In porphyry copper deposits, copper ore minerals are disseminated in igneous intrusions. The goldrich altan burged porphyry was discovered in december 2016 as part of uccessfulthe highly bedrock s drilling programme see xanadus. The miocene wafigolpu gold rich porphyry cuau deposit, and associated epithermal au mineralisation is located in the morobe province of png, and has a currently published resource of 28. Porphyry copper deposit wikipedia republished wiki 2. So this gives us a start in deciding where to focus our exploration because of the extensive subduction during the tertiary i. Morris2 1university of exetercamborne school of mines, penryn, cornwall tr10 9fe, uk. 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. Based on the available data from many porphyry copper deposits, kesleret al. Predating or associated with those fluids are vertical dikes of porphyritic intrusive rocks from which this deposit type derives its name. Metallis expands goldrich mineralization at cole porphyry. Triumph gold announces three additional goldrich drill intersections from blue sky porphyry highlighting rvd1819 with 316. Here we report the results of petrographic, electron microprobe, laser ablation inductively coupled plasma mass spectrometry laicpms, and flotation test studies of gold and associated copper sulfides within a paragenetic framework from the. Porphyry copper deposits account for about 60 percent of the worlds copper.
Sedimenthosted stratabound copper deposits, in which copper is concentrated in layers in sedimentary rocks, account for about 20. Analysis of 55 porphyry copper deposits demonstrates a continuum between porphyry coppergold deposits emplaced at a median depth of 1 km, with a median size of 160 million metric tons of copper. The duolong goldrich porphyry copper deposit is located ca. Porphyry copper deposits are large commonly hundreds to thousands of million tonnes and low to medium in grade 0. Geology and porphyry coppertype alterationmineralization of. Goldrich porphyry copper deposits are important sources of gold in the circumpacific region. Sillitoe, 1979, being arbitrary defined by sillitoe 1979 as. 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. The christmas copper deposit, located in southern gila county, arizona, is part of the major porphyry copper province of southwestern north america. Some thoughts on goldrich porphyry copper deposits.
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. Estimate of undiscovered copper resources of the world, 20. Gold distribution in porphyry copper deposits of kerman. Metallis expands gold rich mineralization at cole porphyry epithermal system on the kirkham property metallis resources inc. Geology of the maricunga belt the maricunga belt, located in northern chile about 700 km north of santiago figs. Pdf distribution of gold in porphyry copper deposits researchgate. These data have been compiled from several sources. Abstract porphyry copper deposits carrying more than 0. The general characteristics of porphyry systems include. Porphyry copper enrichment linked to excess aluminium in. Grade and tonnage data for the worlds 25 largest porphyry copper deposits, based on contained copper metal, and goldrich porphyry deposits, based on contained gold, are listed in tables 1 and 2, respectively, and shown in figure 1. Geology and hydrothermal alteration of the duobuza goldrich. Key features of the priority targets for porphyry copper gold and coppergold skarn deposits in the commonwealth project area are described below and shown on a geology map in figure 4 and a corresponding image of regional government magnetic data in figure 5. The original definition was based on the aumo ratios of porphyry copper deposits with no reference to their copper content, and resulted in the suggestion that gold rich deposits were found largely in island arc regions kesler, 1973.
Gold is an important byproduct in many porphyrytype deposits but the distribution and chemistry of gold in such systems remains poorly understood. The deposits occur in a variety of subductionrelated settings, and may be underlain by crust that is undergoing either extension or compression and that is either oceanic or cratonic in character. Department of mining geology, royal school of mines, imperial college of science and. Sep 10, 2004 gold is an important byproduct in many porphyry type deposits but the distribution and chemistry of gold in such systems remains poorly understood. Jan 14, 2020 porphyry coppergold deposits are large volume, lowgrade disseminations formed by precipitation of copper and gold plus molybdenum from fluids of magmatic origin 1. Magmatic holds the strategic position in emerging goldrich porphyry discovery hotspot, northern molong belt multiple advanced porphyry aucu targets. Pdf distribution of gold in porphyry copper deposits. Goldrich porphyry deposits worldwide conform well to a generalized descriptive model. Porphyry copper gold deposits are large volume, lowgrade disseminations formed by precipitation of copper and gold plus molybdenum from fluids of magmatic origin 1. Preliminary model of porphyry copper deposits usgs. Gold deposits can still be seen today forming in some active geothermal areas.
