Temporalspatial distribution and tectonic setting of. Pdf porphyry copper deposit model ana viana academia. On a proposed plutonic porphyry gold deposit model springerlink. Porphyry copper deposits of the american cordillera. Copper is a moderately incompatible chalcophile element.
Porphyry deposits are the worlds principal resources of cu, mo, and re, and are major. Geology and porphyry coppertype alterationmineralization of. Banks internal deposit data often extend back 10 years or less, making realistic modeling difficult. Within the years production increases and shifted from dominantly oxide to dominantly sulfide ores in the 1950s as the pit deepened. Block model in a multi facies context application to a porphyry copper deposit tools indicators define spatial domains so one can say that they set the geometry of the problem. The copper hill porphyry coppergold project summary the copper hill cuau deposit contains 535,000 tonnes of copper and 1. Analytics forecasts of bank financial statements to augment internal data introduction. Generalized porphyry copper model anatomy and alteration zoning anatomy of calcalkalic porphyry copper and related mineralization alteration zonation patterns in calcalkalic porphyry systems modified from. Geologic map showing the aerial view of a porphyry copper deposit geochemical exploration such a map may look like figure 3. Owing to the complexity, a succinct definition that includes the essential attributes of this deposit class is elusive. They account for about 50 to 60% of world cu production and more than 95% of world mo production.
Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that. The results of the updated engineering cost model analysis for openpit porphyry copper deposits are in agreement with the gradetonnage boundary defining positive economic returns for copper deposits developed between 1989 and 2008. Conceptual model illustrating different styles of magmatic arc porphyry and epithermal cuaumoag mineralisation discussed herein from corbett, 2008 and modified from corbett 2002, 2004. A porphyry is not a rock type, but rock with a particular texture. Copper containing rock, or copper ore, holds only a small percentage of copper. Development of a copper porphyry porphyry copper deposits are copper orebodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the. The big gossans copper gold skarn deposit is the highest grade deposit in the grasberg area. Although christmas is known for skarn deposits in paleozoic carbonate rocks, oregrade porphyry type copper mineralization also occurs in a composite granodioritic intrusive complex and adjacent mafic volcanic country rocks. Geology comments off on porphyry copper deposit model. Moodys analytics forecasts of bank financial statements uses data from as early as 1980, spanning several expansions and recessions. In silicate mineral deposits, the copper is linked with silicon and oxygen. The majority of proposed models are based on data collected from american continent where deposits are numerous and studied in great details sillitoe, 2010. However, unlike the plutonic porphyry copper deposit model, the proposed model is deficient in copper and contains less than 1 percent total sulfides. Crosssection micrographs of the aselectroplated copper deposits plated in the bath with various concentrations of thiourea.
In carbonate deposits, the copper occurs with carbon and oxygen. Cox, 1986, descriptive model of porphyry cu, in mineral deposit models, us. Some of the biggest manmade holes in the ground are porphyry copper mines. The formation of porphyry copper deposits springerlink. Cross section of a porphyry copper deposit showing idealized alteration zoning.
Also listed are smaller deposits of particular significance to the development of the porphyry copper model. Most of the worlds copper is extracted from a type of mineral deposit called a porphyry copper. Illustrated deposit model of a porphyry copper deposit modified from lowell and guilbert, 1970. Porphyry copper definition is a large lowgrade disseminated copper deposit. Photo taken by david briggs, october 2009 propylitic alteration frequently gives the rock a greenish cast as it is characterized by greencolored minerals such as chlorite and epidote, and calcite with minor amounts of pyrite.
The formation of the panguna porphyry copper deposit. Block model in a multi facies context application to a. Fourteen deposits that reported molybde num had a weighted grade of 0. At present, data accumulated for porphyrycopper deposits is quite sufficient for development of typical porphyrycopper deposit model. These deposits provide over 60% of the worlds copper and include other important metals such as molybdenum, gold and silver.
