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Article

Atypical Mineralization Involving Pd-Pt, Au-Ag, REE, Y, Zr, Th, U, and Cl-F in the Oktyabrsky Deposit, Norilsk Complex, Russia

1
Research Laboratory of Industrial and Ore Mineralogy, Cherepovets State University, 5 Lunacharsky Prospect, 162600 Cherepovets, Russia
2
Norilskgeologiya OOO, 11 Grazhdansky Prospect, 195220 Saint-Petersburg, Russia
3
Institute of Mining, Geology and Geotechnology, Siberian Federal University, 79 Svobodny Prospect, 660041 Krasnoyarsk, Russia
4
Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, QC H3A 0E8, Canada
*
Author to whom correspondence should be addressed.
Minerals 2021, 11(11), 1193; https://doi.org/10.3390/min11111193
Submission received: 28 September 2021 / Revised: 13 October 2021 / Accepted: 19 October 2021 / Published: 27 October 2021

Abstract

:
Highly atypical mineralization involving Pd-Pt, Au-Ag, REE, Y, Zr, U, Th, and Cl-F-enriched minerals is found in zones with base metal sulfides (BMS; ~5 vol.% to 20 vol.%) in the eastern portion of the Oktyabrsky deposit in the Norilsk complex (Russia). The overall variations in Mg# index, 100 Mg/(Mg + Fe2+ + Mn), in host-rock minerals are 79.8 74.1 in olivine, 77.7 65.3 in orthopyroxene, 79.9 9.2 in clinopyroxene, and An79.0  An3.7. The span of clinopyroxene and plagioclase compositions reflects their protracted crystallization from early magmatic to late interstitial associations. The magnesian chromite (Mg# 43.9) trends towards Cr-bearing magnetite with progressive buildups in oxygen fugacity; ilmenite varies from early Mg-rich to late Mn-rich variants. The main BMS are chalcopyrite, pyrrhotite, troilite, and Co-bearing pentlandite, with less abundant cubanite (or isocubanite), rare bornite, Co-bearing pyrite, Cd-bearing sphalerite (or wurtzite), altaite, members of the galena-clausthalite series and nickeline. A full series of Au-Ag alloy compositions is found with minor hessite, acanthite and argentopentlandite. The uncommon assemblage includes monazite-(Ce), thorite-coffinite, thorianite, uraninite, zirconolite, baddeleyite, zircon, bastnäsite-(La), and an unnamed metamict Y-dominant zirconolite-related mineral. About 20 species of PGM (platinum group minerals) were analyzed, including Pd-Pt tellurides, bismuthotellurides, bismuthides and stannides, Pd antimonides and plumbides, a Pd-Ag telluride, a Pt arsenide, a Pd-Ni arsenide, and unnamed Pd stannide-arsenide, Pd germanide-arsenide and Pt-Cu arseno-oxysulfide. The atypical assemblages are associated with Cl-rich annite with up to 7.54 wt.% Cl, Cl-rich hastingsite with up 4.06 wt.% Cl, ferro-hornblende (2.53 wt.% Cl), chlorapatite (>6 wt.% Cl) and extensive solid solutions of chlorapatite, fluorapatite and hydroxylapatite, Cl-bearing members of the chlorite group (chamosite; up to 0.96 wt.% Cl), and a Cl-bearing serpentine (up to 0.79 wt.% Cl). A decoupling of Cl and F in the geochemically evolved system is evident. The complex assemblages formed late from Cl-enriched fluids under subsolidus conditions of crystallization following extensive magmatic differentiation in the ore-bearing sequences.

1. Introduction and Geological Context

The Norilsk complex of Permo-Triassic age hosts giant ore deposits, such as the Oktyabrsky deposit of copper, nickel and platinum group elements (PGE), developed close to the northwestern margin of the Siberian Platform in northern Russia (e.g., [1], and references therein). These deposits are genetically related to large-scale sills of gabbro-dolerite and olivine gabbro-dolerite whose emplacement was largely controlled by the NNE-trending Norilsk-Kharayelakh fault (Norilsko-Kharaelakhskiy, Figure 1). They are considered to be feeders of trap basalts, which attain 3.5 km in thickness. Understandably, the Norilsk complex was (and still is) a Mecca for international teams of investigators; indeed, thousands of research articles describe various characteristics of its mineralogy, geology, petrology and geochemistry, and consider models of origin [1,2,3,4,5,6,7,8,9,10]. At the same time, there are mineralized zones of relatively low-grade ores, especially those deposited in peripheral areas or in the vicinity of external contacts, which are much less thoroughly investigated, and thus deserve more attention. In this sense, our goals are focused here on mineralogical studies of ore-bearing zones that have developed in the eastern portion and relatively close to contacts of the Oktyabrsky Cu-Ni-PGE deposit (Figure 1). Some of our findings are new and unusual, and these implications extend our insight into the geochemical evolution and ore potential of the Norilsk complex.

2. Materials and Methods

A total of twenty-six ore-bearing samples collected in a series of boreholes (Figure 2) were studied mineralogically. Quantitative analyses of minerals were performed at the R&D center of Norilsk Nickel at the Institute of Mining, Geology and Geotechnology of the Siberian Federal University, Krasnoyarsk, by means of scanning electron microscopy and energy-dispersive analysis (SEM-EDS) done on a Tescan Vega III SBH system (Tescan Orsay Holding, Brno, Czech Republic) equipped with an Oxford X-Act spectrometer (Oxford Instruments Nanoanalysis, Wycombe, UK). The operating conditions were held at an accelerating voltage of 20 kV and a beam current of 1.2 nA.
The commonly used combinations of X-ray lines were used along with a set of standards provided by Micro-Analysis Consultants Ltd. (MAC, Cambridgeshire, UK; registration no. 11192). The K line was used for oxygen, Si (quartz standard), Ca (wollastonite), K (orthoclase), Na (albite), Cu (synthetic chalcopyrite), Fe, S (pyrite and pyrrhotite) and Ni, as well as Co, Ti, V and Cr; specimens of Al2O3 were used for Al, MgO for Mg, pure Mn for Mn, sphalerite for Zn, and synthetic GaP for P. The F- and Cl-bearing minerals were also analyzed using the K line, with specimens of fluorite and halite as standards. Furthermore, the L line and standards of pure elements were used for Y, La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. The L line and synthetic CeO2 and LaB6 were used for Ce and La. The L line was also used for Nb, Ag, Se and Sb (pure elements and stibnite as standards), as well as for Zr, Cd (pure Zr and Cd), Sn (pure Sn), Te (PbTe), As (arsenopyrite), and Pd and Rh (pure Pd and Rh). The M line was used for Au (pure Au), Ir (Ir), Os (Os), Pt (Pt), Bi (pure Bi), Pb (PbTe), Th (ThO2), U (pure U), and also for Hf (pure Hf). The beam current was measured every 60 min using the MAC cobalt standard (registration no. 9941).
In total, more than two thousand SEM-EDS point-analyses were made. The analytical error for the main components did not exceed 2–3 relative percent and satisfied the requirements for a quantitative analysis. As a test, some of the ore minerals were analyzed by wavelength-dispersive spectroscopy (WDS) on a JEOL JXA-8100 electron microprobe at the Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences in Novosibirsk; the results of these tests were in good mutual agreement.
Reflectance measurements were performed using a LomoMSFU-KYu-30.54.072 microspectrophotomerer (OOO “Lomo”, St. Petersburg, Russia), using a single-crystal silicon standard (KEF 4.5/0.3) provided by the S.I. Vavilov State Optical Institute, an All-Russian Research Center in St. Petersburg, Russia.

3. Results and Observations

Mineral associations and compositional variations were examined in ore-bearing samples in the differentiated sequences of picritic, “taxitic” and olivine-bearing gabbro-dolerite in the eastern portion of the Oktyabrsky deposit (Figure 2). These rocks typically contain about 5 vol. % to 20 vol. % base metal sulfide minerals (BMS) that occur as primary disseminations, angular or droplet-like grains, or as interstitial grains with an irregular shape (e.g., Figure 3a).

3.1. Rock-Forming Minerals and the Accessory Fe-Cr-(Ti) Oxides

The overall variations in the composition of rock-forming silicates are displayed in Table 1 and Table 2. Olivine grains vary compositionally in the range of Mg# values, i.e., 100 Mg/(Mg + Fe2+ + Mn), from 79.8 to 74.1. Grains of orthopyroxene display the range 78.0–65.3. In contrast, compositions of clinopyroxene exhibit much more extensive variations in the diopside-hedenbergite series, with Mg# values in the range 79.9–9.2. The unusually low Mg compositions formed late in the crystallization history (Table 1, Figure 4a). The compositions of plagioclase also cover an impressive range, from early An79.0 to Ab96.3, with the sodic members of the series present in the “intercumulus” (interstitial) association (Table 2, Figure 4b).
Species of Cr-Ti oxides form part of the ore assemblage (Table 3). Accessory grains and aggregates of chromite and Cr-bearing magnetite, hereafter referred to as chromian spinel (Chr) for the sake of simplicity, and ilmenite (Ilm) attain 0.1–0.2 mm in size (Figure 3b and Figure 5a,b and Table 4). The compositions of chromian spinel display a trend of Fe3+ enrichment during crystallization, a reflection of the increasing amounts of the magnetite component (Figure 6a). They display a positive correlation of Al vs. Mg, with a coefficient R of 0.88 based on a total of 33 data-points (n = 33). Additionally, they display a gradual decrease in Mg and Al during crystallization, i.e., in the spinel component (MgAl2O4). Notable levels of Ti (up to 5% TiO2; Table 4) are characteristic of the chromian spinel, as is typical of the Norilsk complex (e.g., [12]). The ilmenite contains up to 5.42 wt.% MgO, i.e., the geikielite component. In addition, grains enriched in the pyrophanite component contain up to 5.05 wt.% MnO.

3.2. Amphiboles and Micas

The amphibole compositions in the ore-bearing specimens that we have investigated consist of members of the calcic, sodic-calcic and Fe-Mg groups (Table 5, Figure 7a) The mica compositions are annitic, unusually chlorine-rich (Table 6, Figure 7b), with up to 5–7 wt.% Cl, and display a close association with platinum group minerals. Amphiboles of series 1 are generally poor in Cl, except for a potassic variety of hastingsite (composition #5 in Table 5) that contains 4.06 wt.% Cl. The variations shown in Figure 8a yield a positive correlation of K with Cl in the amphiboles. Note the presence of a negative correlation of MgO vs. Cl (R = −0.85), along with a positive correlation of FeO vs. Cl (R = 0.84 for n = 35, in which R is the correlation coefficient calculated on the basis of 35 data-points), recorded in the mica compositions (Figure 8b,c).

