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Published: 10 December 2022

Last updated: 29 January 2023

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1

MELFOS, V., M. VAVELIDIS, and K. ARIKAS. "A new occurrence of argentopentlandite and gold from the Au-Ag-rich copper mineralisation in the Paliomylos area, Serbomacedonian massif, Central Macedonia, Greece." Bulletin of the Geological Society of Greece 34, no. 3 (January 1, 2001): 1065. http://dx.doi.org/10.12681/bgsg.17154.

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The Au-Ag-Cu mineralisation in the Paliomylos area is associated with quartz segregations and pegmatoids in the form of boudinaged bodies. The Au, Ag and Cu contents in the ore bodies reach 6.8 ppm, 765 ppm and 0.80 wt%. The ore minerals consist of pyrite, chalcopyrite, sphalerite, pyrrhotite, galena, bismuthinite, argentopentlandite, gersdorffite, cobaltite, aikinite, hessite, native bismuth and gold. Pentlandite contains significant amounts in Ag (13.15 wt%), Au (1.59 wt%) and PGM, demonstrating a formula of Fe5.37 Ni2.56 Ag1.03 Ir0.03 S8.01. On the basis of geological, textural and chemical data, the mineralisation in the studied area was formed under high temperatures.

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2

Radmard, Kaikhosrov, Hassan Zamanian, Mohamad Reza Hosseinzadeh, and Ahmad Ahmadi Khalaji. "Geochemistry and statistical analyses of porphyry system and epithermal veins at Hizehjan in northwestern Iran." Geologos 23, no. 3 (December 20, 2017): 183–200. http://dx.doi.org/10.1515/logos-2017-0020.

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Abstract Situated about 130 km northeast of Tabriz (northwest Iran), the Mazra’eh Shadi deposit is in the Arasbaran metallogenic belt (AAB). Intrusion of subvolcanic rocks, such as quartz monzodiorite-diorite porphyry, into Eocene volcanic and volcano-sedimentary units led to mineralisation and alteration. Mineralisation can be subdivided into a porphyry system and Au-bearing quartz veins within andesite and trachyandesite which is controlled by fault distribution. Rock samples from quartz veins show maximum values of Au (17100 ppb), Pb (21100 ppm), Ag (9.43ppm), Cu (611ppm) and Zn (333 ppm). Au is strongly correlated with Ag, Zn and Pb. In the Au-bearing quartz veins, factor group 1 indicates a strong correlation between Au, Pb, Ag, Zn and W. Factor group 2 indicates a correlation between Cu, Te, Sb and Zn, while factor group 3 comprises Mo and As. Based on Spearman correlation coefficients, Sb and Te can be very good indicator minerals for Au, Ag and Pb epithermal mineralisation in the study area. The zoning pattern shows clearly that base metals, such as Cu, Pb, Zn and Mo, occur at the deepest levels, whereas Au and Ag are found at higher elevations than base metals in boreholes in northern Mazra’eh Shadi. This observation contrasts with the typical zoning pattern caused by boiling in epithermal veins. At Mazra’eh Shadi, quartz veins containing co-existing liquid-rich and vapour-rich inclusions, as strong evidence of boiling during hydrothermal evolution, have relatively high Au grades (up to 813 ppb). In the quartz veins, Au is strongly correlated with Ag, and these elements are in the same group with Fe and S. Mineralisation of Au and Ag is a result of pyrite precipitation, boiling of hydrothermal fluids and a pH decrease.

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3

Verdiansyah, Okki, Damas Muharif, and I. Gde Sukadana. "Indikasi Mineralisasi Tipe Porfiri di Daerah Sumbersari, Kompleks Pengunungan Kulon Progo, Purworejo, Indonesia." EKSPLORIUM 41, no. 2 (November 30, 2020): 115. http://dx.doi.org/10.17146/eksplorium.2020.41.2.5959.

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ABSTRAK Pegunungan Kulon Progo merupakan produk magmatisme Busur Sunda-Banda tersusun atas formasi andesit tua. Daerah Sumbersari merupakan bagian dari gunung api Gajah, batuan gunung api tertua Kulon Progo. Indikasi mineralisasi tipe porfiri ditemukan di daerah ini sehingga menarik untuk diteliti lebih lanjut. Penelitian ini bertujuan untuk mengetahui potensi keterdapatan mineral logam berharga (Cu-Au). Metode penelitian yang digunakan adalah pemetaan geologi, analisis petrografi dan mikroskopi bijih, serta analisis geokimia menggunakan XRF dan ICP-MS. Geologi daerah penelitian terletak pada fasies sentral-proksimal Khuluk Gajah, terususun atas intrusi mikrodiorit, mikrodiorit kuarsa, andesit, andesit basaltik-diorit, dan batugamping. Alterasi hidrotermal berkembang pada batuan beku diorit, mikrodiorit, dan sebagian pada andesit. Alterasi hidrotermal dibagi menjadi beberapa kelompok, yaitu ilit-serisit±biotit sekunder, epidot-aktinolit-kalsit±ilit, epidot-kalsit±ilit, dan ilit-serisit±kuarsa. Beberapa fase mineralisasi berkembang, antara lain fase epidot-aktinolit yang diikuti mineralisasi magnetit-kalkopirit, fase biotit-magnetit-kalkopirit-bornit, dan fase akhir serisit-mineral lempung-pirit menggantikan keseluruhan sistem. Analisis geokimia pada batuan teralterasi menunjukan indikasi mineralisasi Cu-Au dengan kadar 491–1447 ppm (0,14%) Cu dan 0,02–0,3 ppm Au dengan rasio elemen Cu:Au adalah 1,01. Karakter geokimia menunjukkan adanya korelasi kuat Cu terhadap Au.ABSTRACT Kulon Progo Mountain is Sunda-Banda Arc magmatism product composed of an old andesite formation. Sumbersari Area is part of the Gajah volcanic, which is the oldest rock of Kulon Progo volcanics. Indication of porphyry type mineralisation has been found in the area which makes the area interested for further research. The research methodologies are geological mapping, petrography and ore microscopy, and geochemical analysis using XRF and ICP-MS. Geology of the area located in central-proximal facies of Khuluk Gajah, consist of microdiorite, quartz-microdiorite, andesite, basaltic-dioritic andesite intrusions, and limestone. Hydrotermal alteration is developing into certain groups like illite-sericite ± secondary biotite, epidote-actinolite-calcite ± illite, epidot-calcite ± illite, and illite-sericite ± quartz. Some mineralisation phases are developed like epidote-actinolite followed by magnetite-chalcopyrite mineralisation, biotite-magnetite-chalcopyrite-bornite phase and the late phase of sericite-clay-pyrite replacing the entire system. Geochemical analysis on altered rocks show Cu-Au mineralisation indication ranging from 491-1,447 ppm (0.14%) and 0.02-0.3 ppm respectively, with Cu:Au ratio is 1.01. Geochemical characteristic shows strong correlation of Cu to Au.

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4

Blevin, Phillip L., Bruce W. Chappell, and Charlotte M. Allen. "Intrusive metallogenic provinces in eastern Australia based on granite source and composition." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 87, no. 1-2 (1996): 281–90. http://dx.doi.org/10.1017/s0263593300006684.

