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Rhenium in ores of porphyry copper deposits in the Urals
Abstract
sive chalcopyrite‐pyrrhotite and chalcopyrite‐pyrite ores of the Gumeshev skarn porphyry copper deposit (central Urals) and skarn copper deposits of the Tur’ya group (northern Urals) associated with diorite‐quartz diorite plutons (K 2 O up to 1.0‐1.5 wt %), the Re content is 2‐29 ppm. The largest porphyry Mo‐Au‐Cu ore nodes in the Urals with the maximal Re concentration in ores are located in the southern Urals. The age of ore deposits in this area ranges from Late Devonian to Early‐Middle Carboniferous. They are confined to the boundary between the East Ural volcanic zone and the East Ural (Bereznyakov‐Tomin) or the Transural (Mikheevo and Taruta) sialic zone. The ore deposits are associated with quartz diorite‐plagiogranodiorite plutons (K 2 O up to 1.5‐2.0 wt %) that are transitional between the islandarc and continental-margin formations. The Cu/Mo ratio in ores of these deposits varies from 71 to 250, while the Mo content varies from 30 to 200 ppm. Molybdenite is a common mineral, because it is deposited at all stages of mineralization. In copper orebodies, molybdenite occurs in chalcopyrite‐quartz or molybdenite‐quartz veinlets. However, this mineral is usually developed in dry fibrolitic cracks developed after the chalcopyrite ore stage. The molybdenite content commonly does not exceed 40‐70 ppm (0.01‐0.03 ppm or more in some zones). In general, the aureoles of Cu and Mo coincide or are slightly displaced relative to each other. The majority of orebodies lack any correlation between Cu and Mo. Ores of the Late Devonian‐Middle Carboniferous Mikheevo deposit are represented by stringer‐disseminated mineralization in volcanosedimentary rocks and diorite porphyry dikes [6]. These ores are characterized by the maximal Re concentration. In pyrite‐bornite‐chalcopyrite orebodies (Cu 0.3‐ 1.5 wt %), the Re content varies from 0.01 to 2.7 ppm. In general, the Re content varies from 0.2 to 0.5 ppm (Fig. 1c). The Re content is as much as 289 ppm in molybdenite from the early chalcopyrite‐molybdenite‐ quartz veinlet. In molybdenite stringer and dissemina
... Aeromagnetic data extracted from the magnetic anomaly grid of the Former Soviet Union (NGDC, 1997) are shown as a reduced-to-pole map for the Urals in Fig. 2, along with some of the major tectonic zones and faults. Table 1 Identified porphyry copper resources in the Urals [t, metric tons; Mt, million metric tons, %, percent; g/t, grams per metric ton; −, no data; *, classified as a prospect by Singer et al. (2008); **, primarily a skarn deposit; for Lekyn-Talbei, resources are inferred (C2) based on data in Plotinskaya et al. (2017-in Silaev and Andreichev (1982), Petrov et al. (2006), Singer et al. (2008), Plotinskaya et al. (2017--in Grabezhev and Borovikov (1993), Grabezhev et al. (1995), Plotinskaya et al. (2017--in this volume) East Uralian Birgilda* Russia 4.7 0.7 --32,900 Grabezhev and Borovikov (1993), Grabezhev et al. (1995), Kozolov et al. (2002), Plotinskaya et al. (2014b), Romashova (1984), Singer et al. (2008), Vorob'ev et al. Grabezhev (2007), Grabezhev and Borovikov (1993), Girfanov et al. (1991), Lehman et al. (1999), Ocharova et al. (2008), Russian Copper Company (2014) ...
... It is described as a medium-size deposit with average grades of 0.5% Cu, 0.003% Mo; 0.01 to 0.05 ppm Au is reported in pyrite. Ore contains b 0.01 to 0.47 ppm Re (Grabezhev, 2007). A resource has not been delineated at Salavat. ...
... In addition to copper, undiscovered porphyry copper deposits in the Urals may contain significant amounts of molybdenum, gold, and silver. The fact that molybdenite in porphyry copper deposits provides most of the world's rhenium prompted a number of studies of the rhenium content of molybdenite in porphyry copper deposits of the Urals (Grabezhev, 2007(Grabezhev, , 2013Grabezhev and Voudoris, 2014;Plotinskaya et al., 2015). ...
A probabilistic mineral resource assessment of metal resources in undiscovered porphyry copper deposits of the Ural Mountains in Russia and Kazakhstan was done using a quantitative form of mineral resource assessment. Permissive tracts were delineated on the basis of mapped and inferred subsurface distributions of igneous rocks assigned to tectonic zones that include magmatic arcs where the occurrence of porphyry copper deposits within 1 km of the Earth's surface are possible. These permissive tracts outline four north-south trending volcano-plutonic belts in major structural zones of the Urals. From west to east, these include permissive lithologies for porphyry copper deposits associated with Paleozoic subduction-related island-arc complexes preserved in the Tagil and Magnitogorsk arcs, Paleozoic island-arc fragments and associated tonalite-granodiorite intrusions in the East Uralian zone, and Carboniferous continental-margin arcs developed on the Kazakh craton in the Transuralian zone. The tracts range from about 50,000 to 130,000 km² in area. The Urals host 8 known porphyry copper deposits with total identified resources of about 6.4 million metric tons of copper, at least 20 additional porphyry copper prospect areas, and numerous copper-bearing skarns and copper occurrences.
Probabilistic estimates predict a mean of 22 undiscovered porphyry copper deposits within the four permissive tracts delineated in the Urals. Combining estimates with established grade and tonnage models predicts a mean of 82 million metric tons of undiscovered copper. Application of an economic filter suggests that about half of that amount could be economically recoverable based on assumed depth distributions, availability of infrastructure, recovery rates, current metals prices, and investment environment.
... Oscillatory zoning occurs in at least 75 rock-forming and accessory mineral species (Shore & Fowler 1996). It is common in sulfides (e.g., pyrite, arsenopyrite, sphalerite, and fahlores; Cathelineau et al. 1989, Plotinskaya et al. 2005, 2007, Deditius et al. 2008, Large et al. 2009, Cook et al. 2009, 2013, and it has been demonstrated that the growth zones either resulted from the superposition of several hydrothermal events (Barker et al. 2009), or during growth in a single hydrothermal event (Chouinard et al. 2005). Oscillatory zoning in molybdenite may actually be very common. ...