3.3. Compositional Variations of Apatite and Minerals of Zr, REE, Y, Th and U

Apatite is a fairly common accessory mineral in our suite of samples. Grains reach up to 0.5–1 mm in length; they exhibit various shapes, from anhedral or subhedral to nearly euhedral (Figure 9a,b and Figure 10a). High variability in the levels of halogens and hydroxyl (calculated) has been documented (Table 7; Figure 11). These variations were established in both intragranular and grain-to-grain patterns.
Baddeleyite grains (≤10 to 30 µm) appear sporadically in various textural forms, such as (1) a peripheral rim-like aggregate deposited around a core of Mg-enriched ilmenite (hosted by pyrrhotite); (2) inclusions in grains of base metal sulfides (pyrrhotite and cubanite; close to their margins or contacts); and (3) a veinlet-like aggregate of twinned grains of Hf-bearing baddeleyite cutting a host grain of orthopyroxene close to its contact (Figure 10b). Additionally, subhedral grains of baddeleyite occur as composite inclusions enclosed by a grain of titanian phlogopite, in which it is intergrown with zirconolite (Figure 10c). The compositions of eight grains of baddeleyite correspond to ZrO2 with minor incorporation of Ti, Fe and Hf (≤2 wt.% of the oxides each).
Several small grains of zirconolite were also analyzed. Elevated levels of Th and Fe are characteristic. The grain shown in Figure 10c has the following composition: Nb2O5 1.99, SiO2 2.57, TiO2 27.77, ZrO2 35.58, ThO2 8.55, UO2 2.09, Y2O3 3.77, Ce2O3 1.15, Nd2O3 0.79, FeO 5.72, CaO 5.93, and total 95.91 wt.% (sample EF0069-1743.6). The formula calculated on the basis of seven oxygen atoms per formula unit is (Ca0.45Fe0.34Y0.14Th0.14Ce0.03U0.03Nd0.02)Σ1.15Zr1.00(Ti1.48Zr0.23Nb0.06)Σ1.77O7. Presumably, this phase is metamict, in view of its high Th and U contents. The associated baddeleyite (Figure 10c) gave ZrO2 96.12, HfO2 1.65, and TiO2 1.37, for a total of 99.14 wt.%. The host grain of phlogopite has a high content of titanium: SiO2 38.66, TiO2 7.06, Al2O3 13.15, Cr2O3 0.56, FeO 8.95, MgO 18.41, Na2O 1.0 and K2O 11.0, and a total of 98.79 wt.%.
Zircon is rare, and close to being stoichiometric in composition; e.g., SiO2 28.90, ZrO2 64.37, HfO2 1.69, and FeO 1.53, and a total of 96.49 wt.%. Its grains are typically less than 10 µm across; they display a close spatial association with grains of F-enriched apatite (4.44 wt.% F and 0.56 wt.% Cl) and Pd-based minerals of stannide and antimonide compositions, all hosted by a Cl-bearing chamosite-like silicate. The latter has the following composition: SiO2 31.30, Al2O3 9.73, FeO 42.97, MnO 0.76, MgO 1.14, CaO 0.42, K2O 0.63, and Cl 0.96 (or 0.19 apfu), for a total of 87.91 wt.%. Interestingly, tiny grains (≤10 µm) of monazite-(Ce), thorite-coffinite, thorianite and uraninite commonly display an intimate association with the highly Cl-enriched species chlorapatite, and the Cl-rich annite (Figure 12a,b and Figure 13a,b). Representative compositions of selected grains of these minerals are given in Table 8.
In addition, a single inclusion (~2 µm across) of a highly F-enriched composition was encountered, which likely represents bastnäsite-(La), although its composition somewhat deviates from the ideal formula, likely because of analytical difficulties caused by the very tiny grain-size. This grain is hosted by plagioclase (An61.2Ab37.5Or1.4; sample EF0043-1764.3) and has the following composition: La2O3 47.03, Ce2O3 18.81, Pr2O3 6.73, F 12.01, O ≡ F 5.06, and CO2 (by difference) 20.48, for a total of 100.0 wt.%.

3.4. Unnamed (Y,Ca,REE)2Zr2 (Ti,Nb)2TiFe2+O14

Of particular interest are the documented occurrences of an unnamed, Y-dominant, zirconolite-related mineral, hitherto unreported, which occurs as elongate and platy grains commonly associated with the Cl-rich annite (Figure 14a). Representative results of selected analyses (#8 in Table 9) lead to the following formula based on 14 O apfu: (Y0.90Ca0.44Nd0.14Gd0.11Ce0.08Dy0.08Sm0.05Yb0.03Th0.03)Σ1.86Zr2.16Ti1.00(Ti1.90Nb0.10)Σ2.00Fe2+1.03O14. A minor excess in Zr, combined with a related deficit in the total content of cations at the Y site, imply that 0.16 Zr apfu could well be incorporated at the Y site. Yet another potentially new species in the series that is Ca-dominant, (Ca,Y,REE)2Zr2Ti (Ti,Nb)2Fe2+O14, is present in this association (Table 9).
The potentially new Y-dominant mineral has a fairly low reflectance measured in air (Figure 14c, Table 10). Attempts were made to characterize its crystal structure; these failed because the mineral is metamict (I.V. Pekov, written communication), a reflection of its elevated content of Th and U. These phases at Norilsk appear to be related to stefanweissite, (Ca,REE)2Zr2(Nb,Ti)(Ti,Nb)2Fe2+O14, nöggerathite-(Ce), (Ce,Ca)2Zr2(Nb,Ti)(Ti,Nb)2Fe2+O14, and laachite, (Ca,Mn)2Zr2Nb2TiFeO14, which are all zirconolite-related minerals discovered in the Eifel paleovolcanic region, Germany [13,14,15]. The low level of radioactive elements in the relatively young complexes of that region has ensured the preservation of their crystal structure.

3.5. Au-Ag Minerals and Variations in the System PbS-PbSe-PbTe

Argentopentlandite, the Fe-Ni-Ag sulfide (Figure 14b and Figure 15a–c, Table 11), occurs sporadically in the samples investigated, along with other Ag-based species (hessite, acanthite, sopcheite (i.e., Ag-Pd telluride)), in grains varying from 2 µm to 50–70 µm across. Present as well are grains of Au-Ag alloys, in the range 5–15 µm; they typically accompany grains of platinum group minerals. These alloys correspond to the minerals silver (Ag-dominant) and gold (Au-dominant; Table 12), which display an extensive series of intermediate solid solutions (Figure 16).
Our data on argentopentlandite (analyses #3–9, Table 11; Figure 15a–c) have interesting implications. These grains (~5–10 µm to 60 µm across; e.g., Figure 14b), hosted by chalcopyrite or pyrrhotite, or occurring at their boundaries, exhibit unusually high variations in Fe (4.85–5.68), Ni (2.29–3.66) and Ag (0.50–1.00), all quoted in apfu calculated for a total of 17 apfu (Table 11). On the basis of these observations, we infer that: (1) up to 0.5 apfu of Ag at the Ag site can be replaced by another cation, namely Ni; (2) nickel, not Fe, replaces Ag in the structure, and (3) a coupled mechanism (Ag + Fe) → Ni can be inferred, which suggests that a Ni-for-Ag substitution at the Ag site is combined with a Ni-for-Fe substitution at the Fe-Ni site. The presently observed variations in Ag extend those reported previously: (Fe5 ± 0.6Ni3 ± 0.4)Σ8 + xAg1 − xS8 with 0 < x < 0.2, from Mount Windarra, Australia [16,17], and (Fe5 ± 0.77Ni3 ± 0.75)Σ8 + xAg1 ± yS8 ± z, with 0 < x < 0.30, 0 < y < 0.23, 0 < z < 0.30 from El Charcón, Spain [18].
Grains of altaite and members of the galena-clausthalite series (Table 13) typically form small inclusions: <5–10 µm, occasionally 20–25 µm, and rarely up to 50 µm, hosted by chalcopyrite, cubanite or pyrrhotite, or associated with aggregates of grains of chalcopyrite and pentlandite within silicate minerals. A close association with the Cl-rich annite (3.89 wt.% Cl) is observed. In addition, these species of chalcogenides commonly occur in mutual intergrowths or accompany Pd-based bismuthotellurides and, in some instances, are associated with hessite. The analyzed members of the system PbS-PbSe-PbTe display the common Se-for-S substitution (Figure 17), whereas the Se-for-Te (or S-for-Te) exchanges are minor or virtually absent in these solid solutions.

3.6. Base Metal Sulfides and Nickeline

As noted, base metal sulfide mineralization typically develops in the form of large, primary grains with droplet-like or angular shapes, or interstitial disseminations (Figure 3a). It is composed of varying proportions of chalcopyrite, pyrrhotite, troilite, and pentlandite, with lesser amounts of cubanite and rare bornite.
The grains of chalcopyrite-type minerals, analyzed in all of the ore-bearing specimens, display notable variations in Cu and Fe. The overall ranges observed for a total n of 119 data-points are: Cu 0.84–1.10 (mean 0.99), Fe 0.95–1.18 (1.02), and S 1.90–2.06 (2.00), calculated for a total of 4 apfu; the Cu/Fe ratio is in the range 0.75–1.15 (mean 0.97). In the absence of structural data, we cannot specify whether or not the chalcopyrite-derivative sulfides talnakhite Cu18(Fe,Ni)16S32, mooihoekite Cu9Fe9Si16, and haycockite Cu4Fe5S8 [19,20,21,22] are present. In experimental systems, wide variations in Cu/Fe values were reported: 0.67–1.03 in tetragonal chalcopyrite, 0.68–0.92 in cubic haycockite, and 0.93–1.04 in mooihoekite [23].
Compositional series of pyrrhotite and troilite vary greatly (Table 14), as is shown in Figure 18, in comparison with ideal compositions of the known polytypes: orthorhombic pyrrhotite-11C (Fe10S11), hexagonal pyrrhotite-11H (Fe10S11), monoclinic pyrrhotite-4C (Fe7S8), and monoclinic pyrrhotite-5C (Fe9S10) (e.g., [24] and references therein).
Nickeline was observed as a tiny grain (2–3 µm across) analyzed in a polymineralic intergrowth of Pd-Sn-(As) and Pd-Te-Bi compounds. The results of the analysis are Ni 48.20, and As 51.92, for a total of 100.12 wt.%, thus corresponding to Ni1.08As0.92.
A total of sixty-nine grains (n = 69) of pentlandite analyzed in all of the collected specimens (Table 15, Figure 19) gave broad variations: Fe 3.56–5.64, with a mean of 4.70 apfu, and Ni 3.11–5.28, with a mean of 4.18 apfu (and up to 2.18 wt% Co); the average values of the total contents of metals and S are 8.97 and 8.03 apfu, respectively.
Compositional variations in cubanite or isocubanite (or both) were examined on the basis of 33 data-points. A fairly strong negative correlation of Cu vs. Fe (R = –0.95) is recorded. The observed ranges, expressed in weight %, are: Fe 37.08–42.76 (mean 41.12), Cu 22.43–29.28 (23.69), and S 34.51–36.35 (35.45), for a total of 98.37–101.86 (100.25) wt.%. The corresponding variations in apfu are: Fe 1.78–2.04 (mean 1.99), Cu 0.95–1.24 (1.01), and S 2.98–3.04 (3.00); the Cu + Fe values, 2.96–3.02, agree well with the stoichiometry.
The compositions of bornite (n = 3) are stoichiometric, with the possibility of minor Fe-for-Cu substitution, as implied from the observed variations: Fe 11.64–12.71, Cu 62.67–63.35, and S 25.48–25.91, for a total of 100.77–100.90 wt.%, or Cu4.91–4.95Fe1.04–1.13S3.96–4.01 (for a total of 10 apfu).
Tiny grains of sphalerite or wurtzite (n = 8) are Cd-bearing (0.69–2.71 wt.% Cd). The results of a representative analysis are as follows: Zn 56.64, Cd 2.71, Fe 8.41, and S 34.19, for a total of 101.96 wt.%, leading to the formula (Zn0.84Fe0.14Cd0.02)Σ1.00S1.00 (for a total of 2 apfu).