Geology and porphyry coppertype alterationmineralization. Two main goldrich porphyry copper deposits and an received 31 august 2010. The belt comprises gold rich porphyry and preciousmetal epithermal mineralization, formed during late oligocene and miocene hydrothermal events sillitoe et al. Porphyry copper deposits result from the complex interactions and feedbacks of. Key features of the priority targets for porphyry copper gold and copper gold skarn deposits in the commonwealth project area are described below and shown on a geology map in figure 4 and a corresponding image of regional government magnetic data in figure 5.
It is a typical volcanic type in the porphyry copper deposit classifications mcmillan and panteleyev, 1980, which formed in the early cretaceous and the magmatic arc resulted. Role of porphyry models in explora 317 o 320 gt8 ppm cuau 035 au34 0 24co 027. Newberry gold in volcanichosted massive sulfide deposits. Porphyry deposits are natural suppliers of most copper and significant gold to our society. Porphyry copper enrichment linked to excess aluminium in plagioclase b. The maricunga porphyrytype mineralization stands in contrast to the porphyry deposits elsewhere in northern chile, which are associated with more felsic intrusions lacking coeval volcanic rocks, contain large volumes of sericitized rocks, lack abundant orerelated iron oxides, are molybdenum rich, gold poor, and more than ten times larger. Gold abundances in porphyry copper deposits vary greatly, complicating efforts to define gold rich porphyry copper deposits. Lady ilse porphyry aucu, under shallow 515m cover, boda lookalike but bigger rose hill aucu porphyry mineralised system from surface, inc. The miocene wafigolpu goldrich porphyry cuau deposit, and associated epithermal au mineralisation is located in the morobe province of png, and has a currently published resource of 28. Porphyry copper systems 39 0361 012898000000 00 600 39 2000 gold rich porphyry from geology 1 at university of texas. Porphyry gold deposits of the refugio district, maricunga. The original definition was based on the aumo ratios of porphyry copper deposits with no reference to their copper content, and resulted in the suggestion that goldrich deposits were found largely in island arc regions kesler, 1973. Imai, akira, 2002, metallogenesis of porphyry cu deposits of the western luzon arc, philippines kar ages, so3 contents of microphenocrystic apatite and significance of intrusive rocks.
The majority of gold rich porphyry deposits occur in the circumpacific and commonly contain 0. In general, porphyry deposits are characterized by low grades of ore mineralization, a porphyritic intrusive complex that is surrounded by a vein stockwork. Triggers for the formation of porphyry ore deposits in. Location map of the cerro casale ore deposit, in northern chile. Porphyry coppergold deposits are large volume, lowgrade disseminations formed by precipitation of copper and gold plus molybdenum from fluids of. Gold deposits encyclopedia of life support systems.
Geologic setting of the duolong goldrich porphyry copper deposit. Sillitoe, 1979, being arbitrary defined by sillitoe 1979 as those porphyry copper deposits that contain over 0. Cargo porphyry cuau deposit where is the high grade core. The duobuza gold rich porphyry copper district is located in the bangongco metallogenetic belt bgcmb, fig. Granodiorite porphyry and quartz diorite porphyrite are the main ore. Calcalkalic coppergold porphyry deposits copper hill, cargo and marsden were emplaced during a time of regional uplift, erosion and limestone deposition, possibly associated with an arcreversal event glen et al.
Aug 23, 2018 triumph gold intersects strong gold rich porphyry mineralization in the blue sky porphyry, including 125. Gold paragenesis and chemistry at batu hijau, indonesia. Calcalkaline rocks with associated pcd fertile seridune, kerman, iran barzegar, h. In later stages, circulating meteoric fluids may interact with the magmatic. Gold is an important byproduct in many porphyry type deposits but the distribution and chemistry of gold in such systems remains poorly understood. Imai, akira, 2002, metallogenesis of porphyry cu deposits of the western luzon arc, philippines kar ages, so3 contents of microphenocrystic apatite and significance of. The geological characteristics, geochemical signature and. In figure 28, we can see no trend of goldrich porphyry copper deposits. Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Magmatichydrothermal evolution of the cretaceous duolong. Characteristics and controls of the largest porphyry.