... The molybdenite zones consist of linear oscillating zones up to 200 μm wide and 200-600 μm long, which are usually abruptly terminated within single grains. Such a feature is not typical of other oscillatory-zoned minerals, where the oscillatory zones are restricted to, or are parallel with, grain boundaries and include the whole mineral grain or a substantial part of it (Shore & Fowler 1996, Plotinskaya et al. 2005, 2007, Large et al. 2009). The oscillatory zones at Voznesensk consist of parallel bands enriched to varying degrees in Re (0.2-1.0 wt.%). ...
... According to Holten et al. (2000), oscillatory mineral zonation is associated with crystal growth in an open system and is characterized by a continuous or discontinuous mass flux into or through the region in which crystal growth takes place. In an open system, which is characterized by complicated boundary conditions and non-equilibrium states, the coupling of extrinsic and intrinsic processes controls the oscillatory zonation patterns (Shore & Fowler 1996, Holten et al. 2000, Plotinskaya et al. 2005, 2007. As stated by Shore & Fowler (1996) extrinsic mechanisms involve physical or chemical fluctuations within the bulk system that are partially or wholly independent of local crystallization. ...
Molybdenite from the Voznesensk porphyry Cu ± (Mo,Au) deposit, southern Urals, Russia, displays high Re content and a well-documented oscillatory zoning for this mineral. The molybdenite forms part of a quartz-molybdenite-pyrite-chalcopyrite assemblage cemented at low-temperatures by pumpellyite and tobermorite. Oscillatory zoning occurs as micro-bands up to 200 μm wide and 200–600 μm long oriented parallel to the basal cleavage, as well as within basal planes of molybdenite sheets. The micro-bands are Re-enriched to different degrees (0.3–1.0 wt.%, typically they contain 0.6–0.8 wt.% Re). Outside these structures the Re content in molybdenite is up to 0.25 wt.%, usually <0.10–0.15 wt.%. It is suggested that the Re in the Voznesensk molybdenite retains its original growth pattern, marked by sharp concentration variations, and is not the result of leaching through post-crystallization diffusion. Variations in the number, width, and Re-content in individual micro-zones observed within the oscillatory zones may suggest involvement of extrinsic mechanisms of micro-zone formation. However, the Re content of the Voznesensk molybdenite (ICP-MS and EPMA data) is almost uniform along the studied vertical and lateral interval of the mineralization, suggesting no major variation in Re concentration in the fluid and favoring uniform, self-organization processes causing Re enrichment and oscillatory zoning in molybdenite. Despite the strong degree of epigenetic post-crystallization deformation of the molybdenite flakes and their cementation by low-temperature tobermorite, there is no essential change of the primary micro-zoning in the distribution of Re and any evidence of its epigenetic migration.
... Very few reviews which include Uralian porphyry deposits have been published in English (e.g. Ageyeva et al., 1984; Grabezhev, 1992; Grabezhev and Borovikov, 1993; Zvezdov et al., 1993; Seltmann et al., 2014). As a consequence, Uralian porphyry deposits are poorly represented in international literature and databases (http://www. ...
... The Salavat deposit was studied during the period from the 1970s to 1980s and was mentioned in several English language reviews of porphyry deposits (Grabezhev and Borovikov, 1993; Zvezdov et al., 1993). The description below is derived mainly from Minina (1982). ...
Most of the Cu (± Mo,Au) porphyry and porphyry-related deposits of the Urals are located in the Tagil-Magnitogorsk, East-Uralian Volcanic and Trans-Uralian volcanic arc megaterranes. They are related to subduction zones of different ages:
(1) Silurian westward subduction: Cu-porphyry deposits of the Birgilda-Tomino ore cluster (Birgilda, Tomino, and Kalinovskoe)
and the Zeleny Dol Cu-porphyry deposit;
(2) Devonian Magnitogorsk eastward subduction and the subsequent collision with the East European plate: deposits and
occurrences are located in the Tagil (skarn-porphyry Gumeshevskoe etc.) and Magnitogorsk terranes (Cu-porphyry
Salavat and Voznesenskoe, Mo-porphyry Verkhne-Uralskoe, Au-porphyry Yubileinoe etc.), and probably in the Alapaevsk-Techa terrane (occurrences of the Alapayevsk-Sukhoy Log cluster);
(3) Late-Devonian to Carboniferous subduction: deposits located in the Trans-Uralian megaterrane. This includes Late-Devonian to Early Carboniferous Mikheevskoe Cu-porphyry and Tarutino Cu skarn-porphyry, Carboniferous deposits of the Alexandrov volcanic arc terrane (Bataly, Varvarinskoe) and Early Carboniferous deposits formed dew
to eastward subduction under the Kazakh continent (Benkala, etc.).
(4) Continent-continent collision in Late Carboniferous produced the Talitsa Mo-porphyry deposit located in the East Uralian megaterrane.
Porphyry mineralization of the Magnitogorsk megaterrane shows an evolving relationship from gabbro-diorite and quartz diorite in the Middle Devonian (Gumeshevskoe, Salavat, Voznesenskoe) to granodiorite-plagiogranodiorite in the
Late Devonian (Yubileinoe Au-porphyry) and finally to granodiorite in the Carboniferous (Talitsa Mo-porphyry) with a progressive increase in total REE, Rb and Sr contents. This corresponds to the evolution of the Magnitogorsk terrane from a volcanic arc which gave place to an arc-continent collision in the Famennian.
... The western TagylÀMagnitogorsk megazone consists mostly of a series of Silurian to late Devonian oceanic island arcs, which host gold–copper and copper porphyry deposits. They are associated with diorite, quartz diorite, and locally gabbro–diorite porphyries (Grabezhev and Borovikov, 1993), e.g. Gumeshevskoe skarnporphyry deposit in the Tagyl segment, Salavat and Yubileinoe in the Magnitogorsk segment. ...
... The East Uralian volcanic megazone comprises fragments of volcanic arcs of Late Devonian to Early Carboniferous age (Zonenshain et al., 1984; Puchkov, 2000) intruded by syn-and post-collisional Carboniferous to Permian granitic rocks. Copper and minor molybdenum–copper porphyry deposits are mostly related to diorite and quartz diorites (Grabezhev and Borovikov, 1993). These deposits are most economically prospective (Ovcharova et al., 2007), e.g., the Mikheevskoe deposit and the Birgilda–Tomino ore cluster. ...
The Birgilda-Tomino ore cluster in the East Uralian zone, South
Urals, Russia, hosts a variety of Late Paleozoic porphyry copper
deposits (Birgilda, Tomino, Kalinovskoe, etc.), high- and low
sulfidation epithermal deposits (Bereznyakovskoe, Michurino), and
skarn-related base metal mineralization (Biksizak) in carbonate rocks.
