of apatite, magnetite, barite, and fluorite, that may contain economic or anomalous concentrations of rare earth elements, phosphorus, niobium, uranium, thorium, copper, iron, titanium, barium, fluorine, zirconium, and other rare or incompatible...
Apatite is a group of phosphate minerals, usually referring to: hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH-, F-, or Cl- ions, respectively, in the crystal lattice. ...
Monazite powder In geology, the mineral monazite is a reddish-brown phosphate containing rare earth metals and an important source of thorium, lanthanum, and cerium. ...
References Arne, D.C.; Bierlein, F.P.; Morgan, J.W. & Stein, H.J., 2001. Re-Os Dating of Sulfides Associated With Gold Mineralisation in Central Victoria, Australia. Economic Geology, 96, pp1455-1459, 2001.
Elder, D. & Cashman, S. Tectonic Control and Fluid Evolution in the Quartz Hill, California, Lode-gold Deposits. Economic Geology, 87, pp1795-1812, 1992.
Evans, A.M., 1993. Ore Geology and Industrial Minerals, An Introduction., Blackwell Science, ISBN 0-632-02953-6
Groves, D.I. 1993. The Crustal Continuum Model for late-Archaean lode-gold deposits of the Yilgran Block, Western Australia. Mineralium Deposita 28, pp366-374, 1993.
Lang, J.R. & Baker, T., 2001. Intrusion-related gold systems: the present level of understanding. Mineralium Deposita, 36, pp477-489, 2001.
Lindberg, W., 1922. A suggestion for the terminology of certain mineral deposits. Economic Geology, '17, pp. 292-294.
Lowenstern, J.B., 2001. Carbon dioxide in magmas and implications for hydrothermal systems. Mineralium Deposita, 36, pp490-502, 2001.
Pettke, T; Frei, R.; Kramers J.D. & Villa, I. M. 1997. Isotope systematics in vein gold from Brusson, Val d'Ayas (NW Italy); (U+Th)/He and K/Ar in native Au and its flid inclusions. Chemical Geology, 135, pp173-187, 1997. Isotope geochemistry is an aspect of Geology based upon study of the relative and absolute concentrations of the elements and their isotopes in the Earth. ...
White, A.J.R, 2001. Water, restite and granite mineralisation. Australian Journal of Earth Sciences, 48, pp551-555 2001. Restite is the residual material left at the site of melting during the in place production of granite through intense metamorphism. ...
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