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ABSTRACT:Ore element ratios in intrusion-related mineralisation are in part a function of the relative oxidation state and degree of fractionation of the associated granite suite. A continuum from Cu-Au through W to Mo dominated mineralisation related to progressively more fractionated, oxidised I-type magmas can be traced within single suites and supersuites. Such systematic relationships provide strong evidence for the magmatic source of ore elements in granite-related mineral deposits and for the production of the observed ore element ratios dominantly through magmatic processes. The distribution of mineralised intrusive suites can be used to define a series of igneous metallogenic provinces in eastern Australia. In general, there is a correlated evolution in the observed metallogeny (as modelled based on the compatibility of ore elements during fractionation) with increasing degree of chemical evolution of the associated magmatic suite. This is from Cu-Au associated with chemically relatively unevolved magmas, through to Sn and Mo-rich mineralisation associated with highly evolved magmas that had undergone fractional crystallisation. Provinces recognised in that way do not necessarily correlate with the tectonostratigraphic boundaries defined by the near-surface geology, indicating that the areal distribution of some granite source regions in the deep crust is unrelated to upper crustal geology.

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5

Reid, Anthony. "The Olympic Cu-Au Province, Gawler Craton: A Review of the Lithospheric Architecture, Geodynamic Setting, Alteration Systems, Cover Successions and Prospectivity." Minerals 9, no. 6 (June 20, 2019): 371. http://dx.doi.org/10.3390/min9060371.

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The Olympic Cu-Au Province is a metallogenic province in South Australia that contains one of the world’s most significant Cu-Au-U resources in the Olympic Dam deposit. The Olympic Cu-Au Province also hosts a range of other iron oxide-copper-gold (IOCG) deposits including Prominent Hill and Carrapateena. This paper reviews the geology of the Olympic Cu-Au Province by investigating the lithospheric architecture, geodynamic setting and alteration systematics. In addition, since the province is almost entirely buried by post-mineral cover, the sedimentary cover sequences are also reviewed. The Olympic Cu-Au Province formed during the early Mesoproterozoic, ca. 1.6 Ga and is co-located with a fundamental lithospheric boundary in the eastern Gawler Craton. This metallogenic event was driven in part by melting of a fertile, metasomatized sub-continental lithospheric mantle during a major regional tectonothermal event. Fluid evolution and multiple fluid mixing resulted in alteration assemblages that range from albite, magnetite and other higher temperature minerals to lower temperature assemblages such as hematite, sericite and chlorite. IOCG mineralisation is associated with both high and low temperature assemblages, however, hematite-rich IOCGs are the most economically significant. Burial by Mesoproterzoic and Neoproterozoic-Cambrian sedimentary successions preserved the Olympic Cu-Au Province from erosion, while also providing a challenge for mineral exploration in the region. Mineral potential modelling identifies regions within the Olympic Cu-Au Province and adjacent Curnamona Province that have high prospects for future IOCG discoveries. Exploration success will rely on improvements in existing potential field and geochemical data, and be bolstered by new 3D magnetotelluric surveys. However, drilling remains the final method for discovery of new mineral resources.

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6

Sutarto, Sutarto, Arifudin Idrus, Agung Harijoko, Lucas Donny Setijadji, and Franz Michael Meyer. "VEINS AND HYDROTHERMAL BRECCIAS OF THE RANDU KUNING PORPHYRY Cu-Au AND EPITHERMAL Au DEPOSITS AT SELOGIRI AREA, CENTRAL JAVA INDONESIA." Journal of Applied Geology 7, no. 2 (July 27, 2015): 82. http://dx.doi.org/10.22146/jag.26982.

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The Randu Kuning prospect is situated at Selogiri area, Wonogiri, Central Java, Indonesia. This location is about 40 km to the south-east from Solo city or approximately 70 km east of Yogyakarta city. Many Tertiary dioritic rocks related alterationmineralisation were found at the Randu Kuning area and its vicinity, including hornblende microdiorite, hornblende-pyroxene diorite and quartz diorite. Mineralisation type of the Randu Kuning prospect was interpreted as porphyry Cu-Au and a number epithermal Au-base metals deposits in its surrounding. The closed existing of porphyry Cu-Au and epithermal Au-base metals type deposits at the Randu Kuning area produced a very complex of veins and hydrothermal breccias crosscutting relationship. A lot of porphyry veins types were found and observed at the Randu Kuning area, and classiﬁed into at least seven types. Most of the porphyry veins were cross cut by epithermal type veins. Many epithermal veins also are found and crosscut into deeply porphyry vein types. There are genetically at least two type of hydrothermal breccias have recognized in the research area, i.e. magmatic-hydrothermal breccia and phreatomagmatic breccia. Magmatic hydrothermal breccias are mostly occured in contact between hornblende microdiorite or quartz diorite and hornblende-pyroxene diorite, characterized by angular fragments/clasts supported or inﬁlled by silicas, carbonates and sulphides matrix derived from hydrothermal ﬂuids precipitation. Phreatomagmatic breccias are characterized by abundant of the juvenile clasts, indicated contact between hot magma with ﬂuid or water as well as many wall rock fragments such as altered diorites and volcaniclastic rock clasts set in clastical matrix. The juvenile clasts usually compossed by volcanic glasses and aphanitic rocks in rounded-irregular shape. Both veining and brecciation processes have an important role in gold and copper mineralisation of the Randu Kuning Porphyry Cu-Au and epithermal Au-base metals deposits, mostly related to the presence of quartz veins/veinlets containing signiﬁcant sulphides, i.e., quartz with thin centre line sulphides (Abtype) veins, pyrite±chalcopyrite (C type) veinlets, pyrite+quartz± chalcopyrire±carbonate (D type) veins of porphyry types as well as epithermal environment quarts+ sulphides+carbonate veins.

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7

Zamanian, Hassan, and Behrooz Asadollahi. "Geochemistry and ore potential of the Almoughlagh batholith, western Iran." Geologos 19, no. 3 (September 1, 2013): 229–42. http://dx.doi.org/10.2478/logos-2013-0014.

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Abstract The Almoughlagh batholith intruded the dioritic Baba Ali pluton during the Oligo-Miocene; the pluton and is now exposed as a big enclave within the batholith. The pluton intruded the Songhor Series during the Late Kimmeridgian (~136 Ma) orogeny. The intrusion by the batholith transformed the diorite to metadiorite and the impure carbonate units of the Songhor Series. The batholith consists of rock types such as quartz syenite and syenogranite, which have a low average quartz content, and which are metaluminous to peraluminous and calc-alkaline in composition. Comparison of the compositions of the Almoughlagh batholith and the pluton with its Cu, Mo, Fe, Sn, W, Au, and Zn skarn deposits, indicates that the Baba Ali diorite geochemically shows much resemblance with those which could bring about Fe-Cu skarn mineralization, whereas the compositions of the Almoughlagh granitoids resembles those of the plutons associated with Mo and Zn skarn deposits. The associated hydrothermal activity related to the Almoughlagh batholith culminated in magnetite mineralisation in the Baba Ali and the Chenar mines in which copper mineralisation also is considerable.