The deposits are related to quartz diorite and andesite porphyry
intrusions of the K-Na calc-alkaline series, associated to a
subduction-related volcanic arc. We report microprobe analyses of ore
minerals (tetrahedrite-tennantite, sphalerite, Bi tellurides and
sulfosalts, Au and Ag tellurides), as well as fluid inclusion data and
mineral geothermometry. On the basis of these data we propose that the
Birgilda-Tomino ore cluster represents a porphyry-epithermal
continuum, with a vertical extent of about 2-3 km, controlled by
temperature decreases and fS2 and fTe2 increase
from deeper to shallow levels.
... These younger ages are in good agreement with the presence a Late-Devonian to Early Carboniferous Andean-type volcanic arc formed above the subduction zone dipping westward under the East Uralian continent at this time (Samygin and Burtman, 2009; Puchkov, 2013). The molybdenites from the Kalinovskoe deposit display the oldest Silurian age (430.7 ± 1.3 Ma; Fig. 4) corresponding in age to diorites from the same ore field (428 ± 3 Ma and 427 ± 6 Ma; Grabezhev et al., 2013 ). This dataset requires reassessment of the geodynamic position of this ore field and points to the Silurian oceanic volcanic arc which could have been the southern end of the Tagil arc or developed independently (Yazeva and Bochkarev, 1995; Puchkov, 2016). ...
The Urals can be regarded as a significant Cu-Mo-porphyry province, hosting over 30 porphyry deposits. Although their geological structure and ore-forming processes have been studied in great detail, uncertainty remains about their age and related geotectonic setting. In this contribution we report for the first time the Re-Os dating of molybdenites from three Cu-Mo porphyry deposits, namely Kalinovskoe, Mikheevskoe and Talitsa. Three molybdenite samples from the Kalinovskoe deposit yield Silurian Re-Os ages ranging from 427.1 Ma to 431.7 Ma (mean 429.8 ± 4.8 Ma; 2σ standard deviation), and a Re–Os isochron age of 430.7 ± 1.3 Ma (MSWD = 0.63), which coincides with previous U-Pb zircon dating of ore-hosting diorites from the same ore field (427 ± 6 Ma). The molybdenite from the Mikheevskoe deposit gives Re-Os ages of 357.8 ± 1.8 Ma and 356.1 ± 1.4 Ma (mean 357.0 ± 2.4 Ma; Carboniferous/Tournaisian), which corresponds to previous U-Pb dating of zircons from the diorite hosting porphyry deposit (356 ± 6 Ma). The molybdenite from Talitsa Mo-porphyry deposit yields the youngest Re-Os ages of 298.3 ± 1.3 and 299.9 ± 2.9 Ma (mean 299.1 ± 2.3 Ma) at Carboniferous-Permian boundary. Thus, the studied Cu and Mo porphyry deposits are not synchronous and belong to distinct tectonic events of the Urals.
... Mikheevskoye porphyry prospect is hosted by Late Devonian volcano-sedimentary rocks, of andesitic to basaltic composition and overlying Early Carboniferous basaltic volcanic rocks (Grabezhev, 2007). The Paleozoic host rocks are cut by diorite and quartz diorite intrusions of assumed Early Carboniferous age. ...
Abstract:
Mikheevskoye project is a porphyry Cu-Mo open pit mine located in Chelyabinsk region, Russia. Ore extraction started in 2011 and mineral processing started in late 2013. Mikheevskoye project is owned by the Russian Copper Company.
This study examines the effect of hydrothermal alteration zonality and geometallurgical ore body zonality on the mine planning and plant feed quality forecast. The study was conducted at Russian business unit of Outotec, which operates part of the processing plant in Mikheevskoye project.
The empirical part of the study was conducted in October 2013 - January 2014. Geological data for the study was obtained from Outotec office and Russian Copper Company geologists. Some geological data was collected through sampling campaign in the Mikheevskoye open pit. Additional data was gathered through the questionnaire which investigated how processing engineers working on site view the ore body. A questionnaire was distributed among Outotec and Russian Copper Company process engineers.
The results revealed that mine scheduling based on the geometallurgical zoning is potentially possible and feasible in case of porphyry ore deposits. In this case, twelve geometallurgical zones were determined theoretically. Application of hydrothermal alteration zonality helped improve forecast feed grade quality. Based on the results of this study, it was recommended to conduct additional exploration drilling, evaluate the process performance of the samples retrieved in the drilling and to update the model developed in this study accordingly. One of the key findings of the study was estimation of the new payback time for the project on the basis of current market situation.Mikheevskoye projekti on Venäjällä, Chelyabinskin alueella sijaitseva porphyry Cu-Mo malmin avolouhos. Malmilouhinta alueella alkoi vuonna 2011 ja rikastamon toiminta vuoden 2013 lopussa. Mikheevskoye malmiesiintymä ja rikastuslaitos ovat Russian Copper Companyn (RCC, Venäjän kupariteollisuus) omaisuutta.
Tässä tutkimuksessa tarkastellaan vesiliukenemisesta ja lämpötilagradientista syntyneiden muuttumisvyöhykkeiden sekä mineraalivyöhykkeiden (geometallurgiset) vaikutusta louhintasuunnitelmaan ja ennustettavaan rikastamon syötön laatuun. Tutkimusta toteutettiin Outotecin Venäjän alueyksikössä; sama Outotecin yksikkö vastaa vaahdotus- ja vedenpoistopiirin operoinnista Mikheevskoye projektissa.
Tutkimuksen kokeellinen osuus toteutettiin lokakuussa 2013 – tammikuussa 2014. Geologinen tieto tuli Outotecin ja RCC:n geologeilta. Osa geologisesta tiedosta oli kerätty paikan päällä avolouhoksesta näytteenottokampanjan merkeissä. Lisätiedot kerättiin kyselyllä, joka tutkii prosessi-insinöörien ymmärrystä malmiesiintymän piirteistä. Kysely toteutettiin Outotecin ja RCC:n prosessi-insinöörien keskuudessa.
Tutkimuksen tulokset osoittivat, että louhinnan suunnittelu perustuen mineraali- tai geometallurgisiin vyöhykkeisiin on mahdollista käytännössä ja on myös taloudellisesti kannattavaa porhyrymalmiesiintymissä. Tässä tapauksessa 12 teoreettista mineraalivyöhykettä oli otettu käyttöön. Vesiliukenemisesta ja lämpötilagradientista syntyneiden muuttumisvyöhykkeiden huomioon ottaminen auttoi tarkentamaan rikastamon syötteen laadun ennustetta. Tutkimuksen tulosten pohjalta suositellaan tuotantokairausten toteuttamista, niistä kerättyjen näytteiden analysointia prosessikäyttäytymisen osalta sekä tässä tutkimuksessa kehitetyn mallin päivittämistä ko. tulosten pohjalta. Tämän tutkimuksen yksi keskeisiä tuloksia oli uusi arvio projektin takaisinmaksuajasta nykyisten metallihintojen pohjalta.