3.7. Platinum Group Minerals

A total of 20 species of PGM were recognized in the specimens we examined, including some uncommon or potentially unnamed compounds. They can be grouped into the following families: (1) Pd-Pt tellurides, bismuthotellurides and bismuthides (kotulskite PdTe; sobolevskite PdBi; merenskyite PdTe2; moncheite PtTe2; michenerite PdBiTe, and froodite PdBi2); (2) Pd-Ag telluride (sopcheite Ag4Pd3Te4); (3) Pd-Pt stannides, members of the paolovite Pd2Sn-(Pt,Pd)2Sn series; atokite Pd3Sn; rustenburgite Pt3Sn, and niggliite PtSn; (3) Pd antimonides (mertieite-II Pd8Sb3; naldrettite Pd2Sb); (4) Pd plumbides (zvyagintsevite Pd3Pb; plumbopalladinite Pd3Pb2); (5) Pt arsenide (sperrylite PtAs2); (6) Pd-Ni arsenide (majakite PdNiAs); (7) Pd germanide-arsenide (unnamed Pd11Ge3As2 or an As-rich variety of palladogermanide Pd2(Ge,As)); and 8) Pt-Cu arseno-oxysulfide (unnamed PtCu2AsSO3).
Several hundreds of PGM grains were analyzed. They are dominantly located at the boundaries of grains of base metal sulfides (BMS) with silicate minerals (in many cases with the Cl-enriched annite), or are hosted entirely by chalcopyrite or, less commonly, by other BMS. The Pd-Pt tellurides, bismuthotellurides, Pd-Pt stannides and sperrylite are most abundant in the ore-bearing zones. The other species of PGM (#30–50 in Table 3) are subordinate or rare.
The bulk of the PGM grains are characteristically tiny, ranging from ≤1–2 to 10–15 µm for most grains (on the order of 80%). We estimate that about 10–15% of the examined grains exceed 20 µm, whereas ≤5% of the grains attain or exceed 0.1 mm in the longest dimension.
Characteristic textures, associations and compositional variations of PGM are displayed in Figure 20, Figure 21, Figure 22, Figure 23, Figure 24, Figure 25, Figure 26, Figure 27 and Figure 28. Representative analytical results are presented in Table 16, Table 17, Table 18, Table 19 and Table 20. Extensive solid solutions are evident in the kotulskite-sobolevskite series, merenskyite-moncheite series, paolovite-unnamed (Pt,Pd)2Sn series, and a subordinate series of sperrylite toward PtSb2 (Table 16, Table 17 and Table 18, Figure 21a,b, Figure 25 and Figure 26) that also has a pyrite-type structure [25].
Three of the analyzed compounds are noteworthy. The first is unnamed Pd6Sn2As (Table 18), which commonly occurs in direct contact or adjacent to grains of the Cl-rich annite (Figure 27b and Figure 28a). A phase having this formula was previously reported in the Norilsk complex [26]. The likely existence of a separate site for As seems reasonable because of the known differences in the crystal-chemical properties of Sn and As. On the other hand, the possibility of a paolovite structure tending towards a formula Pd2(Sn,As) cannot be excluded. Insufficient grain sizes precluded a structural study.
The second compound, unnamed Pd11Ge3As2 (#11, 12 in Table 20), forms minute grains (10 µm across) associated with majakite, at the boundary of a chalcopyrite grain. Alternatively, this arsenide-germanide could represent Pd2(Ge,As) as an As-enriched variant of palladogermanide (Pd2Ge), discovered at the Marathon deposit, Coldwell complex, Ontario, Canada [27,28].
The third phase is the most uncommon and may well represent the first documented example of a Pt-rich arseno-oxysulfide. Its composition is: Pt 34.20, Cu 30.84, Fe 1.29, As 18.57, S 5.23, and O 9.97, for a total of 100.10 wt.%; this can satisfactorily be recalculated to a formula of (Pt0.82Fe0.11)Cu2.26As1.15S0.76O2.90, based on a total of 8 apfu. The simplified formula is PtCu2AsSO3. As can be seen in Figure 29, this phase formed as a result of the replacement of the precursor sperrylite, which has a notably “pure” and stoichiometric composition (Pt1.01As1.99); it is also associated with an intermediate member of the kotulskite-sobolevskite solid solution: Pd1.01(Te0.50Bi0.49). Note that the observed texture (Figure 29) clearly points to the late formation of the entire grain of intergrown PGM, deposited along the boundary, presumably after the associated grain of Cu-bearing troilite: (Fe0.97Cu0.01–0.02)S1.00.

4. Discussion

4.1. Evidence for Extensive Differentiation in the Ore-Bearing Sequences

The associations of ore-forming elements, which are atypical owing to differences in their geochemical nature (cf. Pd-Pt vs. REE, Y, U, Th), are attributed to their incompatible behavior and mutual accumulation at late stages of crystallization in a system that had attained a high degree of magmatic differentiation. Extensive variations are observed in the compositions of all rock-forming minerals in the eastern portion of the ore deposit (Table 1 and Table 2). The overall variations in the ore-bearing sequences are as follows: olivine Mg# 79.8 → 74.1, orthopyroxene Mg# 77.7 → 65.3, clinopyroxene 79.9 → 9.2, and plagioclase An 79.0 → to 3.7 (Ab 96.3). The oxide mineralization also displays extensive ranges, from the most strong in magnesian chromite (MgO 9.62 wt.%; Mg# 43.9) to Cr-bearing magnetite. Compositions of the associated ilmenite evolved from being relatively enriched in Mg (MgO 5.42%) to showing a buildup in Mn (MnO 5.05%), i.e., from geikielite- to pyrophanite-enriched varieties (Table 4).
The observed trends and ranges of compositions of plagioclase and clinopyroxene (Figure 4a,b) greatly exceed those of olivine and orthopyroxene. This contrast is ascribed to a longer-lasting interval of crystallization of the plagioclase and clinopyroxene, from magmatic down to subsolidus conditions of crystallization in the intercumulus (interstitial) parageneses. In contrast, crystallization of the pair of Ol and Opx was confined to an early magmatic stage. Additionally, considerable variations in Mg and Fe are recorded in the amphibole and mica series, with a progressive decrease in Mg content during crystallization (Figure 6a,b).
Thus, we infer that the early parageneses involved grains of magnesian olivine (Mg# 79.8), orthopyroxene (Mg# 77.7) and clinopyroxene (Mg# 79.9), along with calcic plagioclase (An79.0) plus accessory amounts of magnesian chromite (Mg# 43.9). Interestingly, grains of An79.0 in the eastern Oktyabrsky area nearly coincide in composition with primocrysts of calcic plagioclase reported from layered intrusions: An78 in the Bushveld complex in South Africa [29], An77.6–78.2 in the Sopcha-Nyud-Poaz suite of the Monchepluton complex in the Kola Peninsula [30], and An79.2 in the Kivakka layered intrusion, northern Karelia, Russia [31]. Compositions of crystallizing plagioclase (Figure 4b) evolved normally and gradually toward Na-enrichment to attain the minimum An3.7 in microvolumes of late interstitial melt.
The compositions of chromian spinel display a common trend of increasing Fe3+ (Figure 6a) with a decrease in Mg#, which implies a progressive rise in levels of oxygen fugacity (fO2) during crystallization. The inferred buildup in fO2 in a portion of late fluid was likely important to forming the arseno-oxysulfide phase PtCu2AsSO3, under subsolidus conditions, by the oxidation of a precursor grain of sperrylite (Figure 29). The associated grain of Cu-bearing troilite, (Fe0.97Cu0.01–0.02)S1.00, crystallized prior to the arseno-oxysulfide, thus implying a more reduced environment at the earlier stage.
The positive Mg-Al correlation (Figure 6b) in the spinel phases reflects variations in the spinel sensu stricto component, which coexists with forsterite at high temperatures [32]; these values are expected to decrease during crystallization. The same correlation is characteristic of the chromian spinel from the subvolcanic komatiitic complexes in the Pados-Tundra complex and related intrusions of the Serpentinite Belt, Kola Peninsula, Russia [33].
Notable variations are recorded in compositions of the base metal sulfides. The observed ranges in compositions of pyrrhotite, troilite and pentlandite are especially prominent (Figure 18 and Figure 19). The Fe content of pyrrhotite tends to correlate positively with the Fe:Ni ratio of the coexisting pentlandite, as previously reported in other deposits [34,35]. The observed trend of Ni-enrichment in pentlandite (Figure 19) may reflect a progressive rise in the level of sulfur fugacity, fS2 (cf. [36,37]).
The observed variations in cubanite (or isocubanite, or both) are notable: Fe 1.78–2.04 (mean 1.99), Cu 0.95–1.24 (1.01), and S 2.98–3.04 (3.00), with Cu + Fe 2.96–3.02 apfu. The documented series thus extends toward nonstoichiometric compositions with an excess of Cu. The extent of the excess (1.24 apfu) surpasses that recorded in specimens of nonstoichiometric isocubanite (Cu1.1Fe2.0S3.0) in the system Cu-Fe-S [38]. The results of the latter study show that isocubanite is able to crystallize directly from the melt and does not necessarily represent the result of a solid-phase reaction during the transformation of the intermediate solid solution.
Our textural observations of argentopentlandite (e.g., Figure 14b) imply its crystallization from pockets of a residual sulfide melt at late stages. Our results (Figure 15a–c) show that Ni can substitute up to a half of the Ag site, and is incorporated via a coupled mechanism (Ag + Fe) → Ni, in which the Ni-for-Ag substitution at the Ag site is combined with the Ni-for-Fe substitution at the Fe,Ni site. On the basis of a structural analogy with pentlandite, one can expect that levels of fS2 play an important role in controlling the Ni:Fe ratio in argentopentlandite. Another example of coupled substution, involving Rh and Co, was reported for pentlandite at Bolshoy Khailyk, western Sayans, Russia: Rh3+ + Co3+ + □ → 3 Fe2+ [39]. Related schemes of coupled substitution may well be common in pentlandite-type phases in other deposits.