Porphyry copper deposits are copper orebodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Porphyry copper deposit exploration and resource assessment objectives and guides. Porphyry copper deposits are among the worlds most valuable deposits. The problem is that while most of the magmas at convergent margins are highly oxidized, porphyry. These alteration zones are not in themselves altered but are an important portion of the porphyry related anatomy. Predating or associated with those fluids are vertical dikes of porphyritic intrusive rocks from which this deposit type derives its name. The speciation of sulfur is controlled by oxygen fugacity. Although christmas is known for skarn deposits in paleozoic carbonate rocks, oregrade porphyrytype copper mineralization also occurs in a composite granodioritic intrusive complex and adjacent mafic volcanic country rocks. Porphyry ore deposits are the source of much of the copper, molybdenum, gold and silver used by humans.
Seal introduction porphyry copper deposits result from the complex interactions and feedbacks of many processes. Cu systems at regional, district, and deposit scales. The circles along the streams are locations at which gold au has been panned. Economic filters for evaluating porphyry copper deposit. In sulfide mineral deposits, the copper is linked with sulfur. The deposits and prospects used as examples throughout the text are located and further characterized in figure 1. Cox1 grade and tonnage model of sedimenthosted cu by dennis p. This report contains a revised descriptive model of porphyry copper deposits pcds, the worlds largest source about 60 percent and resource about 65 percent of copper and a major source of.
May 28, 2014 porphyry copper deposits play an important role in the global economy. Consequently, this descriptive model uses a working definition of a porphyry copper deposit. Vertical cross section showing a porphyry copper deposit as it occurs deep within the earth. The christmas copper deposit, located in southern gila county, arizona, is part of the major porphyry copper province of southwestern north america. Coppercontaining rock, or copper ore, holds only a small percentage of copper.
In later stages, circulating meteoric fluids may interact with the magmatic. Copper deposits definition of copper deposits by medical. The geology of copper copper occurs in three different mineral groups see table 51. For the modelling, it seems natural to start with the indicators then continue with the grades and the way they interact with the indicators. Geochemistry of hydrothermally altered rocks from the asarel. Gaseous complexes formed between trichlorides alcl3 and fecl3 and dichlorides. Porphyry copper deposits result from the complex interactions and feedbacks of many processes. Porphyry copper gold deposit model porphyry deposits are the worlds most important source of cu and mo, and are major sources of au, ag, and sn.
If youve seen a picture of a great big openpit mining operation odds are that it was a porphyry copper deposit. In the proposed model, gold is accompanied by scheelite, molybdenite, arsenopyrite, a variety of bismuth sulfides, tellurides, and. Abstract inthispaper,weinvertmagnetic,dcresistivity,inducedpolarizationip,andairborneelectromagneticem data from the mt. Preliminary model of porphyry copper deposits usgs. The dar alu deposit contains 175 million tons of ore, with an average grade of 0. Porphyry ore typically forms in magmatic arcs above subduction zones. Anatomy of porphyryrelated mineralised aucuagmo systems. Part three resources and technology princeton university. Advances in nicupge sulphide deposit models and implications for exploration technologies lightfoot, p. Bingham copper mine, utah, and chuquicamata in chile, and two of the largest. Cox, 1986, descriptive model of porphyry cu, in mineral deposit models, us geological survey, bulletin 1693, p. Thomson resources porphyry copper gold deposit model. Veins described in the geological literature gustafson and hunt, 1975 as b style quartzsulphide veins overprint earlier veins. We believe this porphyry system is analogous to other wellknown worldclass tourmaline breccia porphyry copper deposits, such as the ei teniente porphyry copper deposit 75 mt copper metal in chile and the soledad porphyry copper gold deposit in peru.