... ACTA GEOLOGICA SINICA (English Edition) http://www.geojournals.cn/dzxben/ch/index.aspx http://mc.manuscriptcentral.com/ags Aug. 2014Fig. 1 There is a general evolutionary trend of porphyrybearing magmatism in the Urals from Na to K-Na series in space (from west to east) and from Na via K-Na to K series in time (from Devonian to Carboniferous) noted by Grabezhev and Borovikov (1993).Fig. 3a). ...
... Similarly, Chappaz et al. [2008] have shown that Re/Al molar ratio in lake sediments deposited during the twentieth century are significantly higher than that of pre-industrial times; a result attributed to atmospheric deposition of anthropogenic Re derived from coal burning and nearby smelter emissions. Re occurs in nature as an accessory or trace constituent in sulphide ores such as molybdenites in Cu-Mo porphyries [Berzina et al., 2005;Grabezhev, 2007]. The exploitation of theses ores during the past century is one of the anthropogenic sources of Re. ...
The abundance and distribution of dissolved and particulate Rhenium (Re)
has been measured in several rivers draining the Himalaya and Peninsular
India, from their origin to outflow into the Bay of Bengal and the
Arabian Sea. The large data set resulting from this study on rivers
flowing through a variety of lithologies e.g., the crystallines and
sediments of the Himalaya, Deccan basalts, Vindhyan sediments and the
Indian shield significantly enhances our understanding of the aqueous
geochemistry of Re and also constrains its sources to rivers and fluxes
to the sea. The concentration of dissolved Re in rivers of the Himalaya
and the Peninsular India shows wide range; 1.4 to 72.7 pmol/kg (mean 7.8
pmol/kg) and 0.5 to 122 pmol/kg (mean 15 pmol/kg) respectively. The
discharge weighted average annual flux of dissolved Re transported by
the rivers from these regions are ˜5800 and ˜15,700 mol/year
respectively. The major source of dissolved Re, as determined from
inter-element associations, is black shales for the Himalayan rivers and
pyrites in basalts for the east flowing Deccan rivers. In addition,
there are evidences of considerable anthropogenic supply of Re to some
of the rivers that have very high Re concentrations. Estimates of
anthropogenic supply based on their Re/K ratios suggest that this source
accounts for most of the Re in the Peninsular rivers, particularly the
Godavari. The annual flux of anthropogenic Re transported by the
Peninsular rivers is ˜14,600 mol, most of which is from the
Godavari. This anthropogenic flux accounts for ˜70% of the total
Re supply by the Indian rivers to the adjacent seas and 3.4% of the
global riverine flux to the oceans. The global average,
pre-anthropogenic (natural) concentration of dissolved Re in rivers is
estimated to be ˜3 pmol/kg based on Re-K correlation. This value
is much lower than the contemporary average determined from the measured
concentrations and earlier estimate of natural Re based on
Re-SO4 link.
Molybdenum (Mo) and rhenium (Re) are strategic key metals for the development of modernization. In nature, 99 wt.% of Re is associated with molybdenite minerals via the form of isomorphism, and the element abundance of Mo (about 1.1–1.5 ppm) and Re (about 0.0004–0.0026 ppm) is tremendous in the continental crust. These congenital characteristics make it difficult to separate Mo and Re. In this work, the Mo and Re resource features and products consumption are briefly summarized, and the pre-separation of Mo and Re from minerals or secondary alloy scraps, and the deep separation of the dissolved Mo and Re from solutions are systematically reviewed. Pyrometallurgy approaches are suitable for the treatment of high-grade Mo concentrates, however it lacks vast energy consumption and SO2 emission. Hydrometallurgical process is appropriate to deal with low-grade Mo concentrates, but leaching efficiency of Mo is low and numerous expensive oxidants are consumed. As for deep separation of Mo and Re from the solutions, selective chemical precipitation, ion exchange, and solvent extraction are commonly used in industry to separate Mo and Re. Due to separation efficiency, Mo and Re mixture solutions with low concentrations generally lower than 0.5 g/L are concomitantly generated after ion exchange and solvent extraction. Selective adsorption is a prospective method to separate Mo and Re from ultra-low concentration solutions, while the existing preparation technologies of high-selectivity adsorbents are characterized as complex and expensive. Developing facile and low-cost preparation of adsorbents is a promising research orientation for clean and deep separation of Mo and Re from solutions.
This report contains data on the Re content of molybdenite samples collected from a wide variety of mineral deposits in Canada and a few deposits from outside Canada. Estimates of Re resources based on this data indicate that porphyry Cu, Cu-Mo and Cu-Au deposits have the most resources and the greatest potential for Re production in Canada, primarily as a by-product of Mo production. Other deposit types with potential for Re production as a by-product include sediment-hosted Cu and U deposits, PGE-rich Ni-Cu deposits associated with mafic and ultramafic rocks and vein deposits with high Re grades.
The overwhelming majority of porphyry Mo-Au-Cu deposits in the Urals are related to the low-K quartz diorite minor intrusions of the island-arc type, which were formed from Silurian Middle-Late Carboniferous. In the South Urals, the Cu/Mo ratio of ore decreases eastward along with enrichment in Re. At the same time, molybdenite is depleted in this metal in compliance with more sialic crust and potassium content in ore-bearing dioritic rocks. Quartz diorites at the highest-Re deposits contain 1-2 wt % K2O. At most Early-Middle Devonian deposits and occurrences of the western Tagil-Magnitogorsk-West Mugodzhary femic megazone, molybdenite is sporadic. The Re content in rocks was mainly determined using the kinetic method and to a lesser extent with ICP-MS. A Cameca SX-100 microprobe was also used for study of molybdenite. The Cu/Mo ratio of ore exceeds 600; the Mo content is commonly 1-15 ppm (occasionally up to 30 ppm and higher); the Re content is up to 0. 01-0. 04 ppm, sporadically increasing to 0. 08-0. 17 ppm. At the same time, the Re content in molybdenite often reaches 0. 2-0. 4 wt %. The highest Re concentration was established in the ore of the largest Mikheevsky deposit formed in the Late Devonian-Early Carboniferous and localized in the easternmost part of the East Ural sialic-femic megazone. The Re content in the orebodies of this deposit often reaches 0. 2-0. 5 ppm (up to 1. 4-2. 7 ppm) and 0. 21 wt % in molybdenite. The average Mo grade of ore is 80 ppm and Cu/Mo ratio is 66. These data and Sr isotopic composition of ore-bearing granitoid and metasomatic rocks [(⁸⁷Sr/⁸⁶Sr)t = 0. 7038-0. 7051; (e{open}Nd)t = 3-7] testify to the mantle source of matter with insignificant admixture of crustal material. The same is apparently valid for Re and Cu in contrast to Mo. This statement is corroborated by the inverse correlation between Cu/Mo and Mo/Re ratios in the ore. Fluid-crystal fractionation of ore-bearing dioritic rocks is accompanied by enrichment of ore in Mo and by decrease in Re content in molybdenite. In the Tarutino ore field, the pyrite-chalcopyrite mineralization gives way to the molybdenite mineralization in line with in-sequence intrusion of diorite with quartz-bearing groundmass and granodiorite porphyry. Because of increasing silica content in granitoids, the Re concentration in molybdenite commonly remains below 0. 07 wt % as is noted at the rare deposits localized in the sialic megazones.