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8

Idrus, Arifudin, Aji Syailendra Ubaidillah, I. Wayan Warmada, and Syafruddin Maula. "Geology, Rock Geochemistry and Ore Fluid Characteristics of the Brambang Copper-Gold Porphyry Prospect, Lombok Island, Indonesia." Journal of Geoscience, Engineering, Environment, and Technology 6, no. 1 (March 29, 2021): 67–73. http://dx.doi.org/10.25299/jgeet.2021.6.1.6145.

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Brambang is one of the porphyry copper-gold prospects/deposits situated along eastern Sunda arc. This study is aimed to understand geological framework, alteration geochemistry and ore fluid characteristics of the prospect. Fieldworks and various laboratory analyses were performed including petrography, ore microscopy, rock geochemistry, chlorite chemistry and fluid inclusion microthermometry. The prospect is composed of andesitic tuff and diorite which are intruded by tonalite porphyries. Tonalite porphyries are interpreted as ore mineralisation-bearing intrusion. Various hydrothermal alterations are identified including potassic, phyllic, propylitic, advanced argillic and argillic types. Ore mineralisation is characterized by magnetite and copper sulfides such as bornite and chalcopyrite. Potassic alteration is typified by secondary biotite, and associated with ore mineralisation. Mass balance calculation indicates SiO2, Fe2O3, K2O, Cu and Au are added during potassic alteration process. Ore forming fluid is dominated by magmatic fluid at high temperature (450-600ºC) and high salinity (60-70 wt. % NaCl eq.). Hydrothermal fluid was diluted by meteoric water incursion at low-moderate temperature of 150-400ºC and salinity of 0.5-7 wt. % NaCl eq.

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9

Krcmarov, R. L., and J. I. Stewart. "Geology and mineralisation of the Greenmount Cu‐Au‐Co deposit, southeastern Marimo Basin, Queensland." Australian Journal of Earth Sciences 45, no. 3 (June 1998): 463–82. http://dx.doi.org/10.1080/08120099808728404.

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10

Blevin, Phillip L., and Bruce W. Chappell. "The role of magma sources, oxidation states and fractionation in determining the granite metallogeny of eastern Australia." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 83, no. 1-2 (1992): 305–16. http://dx.doi.org/10.1017/s0263593300007987.

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ABSTRACTThe ore-element associations of granite-related ore deposits in the eastern Australian Palaeozoic fold belts can be related to the inferred relative oxidation state, halogen content and degree of fractional crystallisation within the associated granite suites. Sn mineralisation is associated with both S- and I-type granites that are reduced and have undergone fractional crystallisation. Cu and Au are associated with magnetite- and/or sphene-bearing, oxidised, intermediate I-type suites. Mo is associated with similar granites that are more fractionated and oxidised. W is associated with a variety of granite types and shows little dependence on inferred magma redox state. The observed ore deposit-granite type distribution in eastern Australia, and the behaviour of ore elements during fractionation, is consistent with models of ore element sequestering by sulphides and Fe-Ti phases (e.g. pyrrhotite, ilmenite, sphene, magnetite) whose stability is nominally fO2-dependent. Fractional crystallisation acts to amplify this process through the progressive removal of compatible elements and the concentration of incompatible elements into decreasing melt volumes. The halogen content is also important. S-type granites are poorer in Cl than I-types. Cl decreases and F increases in both S- and I-type granites with fractional crystallisation. Low Cl contents combined with low magma fO2 in themselves seem to provide an adequate explanation for the rarity of Mo, Cu, Pb and Zn type mineralisation with S-type granites. Although such properties of granite suites seem adequately to predict the associated ore-element assemblage to be expected in associated mineral deposits, additional factors determine whether or not there is associated economic mineralisation.

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11

Heilimo, Esa, Sini Halonen, Satu Mertanen, Sami Niemi, and Perttu Mikkola. "Hiekkapohja hydrothermal system – ore mineral, lithogeochemical and paleomagnetic evidence from the Paleoproterozoic Central Finland Granitoid Complex." Bulletin of the Geological Society of Finland 94, no. 2 (December 27, 2022): 145–64. http://dx.doi.org/10.17741/bgsf/94.2.003.

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The Paleoproterozoic Svecofennian Central Finland Granitoid Complex (CFGC) has been regarded as an area of low mineralisation potential. The Hiekkapohja area, 20km north-east of the town of Jyväskylä, host a concentration of variable metalliferous showings. Samples from mineralised boulders and outcrops display variable combinations of anomalously high concentrations of Cu, Mo, Zn, Pb, W, Pb, Ag, As, and Au. The area is composed mainly of peraluminous and ferroan granitoids. The dominant porphyritic Hiekkapohja granodiorite (~1.88 Ga) is cross-cut by the equigranular Soimavuori granite of similar age. The porphyritic Lehesvuori granite on the western side of the study area represents marginally older (~1.89 Ga) magmatism. The paragenetic sequence of the ore minerals shows that the Hiekkapohja area has been affected by at least two separate stages of hydrothermal activity. The first mineralisation stage was widespread, crystallising typically chalcopyrite, pyrrhotite, sphalerite, galena, arsenopyrite, magnetite and Ag-bearing minerals. After the first stage, a low temperature oxidising phase formed hematite and marcasite. The second mineralisation stage enclosed low temperature minerals, such as marcasite and native Ag and Ag-minerals, as inclusions inside chalcopyrite, pyrite, pyrrhotite, sphalerite, and arsenopyrite. The mineralised samples typically display signs of K-metasomatism and less commonly signs of propylitic alteration. During the second mineralisation stage the fluid flow was controlled by the dominant 120°–135° trending shear zones. Both the hydrothermal activity and the regional geology indicate that porphyry type ore forming processes have occurred in the Hiekkapohja area. Paleoproterozoic resetting of the remanent magnetisation is further evidence for the role of the hydrothermal system.

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12

Campbell, I. H., D. M. Compston, J. P. Richards, J. P. Johnson, and A. J. R. Kent. "Review of the application of isotopic studies to the genesis of Cu‐Au mineralisation at Olympic Dam and Au mineralisation at Porgera, the Tennant Creek district and Yilgarn Craton." Australian Journal of Earth Sciences 45, no. 2 (April 1998): 201–18. http://dx.doi.org/10.1080/08120099808728382.

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13

El Arbaoui, Amal, Ismaïla N’Diaye, Zaineb Hajjar, Amina Wafik, Abdelhak Boutaleb, Said Ilmen, Abderrahim Essaifi, and Mohammed Bouabdellah. "Fluid Origin and Evolution of the Roc Blanc Silver Deposit (Jebilet Massif, Variscan Belt, Morocco): Constraints from Geology and Fluid Inclusions." Geofluids 2022 (December 7, 2022): 1–22. http://dx.doi.org/10.1155/2022/3882516.

