In addition, porphyry deposits may host valuable byproducts. A plate tectonic model for the origin porphyry copper deposits richard h. Byproducts of porphyry copper and molybdenum deposits rare. The majority of goldrich porphyry deposits occur in the circumpacific and commonly contain 0. Major miners look to copper porphyry deposits for largetonnage, lowcost operations. Everything you need to know about copper porphyries. In general, porphyry deposits are characterized by low grades of ore mineralization, a porphyritic intrusive complex that is surrounded by a vein stockwork. Dunn, 1982, 1984, although alteration and mineralization in the area suggested to earlier geologists that a porphyry copper deposit should occur in the district kuelmer, 1954. Porphyry copper deposits are very large mineralized. Thomson resources 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.
Much of the worlds economic copper resources are hosted in porphyry copper deposits pcds, shallow level magmatic intrusions associated mostly with thick 45 km magmatic arcs, such as mature island arcs and continental arcs. Introduction porphyry copper deposits pdcs arguably represent the most economically important class of nonferrous metallic mineral resources, as nearly threequarters of the worlds cu, half of the worlds mo, one. Among the first recognized as having porphyry copper potential by midcentury were the disseminated ores at silver bell, described by richard and courtright 1954. The geological characteristics, geochemical signature and. Generalized ages of all porphyry copper deposits in. Newcrest mining limited, exploration dept, orange, nsw, australia 2. Breccias associated with porphyry copper deposits have been a source of fascination for many researchers. Porphyry deposits can, however, be very large, so by extracting and processing very large amounts of low grade ore, enough copper can be found for it to be economically worthwhile.
Briggs over the last several years, many of you have probably heard the term porphyry copper and wondered what everyone is talking about. Copper porphyry deposits are almost always mined in industrialscale open pit operations. Skarn and porphyry deposits nsw resources and energy. Other readers will always be interested in your opinion of the books youve read. Porphyry ore typically forms in magmatic arcs above subduction zones. Considering this, the research reported here is, in many respects, a reconnaissance study, aimed at identifying geochemical features and trends. Not only do skarns provide vectors to ore but they may provide clues as to scale of blind porphyries recognition of skarn mineralisation at big cadia was important to the recognition of the large cadia porphyry system. Whether youve loved the book or not, if you give your honest and detailed thoughts then people will find new books that are right for them. Chemical and isotopic data cited are consistent with the generation of the com ponents of calcalkaline igneous rocks and porphyry ore deposits by partial melting.
Geology of the spence porphyry copper deposit miguel tapia bhp billiton, antofagasta, chile miguel. Dont forget the poor little skarns at your porphyry. Associated deposit types a variety of deposit types are spatially, if not genetically, related to porphyry copper mineralization, including skarns, polymetallic veins and replacements, and epithermal veins. On the basis of detailed examination of the alteration pattern and paleothermal environment, another target is. Porphyry copper deposits of the american cordillera. They account for about 50 to 60% of world cu production and more than 95% of world mo production. What investors need to know about porphyry copper deposits. Hydrogen and oxygen isotope ratios in minerals from. Characteristics of porphyry aucu systems in the ordovician macquarie arc of nsw bruce mowat, goldminco, mitchell hwy, orange nsw 2800 stuart smith, oxiana ltd, 9th floor, 31 queen st, melbourne, vic 3000. Porphyry cuau deposits display complex patterns of zonation in alteration and mineralisation which result from the overprinting of many prograde and retrograde events. A plate tectonic model for the origin of porphyry copper deposits.
Therefore, porphyry cu deposits are usually oxidized with oxygen fugacities dfmq. Mineralization of cu ores tend to occur at the tops of porphyry systems in cupolas. Characteristics of porphyry aucu systems in the ordovician. 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. Arizona is abundantly endowed with copper deposits. It refers to large, relatively low grade, epigenetic, intrusionrelated deposits that can be mined using mass mining techniques. Brassyyellow chalcopyrite is the primary copper bearing mineral in porphyry deposits.
Copper skarn deposits occur near many porphyry copper host intru. Porphyry cu systems host some of the most widely distributed mineralization types at convergent plate boundaries, including porphyry deposits centered on intrusions. Singer and others published porphyry copper deposits of the world. The term porphyry copper is derived from the texture of the igneous rock that forms. In this study, simplified engineering cost models were used to estimate the economic fraction of resources contained in undiscovered porphyry copper deposits, predicted in a global assessment of copper resources. Copper porphyry is a form of copper deposit that is often characterized as lowgrade, typically with 0.