Most of porphyry deposits are located in the South and Middle segments of the Urals. They are confined to three main N-S trending volcanic belts, i.e. the Tagyl−Magnitogorsk (Salavat, Yubileynoe, Voznesenskoe etc.), East-Uralian (Birgilda-Tomino ore cluster, Mikheevskoe etc) and Valerianovka (Benkala, Batala, etc.) megazones. Usually they are genetically linked with subduction-related calc-alkaline low K intrusions.
The Tarutinsk deposit as a product of a skarn copper porphyry system differs from proper copper skarn and copper-magnetite skarn deposits by development of acid-type alteration (sericitization) in granitoids. Secondary transformation and sulfidization of skarns were coeval with the formation of strong sericitization zones with vein-disseminated ore mineralization in granitoids. These zones are located below skarn orebodies and, together with skarns, compose structures (conduits) gently dipping to the massif center. The sericitization temperature was below 350degreesC (sericite of 2M(1) + 1M modifications). The vein-disseminated pyrite-chalcopyrite mineralization (Cu = 0.5-2.4 wt %, Au = 0.1-0.4 ppm, Mo = 20 ppm) in skarns and granitoids was formed at T = 170-295degreesC and P = 0.25-0.47 kbar. Magmatic fluid (delta(18)O = +4.7...+8.6parts per thousand) participated in the vein ore mineralization in skarn zones. Transformation of granitoids at some distance from skarn zones was related to fluid with a significant role of meteoric water (delta(18)O = -0.8...+7.7parts per thousand). Associated weak bulk sericitization was changed for propylitization with a decrease of S and Cu contents in the altered granitoids. Sulfur in pyrite has a juvenile isotopic composition (delta(34)S = -1...+3parts per thousand).
The porphyry-type Pagoni Rachi Mo–Cu–Te–Ag–Au prospect, in northern Greece, is a porphyry-epithermal system hosted by an Oligocene dacite porphyry and quartz–feldspar porphyry dikes. The rare mineral rheniite (ReS2) and molybdenite, with very high contents of Re (up to 4.7 wt% Re), occur in quartz veins along with Fe–Cu sulfides, Pb-, Sn-, and Cl-bearing oxides, hematite, ilmenite and tellurides of Bi; these veins are spatially related to sericitic and transitional sericitic–sodic–potassic alteration. Earlier-formed gold-bearing quartz and magnetite veins with sodic–potassic–calcic alteration and late precious-metal telluride-rich carbonate–quartz veins with argillic alteration contain only minor amounts of molybdenite. The composition of rheniite ranges from almost pure, stoichiometric rheniite with low Mo content to rheniite with up to 5.99 wt% Mo. Petrographic, scanning electron microscope, and structural studies suggest that the high Re content of molybdenite from Pagoni Rachi is the result of the isovalent Re-for-Mo substitution in molybdenite. This fact is corroborated by the progressive shortening of the Mo–S mean bond-distance (from 2.414 Å in pure molybdenite to 2.355 Å), as well as by the isotropic decrease of the unit-cell values with the increase of the Re:Mo ratio. The structural analysis of four molybdenite crystals, with the highest Re content ever reported in nature, demonstrates that they crystallize as the 2H polytype and not the 3R polytype, as previously hypothesized, thus suggesting that Re concentration does not correlate with a specific polytype. The fluid inclusions in quartz in the Re-bearing molybdenite–rheniite veins at Pagoni Rachi show that they homogenize to either the liquid or vapor phases (354 to 428°C) or by halite dissolution at 317 to 585°C, which equates to salinities of 40 to 59 wt% NaCl equiv. Rheniite and molybdenite likely precipitated as temperatures fell below 400°C during phase separation under relatively oxidizing conditions, at elevated chlorine activity, and from relatively acid hydrothermal solutions. However, the presence of Pb oxides, Sn-bearing minerals and tellurides is compelling evidence that rheniite and Re-rich molybdenite may have formed directly from the vapor as sublimates, in a manner similar to the way they are deposited at the Kudriavy volcano, Kurile Islands.