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The Roc Blanc Pb-Zn-Ag-Au vein deposit is located in the NW of Marrakech, in the Central Jebilet massif. It is spatially related to Bramram-Tabouchennt-Bamega (BTB) granodioritic pluton (ca. 330 Ma) metamorphism aureole. The main veins hosted in black shales are oriented N-S to NNW-SSE. Pb-Zn-Ag-Au ore is associated with quartz, chlorite, sericite, and carbonate gangue minerals. Two major stages of ore deposition were distinguished. The preore stage (stage I) comprises two quartz-mineralised vein generations with Fe, As, Zn, and Cu ores (vg1 and vg2). The main ore stage (stage II) consists mainly on Ag, Au, Pb, Zn, Cu, and Sb ores, which is hosted by carbonaceous vein (vg3) and by two late quartz generations veins (vg4 and vg5 with a geodic quartz). Three types of fluid inclusions have been recognized in silver mineralisation bearing quartz veins according to petrographic investigations, microthermometry, and Raman spectroscopy studies: (i) liquid-rich H2O-N2-CH4±CO2-(salt) fluid inclusions (type 1), (ii) vapour-rich H2O-CO2-CH4-N2-(salt) fluid inclusions (type 2), and (iii) aqueous H2O-(salt) fluid inclusions (type 3). The interpretation of fluid inclusion data shows a mixing of two fluids that are metamorphic and surface to subsurface origin, trapped at boiling state. The first mineralised stage was deposited at 350 ± 20 ° C (this temperature of ore deposition was supported also by chlorite geothermometry) with salinity of 13.7 wt% NaCl equiv., while the deposition of the argentiferous stage, which consists of the main economic mineralisation of the Roc Blanc deposit, occurs during decreasing temperature at 150°C with a salinity of 12.1 wt% NaCl equiv. The all-mineralised ore was deposited at relatively low pressure, below ~1-1.1 kbar. So, fluid dilution and cooling are probably the main factor for silver deposition in the Roc Blanc polymetallic vein deposit. In addition, fluid inclusion studies reveal that the mineralising fluid corresponds to a mixture of metamorphic fluid (H2O-CH4-N2-CO2) with surface to subsurface aqueous gas-free fluids (H2O-salt, meteoric, or brine).

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14

Griessmann, Martin, Andreas Schmidt Mumm, Thomas Seifert, and Colin Conor. "The mineralising system of the Mt. Mulga barite–magnetite–Cu–Au mineralisation, Olary Domain, South Australia." Journal of Geochemical Exploration 101, no. 1 (April 2009): 44. http://dx.doi.org/10.1016/j.gexplo.2008.12.059.

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15

Morey, A. A., F. P. Bierlein, D. P. Cherry, and G. Turner. "Genesis of greenstone‐hosted Cu–Au mineralisation at Hill 800, Mt Useful Slate Belt, eastern Victoria." Australian Journal of Earth Sciences 49, no. 5 (October 2002): 787–99. http://dx.doi.org/10.1046/j.1440-0952.2002.00954.x.

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16

Smith, W. D., W. D. Maier, and I. Bliss. "Contact-style magmatic sulphide mineralisation in the Labrador Trough, northern Quebec, Canada: implications for regional prospectivity." Canadian Journal of Earth Sciences 57, no. 7 (July 2020): 867–83. http://dx.doi.org/10.1139/cjes-2019-0137.

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The Labrador Trough in northern Quebec is currently the focus of ongoing exploration for magmatic Ni-Cu-platinum group element (PGE) sulphide ores. This geological belt hosts voluminous basaltic sills and lavas of the Montagnais Sill Complex, which are locally emplaced among sulphidic metasedimentary country rocks. The recently discovered Idefix PGE-Cu prospect represents a stack of gabbroic sills that host stratiform patchy disseminated to net-textured sulphides (0.2–0.4 g/t PGE+Au) over a thickness of ∼20 m, for up to 7 km. In addition, globular sulphides occur at the base of the sill, adjacent to the metasedimentary floor rocks. Whole-rock and PGE geochemistry indicates that the sills share a common source and that the extracted magma underwent significant fractionation before emplacement in the upper crust. To develop the PGE-enriched ores, sulphide melt saturation was attained before final emplacement, peaking at R factors of ∼10 000. Globular sulphides entrained along the base of the sill ingested crustally derived arsenic and were ultimately preserved in the advancing chilled margin.

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17

Robb, L. J., L. A. Freeman, and R. A. Armstrong. "Nature and longevity of hydrothermal fluid flow and mineralisation in granites of the Bushveld Complex, South Africa." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 91, no. 1-2 (2000): 269–81. http://dx.doi.org/10.1017/s0263593300007434.

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The Lebowa Granite Suite of the Bushveld Complex is a large, 2054 Ma old, A-type batholith, characterised by numerous relatively small magmato-hydrothermal, polymetallic ore deposits. The mineralisation is represented by a three-stage paragenetic sequence: early magmatic Sn-W-Mo-F ores (600°C > T > 400°C), followed by a Cu-Pb-Zn-As-Ag-Au paragenesis (400°C > T > 200°C) and then late-stage Fe-F-U mineralisation (< 200°C). The first stage of mineralisation (typified by the endogranitic Zaaiplaats tin deposit) is related to incompatible trace element concentration during crystal fractionation and subsequent fluid saturation of the magma. Evolution of the late magmatic fluids as they were channelled along fractures, as well as mingling with externally derived connate or meteoric fluids, resulted in the deposition of the second stage of mineralisation (typified by the fracture-related, endogranitic Spoedwel and Albert deposits and the exogranitic, sediment-hosted Rooiberg mine) which is dominated by polymetallic sulphide ores. As the externally derived fluid component became progressively more dominant, oxidation of the polymetallic sulphide assemblage and precipitation of hematite, pitchblende and fluorite occurred generally along the same fracture systems that hosted the earlier sulphide paragenesis.Small hydrothermal zircons trapped along quartz growth zones from the Spoedwel deposit yield a U-Pb concordia age of 1957 ± 15 Ma. Whole-rock Rb-Sr age determinations from the Lebowa Granite Suite fall in the range 1790 ± 114 Ma to 1604 ± 70 Ma and are interpreted to reflect alkali element mobility and isotopic resetting during exhumation of the Bushveld granite. In contrast to thermal modelling which indicates that hydrothermal activity should have ceased within 4 my of emplacement, isotopic evidence suggests that mineralisation was long-lived, but episodic, and that fluid flow events were linked to major periods of Palaeo- and Mesoproterozoic orogenic activity along the margins of the Kaapvaal Craton. During these orogenic episodes, fluid flow was enhanced by tectonically induced fluid over-pressuring and/or exhumation of the Bushveld Complex.

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Kankara, Aliyu Ibrahim, and Terlumun Adagba. "Geochemical investigation of gold and chalcophile minerals of Rawayau Area Katsina State, Nigeria." Dutse Journal of Pure and Applied Sciences 8, no. 2a (June 24, 2022): 126–39. http://dx.doi.org/10.4314/dujopas.v8i2a.14.

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This present study investigated the Gold and Chalcophile mineralisation potentials of the Rawayau area in Northwestern Nigeria. The aim of the investigation is to delineate the likely Gold and Chalcophile mineralisation occurrences in the study area so as to aid further exploration studies that will identify Gold rich targets worth investing resources for detail exploration project before mining. To achieve this, 17 samples (7 rock samples and 10 sediments) were collected and subjected to laboratory analysis at the National Geologic Survey Agency (NGSA) in Kaduna. The geochemical study showed that the Au concentration ranged from below detection level (bdl) to 0.09ppm in the rock samples, while ranging from 0.013ppm to 0.137ppm in the sediments. Ag concentration ranged from 0.37ppm to 0.97ppm with in the rock samples, while ranging from 0.088ppm to 0.229ppm in the sediments, thus showing a higher concentration in both rock and sediments than Au. Significant positive relationship was observed between Ni, Cr, Cu, Mn, Fe, Zn and Co from the correlation analysis. It also revealed a subsurface increment of Gold and Chalcophile concentration of Nickel, Copper and Zinc with higher concentration of Nickel, Copper, Zinc, Manganese, Chromium and Lead in comparison to Gold and Silver. The study concludes that the Rawayau area holds much prospects for Gold and other minerals. It is suggested that further exploratory studies be carried out so as to pave way for the commencement of mining activities in the study area”.