Porphyry copper gold deposits form in a variety of volcanic environments, most commonly in continental margins and intraoceanic arcs. Porphyry copper deposit prognosis in the middle region of. Much of the early his tory of these deposits has been recorded from economic and engi. The 829 deposits listed in table 1 of this report were compiled from the azmils database of over 3,000 deposits that list copper as a commodity. Mar 28, 2018 porphyry cu deposit may exist beneath the lithocap.
In later stages, circulating meteoric fluids may interact with the magmatic. Stochastic modelling of deep magmatic controls on porphyry copper. These are large scale magmatichydrothermal systems associated with a series of porphyritic intrusions, which result in extensive alteration footprints that we map and model to target high grade copper gold mineralization. Pdf batholithvolcano coupling in the metallogeny of porphyry copper deposits. The consistently defined deposits in this file provide the foundation for grade and tonnage models included here and for mineral deposit density models singer and others, 2005. Collectively, these type of deposits are known as porphyry copper deposits. The general attributes of porphyry copper deposits are summarized below.
Porphyry cu and porphyry mo deposits are large to giant deposits ranging up to 20 and 1. Scribd is the worlds largest social reading and publishing site. The composition of rhomb porphyry places it in the trachytelatite classification of the qapf diagram. Porphyry deposits, our main source of copper and of significant amounts of mo, re and au, form at convergent margins in association with. Trace element concentrations in porphyry copper deposits from. Anatomy of porphyryrelated mineralised aucuagmo systems. Till geochemical and mineralogical case studies and surveys carried out around porphyry deposits in glaciated terrain are described here in two sections. In kerman province in south of iran, there is a sub tectonic zone named dahajsar doiyeh, northern parts of dahajsardoiyeh belt that is shown by black rectangle figure 1 study to determine the relationship between tectonic factors a nd.
Copper skarn deposits occur near many porphyry copper host intru sions that intruded carbonatebearing units einaudi and others, 1981, and skarn mineral zoning patterns may be useful in the targeting of a potentially associated porphyry copper deposit meinert and others, 2005. The problem is that while most of the magmas at convergent margins are highly oxidized, porphyry cu. Database and grade and tonnage models, 2008 by donald a. Sillitoe abstract the theory of lithosphere plate tectonics, embodying the concepts of seafloor spread ing, transform faulting, and underthrusting at continental margins and island arcs, is. Possible regimes where cu may be mobilized include hydrothermal circulation at midocean ridge centers, dehydration or melting of the. Sillitoe 27 west hill park, highgate village, london n6 6nd, england abstract porphyry cu systems host some of the most widely distributed mineralization types at convergent plate boundaries, including porphyry deposits centered on intrusions. This publication contains a computer file of information on porphyry copper deposits from around the world. The intrusives also simulates the limestone altering its composition and forming and endo skarns. 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 term porphyry copper now includes engineering as well as geological considerations. This report is an evaluation of the mineral resource potential of these lands, but is limited to the following types of deposits. Quartz sulphide gold copper deposits, which form at deepest crustal levels close to porphyry intrusions, comprise dominantly iron sulphides and quartz, mostly as veins and veinbreccias. 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. Rhomb porphyry is a volcanic rock with graywhite large porphyritic rhombusshaped phenocrysts embedded in a very finegrained redbrown matrix.
Locations of all porphyry copper deposits in the porcu. The cost models of camm 1991 were updated with a cost index to reflect increases in mining and milling costs since 1989. Porphyry and hydrothermal copper and gold deposits. Porphyry copper deposit exploration and resource assessment objectives and guides. Numerous papers are in the societys publications and are listed in the appendix below.
Economic filters for evaluating porphyry copper deposit. Locations and generalized ages of all porphyry copper deposits located in. Because some porphyry mo deposits contain significant w, the few papers that document mow and w porphyry deposits are also provided in this subsection. Rule of structural factors in formation of porphyry copper. Centre for excellence in o re deposits, university of tasmania, tasmania, australia abstract. Exploring porphyry copper depositsin the central iran. Porphyry copper, gold, and molybdenum deposits society of. Exploring porphyry copper deposits in the central iran using remote sensing techniques akram mahan, ramin arfania isfahan khorasgan branch, islamic azad university, isfahan, iran abstract this study used the ability of remote sensing technology to identify alteration zones in porphyry copper mining and iron oxides of area in south nain dis. Porphyry copper deposits are large commonly hundreds to thousands of million tonnes and low to medium in grade 0.