The geochemistry of rhenium in ores of copper porphyry deposits from various regions has been con� sidered in numerous papers presented in the reviews (1-3 and others). We have recently systematized anal� yses for the Urals (4). Estimations of this element in different parts of separate molybdenite grains are very scarce (3, 5, 6, and others). Data on rhenium scanning in molybdenite grains are not available. However, the pattern of rhenium distribution in molybdenite grains is very important for understanding of the conditions of its precipitation and further redistribution within deposits especially those that have undergone low� temperature modifications and deformations. Patterns of rhenium distribution in separate molybdenite grains were obtained by scanning on the SX�100 microprobe at the Institute of Geology and Geochemistry, Ural Division, Russian Academy of Sciences. The diameter of the beam was 1 μm, U = 25 kV, I = 30 nA, and the detection limit of rhenium is 0.02 wt %. The standards were presented by metallic rhenium, molybdenum, and pyrite. The ReMα line was analytical. The neighboring CaK α line becomes gently sloping near the ReM α line and practically does not influence the measured rhenium concentration, but clearly fixes calcite grains (Fig. 1) because of the duration of significant exposure. Backscattered elec� tron study of the polygon and scanning using the CaK α spectral line provides evidence for the absence of cal� cite in the areas of high rhenium concentrations. In the preliminary stage of this study, rhenium concen� trations were measured in single microareas of molybdenite grains. Grains with high rhenium con� centrations were subjected to scanning. The scanning polygon was approximately limited by the contours of the molybdenite grains. The exposure time for the two samples described here was 16 and 6 h. Most copper porphyry deposits of the Urals are paragenetically controlled (7) by lowpotassium small intrusions of (gabbro)-diorite-plagiogranodiorite composition with an absolute prevalence of quartz diorite or quartz diorite porphyry related to mesoand hypabyssal depth facies ("diorite" model). The age varies from S to C2. Plagiogranitoids are hydrother� mally altered everywhere. Less serecitized and propyl� itized quartz diorites are characterized by low values of the ( 87 Sr/ 86 Sr)t ratio (from 0.7038-0.7048 to 0.7052), high εNd(T) values (4.1-7.5, in single samples decreas� ing to 0.9-2), and low TR concentrations (29- 67 ppm), without the Eu anomaly (8). These data evi� dence that orebearing granitoids contain a prevailing portion of the mantle component; they should be related to the island arc geochemical type being formed at the expense of the metabasic source in the lower crust-upper mantle or in the upper mantle. Judging from the low 87 Sr/ 86 Sr ratio (0.704-0.705) in vein carbonates, δ 18 О (7.4…8.5‰, SMOW), δD (-49…-61‰, SMOW), and δ 34 S (0 ± 2‰, CDT), CDT) in other hydrothermal minerals, the initial fluid had a magmatic nature and inherited the geochemical characteristics of orebearing granitoids. Thus, rhe� nium may also have a mantle primary source. The magmatic parameters of the fluid are also typical for many other hydrothermal deposits (9 and others). Common values of the Cu/Mo ratio in deposits of the Urals with a dioritoid substrate are 70-400, with cop� per contents of 0.3-0.8 wt %, molybdenum contents of 5-27 (up to 80 and higher) ppm, rhenium contents of up to 0.3-2 ppm (4). The concentration of rhenium in molybdenite varies significantly reaching 0.63 wt %, as is evident from our recent measurements (see below). Deposits of the "diorite" model are consid� ered to be very favorable for rhenium accumulation in ores (1 and others). However, sometimes significant rhenium concentrations (0.1-0.3 wt % and higher) are also observed in molybdenites from deposits of "monzonite" and "granodiorite" models, for which
The Xiaoliugou is a large-scale W (Mo) deposit newly explored in the Northern Qilian Mountains Caledonian fold belt, Northwestern China. It is a vein and skarn type deposit genetically associated with the Xiaoliugou Caledonian granodiorite stock. Re-Os isotopic dating for the molybdenite in the deposit yields an isochron age of 462 ± 13 Ma (2σ) and model ages of 436 to 496 Ma. These results suggest that W-Mo mineralization occurred before the collision of plates, and mineralized substances mainly originated from the crust.
The Bereznyakovskoe ore field is situated in the Birgil’da-Tomino ore district of the East Ural volcanic zone. The ore field comprises several centers of hydrothermal mineralization, including the Central Bereznyakovskoe and Southeastern Bereznyakovskoe deposits, which are characterized in this paper. The disseminated and stringer-disseminated orebodies at these deposits are hosted in Upper Devonian-Lower Carboniferous dacitic-andesitic tuff and are accompanied by quartz-sericite hydrothermal alteration. Three ore stages are recognized: early ore (pyrite); main ore (telluride-base-metal, with enargite, fahlore-telluride, and gold telluride substages); and late ore (galena-sphalerite). The early and the main ore stages covered temperature intervals of 320–380 to 180°C and 280–300 to 170°C, respectively; the ore precipitated from fluids with a predominance of NaCl. The mineral zoning of the ore field is expressed in the following change of prevalent mineral assemblages from the Central Bereznyakovskoe deposit toward the Southeastern Bereznyakovskoe deposit: enargite, tennantite, native tellurium, tellurides, and selenides → tennantite-tetrahedrite, tellurides, and sulfoselenides (galenoclausthalite) → tetrahedrite, tellurides, native gold, galena, and sphalerite. The established trend of mineral assemblages was controlled by a decrease in \(
f_{S_2 }
\), \(
f_{Te_2 }
\) and \(
f_{O_2 }
\) and an increase in pH of mineral-forming fluids from early to late assemblages and from the Central Bereznyakovskoe deposit toward the Southeastern Bereznyakovskoe deposit. Thus, the Central Bereznyakovskoe deposit was located in the center of an epithermal high-sulfidation ore-forming system. As follows from widespread enargite and digenite, a high Au/Ag ratio, and Au-Cu specialization of this deposit, it is rather deeply eroded. The ore mineralization at the Southeastern Bereznyakovskoe deposit fits the intermediate- or low-sulfidation type and is distinguished by development of tennantite, a low Au/Ag ratio, and enrichment in base metals against a lowered copper content. In general, the Bereznyakovskoe ore field is a hydrothermal system with a wide spectrum of epithermal mineralization styles.
By analogy with other metallogenic belts of the Circum-Pacific ring, the metallogenic belts in the Northeast of Russia are
promising for discovery of large and superlarge porphyry-type Au-Cu-Mo deposits. The spatial distribution of these deposits
is controlled by intrusive domes in Middle Paleozoic, Late Jurassic-Early Cretaceous, and Late Cretaceous volcanic belts.
New data on formation conditions and sources of ore matter are presented in this paper with respect to the deposits of the
Baim and Koni-P’yagina ore districts of the Oloi and Uda-Murgal metallogenic belts. Some aspects of a geological and genetic
model of the porphyry copper ore-magmatic system are discussed.
The Elatsite porphyry copper deposit occurs in an island-arc setting hosted by Late Cretaceous monzonitic-monzodioritic porphyry stocks which were emplaced into Precambrian-Cambrian phyllites. Trace element data of the Late Cretaceous intrusive rocks suggest that they are I-type volcanic arc granitoids. Two main ore mineral assemblages are distinguished: (1) magnetite-bornite-chalcopyrite, and (2) chalcopyrite-pyrite. The first one is linked to potassic-propylitic, and the second to phyllic-argillic alteration. Minor ore minerals are hematite, molybdenite, sphalerite, pyrrhotite, marcasite, hessite, and solid solutions of linnaeite-siegenite-carrollite, tetrahedrite-tennantite, clausthalite-galena, gold-electrum and merenskyite-moncheite. Precious-metal contents are relatively high throughout the deposit but Au, Pd and Pt are concentrated more strongly in the magnetite-bornite-chalcopyrite assemblage. Average grades of Au, Ag, Pd and Pt calculated for the 0.33% Cu ore body are 0.96, 0.19, 0.007 and 0.002 g/t respectively. Analyses of flotation concentrates revealed 25.6% Cu, and Ag, Au, Pd and Pt contents of 33.0, 13.6, 0.72 and 0.15 g/t respectively. The copper mineralisation at Elatsite took place at pressures of 120 to 300 bar, corresponding to depths of formation of 1 to 3 km under hydrostatic conditions. The precious metals were probably transported jointly as chloride complexes in highly saline magmatic-hydrothermal solutions. The fluids had temperatures of 340 to >700 C and salinities of 28 to 64% NaCl, and mixed with meteoric water.