4.2. Evidence for Cl-Enrichment in Ore-Forming Fluids

The occurrences of atypical mineralization that we investigated are related to moderately low-sulfide zones that developed relatively close to the external contacts of the Oktyabrsky ore deposit (Figure 1). This mineralization involves diverse assemblages of minerals of Pd-Pt, Au-Ag, REE, Y, Zr, Th, and U, which coexist with Cl- and F-enriched species. The ore minerals are associated with Cl-enriched hastingsite (4.06 wt.% Cl: # 5, Table 5), ferro-hornblende (2.53 wt.% Cl: #7, Table 5), the chlorine-rich annitic mica (up to 7.54 wt.% Cl; #18, Table 6), chlorapatite (>6 wt.% Cl: Table 7, Figure 11), Cl-bearing members of the chlorite group (chamosite; up to 0.96 wt.% Cl), and a Cl-bearing serpentine (up to 0.79 wt.% Cl).
The Cl-enriched species coexist with assemblages rich in REE, Y, Zr, U, Th, Au-Ag and Pd-Pt. Note, for example, the documented associations of monazite-(Ce) with chlorapatite (Figure 12a), thorite and uraninite, of the unnamed zirconolite-related phase with grains of Cl-rich annite (Figure 13a,b and Figure 14a), and of the platinum group minerals (sobolevskite-kotulskite, mertieite, Pd-Sn-(As) alloy and sperrylite) with the Cl-rich annite (Figure 22b, Figure 24b, Figure 27a,b and Figure 28a,b). In addition, the veinlet-like grains of sperrylite display an intimate association with a Cl-rich apatite (4.17 wt.% Cl). These findings point to the existence of high levels of Cl in the fluid medium during the crystallization of the ore-bearing sequences.
The compositional variations (Table 5 and Table 6 and Figure 7a–c) show a clear relationship between the Cl-enrichment and corresponding enrichments in K and Fe in compositions of the amphiboles and micas. These relationships are consistent with crystallochemical concepts [40]. The positive Fe vs. Cl correlation (Figure 8c) and the observed relationships of Cl with K indicate that Cl efficiently accumulated in a fluid phase associated with portions of late intersitial melts rich in Fe and K.
A close association of Pd-Ag tellurides with a Cl-rich amphibole, i.e., the Cl-dominant analogue of ferro-pargasite (up to 4.5 wt.% Cl; 1.2 Cl apfu), was previously reported from the Lukkulaisvaara layered intrusion, Kola Peninsula, Russia. Pods of plagioclase-bearing orthopyroxenite rich in Cu-Fe-Ni sulfide mineralization and rich in Pd, Pt and Ag probably formed by the in situ crystallization of isolated volumes of H2O-saturated melt at Lukkulaisvaara [41,42]. Inclusions of lukkulaisvaaraite, Pd14Ag2Te9 [43], hosted by grains of ferro-chloro-pargasite, clearly formed in a Cl-rich environment [41]. Another occurrence of ferro-chloro-pargasite (4.1 wt.% Cl), reported at Mount Poaz in the Monchepluton layered complex, Kola Peninsula, Russia, formed as a result of an autometasomatic reaction involving a hydrous fluid with plagioclase and pyroxene [30]. This rare species of amphibole, containing up to 6.34 wt.% Cl and 1.74 Cl apfu, was also described in the Tudor gabbroic complex, north of Madoc, Ontario, Canada [44]. Interestingly, notable amounts of Cl are present in shoshonite-type (K-enriched) silicate melt inclusions hosted by PGE alloys [45].
A strong Cl-enrichment in the medium also accounts for the abundance of Cl-rich apatite in the ore zones. Extensive solid solutions involving the components chlorapatite, fluorapatite and hydroxylapatite are documented in the F-Cl-OH diagram (Figure 11). These variations extend to the end member chlorapatite and involve compositionally heterogeneous, cryptically zoned grains, as well as grain-to-grain variations present in the same sample (Table 7, Figure 10). These characteristics are consistent with data on apatite compositions from the Monchepluton layered complex, in which the degassing of the crystallizing melt caused a decoupling of Cl and F [30]. Fluorine mostly remained in the melt; in contrast, Cl was partitioned efficiently into an H2O-bearing fluid phase. Consequently, the early-stage apatite incorporated combinations of OH and F, with a low content of Cl. At a late stage, chlorapatite crystallized from a Cl-rich fluid, and ferro-chloro-pargasite formed at Poaz [30]. The geochemical behavior of Cl was traced on the basis of findings related to apatite from layered intrusions. The maximum Cl recorded in compositions of apatite, close to the level of the Pd-Pt horizon, likely corresponds to the first appearance and the massive crystallization of plagioclase primocrysts at Kivakka, Karelia, Russia [31,46]. Similarly, a relationship exists between the stratigraphic levels of the crystallization of chlorapatite and zones of relative Pd-Pt enrichments at Kläppsjö, Sweden [47]. Especially high contents of Cl are present in a compound of Pb-Cl-(OH) composition associated with PGM in the Merensky Reef, Bushveld complex, South Africa [48]. Occurrences of bowlesite, PtSnS [49], are present in the Reef. In layered intrusions, chlorapatite typically tends to occur in lower units of ultramafic cumulates [50,51,52]. However, no definite relationships have been found at Monchepluton, Russia, between extents of magnesium enrichment and levels of Cl in the apatite [30].
Our study reveals the presence of apatite grains of varying compositions, which can range from fluorapatite to chlorapatite in the same sample (Table 7). These variations are attributed to the process of the degassing of the crystallizing melt, with the decoupling of Cl and F. The presence of micrometric inclusion of a La-dominant carbonate-fluoride phase, related to bastnäsite (hosted by plagioclase), is consistent with the inferred decoupling of F from Cl. The likely source of Cl at Norilsk is thus presumably intrinsic and related to magmatic differentiation. This inference is consistent with the exotic occurrences of Pd-Bi chlorides documented in the ore of this complex [53].

4.3. Characteristic Features of Pd-Pt Mineralization

The zones of noble metal mineralization investigated in the eastern part of the Oktyabrsky deposit bear some notable similarities to the classic deposits at Norilsk. For instance, the major species of PGM, i.e., Pd-(Ag)-Pt tellurides, bismuthotellurides and Pd-Pt stannides (Table 3), are generally common in the massive or high-grade deposits rich in sulfides of the Norilsk complex (cf. [2,26]). Furthermore, a close association with Au-Ag alloys is present, as is very typical at Norilsk.
On the other hand, there are certain prominent and distinctive characteristics, based on our findings. (1) The mean dimension of PGM grains is micrometer-sized (≤10 µm across) in the ore assemblages examined. (2) The majority of the PGM exhibit evidence of late crystallization, commonly taking place after the deposition of grains of the associa-ted base metal sulfides (BMS). As a result, these PGM phases typically occur at the boundary of the BMS with silicate minerals (Figure 20a,b, Figure 22a,b, Figure 23a,b, Figure 27a,b and Figure 29). (3) The documented association of PGM with the Cl-enriched species is important, including representatives of the series of chlorine-enriched micas and amphiboles (Figure 22b, Figure 24b, Figure 27a,b and Figure 28a,b). (4) The atypical association of PGM with various species enriched in REE, Y, Zr, Th, U, and Cl-F is a prominent feature. (5) Species of Pd-Pt-Cu stannides, i.e., taimyrite, cabriite and tatyanaite, which are very abundant in the massive sulfide ores [2,54,55,56,57], are virtually absent in our specimens. (6) The occurrence of a Ge-bearing phase of PGM, i.e., the unnamed Pd11Ge3As2 or Pd2(Ge,As), is a distinctive feature. The Ge-based species of PGM occur very rarely worldwide, with a type locality known in the Marathon Cu-Pd deposit of the Coldwell alkaline complex in Canada [27,28]. They are also found in the Yoko-Dovyren pluton, Baikal region, Russia [58]. (7) The appearance of an arseno-oxysulfide phase, PtCu2AsSO3 hitherto unreported, was a result of a local buildup of fO2 during a late fluid and subsolidus reaction with the precursor sperrylite (Figure 29). Copper was likely remobilized and contributed by the fluid, and was likely released from the associated chalcopyrite, whereas the S was contributed by the associated troilite.
Several PGE-based oxides have been described in different settings and complexes, including Pb-, Sb-, Bi-, and Tl-bearing oxides, which reflect the compositions of the precursor PGM grains [59,60,61,62,63,64]. However, at least some of these grains could be composed of cryptic mixtures. No bonding was found to occur between platinum and oxygen in a Pt-Fe oxide grain studied by X-ray absorption spectroscopy [65], and so this likely corresponds to a mixture rather than a single mineral species.
The textural relations (Figure 20a,b, Figure 22a,b, Figure 23a,b, Figure 27a,b and Figure 29) are indicative of the late crystallization of the complex mineralization of Pd-Pt-Au-Au and associated species enriched in REE, Y, Zr, U, and Th (Figure 12a,b, Figure 13a,b and Figure 14a) from batches of Cl-enriched fluid under submagmatic conditions of crystallization. The low temperatures of the deposition of the PGM are consistent with experimental results. The values of the upper limit of stability are low for synthetic analogues of sopcheite Ag4Pd3Te4 (383 °C), froodite PdBi2 (∼480 °C), michenerite Pd-Te-Bi (501 °C), sobolevskite PdBi and kotulskite PdTe (∼750 °C) [66,67,68,69]. In addition, synthetic specimens of kotulskite, merenskyite PdTe2, atokite Pd3Sn and paolovite Pd2Sn are stable at 400 °C in the systems Pd-Sn and Pd-Te [70]. It is likely that a high-temperature crystallization (>800 °C) of sperrylite can proceed directly from a silicate melt [71], as was proposed in the case of this PGM in a low-sulfide horizon of the Noril′sk 1 intrusion, Russia [10]. However, this mode of origin appears highly unlikely in our case. Indeed, veinlets or rim-like grains of sperrylite have formed in the specimens examined, such as those shown in Figure 5b and Figure 29. These conclusively point to the late formation of the entire ore assemblage in the presence of Cl and other volatiles in the growth medium at a low temperature during a submagmatic stage of crystallization. This inference is corroborated by the occurrence of hydrothermally formed sperrylite in the Imandra layered complex, Kola Peninsula, Russia [72]. In addition, sperrylite is the main species of PGM in the Copper Cliff South mine associa-ted with the Sudbury structure, Ontario, Canada, at which the existence of Cl-bearing fluids is inferred [73].