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Pribavkin, S. V., A. V. Коrovko, and I. A. Gottman. "Geological structure and petrology of the Nizhne-Sinyachikhinsky granitoid massif (Alapayevsk-Sukhoi Log porphyry copper zone, the Middle Urals)." LITHOSPHERE (Russia) 20, no. 2 (April 25, 2020): 212–23. http://dx.doi.org/10.24930/1681-9004-2020-20-2-212-223.

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Research subject. The geological structure and rock composition of the Nizhne-Sinyachikhinsky plagiogranite massif, which is part of the Alapaevsk-Sukholozhsky zone, is promising for the Cu(Au,Mo)-porphyric mineralization type, were studied. The aim was to determine the formation features of these rocks and compare them with the productive granitoids of Ural porphyry deposits of similar age. Materials and methods. The mineral composition of the rocks was determined using a JEOL JSM 6790LV scanning electron microscope with an INCA Energy 450 X-Max 80 EDS spectrometer and a CAMECA SX-100 electron microprobe analyser. The rock composition was obtained by X-ray fluorescence spectrometry on a SRM-35 and XRF-1800 spectrometers with the titrimetric determination of FeO. The concentrations of rare and rare-earth elements were determined on an ELAN 9000 inductively coupled plasma mass spectrometer at the Geoanalitik Center for Collective Use of the Ural Branch of the Russian Academy of Sciences. Results. For the first time, an early tonalite-plagiogranite series was identified in the structure of the massif. This series is represented by tonalites of the hypabyssal appearance, broken through by the dikes of plagiogranite-porphyry. It was shown that the separation of plagiogranite-porphyry melts from magmas of the mafic composition occurred at the base of the island-arc construction, and their crystallisation was carried out in an intermediate chamber at a pressure of 1.8–2.3 kbar. In contrast, the plagiogranites of the main phase of the massif were separated from the parent melt in an intermediate chamber located at the level of the upper crust, and their crystallisation occurred at a pressure of 1.5–2.0 kbar. Conclusions. A comparison of the main phase plagiogranites and the isolated early-series plagiogranite-porphyry indicates their similar composition, as well as their similarity in age with the granitoids of the Southern Urals, productive in terms of the porphyry mineralisation type. The concentrations of F, Cl and S in the apatites and amphiboles of the rocks under study is an argument in favour of their belonging to andesitoid formations that are productive in terms of the Cu (Au)-porphyry mineralisation type. The absence of the sulphide mineralisation of this type can be explained by a more significant depth of rock formation and their erosion section.

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Perkins, C., and L. A. I. Wyborn. "Age of Cu‐Au mineralisation, Cloncurry district, eastern Mt Isa Inlier, Queensland, as determined by40Ar/39Ar dating∗." Australian Journal of Earth Sciences 45, no. 2 (April 1998): 233–46. http://dx.doi.org/10.1080/08120099808728384.

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Milu, Viorica, Jacques L. Leroy, and Patrice Piantone. "The Bolcana Cu–Au ore deposit (Metaliferi Mountains, Romania): first data on the alteration and related mineralisation." Comptes Rendus Geoscience 335, no. 8 (August 2003): 671–80. http://dx.doi.org/10.1016/s1631-0713(03)00120-2.

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22

Lowczak, Jessica N., Ian H. Campbell, Helen Cocker, Jung-Woo Park, and David R. Cooke. "Platinum-group element geochemistry of the Forest Reef Volcanics, southeastern Australia: Implications for porphyry Au-Cu mineralisation." Geochimica et Cosmochimica Acta 220 (January 2018): 385–406. http://dx.doi.org/10.1016/j.gca.2017.09.052.

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23

Dora, M. L., and K. R. Randive. "Chloritisation along the Thanewasna shear zone, Western Bastar Craton, Central India: Its genetic linkage to Cu–Au mineralisation." Ore Geology Reviews 70 (October 2015): 151–72. http://dx.doi.org/10.1016/j.oregeorev.2015.03.018.

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24

Hulkki, Helena, Anne Taivalkoski, and Marja Lehtonen. "Signatures of Cu (-Au) mineralisation reflected in inorganic and heavy mineral stream sediments at Vähäkurkkio, north-western Finland." Journal of Geochemical Exploration 188 (May 2018): 156–71. http://dx.doi.org/10.1016/j.gexplo.2018.01.012.

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25

Clark, David A., and Phillip W. Schmidt. "Petrophysical Properties of the Goonumbla Volcanic Complex, NSW: Implications for Magnetic and Gravity Signatures of Porphyry Cu-Au Mineralisation." ASEG Extended Abstracts 2001, no. 1 (December 2001): 1–4. http://dx.doi.org/10.1071/aseg2001ab020.

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26

Clark, David A., and Phillip W. Schmidt. "Petrophysical Properties of the Goonumbla Volcanic Complex, NSW: Implications for Magnetic and Gravity Signatures of Porphyry Cu-Au Mineralisation." Exploration Geophysics 32, no. 3-4 (September 2001): 171–75. http://dx.doi.org/10.1071/eg01171.

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Sutarto, Sutarto, Arifudin Idrus, Sapto Putranto, Agung Harjoko, Lucas D. Setijadji, Franz M. Meyer, and Rama Danny. "HYDROTHERMAL ALTERATION AND VEIN TYPES OF THE RANDU KUNING PORPHYRY Cu-Au DEPOSIT AT SELOGIRI AREA, WONOGIRI." Buletin Sumber Daya Geologi 9, no. 1 (May 8, 2014): 48–61. http://dx.doi.org/10.47599/bsdg.v9i1.121.

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Many Tertiary hydrothermal altered dioritic composition intrusive rocks were found at the Randu Kuning area and its vicinity, Selogiri, including hornblende microdiorite, hornblende-pyroxene diorite and quartz diorite. The hydrothermal fluids which responsible for the alteration and mineralization at the area is associated with the occurence of the horblende microdiorite intrusion. The alteration zone at the Randu Kuning area and its vicinity can be divided intoseveral hydrothermal alteration zones, such as potassic (magnetite-biotite-K feldspar), prophyllitic (chlorite-magnetite-epidote-carbonate), phyllic (quartz-sericite-chlorite) and argillic (clay mineral-sericite). The alteration pattern in the Randu Kuning porphyry Cu-Au deposit is tipically a diorite model characterising by the domination of potassic alteration and prophyllitic zone. Phyllic and argillic alteration types are restrictive found within the fault zones. A lot of porphyry vein types were found and observed at the Randu Kuning area, and classified into at least seven vein types. The paragenetic sequence of those veins from theearliest to the latest respectively are 1). Magnetite-chalcopyrite±quartz-biotite veinlets, 2). Quartz±magnetite (A type) veins, 3). Banded/Laminated quartz-magnetite (M type) veins, 4). Quartz±K feldspar (B type)veins, 5). Quartz with thin centre line sulphide (AB type) veins, 6). Pyrite±chalcopyrite (C type) veinlets, and 7). Pyrite-quartz+chalcopyrire+carbonate (D type) veins. Gold and copper mineralisation of the Randu Kuning Porphyry Cu-Au deposit, mostly related to the presence of quartz veins/veinlets containing sulfide i.e. Quartz with thin centre line sulphide veins, Pyrite±chalcopyrite veinlets, and Pyrite-quartz+chalcopyrire+carbonate veins.