The Gumeshevsk copper skarn deposit, which is known from the early 18th century thanks for its high-quality malachite, is located in the eastern, marginal part of the Tagil volcanic zone in the Central Urals. The deposit is paragenetically related to a small D 1-2 quartz diorite intrusion of island-arc type. A distinctive feature of the deposit is the wide occurrence of primary epidote-bearing skarn columns. The bimetasomatic column can be presented in the following generalized scheme: granitoid - amphibole epidosite - amphibole epidote-garnet endoskarn (often with pyroxene) - actinolite garnet exoskarn (sometimes with pyroxene) - marble. The skarns developed at relatively low temperatures (330-380°C, according to the epidote-garnet thermometer). All minerals display a clearly pronounced tendency of their Fe mole fraction to increase from the epidosites to exoskarns, perhaps, owing to an increase in the Fe activity in the fluid in this direction. Minerals often had not attained equilibrium with one another in the outer portions of the endoskarn columns. A significant role in the skarn process was played by the redistribution of Si and Ca of the pristine rocks at the active introduction of Fe and removal of alkalis. The epidosites and exoskarns are insignificantly enriched in Al, whose small amounts were removed from the epidote-garnet zone of the endoskarn columns. The rocks are characterized by widespread retrograde alterations, including CO 2 metasomatism and potassic acid leaching of the granitoids. The sulfur is supposedly of juvenile provenance (the sulfides have δ 34S = 0 ± 2%), while the carbon dioxide was juvenile and local (the carbonate has δ 18O from +12.5 to +19.2% and δ 13C from -2.7 to +0.7%). The zoning of the skarns and the character of their retrograde alterations at the deposit are significantly different from those at ore fields of the copper-magnetite skarn type in the Urals.
The evolution of ideas in the last few decades on the duration and sequence of the development of mineral parageneses (epochs, megastages, and stages) during the mineral deposit formation is reviewed. The author concluded that the prolonged period of the prehistory of the formation of economic ore accumulations is very important. This is also very important for understanding the nature of metallogenic specialization, the extent of ore-bearing potential, and for distinguishing evolutionary series of ore deposits. By the example of gold deposits, the relations between the megastages and stages of the evolution of postmagmatic solutions and megastages and stages of ore mineralization reflecting pulsation in the course of ore genesis are discussed. The main sequence in the development of mineral parageneses, steadily preserved in various types of ore deposits, is regarded as an instrument for the analysis of the megastage and stage of ore formation and evolutionary systematics of mineral deposits.
Spatial distribution of models within known porphyry copper provinces suggests that those deposits that developed within a continental crust that includes a cratonic environment are more likely to contain significant byproduct molybdenum. Those that developed in areas of thin continental crust tend to have anomalously high byproduct gold. Isotope studies indicate that although the Pb, S, and Rb-Sr components of the deposit may be largely mantle-derived, water may be both magmatic (deep seated) and meteoric. The potassic alteration zone common to both the Lowell and Guilbert and the diorite models appears to be associated with magmatic-hydrothermal fluids. Maps, tables, and diagrams illustrate findings.
Re-Os isotopes in pyrite and chalcopyrite from early high-temperature
hypogene alteration assemblages in Chilean porphyry copper deposits
identify the source of Os and, by inference, Cu in these ore systems.
Typical concentrations for Os in both pyrite and chalcopyrite are
between 7 and 30 ppt (10-12 g/g), and for Re between 0.200
and 10 ppb (10-9 g/g). Re-Os isochrons yield ages and initial
187Os/188Os ratios for the sulfides. The isotopic
data reflect the relative contributions of copper from the mantle and
crust in Chilean porphyry copper deposits. Seven ore deposits that
reside in different tectonic terranes and represent distinct epochs of
mineralization in Chile were studied. The initial osmium ratios of the
first stage of mineralization at each of the deposits range from 0.15 to
5. These values are more radiogenic than the present chondritic mantle
(˜0.13), and indicate significant crustal contributions of Os to
the magmatic and/or hydrothermal systems. There is a strong
correspondence between the total copper content and initial Os isotopic
ratios in base-metal porphyry deposits. The larger deposits have lower
initial Os ratios than the smaller, less significant deposits. This
relationship implies that larger deposits acquire a greater proportion
of Os from the mantle. The initial Os ratio of samples in the central
segment of porphyry copper deposits of northern Chile also decreases
with decreasing age of the deposit. A plausible interpretation of the
Re-Os data is that the later and larger deposits use regional tectonic
and structural features that allow sampling of deeper more primitive
magmatic sources.
Rhenium (Re) is one of the least abundant elements in Earth, averaging 0.28 ppb in the primitive mantle. The unique occurrence of rheniite ReS2 (74.5 wt% of Re) in Kudryavy volcano precipitates raises questions about recycling of Re-rich reservoirs within the Kurile–Kamchatka volcanic Island arc setting. The sources of this unique Re enrichment have been inferred from studies of Re–Os isotope systematic and trace elements in volcanic gases, sulphide precipitates and host volcanic rocks. The fumarolic gas condensates are enriched in hydrophile trace elements relative to fluid-immobile elements and exhibit high Ba/Nb (133–204), Rb/Y (16–406) and Th/Zr (0.01–0.25) ratios. They are characterised by high Re (7–210 ppb) and Os abundances (0.4–0.9 ppb), with 187Os/188Os ratios in a range 0.122–0.152. This Os isotopic compositional range is similar to that of the peridotite xenoliths from the metasomatised mantle wedge above the subducted Pacific plate, the radiogenic isotopic signature of which is probably due to radiogenic addition from a slab-derived fluid.