Other types of deposits, such as skarns and polymetallic veins can occur near the porphyry copper deposits. Advances in geological models and exploration methods for. Field based vectors used to explore for porphyry cuau deposits. Porphyry copper deposits pcds represent shallow level intrusions 25 km in the crust. Advances in geological models and exploration methods for copper gold porphyry deposits holliday, j. 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. Pdf porphyry copper systems introduction miguel peral.
The copper flat porphyry copper deposit in the northern part of the hillsboro district was discovered in 1975 castellano et al. Byproducts of porphyry copper and molybdenum deposits. Gold was produced from the getchell and cortez mines long before the carlin. Copper is a moderately incompatible chalcophile element. The speciation of sulfur is controlled by oxygen fugacity. Remarkably few publications chesu, 1983, cioaca et al. Geology and metallogeny of copper deposits springerlink. Porphyry copper deposits typically are large deposits and are mined mostly by open pit methods and can have byproduct production of gold, silver, molybdenum, and other metals. Mineral deposits of nevada society of economic geologists. The problem is that while most of the magmas at convergent margins are highly oxidized, porphyry cu deposits are very rare, suggesting that high oxygen fugacity alone is not sufficient. The formation of porphyry copper deposits springerlink. Porphyry ore deposits are low grade meaning that the amount of the element that you want in this case, copper isnt very high.
Porphyry deposits represent an important resource of copper. Preliminary model of porphyry copper deposits usgs. A plate tectonic model for the origin of porphyry copper. The formation of porphyry copper deposits institute of geochemistry. Agenda localisation of porphyry cuau deposits pcd factors that contribute to the high cuau grades in porphyry deposits and metal zonations stage model for the evolution of porphyry cuau deposits incorporating time. Predating or associated with those fluids are vertical dikes of porphyritic intrusive rocks from which this deposit type derives its name. Porphyry copper deposit model, chapter b of mineral deposit. Porphyry ore deposits are the source of much of the copper, molybdenum, gold and silver used by humans.
Pdf the formation of porphyry copper deposits researchgate. We take a look at what makes for a copper porphyry takeover target. May 28, 2014 copper in these deposits generally occurs in copper iron sulfide minerals such as chalcopyrite cufes 2 and bornite cu 5 fes 4. A brief discussion of the porphyry copper subtypes is in the appendix. 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. It can be most easily distinguished from pyrite by its more colourful tarnish. 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 systems commonly define linear belts, some many. The general characteristics of porphyry systems include. Generalized models of porphyry copper deposits anatomy. Porphyry deposits can, however, be very large, so by extracting and processing very large amounts of low grade ore, enough copper can be. These patterns are best analysed in the light of the model for the overprinting stages of porphyry evolution figure 3.
It refers to large, relatively low grade, epigenetic, intrusionrelated deposits. Porphyry deposits are one of the most important sources of copper and molybdenum, and are also major sources of silver, gold, and tin. Porphyry deposits are very large, polymetallic systems that typically contain copper along with other important metals. Pdf porphyry copper systems daniela olivares sedan. The major products from porphyry copper deposits are copper and molybdenum or copper and gold. However, a wellknown, but unresolved paradox, is that arc magmas traversing thick crust, particularly in continental arcs, are generally depleted in cu whereas in.
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. Only the copper records with oxide as the modifier are listed in this report. Porphyry cu deposits in china contain a total resource of 47 million tonnes mt cu at average grades ranging mostly from 0. Porphyry deposits are the worlds principal resources of cu, mo, and re, and are major resources of au and ag. The ruth and yerington districts porphyry copper deposits have had a long history of exploration and production.
Hydrogen and oxygen isotope ratios in minerals from porphyry. How to make porphyry copper deposits sciencedirect. The o 18 o 16, dh and c c 12 values, where applicable, were measured on quartz 40 samples, kfeldspar 12, biotite 16, sericite 23, and calcite 7 from potassic, sericitic and argillic alteration assemblages and from fresh igneous rocks and veins in 9 north american porphyry copper and molybdenum deposits, and in 4 other hydrothermal mineral deposits. Therefore, porphyry cu deposits are usually oxidized with oxygen fugacities. Porphyry copper deposits are very large mineralized systems that are typically formed by relatively small intrusions stocks, which are several thousand. Porphyry cu deposit may exist beneath the lithocap. A different but closely related group of deposits to porphyry copper deposits are the skarn deposits.
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