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28

Williams, P. K., and G. A. Fraser. "The Use of Transient Electromagnetics In the Exploration For Conductive Sulphides Associated With Cu-Au Mineralisation, at Moonta, South Australia." Exploration Geophysics 23, no. 3 (June 1992): 507–14. http://dx.doi.org/10.1071/eg992507.

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29

Kontonikas-Charos, Alkis, Cristiana L. Ciobanu, Nigel J. Cook, Kathy Ehrig, Sasha Krneta, and Vadim S. Kamenetsky. "Feldspar evolution in the Roxby Downs Granite, host to Fe-oxide Cu-Au-(U) mineralisation at Olympic Dam, South Australia." Ore Geology Reviews 80 (January 2017): 838–59. http://dx.doi.org/10.1016/j.oregeorev.2016.08.019.

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30

Graham, S. D., D. A. Holwell, I. McDonald, G. R. T. Jenkin, N. J. Hill, A. J. Boyce, J. Smith, and C. Sangster. "Magmatic Cu-Ni-PGE-Au sulfide mineralisation in alkaline igneous systems: An example from the Sron Garbh intrusion, Tyndrum, Scotland." Ore Geology Reviews 80 (January 2017): 961–84. http://dx.doi.org/10.1016/j.oregeorev.2016.08.031.

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31

Armistead, Sheree E., Peter G. Betts, Laurent Ailleres, Robin J. Armit, and Helen A. Williams. "Cu-Au mineralisation in the Curnamona Province, South Australia: A hybrid stratiform genetic model for Mesoproterozoic IOCG systems in Australia." Ore Geology Reviews 94 (March 2018): 104–17. http://dx.doi.org/10.1016/j.oregeorev.2018.01.024.

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32

Maidment, D. W., D. L. Huston, N. Donnellan, and A. Lambeck. "Constraints on the timing of the Tennant Event and associated Au–Cu–Bi mineralisation in the Tennant Region, Northern Territory." Precambrian Research 237 (October 2013): 51–63. http://dx.doi.org/10.1016/j.precamres.2013.07.020.

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33

Holwell, David A., Thomas Abraham-James, Reid R. Keays, and Adrian J. Boyce. "The nature and genesis of marginal Cu–PGE–Au sulphide mineralisation in Paleogene Macrodykes of the Kangerlussuaq region, East Greenland." Mineralium Deposita 47, no. 1-2 (January 8, 2011): 3–21. http://dx.doi.org/10.1007/s00126-010-0325-4.

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34

Mark, G., N. H. S. Oliver, and M. J. Carew. "Insights into the genesis and diversity of epigenetic Cu – Au mineralisation in the Cloncurry district, Mt Isa Inlier, northwest Queensland." Australian Journal of Earth Sciences 53, no. 1 (February 2006): 109–24. http://dx.doi.org/10.1080/08120090500434583.

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35

Glen, R. A., A. J. Crawford, and D. R. Cooke. "Tectonic setting of porphyry Cu – Au mineralisation in the Ordovician – Early Silurian Macquarie Arc, Eastern Lachlan Orogen, New South Wales." Australian Journal of Earth Sciences 54, no. 2-3 (March 2007): 465–79. http://dx.doi.org/10.1080/08120090701221672.

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36

Barton, Mark D. "Granitic magmatism and metallogeny of southwestern North America." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 87, no. 1-2 (1996): 261–80. http://dx.doi.org/10.1017/s0263593300006672.

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ABSTRACT:In southwestern North America, late Palaeozoic through Cenozoic granitoids and their related mineral deposits show consistent patterns that can be interpreted in terms of combined provincial, exposure and process controls. Voluminous Cordilleran magmatism began in the Permian and continued with few major interruptions through the Mesozoic and Cenozoic, reaching maximum fluxes in the mid-Jurassic, Late Cretaceous and Oligocene. Two distinctive types of broad-scale igneous suites formed. The first type consists of calc-alkaline to alkaline suites that vary regularly with time from early intermediate-mafic centres to late felsic centres over intervals lasting 20–50 Ma. These suites formed during periods of stable convergence and compressional tectonics, most notably in the late Mesozoic and early–mid-Cenozoic. The second type is compositionally varied, but shows no obvious secular variation in composition. This type formed during neutral to extensional tectonics in the mid-Mesozoic and the mid- to late Cenozoic. Regional (west to east) and secular (old to young) changes from calcic to alkalic compositions do not correspond to basement types; they point to tectonic rather than crustal controls on magmatic evolution, although basement signatures are clearly transmitted in isotopic systematics. Contrasting types of intrusive centres formed in the same lithospheric columns, suggesting that variability reflects thermal and stress regimes, subcrustal magma flux and crustal thickness. Simple thermal and mechanical models of limits on assimilation and magma uprise are broadly consistent with these patterns.Igneous-related mineralisation is ubiquitous where epizonal environments are preserved, thus preservation (and exposure) form the first-order filter on metallogeny. Mineralisation includes porphyry, skarn, epithermal, replacement and syngenetic deposits of widely varying styles, metal contents and links to magmatic heat and materials. Metal contents and alteration styles correlate closely with igneous compositions and are broadly independent of setting, although systematic regional variations in metal ratios are documented. Ore element suites vary from Cu–Au–Fe associated with (quartz) dioritic to monzonitic intrusive centres through Cu–Zn–Mo–Pb–Ag–W–Au associated with broadly granodioritic centres, and finally to F–Mo–Zn–W–Ag–Be associated with metaluminous to strongly peraluminous granitic centres. A model that includes both composition and process controls rationalises this igneous correlation and the lack of strong regional control. Key features are (1) mineralogical controls on fluid compositions and (2) the efficacy of magmatic processes in producing voluminous ore-forming aqueous fluids. This interpretation is supported by field relationships, igneous petrographic and isotopic data, and theoretical considerations.

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37

Brathwaite, R., M. Simpson, K. Faure, and D. Skinner. "Telescoped porphyry Cu-Mo-Au mineralisation, advanced argillic alteration and quartz-sulphide-gold-anhydrite veins in the Thames District, New Zealand." Mineralium Deposita 36, no. 7 (October 2001): 623–40. http://dx.doi.org/10.1007/s001260100182.

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38

Dimitrova, Dimitrina, Nikolaya Velitchkova, Vassilka Mladenova, Tsvetan Kotsev, and Dimitar Antonov. "Heavy metal and metalloid mobilisation and rates of contamination of water, soil and bottom sediments in the Chiprovtsi mining district, Northwestern Bulgaria." Geologica Balcanica 45 (2016): 47–63. http://dx.doi.org/10.52321/geolbalc.45.0.47.