Data on the solubility of Re metal in subcritical hydrothermal solutions presented in Xiong and Wood (2001) have been reinterpreted assuming that the following reaction controlled dissolved Re concentrations: ReO2( s ) + 2H2O( l ) ↔ Re(OH)4( aq ). The formation of ReO2( s ) on the surface of Re metal at the conditions of the previous experiments was demonstrated conclusively in a new experiment using X-ray photoelectron spectroscopy (XPS). The temperature dependence (200°–25°C) of the equilibrium constant for the above reaction at − 4700 ± 760 infinite dilution can be expressed as \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathit{K}\ =\ \frac{{-}4700\ {\pm}\ 760}{\mathit{T}}\ +\ 6.2\ {\pm}\ 2.0(2{\sigma})\) \end{document}. These new equilibrium constants predict that metallic rhenium, ReO2( s ), and ReS2( s ) have much lower solubilities than those implied in Xiong and Wood (2001). Based upon the new equilibrium constants, the free energy of formation, the enthalpy of formation, and entropy at the reference state (298.15 K and 1 bar) for the neutral rhenium species, Re(OH)4( aq ) (also alternatively formulated as ReO(OH)2( aq )), are derived in this study. Based on derived equilibrium constants at 25°C for dissolution of ReS2( s ) as Re(OH)4( aq ), we predict that rhenium can be enriched in the reduced zone in supergene environments in porphyry copper-molybdenum deposits.
The low Re abundance in arc-type volcanic rocks characterized by high Os-187/Os-188 ratios is an unsolved puzzle of the Re-187-Os-187 isotope system, leaving a significant gap in our understanding of the evolution of the upper mantle-continental crust system. Here we report new observations of high Re concentrations in fresh, submarine-erupted-i.e., relatively undegassed-island are-like volcanic glasses dredged from the eastern Manus Basin, offshore Papua New Guinea. These observations, together with previously published reports of high Re concentrations in are-type melt inclusions, indicate that undergassed arc-type volcanic rocks and the mantle wedge are enriched in Re. Consequently, the Re concentration in the continental crust is likely to be as high as similar to2 ppb, much higher than previously estimated. The low Re concentrations in subaerial arc-type volcanic rocks are probably due to Re loss during magma degassing.
The Re–Os (rhenium–osmium) chronometer applied to molybdenite (MoS2) is now demonstrated to be remarkably robust, surviving intense deformation and high-grade thermal metamorphism. Successful dating of molybdenite is dependent on proper preparation of the mineral separate and analysis of a critical quantity of molybdenite, unique to each sample, such that recognized spatial decoupling of 187Re parent and 187Os daughter within individual molybdenite crystals is overcome. Highly precise, accurate and reproducible age results are derived through isotope dilution and negative thermal ion mass spectrometry (ID-NTIMS). Spatial decoupling of parent–daughter precludes use of the laser ablation ICP-MS microanalytical technique for Re–Os dating of molybdenite. The use of a reference or control sample is necessary to establish laboratory credibility and for interlaboratory comparisons. The Rb–Sr, K–Ar and 40Ar/39Ar chronometers are susceptible to chemical and thermal disturbance, particularly in terranes that have experienced subsequent episodes of hydrothermal/magmatic activity, and therefore should not be used as a basis for establishing accuracy in Re–Os dating of molybdenite, as has been done in the past. Re–Os ages for molybdenite are almost always in agreement with observed geological relationships and, when available, with zircon and titanite U–Pb ages. For terranes experiencing multiple episodes of metamorphism and deformation, molybdenite is not complicated by overgrowths as is common for some minerals used in U–Pb dating (e.g. zircon, monazite, xenotime), nor are Re and Os mobilized beyond the margins of individual crystals during solid-state recrystallization. Moreover, inheritance of older molybdenite cores, incorporation of common Os, and radiogenic Os loss are exceedingly rare, whereas inheritance, common Pb and Pb loss are common complications in U–Pb dating techniques. Therefore, molybdenite ages may serve as point-in-time markers for age comparisons.
Rhenium and osmium isotopes in sulfide minerals from the Bagdad porphyry Cu–Mo deposit have been used to determine timing of mineralization and the source of osmium and, by inference, ore metals. Molybdenite, chalcopyrite and pyrite were analyzed mainly from the quartz monzonite and porphyritic quartz monzonite units, which are characterized by moderate to strong potassic alteration (secondary biotite and K-feldspar). Rhenium concentrations in molybdenite are between 330 and 642ppm. Four Re–Os analyses of two molybdenite samples from the quartz monzonite and porphyritic quartz monzonite yield a weighted average age of 71.80.2Ma (2s). Analyses of a third sample from a molybdenite vein in Precambrian rocks, outside of the main ore zone, yield a weighted average age of 75.90.2Ma (2s), and provide evidence of two separate mineralization episodes. Chalcopyrite samples contain 6 to 12ppt Os and 1.7 to 4.1ppb Re; 187Os/ 188Os initial ratios are between 0.1 and 0.8. Pyrite samples have osmium and rhenium concentrations varying in the range 8–17ppt and 3.9–6.8ppb, respectively. Analyses from these pyrite samples yield an eight-point isochron with an age of 7715Ma (2s) and an initial 187Os/ 188Os ratio of 2.10.8 (MSWD=0.90). The results presented here add to the growing body of work indicating that porphyry-type mineralization is produced by long-term, multiple episodes of magmatism and associated mineralization. The data also support the hypothesis that a significant part of the metals and magmas may have a crustal source, as has been suggested for other copper deposits and districts in Arizona.
Rhenium Resource Potential in the Territory of Russia
- G N Trach
- S M Beskin
Vertical Ore-Metasomatic Zoning of the Tomino Porphyry Copper Ore Cluster
- A I Grabezhev
- O V Rusinova
- A P Zhukhlistov
Produktivnye granitoidy i metasomatity medno-porfirovykh mestorozhdenii (Procuctive Granitoids and Metasomatic Rocks of Porphyry Copper Deposits)
- A I Grabezhev
- E A Belgorodskiy
Genetic Aspects of Polytypism and Rhenium Contents of Molybdenites from Porphyry Copper Deposits
- L E Filimonova
- N M Zhukov
- A T Malyavskaya
Re Content in Molybdenite As a Criterion of Estimation of Molybdenum Deposits molibdenovykh mestorozhdenii
- V S Popov
- Kudryavtsev
- K Yu
Microprobe Study of Re-Bearing Minerals, in Teoreticheskie i obshchemetodicheskie voprosy rentgenospektral’nogo analiza (Theory and Technique of X-Ray Spectroscopy)
- I M Kulikova
- O A Nabelkin
- I E Maksimyuk
Behavior of Rhenium in Ore Formation
- V I Rekharsky
- Savel
- L V Eva
- E K Lange
Variations in Rhenium Content of Molybdenite
- D L Giles
- J H Shilling
Productive Granitoids and Metasomatites of Porphyry Copper Deposits
- A I Grabezhev
- E A Belgorodskii