5. Conclusions

1. The compositional variations described here document the extensive differentiation of the primary melt attained in ore-bearing zones close to the eastern contact of the Oktyabrsky ore deposit. As a result, a great variety of ore constituents (e.g., Pd-Pt, Au-Ag, REE, Y, Zr, U and Th), all rather incompatible, accumulated in that zone. Involved as well were chalcogens (S, Se, Te, O), semimetals (Sb, As, Ge) and metals (Bi, Pb, Sn), which can form ligands with the PGE in a Cl-rich fluid.
2. The newly recognized style of complex mineralization enriched in the incompatible constituents represents a variant of ore at Norilsk, the potential value of which may be enhanced by the complexity and diversity of the ore constituents.
3. We suppose that the abundance of Cl and other volatiles in the fluid-enriched system has promoted the remobilization and deposition of polycomponent mineralization in zones of deuteric alteration, likely controlled by faults, or in ore zones of contact type, or possibly even in detached zones hosted by wallrocks in the exocontact of the Norilsk complex. One can expect such zones to resemble the Kirrakkajuppura PGE mineralization of the Penikat complex in Finland, which has huge grades of Pd and Pt that developed in virtually BMS-free rocks [60,61].

Author Contributions

The authors wrote the article together. A.Y.B., interpretations, conclusions, writing; I.I.N., investigations, sampling, writing; A.A.N., writing, diagrams, discussions; B.M.L., observations, analytical results, writing; S.A.S., analytical results, reflectance measurements, diagrams, writing; R.F.M., discussions, conclusions, writing. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no specific grant.

Data Availability Statement

The data are available upon reasonable request (from A.Y.B.).

Acknowledgments

We thank the Editorial board members and three anonymous reviewers for their constructive comments. We are grateful to Igor V. Pekov for his attempts to study the zirconolite-related mineral via single-crystal diffraction. Support from the Cherepovets State University is acknowledged (A.Y.B. and A.A.N.).

Conflicts of Interest

The authors declare no conflict of interest.