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Geochemical studies of seasonally collected mine, stream and drinking waters, bottom sediments (mine and stream) and soil samples from all mining sections were carried out in order to assess the rates of pollution in the immediate proximity to underground mining facilities and related waste rock dumps. The determined concentrations of studied elements in water (As, Pb, Cu, Zn and Sb) show spatial distribution corresponding to ore mineralisation in different sections. Arsenic concentrations show gradual decrease in west-east direction, whereas Pb concentrations peak in the central and eastern sections. Arsenic and, to a lesser extent, Pb proved to be major pollutants in mine and surface waters, as well as in bottom sediments and soils. Detailed geochemical study of soils revealed strong spatial relation with host rocks and ore mineralogy. Comparisons with state guidelines for harmful elements revealed that alluvial and meadow soils in close proximity to waste dumps contain As, Pb, Cu, Zn and Cd above maximum permissible levels. It was also found that, compared to other Bulgarian and world alluvial (fluvisol) soils and the upper continental crust, the soils in Chiprovtsi mining district are enriched in Te, Re, W, Pd, Au, Ag, Mo, Ti, Mn, Co, Se, Sb, Bi and Cs. Since the processes of weathering and oxidation of mine waste remaining in the area continue naturally, the pollution with As and Pb will presumably carry on with decreasing effect.

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Xu, Bo, Zeng-Qian Hou, Yuan-Chuan Zheng, Rui Wang, Ming-Yue He, Li-Min Zhou, Zi-Xuan Wang, Wen-Yan He, Ye Zhou, and Yu Yang. "In situ elemental and isotopic study of diorite intrusions: Implication for Jurassic arc magmatism and porphyry Cu-Au mineralisation in southern Tibet." Ore Geology Reviews 90 (November 2017): 1063–77. http://dx.doi.org/10.1016/j.oregeorev.2017.04.036.

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40

Tedesco, Adam. "Late-stage orogenic model for Cu-Au mineralisation at Kanmantoo mine: New insights from titanium in quartz geothermometry, fluid inclusions and geochemical modelling." Journal of Geochemical Exploration 101, no. 1 (April 2009): 103. http://dx.doi.org/10.1016/j.gexplo.2008.11.043.

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41

Jones, B. M. "The Abancay Batholith, Late Eocene crustal thickening, multiple mixing-differentiation cycles, and porphyry Cu–Au mineralisation on the Altiplano at Antapaccay, Southern Peru." Geochimica et Cosmochimica Acta 70, no. 18 (August 2006): A297. http://dx.doi.org/10.1016/j.gca.2006.06.602.

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42

Blevin, Phillip. "The petrographic and compositional character of variably K-enriched magmatic suites associated with Ordovician porphyry Cu-Au mineralisation in the Lachlan Fold Belt, Australia." Mineralium Deposita 37, no. 1 (February 1, 2002): 87–99. http://dx.doi.org/10.1007/s00126-001-0232-9.

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43

Ishbaev, Kh D., A. Kh Shukurov, and K. M. Kosbergenov. "Lamprophyres and mineralization of the Koytash ore field (Southern Tien Shan)." LITHOSPHERE (Russia) 20, no. 2 (April 25, 2020): 231–53. http://dx.doi.org/10.24930/1681-9004-2020-20-2-231-253.

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Research subject. The Koytash ore field is located in the potentially productive Au, Ag, W, Mo, Ti, Fe, Cu, Pb, Zn and REE North Nuratau mineralisation zone of Tien Shan. The authors undertook a study of the composition of dikes breaking through the Paleozoic ore-bearing formations, as well as their petro- and ore-generating role in the formation of the Koytash-Ugat sulphide-rare-metal (W, Mo, Fe) specialised mineralisation. Materials and methods. A study of rock and mineral composition was performed at the Institute of Geology and Geophysics named after Kh.M. Abdullaev. The content of petrogenic and rare elements in rocks and sulphides was determined by ICP-MS using an ICPE-9000 mass-spec trometer in the Central Laboratory of the State Committee for Geology of the Republic of Uzbekistan. The chemical analysis of minerals was performed using a Jeol-8800Rh electronic microanalyser at the Institute of Geology and Geophysics named after Kh.M. Abdullaev. The micrographs of transparent sections were obtained using Nikon Optiphot 2 Pol and Polam R-311 microscopes. Results and conclusions. The conducted study showed that, in terms of their structure, the Koytash ore field dike formations can be regarded as lamprophyres. In terms of their chemical composition, these formations are mafic and intermediate rocks of the subalkaline series. It was found that the composition of lamprophyre dikes correlates with the size of the erosion section. Their melanocratic varieties are confined to the southern part of the intrusion (absolute elevations are 1000–1200 m), and leucocratic – to the northern (about 1900 m). This is assumed to be the result of crystallization differentiation of a single initial melt. The dikes of the Koytash ore field lamprophyres break through not only sulphide-rare-metal bodies of the Koytash-Ugat strip, but also skarn and carbonate rocks and, in turn, are broken through by quartz-polymetallic ore-bearing veins, which testifies to their inter-ore character.

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Guice, George L., Tuomo Törmänen, Bartosz T. Karykowski, Bo Johanson, and Yann Lahaye. "Precious metal mineralisation in the Sotkavaara Intrusion, northern Finland: Peak Pt, Pd, Au and Cu offsets in a small intrusion with poorly-developed magmatic layering." Ore Geology Reviews 89 (October 2017): 701–18. http://dx.doi.org/10.1016/j.oregeorev.2017.07.010.

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45

Yuan, Feng, Xiaohui Li, Taofa Zhou, Yufeng Deng, Dayu Zhang, Chao Xu, Ruofei Zhang, Cai Jia, and Simon M. Jowitt. "Multifractal modelling-based mapping and identification of geochemical anomalies associated with Cu and Au mineralisation in the NW Junggar area of northern Xinjiang Province, China." Journal of Geochemical Exploration 154 (July 2015): 252–64. http://dx.doi.org/10.1016/j.gexplo.2014.11.015.

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46

Coote, Anthony, and Mike Erceg. "Application of Petrology & Geology to the Interpretation of Geophysical Data in Defining Economic Porphyry-Related Cu-Au Mineralisation Along the Ekuti Range, Morobe Province, PNG." ASEG Extended Abstracts 2016, no. 1 (December 2016): 1–8. http://dx.doi.org/10.1071/aseg2016ab192.

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Williams, Megan R., David A. Holwell, Richard M. Lilly, George N. D. Case, and Iain McDonald. "Mineralogical and fluid characteristics of the fluorite-rich Monakoff and E1 Cu–Au deposits, Cloncurry region, Queensland, Australia: Implications for regional F–Ba-rich IOCG mineralisation." Ore Geology Reviews 64 (January 2015): 103–27. http://dx.doi.org/10.1016/j.oregeorev.2014.05.021.