Geology and porphyry coppertype alterationmineralization. Analytics forecasts of bank financial statements to augment internal data introduction moodys analytics forecasts of bank financial statements uses data from as early as 1980, spanning several expansions and recessions. A plutonic porphyry gold deposit model is proposed that is imilar to the plutonic porphyry copper deposit model. Preliminary model of porphyry copper deposits byron r. Optimum conditions for development of giant porphyry copper deposits. Why no porphyry copper deposits in japan and south korea. May 31, 2015 development of a copper porphyry porphyry copper deposits are copper orebodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the. An analysis of the amount and location of undiscovered mineral resources that are likely to be economically recoverable is important for assessing the longterm adequacy and availability of mineral supplies. Clay minerals of hydrothermal origin associated with porphyry copper deposits are commonly zoned at the deposit or prospect scale e. Porphyry copper deposit model, chapter b of mineral deposit. The project has been extensively explored over many years by multiple owners. Porphyry copper deposits commonly contain hundreds of millions of metric tons of. This report contains a revised descriptive model of porphyry copper deposits pcds, the worlds largest source about 60 percent and resource about 65 percent of copper and a major source of molybdenum, gold and silver. At present, data accumulated for porphyry copper deposits is quite sufficient for development of typical porphyry copper deposit model.
Generalized models of porphyry copper deposits anatomy. Geological survey scientific investigations report 20105070b, 169 p. Milligan coppergold porphyry deposit and jointly interpret the inversion results with available geological and mineralization data. Active geothermal systems exploited for the production of electrical energy provide analogies.
Porphyry copper deposits commonly contain hundreds of millions of metric tons of ore that averages a fraction of 1 percent copper by weight. It is located 5 kilometres north of molong in eastern new south wales and is held 100% by golden cross resources ltd gcr figure 1. Seal porphyry copper deposits result from the complex in teractions and feedback s of many. Inversion of geophysical data over a copper gold porphyry.
Jan 11, 2014 model, chapter b of mineral deposit models for resource assessment. For the modelling, it seems natural to start with the indicators then continue with the. Porphyry copper deposit, large body of rock, typically a porphyry of granitic to dioritic composition, that has been fractured on a fine scale and through which chalcopyrite and other copper minerals are disseminated. The problem is that while most of the magmas at convergent margins are highly oxidized, porphyry cu. Geological surveyscientific investigations report 20105070bporphyry copper deposit model 2. Ray mine, arizona, one of the largest porphyry copper deposits in the united states. Locations of all porphyry copper deposits in the porcu. The initial deposit model consists of a vertical monzonitic stock. Approximately 5060 percent of the worlds copper, and 95 percent of. Codes the australian research councils centre for excellence in ore deposit research, university of tasmania, private bag 126, hobart, tasmania 7001, australia. Porphyry copper deposits are known for their low grades and very high tonnage.
Information on porphyry copper deposits from around the world with grade and tonnage models, a general classification based on geologic setting, mineralogy, with data allowing locations of these deposits to be plotted using gis. This requires an economic evaluation of estimates of undiscovered resources generated by traditional resource assessments singer and menzie, 2010. Geological survey usgs mineral resources program develops mineraldeposit models for application in usgs mineralresource assessments and other mineral resourcerelated activities within the. The dar alu deposit, and bondarehanza and kerver porphyry copper prospects are located in the eastcentral and southeastern parts of the kerman porphyry copper belt. Inversion of geophysical data over a copper gold porphyry deposit. A geologist at the university of exeter has developed a new and relatively inexpensive way to establish whether certain types of magmatic rocks are more likely to contain valuable metal deposits.
Porphyry copper definition of porphyry copper by merriam. Pdf on jan 1, 2019, sasan maleki and others published porphyry copper deposit model find, read and cite all the research you need on researchgate. Photo taken by david briggs, october 2009 propylitic alteration frequently gives the rock a greenish cast as it is characterized by greencolored minerals such as chlorite and epidote, and calcite with minor amounts of. The annealing behavior of copper deposit electroplated in. Abstract this analysis concludes that there is little realistic likelihood of discovering large, high. A comparative study of porphyrytype copper deposit. Most of the rock is unwanted material, typically referred to as gangue. The resultant geologic model is then used as the basis for a brief synthesis of porphyry cu genesis and discussion of exploration guidelines.
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