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Figure 1. Generalized scheme of geology of the Norilsk area, after [1] and references therein. The labels from DB to Ps pertain to original names of the regional faults, which are used historically in the Russian literature. The study area is shown schematically by the red square symbol.
Figure 1. Generalized scheme of geology of the Norilsk area, after [1] and references therein. The labels from DB to Ps pertain to original names of the regional faults, which are used historically in the Russian literature. The study area is shown schematically by the red square symbol.
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Figure 2. Geology of the area investigated, with the location of boreholes sampled in the eastern portion of the Oktyabrsky ore deposit. The study area is shown in Figure 1.
Figure 2. Geology of the area investigated, with the location of boreholes sampled in the eastern portion of the Oktyabrsky ore deposit. The study area is shown in Figure 1.
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Figure 3. (a) shows the representative texture of mineralized gabbro-dolerite; it consists of large interstitial grains of base metal sulfides (BMS) hosted by a fine-grained matrix of rock-forming silicates (gray). (b) displays an aggregate of euhedral grains of chromian spinel (Chr) associated with olivine (Ol) and a calcic plagioclase (An). Srp is a member of the serpentine group. These back-scattered electron images (BEI) were obtained by scanning electron microscopy (SEM).
Figure 3. (a) shows the representative texture of mineralized gabbro-dolerite; it consists of large interstitial grains of base metal sulfides (BMS) hosted by a fine-grained matrix of rock-forming silicates (gray). (b) displays an aggregate of euhedral grains of chromian spinel (Chr) associated with olivine (Ol) and a calcic plagioclase (An). Srp is a member of the serpentine group. These back-scattered electron images (BEI) were obtained by scanning electron microscopy (SEM).
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Figure 4. (a) shows the compositional ranges of monoclinic and orthorhombic pyroxenes, shown by the blue and orange symbols, respectively, in terms of a Ca-Mg-Fe plot. The samples were taken from mineralized zones in the eastern portion of the Oktyabrsky ore deposit. Labels: Wo is wollastonite; En is enstatite, and Fs is ferrosilite. The pyroxene nomenclature is after [11]. (b) displays the existence of a continuous series of compositions of plagioclase in these zones, in terms of the components albite (Ab) and anorthite (An).
Figure 4. (a) shows the compositional ranges of monoclinic and orthorhombic pyroxenes, shown by the blue and orange symbols, respectively, in terms of a Ca-Mg-Fe plot. The samples were taken from mineralized zones in the eastern portion of the Oktyabrsky ore deposit. Labels: Wo is wollastonite; En is enstatite, and Fs is ferrosilite. The pyroxene nomenclature is after [11]. (b) displays the existence of a continuous series of compositions of plagioclase in these zones, in terms of the components albite (Ab) and anorthite (An).
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Figure 5. (a) (BSE) displays a globular grain of chromite (Chr) hosted by a member of the serpentine group (Srp). A grain of accessory ilmenite (Ilm), shown in (b) (BSE) in association with chalcopyrite (Ccp), is partially mantled by a rim of platinum group minerals (PGM): mertieite-II (Met-II) and sperrylite (Spy); a grain of calcic amphibole is labeled Amp. These BSE images were taken with the SEM.
Figure 5. (a) (BSE) displays a globular grain of chromite (Chr) hosted by a member of the serpentine group (Srp). A grain of accessory ilmenite (Ilm), shown in (b) (BSE) in association with chalcopyrite (Ccp), is partially mantled by a rim of platinum group minerals (PGM): mertieite-II (Met-II) and sperrylite (Spy); a grain of calcic amphibole is labeled Amp. These BSE images were taken with the SEM.
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Figure 6. Compositional variations in grains of chromian spinel in the eastern portion of the Oktyabrsky ore deposit are shown in terms of the plots Cr-Al-Fe3+ (a) and Mg vs. Al (b), expressed in values of atoms per formula unit (apfu).
Figure 6. Compositional variations in grains of chromian spinel in the eastern portion of the Oktyabrsky ore deposit are shown in terms of the plots Cr-Al-Fe3+ (a) and Mg vs. Al (b), expressed in values of atoms per formula unit (apfu).
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Figure 7. A plot of FeO vs. MgO (wt.%) shows compositional variations in the calcic, sodic-calcic and calcian Fe-Mg amphiboles (a) and in the micas (b).
Figure 7. A plot of FeO vs. MgO (wt.%) shows compositional variations in the calcic, sodic-calcic and calcian Fe-Mg amphiboles (a) and in the micas (b).
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Figure 8. (a), a plot of K2O vs. Cl (wt.%), shows a positive correlation of K with Cl in compositions of the calcic, sodic-calcic and calcian Fe-Mg amphiboles. (b,c) display a negative correlation of MgO vs. Cl (wt.%) and a positive correlation of FeO vs. Cl in the compositions of micas.
Figure 8. (a), a plot of K2O vs. Cl (wt.%), shows a positive correlation of K with Cl in compositions of the calcic, sodic-calcic and calcian Fe-Mg amphiboles. (b,c) display a negative correlation of MgO vs. Cl (wt.%) and a positive correlation of FeO vs. Cl in the compositions of micas.
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Figure 9. (a) is a BSE image of grains of apatite (Ap), which occur as elongate, partly subhedral or skeletal grains, enriched in Cl (3.87–5.93 wt.%), in association with grains of amphibole (Amp) and base metal sulfides (BMS). (b) (BSE) shows a grain of accessory apatite (Ap) that is strongly heterogeneous in the distribution of Cl (up to 5.34–6.74 wt.% Cl: brighter areas) and of F (2.48–3.15 wt.%). The associated minerals are a plagioclase (Pl) enriched in the Ab component and a Fe-enriched member of the chlorite group (Chl).
Figure 9. (a) is a BSE image of grains of apatite (Ap), which occur as elongate, partly subhedral or skeletal grains, enriched in Cl (3.87–5.93 wt.%), in association with grains of amphibole (Amp) and base metal sulfides (BMS). (b) (BSE) shows a grain of accessory apatite (Ap) that is strongly heterogeneous in the distribution of Cl (up to 5.34–6.74 wt.% Cl: brighter areas) and of F (2.48–3.15 wt.%). The associated minerals are a plagioclase (Pl) enriched in the Ab component and a Fe-enriched member of the chlorite group (Chl).
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Figure 10. (a) (BSE) shows a subhedral grain of chlorapatite (Clap; 6.44–6.51 wt.% Cl) associated with a grain of calcic amphibole (Amp). A BSE image in (b) displays a veinlet-like aggregate of twinned grains of Hf-bearing baddeleyite (Bdy) that transects a host grain of orthopyroxene (Opx) close to its contact with plagioclase (Pl). (c) is a BSE image showing subhedral grains of baddeleyite (Bdy) intergrown with zirconolite (Zrc) hosted by a grain of titanian phlogopite (Phl).
Figure 10. (a) (BSE) shows a subhedral grain of chlorapatite (Clap; 6.44–6.51 wt.% Cl) associated with a grain of calcic amphibole (Amp). A BSE image in (b) displays a veinlet-like aggregate of twinned grains of Hf-bearing baddeleyite (Bdy) that transects a host grain of orthopyroxene (Opx) close to its contact with plagioclase (Pl). (c) is a BSE image showing subhedral grains of baddeleyite (Bdy) intergrown with zirconolite (Zrc) hosted by a grain of titanian phlogopite (Phl).
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Figure 11. Triangular Cl-F-OH plot showing the overall compositional variations (based on a total of 83 data-points) in accessory grains of apatite in mineralized zones in the eastern portion of the Oktyabrsky ore deposit. The label Fap is fluorapatite, Clap is chlorapatite, and Hap is hydroxylapatite.
Figure 11. Triangular Cl-F-OH plot showing the overall compositional variations (based on a total of 83 data-points) in accessory grains of apatite in mineralized zones in the eastern portion of the Oktyabrsky ore deposit. The label Fap is fluorapatite, Clap is chlorapatite, and Hap is hydroxylapatite.
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Figure 12. (a) (BSE) shows a grain of monazite-(Ce), labeled Mnz-Ce, located at the boundary of a grain of chlorapatite, Clap (6.11 wt.% Cl) with clinopyroxene (Cpx); Ccp is chalcopyrite. (b) (BSE) shows a tiny grain of thorite (Thr) at the contact of orthopyroxene (Opx) and chalcopyrite (Ccp) grains.
Figure 12. (a) (BSE) shows a grain of monazite-(Ce), labeled Mnz-Ce, located at the boundary of a grain of chlorapatite, Clap (6.11 wt.% Cl) with clinopyroxene (Cpx); Ccp is chalcopyrite. (b) (BSE) shows a tiny grain of thorite (Thr) at the contact of orthopyroxene (Opx) and chalcopyrite (Ccp) grains.
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Figure 13. (a) (BSE) shows a tiny and subhedral grain of thorite-coffinite (Thr) associated with a Fe-Mg amphibole (Amp) and a Cl-rich mica related to annite, Ann (7.42 wt.% K2O, 7.54 wt.% Cl); Pl is an Ab-rich plagioclase. (b) (BSE) shows a minute grain of uraninite (Urn) associated intimately with a grain of Cl-rich annite, Ann (10.23 wt.% K2O, 4.86 wt.% Cl).
Figure 13. (a) (BSE) shows a tiny and subhedral grain of thorite-coffinite (Thr) associated with a Fe-Mg amphibole (Amp) and a Cl-rich mica related to annite, Ann (7.42 wt.% K2O, 7.54 wt.% Cl); Pl is an Ab-rich plagioclase. (b) (BSE) shows a minute grain of uraninite (Urn) associated intimately with a grain of Cl-rich annite, Ann (10.23 wt.% K2O, 4.86 wt.% Cl).
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Figure 14. (a) (BSE) shows a platy grain of an unnamed (Y-rich) mineral labeled UN, which has an empirical formula (Y,Ca,REE)2Zr2(Ti,Nb)2Ti Fe2+O14 and is associated closely with a Cl-rich annitic mica (Ann) with 10.89 wt.% K2O and 5.48 wt.% Cl, at the boundary with a sodic plagioclase (Pl). (b) (BSE) displays an irregular grain of argentopentlandite (Apn) in association with chalcopyrite (Ccp), pyrrhotite (Pyh) and magnetite (Mag). Figure 14c shows reflectance spectra measured in air for grains of the zirconolite-type unnamed oxide (Y-dominant) from the Oktyabrsky ore deposit.
Figure 14. (a) (BSE) shows a platy grain of an unnamed (Y-rich) mineral labeled UN, which has an empirical formula (Y,Ca,REE)2Zr2(Ti,Nb)2Ti Fe2+O14 and is associated closely with a Cl-rich annitic mica (Ann) with 10.89 wt.% K2O and 5.48 wt.% Cl, at the boundary with a sodic plagioclase (Pl). (b) (BSE) displays an irregular grain of argentopentlandite (Apn) in association with chalcopyrite (Ccp), pyrrhotite (Pyh) and magnetite (Mag). Figure 14c shows reflectance spectra measured in air for grains of the zirconolite-type unnamed oxide (Y-dominant) from the Oktyabrsky ore deposit.
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Figure 15. Plots of contents of Fe vs. Ag (a), Fe vs. Ni (b), and Ni vs. Ag (c) in argentopentlandite are presented in terms of apfu (for a total of 17 apfu).
Figure 15. Plots of contents of Fe vs. Ag (a), Fe vs. Ni (b), and Ni vs. Ag (c) in argentopentlandite are presented in terms of apfu (for a total of 17 apfu).