Triumph gold intersects strong goldrich porphyry mineralization in the blue sky porphyry, including 125. Gold rich porphyry copper deposits are important sources of gold in the circumpacific region. Sedimenthosted stratabound copper deposits, in which copper is concentrated in layers in. Goldrich porphyry copper deposits of the circumpacific. There are six worldclass settings for magmatichydrothermal gold deposits. Sillitoe and their role in exploration and discovery gold in skarns related to epizonal intrusions l. Mtlff is pleased to announce assay results from the coleetta porphyry epithermal system clustered on the northern end of the 7. The early cretaceous duolong goldrich porphyry copper deposit is a newly discovered deposit with proven 5. Mtlff is pleased to announce assay results from the coleetta porphyryepithermal system clustered on the northern end of the 7.
Porphyry copper enrichment linked to excess aluminium in plagioclase. Porphyry copper deposits represent an important resource and the dominant source of copper that is mined today to satisfy global demand. Gold paragenesis and chemistry at batu hijau, indoneisa. Gold abundances in porphyry copper deposits vary greatly, complicating efforts to define goldrich porphyry copper deposits. Deposit and district locations are shown on figure 2.
Magmatic holds the strategic position in emerging gold rich porphyry discovery hotspot, northern molong belt multiple advanced porphyry aucu targets. The duobuza goldrich porphyry copper district is located in the bangongco metallogenetic belt bgcmb, fig. Characteristics and controls of the largest porphyry copper. Gold endowments of porphyry deposits controlled by. Supplementary table 1 literature sources of data used in fig. Mineralogy and mineral chemistry of the cretaceous duolong. The goldrich altan burged porphyry was discovered in december 2016 as part of uccessfulthe highly bedrock s drilling programme see xanadus asx announcement 22 december 2016. Two main gold rich porphyry copper deposits and an received 31 august 2010. Triumph gold announces three additional goldrich drill.
Gold is normally present in potassium silicate alteration, which commonly carries an unusually high magnetite content. Analysis of 55 porphyry copper deposits demonstrates a continuum between porphyry copper gold deposits emplaced at a median depth of 1 km, with a median size of 160 million metric tons of copper. Porphyry ore deposits are the source of much of the copper, molybdenum, gold and silver used by humans. Goldrich porphyry systems in the maricunga belt, northern. Basic characteristics of goldrich porphyry copper deposits and their. At this deposit,abundant magnetite is associated with cu. The property is situated within the prolific golden triangle in northwest british columbia, an area known for hosting worldclass deposits such as. Porphyry deposits represent an important resource of copper. Gold endowments of porphyry deposits controlled by precipitation. Reconstruction of the porphyry systems suggests that gold bearing quartz stockworks were generated 600 to 1,000 m beneath paleosurfaces. Gold rich porphyry deposits worldwide conform well to a generalized descriptive model. Calcalkalic copper gold porphyry deposits copper hill, cargo and marsden were emplaced during a time of regional uplift, erosion and limestone deposition, possibly associated with an arcreversal event glen et al. Geology, petrology and geochemical characteristics of alteration zones within the.
In particular, this usage does not restrict iocg to those deposits containing economic concentrations of copper andor gold cf. The majority of goldrich porphyry deposits occur in the circumpacific and commonly contain 0. Locations of all porphyry copper deposits in the porcu. The ore deposits hosted in the maricunga belt contain resources totalling more than 1. Geology and hydrothermal alteration of the duobuza. Pdf analysis of 55 porphyry copper deposits demonstrates a continuum between porphyry coppergold. Gold rich porphyry mineralization in the maricunga belt is closely comparable to that in the philippines because of the association with dioritic to quartz dioritic porphyry stocks intruded into andesitic. Meinert gold deposits related to reduced granitic intrusions j. Jun 25, 2011 the duolong goldrich porphyry copper deposit was recently discovered and represents a giant prospect inferred resources of 45 mt finecu with a grade of 0. This model incorporates six main facies of hydrothermal alteration and mineralization, which are zoned upward and outward with respect to composite porphyry stocks of cylindrical form atop much larger parent plutons. Porphyry ore typically forms in magmatic arcs above subduction zones. Society of economic geologists special publication 11, p.
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