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48

Large, Simon J. E., Jörn-Frederik Wotzlaw, Marcel Guillong, Albrecht von Quadt, and Christoph A. Heinrich. "Resolving the timescales of magmatic and hydrothermal processes associated with porphyry deposit formation using zircon U–Pb petrochronology." Geochronology 2, no. 2 (July 31, 2020): 209–30. http://dx.doi.org/10.5194/gchron-2-209-2020.

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Abstract. Understanding the formation of economically important porphyry Cu–Au deposits requires knowledge of the magmatic-to-hydrothermal processes that act within the much larger magmatic system and the timescales on which they occur. We apply high-precision zircon geochronology (chemical abrasion–isotope dilution–thermal ionisation mass spectrometry; CA–ID–TIMS) and spatially resolved zircon geochemistry (laser ablation inductively coupled plasma mass spectrometry; LA-ICP-MS) to constrain the magmatic evolution of the underlying magma reservoir at the Pliocene Batu Hijau porphyry Cu–Au deposit. We then use this extensive dataset to assess the accuracy and precision of different U–Pb dating methods of the same zircon crystals. Emplacement of the oldest pre- to syn-ore tonalite (3.736±0.023 Ma) and the youngest tonalite porphyry to cross-cut economic Cu–Au mineralisation (3.646±0.022 Ma) is determined by the youngest zircon grain from each sample, which constrains the duration of metal precipitation to fewer than 90±32 kyr. Overlapping spectra of single zircon crystallisation ages and their trace element distributions from the pre-, syn and post-ore tonalite porphyries reveal protracted zircon crystallisation together with apatite and plagioclase within the same magma reservoir over >300 kyr. The presented petrochronological data constrain a protracted early >200 kyr interval of melt differentiation and cooling within a large heterogeneous magma reservoir, followed by magma storage in a highly crystalline state and chemical and thermal stability over several tens of thousands of years during which fluid expulsion formed the ore deposit. Irregular trace element systematics suggest magma recharge or underplating during this final short time interval. The comparison of high-precision CA–ID–TIMS results with in situ LA-ICP-MS and a sensitive high-resolution ion microprobe (SHRIMP) U–Pb geochronology data from the same zircon grains allows a comparison of the applicability of each technique as a tool to constrain dates and rates on different geological timescales. All techniques provide accurate dates but with different precision. Highly precise dates derived by the calculation of the weighted mean and standard error of the mean of the zircon dates obtained by in situ techniques can lead to ages of unclear geological significance that are older than the maximum ages of emplacement given by the CA–ID–TIMS ages of the youngest zircons in each sample. This lack of accuracy of the weighted means is due to the protracted nature of zircon crystallisation in upper crustal magma reservoirs, suggesting that standard errors should not be used as a means to describe the uncertainty in those circumstances. We conclude from this and similar published studies that the succession of magma and fluid pulses forming a single porphyry deposit and similarly rapid geological events are too fast to be reliably resolved by in situ U–Pb geochronology and that assessing the tempo of ore formation requires CA–ID–TIMS geochronology.

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Hart, Craig J. R., John L. Mair, Richard J. Goldfarb, and David I. Groves. "Source and redox controls on metallogenic variations in intrusion-related ore systems, Tombstone-Tungsten Belt, Yukon Territory, Canada." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 95, no. 1-2 (March 2004): 339–56. http://dx.doi.org/10.1017/s0263593300001115.

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ABSTRACTThe Tombstone, Mayo and Tungsten plutonic suites of granitic intrusions, collectively termed the Tombstone-Tungsten Belt, form three geographically, mineralogically, geochemically and metallogenically distinct plutonic suites. The granites (sensu lato) intruded the ancient North American continental margin of the northern Canadian Cordillera as part of a single magmatic episode in the mid-Cretaceous (96–90 Ma). The Tombstone Suite is alkalic, variably fractionated, slightly oxidised, contains magnetite and titanite, and has primary, but no xenocrystic, zircon. The Mayo Suite is sub-alkalic, metaluminous to weakly peraluminous, fractionated, but with early felsic and late mafic phases, moderately reduced with titanite dominant, and has xenocrystic zircon. The Tungsten Suite is peraluminous, entirely felsic, more highly fractionated, reduced with ilmenite dominant, and has abundant xenocrystic zircon. Each suite has a distinctive petrogenesis. The Tombstone Suite was derived from an enriched, previously depleted lithospheric mantle, the Tungsten Suite is from the continental crust including, but not dominated by, carbonaceous pelitic rocks, and the Mayo Suite is from a similar sedimentary crustal source, but is mixed with a distinct mafic component from an enriched mantle source.Each suite has a distinctive metallogeny that is related to the source and redox characteristics of the magma. The Tombstone Suite has a Au-Cu-Bi association that is characteristic of most oxidised and alkalic magmas, but also has associated, and enigmatic, U-Th-F mineralisation. The reduced Tungsten Suite intrusions are characterised by world-class tungsten skarn deposits with less significant Cu, Zn, Sn and Mo anomalies. The Mayo Suite intrusions are characteristically gold-enriched, with associated As, Bi, Te and W associations. All suites also have associated, but distal and lower temperature Ag-Pb- and Sb-rich mineral occurrences. Although processes such as fractionation, volatile enrichment and phase separation are ultimately required to produce economic concentrations of ore elements from crystallising magmas, the nature of the source materials and their redox state play an important role in determining which elements are effectively concentrated by magmatic processes

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Basori, Mohd Basril Iswadi, Sarah Gilbert, Khin Zaw, and Ross Large. "Geochemistry of Sphalerite from the Permian Volcanic-Hosted Massive Sulphide (VHMS) Deposits in the Tasik Chini Area, Peninsular Malaysia: Constraints for Ore Genesis." Minerals 11, no. 7 (July 5, 2021): 728. http://dx.doi.org/10.3390/min11070728.

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Abstract:

The Bukit Botol and Bukit Ketaya deposits are two examples of volcanic-hosted massive sulphide (VHMS) deposits that occur in the Tasik Chini area, Central Belt of Peninsular Malaysia. The mineralisation is divided into subzones distinguished by spatial, mineralogical, and textural characteristics. The primary sulphide minerals include pyrite, chalcopyrite, sphalerite, and galena, with lesser amounts of Sn- and Ag-bearing minerals, with Au. However, pyrrhotite is absent from both deposits. This study presents the results of sphalerite chemistry analysed by using an electron microprobe. Two types of sphalerite are recognised: sphalerite from the Bukit Botol deposit reveals a range of <DL to 24.0 mole% FeS, whereas sphalerite from the Bukit Ketaya deposit shows a range of <DL to 3 mole% FeS. Significant variations are shown in Zn, Cu, Cd, and Ag levels. Although the sphalerite has a wide variation in composition, a discernible decreasing Fe trend is exhibited from the stringer zone towards massive sulphide. This compositional variation in sphalerites may in part reflect variable temperature and activity of sulphur in the hydrothermal fluids during ore formation. Alternatively, the bimodal composition variations suggest that mineral chemistry relates to contrasting depositional processes. The Zn/Cd ratios for sphalerite from both these deposits are similar to those exhibited by volcano−sedimentary deposits with a volcanic origin. Therefore, the consistently low Cd concentrations and moderate to high Zn/Cd ratios suggest mixing of seawater and minor magmatic fluids controlling the chemistry of sphalerite at both deposits during their formation.

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