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Figure 16. Compositional variations in Au vs. Ag in grains of Au-Ag alloys, expressed in weight %. A total of 69 data-points are plotted.
Figure 16. Compositional variations in Au vs. Ag in grains of Au-Ag alloys, expressed in weight %. A total of 69 data-points are plotted.
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Figure 17. Compositional variations in Se vs. S, expressed in values of atoms per formula unit (apfu; calculated for Σatoms = 2), in grains of members of the galena-clausthalite series. A total of 32 data-points are plotted.
Figure 17. Compositional variations in Se vs. S, expressed in values of atoms per formula unit (apfu; calculated for Σatoms = 2), in grains of members of the galena-clausthalite series. A total of 32 data-points are plotted.
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Figure 18. Compositional variations in Fe (+Ni) vs. S, expressed in values of atomic percent (calculated for Σatoms = 100 at.%), in grains of troilite (Tro) and pyrrhotite. A total of 79 data-points are plotted. For comparison, ideal compositions of pyrrhotite polytypes are shown (i.e., orthorhombic 11C, Fe10S11; hexagonal 11H, Fe10S11; monoclinic 4C, Fe7S8; and monoclinic 5C Fe9S10).
Figure 18. Compositional variations in Fe (+Ni) vs. S, expressed in values of atomic percent (calculated for Σatoms = 100 at.%), in grains of troilite (Tro) and pyrrhotite. A total of 79 data-points are plotted. For comparison, ideal compositions of pyrrhotite polytypes are shown (i.e., orthorhombic 11C, Fe10S11; hexagonal 11H, Fe10S11; monoclinic 4C, Fe7S8; and monoclinic 5C Fe9S10).
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Figure 19. Compositional variations in Ni vs. Fe, expressed in values of apfu (calculated for Σatoms = 17 apfu), in grains of pentlandite sampled in the eastern portion of the Oktyabrsky ore deposit. A total of 69 data-points are plotted.
Figure 19. Compositional variations in Ni vs. Fe, expressed in values of apfu (calculated for Σatoms = 17 apfu), in grains of pentlandite sampled in the eastern portion of the Oktyabrsky ore deposit. A total of 69 data-points are plotted.
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Figure 20. (a) BSE image of a tiny and roundish grain of a member of the kotulskite-sobolevskite series (Ktu) associated with a narrow zone of secondary alteration (dark in the BSE) developed along the contact of chalcopyrite (Ccp) and orthopyroxene (Opx) grains. (b) (BSE) shows Rh-bearing sperrylite (3.47 wt.% Rh) in intergrowth with a grain of sobolevskite (Sov); Ccp is chalcopyrite, and Pl is a sodic plagioclase.
Figure 20. (a) BSE image of a tiny and roundish grain of a member of the kotulskite-sobolevskite series (Ktu) associated with a narrow zone of secondary alteration (dark in the BSE) developed along the contact of chalcopyrite (Ccp) and orthopyroxene (Opx) grains. (b) (BSE) shows Rh-bearing sperrylite (3.47 wt.% Rh) in intergrowth with a grain of sobolevskite (Sov); Ccp is chalcopyrite, and Pl is a sodic plagioclase.
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Figure 21. Compositional variations in Bi vs. Te, expressed in apfu (calculated for a total of 2 and 3 apfu in Figure 21a,b, respectively), in grains of members of the kotulskite-sobolevskite series (a) and of the merenskyite-moncheite series (Mrk-Mon) and michenerite (Mch) (b). Totals of 61 and 24 data-points are plotted in Figure 21a,b, respectively.
Figure 21. Compositional variations in Bi vs. Te, expressed in apfu (calculated for a total of 2 and 3 apfu in Figure 21a,b, respectively), in grains of members of the kotulskite-sobolevskite series (a) and of the merenskyite-moncheite series (Mrk-Mon) and michenerite (Mch) (b). Totals of 61 and 24 data-points are plotted in Figure 21a,b, respectively.
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Figure 22. BSE images show grains of froodite (Fro) hosted by pyrrhotite (Pyh) in (a), and in (b), a grain of sperrylite (with 2.28 wt.% Sb) having a narrow rim of sobolevskite (Sov), also Sb-bearing (3.73 wt.%), intergrown with a mertieite-II-related phase (Met-II). Ann is a grain of Cl-rich annite with 10.67 wt.% K2O and 4.86 wt.% Cl.
Figure 22. BSE images show grains of froodite (Fro) hosted by pyrrhotite (Pyh) in (a), and in (b), a grain of sperrylite (with 2.28 wt.% Sb) having a narrow rim of sobolevskite (Sov), also Sb-bearing (3.73 wt.%), intergrown with a mertieite-II-related phase (Met-II). Ann is a grain of Cl-rich annite with 10.67 wt.% K2O and 4.86 wt.% Cl.
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Figure 23. BSE images of a euhedral grain of Sb-rich sperrylite (with 7.79 wt.% Sb; Spy), enclosed within chalcopyrite (Ccp) in (a) and, in (b), a grain of moncheite (Mon) located at the contact of plagioclase rich in Ab (Pl) and cubanite (Cbn).
Figure 23. BSE images of a euhedral grain of Sb-rich sperrylite (with 7.79 wt.% Sb; Spy), enclosed within chalcopyrite (Ccp) in (a) and, in (b), a grain of moncheite (Mon) located at the contact of plagioclase rich in Ab (Pl) and cubanite (Cbn).
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Figure 24. (a) BSE image of a rim-like aggregate of grains of moncheite (Mon) and Au-Ag alloy located along the boundary of the composite grain chalcopyrite (Ccp)-pyrrhotite (Pyh) with plagioclase rich in Ab (Pl). (b) BSE image of a Pd-Sn-(As) alloy grain (with submicrometric inclusions of a bright phase in the center), which occurs in contact with pentlandite (Pn), we see a grain of calcic amphibole, labeled Amp, and a grain of annite containing K (9.60 wt.% K2O) and Cl (3.27 wt.% Cl), labeled Ann.
Figure 24. (a) BSE image of a rim-like aggregate of grains of moncheite (Mon) and Au-Ag alloy located along the boundary of the composite grain chalcopyrite (Ccp)-pyrrhotite (Pyh) with plagioclase rich in Ab (Pl). (b) BSE image of a Pd-Sn-(As) alloy grain (with submicrometric inclusions of a bright phase in the center), which occurs in contact with pentlandite (Pn), we see a grain of calcic amphibole, labeled Amp, and a grain of annite containing K (9.60 wt.% K2O) and Cl (3.27 wt.% Cl), labeled Ann.
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Figure 25. A triangular plot of Pd-Pt-Sn (apfu) shows the series paolovite-unnamed (Pt,Pd)2Sn from the eastern portion of the Oktyabrsky ore deposit.
Figure 25. A triangular plot of Pd-Pt-Sn (apfu) shows the series paolovite-unnamed (Pt,Pd)2Sn from the eastern portion of the Oktyabrsky ore deposit.
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Figure 26. A plot of Sb vs. As, expressed in weight %, in compositions of sperrylite from the eastern portion of the Oktyabrsky ore deposit.
Figure 26. A plot of Sb vs. As, expressed in weight %, in compositions of sperrylite from the eastern portion of the Oktyabrsky ore deposit.
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Figure 27. (a) BSE image of a two-phase grain of galena (Gn) and sobolevskite-kotulskite (Sov) included in Cl-enriched annite, with 7.73 wt.% K2O and 4.04 wt.% Cl, labeled Ann. (b) BSE image of the unnamed Pd6Sn2As (labeled UN), which occurs at the contact of grains of chalcopyrite (Ccp) and an annitic mica (Ann) containing 10.49 wt.% K2O and 4.32 wt.% Cl.
Figure 27. (a) BSE image of a two-phase grain of galena (Gn) and sobolevskite-kotulskite (Sov) included in Cl-enriched annite, with 7.73 wt.% K2O and 4.04 wt.% Cl, labeled Ann. (b) BSE image of the unnamed Pd6Sn2As (labeled UN), which occurs at the contact of grains of chalcopyrite (Ccp) and an annitic mica (Ann) containing 10.49 wt.% K2O and 4.32 wt.% Cl.
Minerals 11 01193 g027
Figure 28. (a) (BSE) displays a platy grain of unnamed Pd6Sn2As (UN) associated with chalcopyrite (Ccp), a Fe-rich member of the chlorite group (Chl), Mn-rich ilmenite (5.45 wt.% MnO) and annitic mica (Ann) containing 8.14 wt.% K2O and 3.52 wt.% Cl. (b) (BSE) shows a composite grain of the sobolevskite-kotulskite series (Sov-Ktu) located along the boundary of pyrrhotite (Pyh) with annitic mica (Ann) containing 10.64 wt.% K2O and 4.65 wt.% Cl.
Figure 28. (a) (BSE) displays a platy grain of unnamed Pd6Sn2As (UN) associated with chalcopyrite (Ccp), a Fe-rich member of the chlorite group (Chl), Mn-rich ilmenite (5.45 wt.% MnO) and annitic mica (Ann) containing 8.14 wt.% K2O and 3.52 wt.% Cl. (b) (BSE) shows a composite grain of the sobolevskite-kotulskite series (Sov-Ktu) located along the boundary of pyrrhotite (Pyh) with annitic mica (Ann) containing 10.64 wt.% K2O and 4.65 wt.% Cl.
Minerals 11 01193 g028
Figure 29. BSE image shows the development of a Pt-Cu arseno-oxysulfide (unnamed PtCu2AsSO3), labeled UN, which replaces sperrylite (Spy) along the boundary of a grain of troilite (Tro) with silicate minerals (dark gray and black in BSE). The label Ktu is kotulskite.
Figure 29. BSE image shows the development of a Pt-Cu arseno-oxysulfide (unnamed PtCu2AsSO3), labeled UN, which replaces sperrylite (Spy) along the boundary of a grain of troilite (Tro) with silicate minerals (dark gray and black in BSE). The label Ktu is kotulskite.
Minerals 11 01193 g029
Table 1. Compositions of grains of olivine and pyroxenes in the eastern portion of the Oktyabrsky ore deposit.
Table 1. Compositions of grains of olivine and pyroxenes in the eastern portion of the Oktyabrsky ore deposit.
#Sample SiO2TiO2Al2O3FeOMnOMgOCaOTotal
(wt.%)
Mg#
1EF0040-1706.4Ol39.000021.910.4838.800.08100.2775.5
2EF0040-1706.4 38.680022.330.3539.100.20100.6675.4
3EF0043-1748.4 39.620023.430.3938.140.15101.7374.1
4EF0065-1714.8 39.210021.150.4939.620100.4776.5
5EF0066-1684.4 39.920020.880.4539.900101.1576.9
6EF0066-1684.4 40.200018.730.3642.320101.6179.8
7EF0069-1743.6 39.090021.68038.89099.6676.2
8EF8057-1572.3 39.220019.960.3540.490100.0178.0
9EF0040-1706.4Opx54.600018.51026.861.51101.4875.6
10EF0040-1706.4 55.4500.3615.800.3727.080.7699.8273.9
11EF0042-1722.3 52.840017.320.5625.771.4397.9274.9
12EF0042-1722.3 56.050.680.9614.04027.032.18100.9474.3
13EF0043-1764.3 52.520.680.7717.690.4824.131.8298.0970.4
14EF0062-1597.4 54.640.37015.48027.730.5798.7976.1
15EF0063-1744.3 53.360021.090.8722.771.2599.3465.3
16EF0065-1714.8 56.970013.69028.341.75100.7576.7
17EF0065-1714.8 54.750016.22026.731.4499.1474.9
18EF0065-1714.8 57.010014.87028.801.22101.9077.1
19EF67-1707.8 54.8301.1016.79026.120.6499.4871.9
20EF67-1707.8 56.290016.310.3926.811.36101.1672.9
21EF0069-1743.6 57.330.45013.830.5229.431.11102.6777.7
22EF0035-1553.75Cpx51.190023.321.322.9823.93102.7417.4
23EF0040-1706.4 55.49007.19016.9021.91101.4978.7
24EF0043-1764.3 51.8400.7713.88012.6019.9799.0661.7
25EF0061-1603.3 48.410026.450.714.8918.5499.0025.5
26EF0065-1713.3 55.5400.815.87016.3723.28101.8779.8
27EF0066-1684.4 52.380012.420.8510.0524.34100.0356.9
28EF67-1707.8 48.990024.250.872.3523.1499.6014.5
29EF0069-1757.8 50.470022.540.853.5322.85100.2420.2
30EF8057-1572.3 56.5200.945.76017.8121.74102.7779.9
31EF00566-1568.7 52.820013.300.6512.5720.67100.0161.1
32EF00566-1568.7 48.2400.7723.862.401.4822.6099.359.2
Note. These results of SEM-EDS analyses are listed in weight %. Ol is olivine; Opx is orthopyroxene; and Cpx is clinopyroxene. Zero stands for “not detected” or “not analyzed”. Mg# = 100 Mg/(Mg + Fe2+ + Mn).
Table 2. Compositions of grains of plagioclase in the eastern portion of the Oktyabrsky ore deposit.
Table 2. Compositions of grains of plagioclase in the eastern portion of the Oktyabrsky ore deposit.
#SampleSiO2Al2O3FeOCaONa2OK2OTotal
(wt.%)
An
(mol.%)
AbOr
1EF0035-1546.252.9528.891.5112.223.910.2999.7762.236.01.8
2EF0035-1553.7569.2520.090.571.129.810.61101.455.790.63.7
3EF0035-1553.7568.6718.7100.7110.14098.233.796.30.0
4EF0040-1706.462.7022.560.494.397.590.9598.6822.871.35.9
5EF0040-1706.466.0821.580.392.948.591.49101.0714.576.78.8
6EF0040-1706.453.2329.590.8112.614.230.31100.7861.137.11.8
7EF0043-1748.464.2723.850.595.128.330.30102.4624.973.31.7
8EF0043-1748.460.9325.320.677.187.000.22101.3235.763.01.3
9EF0043-1764.354.6028.810.6212.794.330.24101.3961.237.51.4
10EF0061-1603.366.9822.280.323.118.831.23102.7515.177.77.1
11EF0061-1603.370.2620.5200.9111.050102.744.495.60.0
12EF0063-1744.357.0427.130.859.475.880.25100.6246.452.11.5
13EF0065-1713.364.5222.640.534.448.130.24100.5022.875.71.5
14EF0065-1714.852.3130.910.6013.733.560.25101.3667.131.51.5
15EF0065-1714.858.2126.680.589.466.280.39101.6044.453.42.2
16EF0066-1684.448.9532.140.4216.192.450100.1578.521.50.0
17EF0066-1726.0558.2325.960.758.736.050.60100.3242.853.73.5
18EF67-1707.867.1521.450.942.839.260.69102.3213.982.14.0
19EF67-1712.053.0828.531.2611.534.420.3399.1557.940.22.0
20EF67-1724.6553.0129.460.7212.554.060.27100.0762.136.31.6
21EF67-1724.6559.5825.260.647.896.340.71100.4239.056.84.2
22EF0069-1743.661.8323.810.515.747.700.42100.0128.569.12.5
23EF0069-1743.649.4832.93015.712.310100.4379.021.00.0
24EF0069-1743.651.2632.460.5415.812.710102.7876.323.70.0
25EF0062-1615.465.8120.350.781.379.75098.067.292.80.0
26EF0066-171767.7519.540.540.7810.43099.044.096.00.0
27EF0066-171765.7920.202.471.759.610.57100.398.887.73.4
Note: These results of SEM-EDS analyses are listed in weight %. Zero stands for “not detected” or “not analyzed”. Proportions of end members (An: anorthite; Ab: albite; and Or: orthoclase) are expressed in mol.%.
Table 3. List of ore minerals in the investigated zones of mineralization in the eastern portion of the Oktyabrsky ore deposit.
Table 3. List of ore minerals in the investigated zones of mineralization in the eastern portion of the Oktyabrsky ore deposit.
#SpeciationMineralCompositional VarietyMain or CommonSubordinate Minor or Rare
1Base metal sulfidesPyrrhotite; Fe1 − xSNi-Cu-bearing Troilite; FeS×
2 Chalcopyrite; CuFeS2 ×
3 Pentlandite (Fe,Ni)9S8Co-bearing×
4 Cubanite (and/or isocubanite); CuFe2S3 ×
5 Bornite; Cu5FeS4 ×
6 Pyrite; FeS2Co-bearing ×
7Pb sulfideGalena; PbSSe-bearing ×
8Ag-Fe-Ni sulfideArgentopentlandite; Ag(Fe,Ni)8S8 ×
9Zn sulfideSphalerite (and/or wurtzite); ZnS Fe-Cd-bearing ×
10Ag sulfideAcanthite; Ag2S ×
11Ag tellurideHessite; Ag2Te ×
12Pb tellurideAltaite; PbTeSe-bearing ×
13Pb selenideClausthalite; PbSeS-bearing ×
14Ni arsenideNickeline NiAs ×
15Au-Ag alloysNative silverAu-bearing ×
16 Native goldAg-bearing ×
17Fe-Cr-Ti oxidesChromite; FeCr2O4Mg-(Ti)-bearing ×
18 Magnetite; Fe3O4Cr-(Ti)-bearing ×
19 Ilmenite; FeTiO3Mg-Mn-bearing ×
20Zr silicateZircon; ZrSiO4Hf-bearing ×
21Th silicateThorite; ThSiO4Solid solution with coffinite; U(SiO4)1 − x(OH)4x ×
22Zr oxideBaddeleyite; ZrO2Hf-bearing ×
23Zr-Ti oxideZirconolite; (Ca,Y)ZrTi2O7Th-(Fe)-bearing ×
24Th-U oxydesThorianite; ThO2 ×
25 Uraninite; UO2U(SiO4)1 − x(OH)4x ×
26Ce-REE phosphateMonazite-(Ce); (Ce,La,Nd,Th)PO4 ×
27A zirconolite-type oxide (Ca-dominant)Unnamed
(Ca,Y,REE)2Zr2 Ti(Ti,Nb)2Fe2+O14
×
28A zirconolite-type oxide (Y-dominant)Unnamed (Y,Ca,REE)2Zr2 Ti(Ti,Nb)2Fe2+O14 ×
29La-dominant carbonate-fluorideBastnäsite(?) (La,Ce,Y)CO3F ×
30Pd-(Ag)-Pt tellurides, bismuthotellurides and bismuthidesKotulskite; PdTe Bi-Sb-bearing×
31 Sobolevskite; PdBi Te-Sb-bearing×
32 Merenskyite; PdTe2Pt-(Bi)-bearing ×
33 Moncheite; PtTe2Pd-(Bi)-bearing ×
34 Michenerite; PdBiTe ×
35 Froodite; PdBi2 ×
36 Sopcheite; Ag4Pd3Te4 ×
37Pd-Pt stannidesPaolovite; Pd2Sn Pt-bearing×
38 Atokite; Pd3Sn ×
39 Rustenburgite; Pt3Sn Pd-bearing ×
40 Niggliite; PtSn
41Pd antimonidesMertieite-II; Pd8Sb3 ×
42 Naldrettite; Pd2Sb ×
43Pd plumbidesZvyagintsevite; Pd3Pb ×
44 Plumbopalladinite; Pd3Pb2 ×
45Pt arsenideSperrylite; PtAs2Sb-bearing×
46Pd-Ni arsenideMajakite; PdNiAs ×
47Pd germanide-arsenideUnnamed Pd11Ge3As2 ×
48Pd stannoarsenideUnnamed Pd6Sn2As ×
49Pt-Pd stannideUnnamed (Pt, Pd)2SnPd-bearing ×
50Pt-Cu arseno-oxysulfideUnnamed PtCu2AsSO3 ×
Note: The estimation of relative abundances of species of platinum group minerals (PGM), listed under numbers 30 to 50, is the reflectance of their encountered frequency observed among the entire population of PGM grains and not among all of the ore species listed.
Table 4. Compositions of grains of chromian spinels and ilmenite in the eastern portion of the Oktyabrsky ore deposit.
Table 4. Compositions of grains of chromian spinels and ilmenite in the eastern portion of the Oktyabrsky ore deposit.
#Sample TiO2Al2O3Cr2O3V2O3FeO
Total
FeO
Calc.
Fe2O3 Calc.MnOMgOTotal
(wt.%)
Mg#Cr#Fe3+#
1EF0035-1534.1Chr3.242.1513.43071.1928.9146.9803.3298.0417.080.759.4
2EF0040-1706.4 3.372.6816.280.9771.1932.3843.1301.76100.578.880.354.5
3EF0062-1597.4 2.941.701.77087.1332.3360.9001.34100.986.941.162.9
4EF0065-1713.3 4.504.8426.441.0055.2032.1225.6502.1996.7410.878.641.8
5EF0065-1714.8 1.8716.0239.070.5333.2222.4511.9709.15101.0642.162.132.4
6EF0065-1714.8 2.0215.4639.960.4633.5522.6312.1409.24101.9142.163.432.6
7EF0065-1714.8 3.9012.7736.470.7137.5024.8714.030.438.19101.3836.665.733.7
8EF0066-1684.4 2.0516.6838.98031.7921.8011.1009.57100.1843.961.131.4
9EF0066-1684.4 2.3215.7238.070.3832.7422.2411.6709.2299.6242.561.932.1
10EF0066-1684.4 1.0210.6234.070.4747.3327.2922.270.544.39100.6721.968.342.3
11EF0069-1743.6 1.3719.4237.120.3531.2722.0810.2209.1999.7442.656.229.4
12EF0069-1743.6 1.4020.0337.870.2831.3022.1110.2109.62101.5243.755.929.4
13EF0069-1743.6 2.4915.1938.340.5332.9122.2111.8909.37100.0242.962.932.5
14EF0062-1615.4 3.7410.5824.440.2653.9830.7125.8603.8199.4018.160.843.1
15EF-0040-1706.4Ilm54.0100042.34000.894.26101.5014.9--
16EF0040-1706.4 47.6400049.250002.1199.007.1--
17EF0040-1706.4 48.0700047.000003.6698.7312.2--
18EF0043-1764.3 51.23001.2443.52000.652.599.149.2--
19EF0066-1726.05 52.4400046.70001.100100.240.0--
20EF67-1724.65 54.6600040.82005.050100.530.0--
21EF67-1724.65 54.2000042.21004.520100.930.0--
22EF8057-1572.3 54.8301.15040.58000.715.42102.6919.0--
23EF0066-1717 53.0800046.73000.620100.430.0--
Note: The indices Mg# = 100 Mg/(Mg + Fe2 + +Mn); Cr# = 100 Cr/(Cr + Al); and Fe3+# = 100 Fe3+/(Fe3 + +Fe2+) all calculated on the basis of values expressed in atoms per formula unit (apfu).
Table 5. Compositions of grains of calcic, sodic-calcic and calcian Fe-Mg amphiboles in the eastern portion of the Oktyabrsky ore deposit.
Table 5. Compositions of grains of calcic, sodic-calcic and calcian Fe-Mg amphiboles in the eastern portion of the Oktyabrsky ore deposit.
#GroupNameSampleSiO2TiO2Al2O3Cr2O3FeOMnOMgOCaONa2OK2OClO ≡ ClTotal
1Calcic Ferro-actinoliteEF0035-1553.7551.3900.83027.570.406.2211.980000.0098.39
2Calcic Ferro-actinoliteEF0035-1553.7551.9003.12024.8907.7312.0900.300.350.08100.38
3Calcic Magnesio-hornblendeEF0040-1706.447.040.778.77010.00017.0011.822.200.420.270.0698.29
4Calcic Magnesio-hornblendeEF0040-1706.447.300.457.4309.71016.6811.801.970.360.220.0595.92
5Calcic chloro potassicHastingsiteEF0043-1764.338.720.739.03028.690.432.6910.720.902.404.060.9298.37
6Calcic Ferro-hornblendeEF0043-1764.344.9307.10027.851.422.6410.3400.750.440.1095.47
7Calcic chlorianFerro-hornblendeEF0043-1764.344.350.576.97025.8306.2210.0301.082.530.5797.58
8Calcic ActinoliteEF0061-1603.354.170 016.48013.7113.170000.0097.53
9Calcic Ferro-hornblendeEF0061-1603.347.1504.72031.730.851.5111.9401.020.420.1099.34
10CalcicMagnesio-hastingsiteEF0062-1597.4144.803.208.7108.65016.7211.462.760.6400.0096.94
11CalcicEdeniteEF0066-1684.447.732.279.331.366.97017.3111.363.68000.00100.01
12Sodic-calcicBarroisiteEF0066-1684.445.951.809.501.846.79016.858.704.00000.0095.43
13Calcic chlorian potassianFerro-hornblendeEF0066-1726.0544.3707.22026.720.264.9411.490.901.292.080.4799.27
14Calcic chlorianFerro-hornblendeEF0066-1726.0545.650.306.08025.8106.0911.430.741.071.770.4098.94
15Calcic chlorianFerro-hornblendeEF0066-1726.0546.9405.86025.740.345.9911.740.741.201.930.44100.48
16Calcic Magnesio-hornblendeEF0069-1743.647.902.398.8607.94017.6811.572.6200.230.0599.19
17Calcic Ferro-actinoliteEF0069-1757.850.0602.63029.6404.0512.3300.4500.0099.16
18Calcic Ferro-actinoliteEF0069-1757.852.5401.13029.760.414.7612.270000.00100.87
19Na-Ca-Mg-Fe Ferro-actinoliteEF0069-1757.847.0703.44029.7107.208.480000.0095.90
20Calcic Ferro-actinoliteEF0057-1590.547.5200033.410.870.9111.430000.0094.14
21Calcic ActinoliteEF0062-1615.453.8500.72017.350.6711.7213.850000.0098.16
22Calcic ActinoliteEF0062-1615.454.6200.81018.860.4411.7212.650000.0099.10
23Calcic ActinoliteEF0062-1615.451.9202.85017.790.4913.7511.570000.0098.37
24Calcic Ferro-actinoliteEF0066-171748.2402.95030.071.451.0914.5700.580.300.0799.25
25Calcic Ferro-actinoliteEF0066-171750.2301.62032.320.612.1211.6400.3600.0098.90
26Calcic Magnesio-hornblendeEF0066-171747.601.185.31017.730.5212.5010.481.620.840.220.0598.00
27Calcic chlorianFerro-hornblendeEF0066-171743.490.627.27025.700.285.6411.431.121.001.390.3197.94
28Calcic Ferro-actinoliteEF0066-171746.8904.29031.620.301.4111.4900.720.230.0596.95
29Mg-Fe calcianFerro-gedriteEF0066-171729.2500.38048.990.61014.310000.0093.54
30Mg-Fe calcianFerro-gedriteEF0066-171729.971.350049.630.70014.010000.0095.66
31Mg-Fe calcianFerro-gedriteEF0066-171728.8600.85047.880.96014.690000.0093.24
32Mg-Fe calcianFerro-gedriteEF0066-171729.2900049.710.74014.190000.0093.93
33Calcic Ferro-actinoliteEF0056-1568.751.0500.83024.340.537.4113.220000.0097.38
34Calcic Ferro-hornblendeEF0056-1568.749.9305.27022.590.409.6011.6400.631.100.25101.16
35Calcic Ferro-actinoliteEF0056-1568.752.8602.36029.640.714.7311.880000.00102.18
Table 6. Compositions of grains of micas in the eastern portion of the Oktyabrsky ore deposit.
Table 6. Compositions of grains of micas in the eastern portion of the Oktyabrsky ore deposit.
#SampleSiO2TiO2Al2O3Cr2O3FeOMnOMgOCaONiONa2OK2OClO≡ClTotal
1EF0035-1534.139.662.3013.6407.01023.25000.789.480.360.0896.48
2EF0035-1546.237.221.8312.11022.42011.5600011.032.090.4798.26
3EF0040-1706.438.494.1513.4007.76019.9800011.140.220.0595.14
4EF0043-1748.438.966.5212.220.509.24018.66000.989.770.140.0396.99
5EF044-1801.0533.070.7311.45031.4904.7900010.674.861.1097.06
6EF0061-1603.337.160.5510.64030.4905.4700010.895.481.24100.68
7EF0061-1603.336.78010.64031.570.275.740.60009.074.310.9798.98
8EF0062-1597.440.693.4011.5805.94022.06000.5910.760.270.0695.29
9EF0062-1597.440.413.2512.4308.75022.0600010.940.170.0498.01
10EF0063-1744.340.113.9414.89011.87018.3200010.300.370.0899.8
11EF0065-1714.835.563.0911.920.519.76017.15001.159.480.230.0588.85
12EF0065-1714.838.254.8212.70.5011.86018.760009.560.190.0496.64
13EF0066-1726.0534.530.5812.11031.0205.6900010.963.890.8898.78
14EF0066-1726.0535.75012.28032.1606.140007.734.040.9198.1
15EF67-1707.837.874.6512.34012.07017.1100.46011.840.250.0696.59
16EF67-1724.6530.401.6711.30032.460.565.770006.531.730.3990.42
17EF67-1724.6533.312.0911.79036.2900.3600010.494.320.9898.65
18EF67-1724.6537.5908.71038.430.501.480007.427.541.70101.67
19EF67-1724.6534.64011.20036.250.352.2100010.234.861.1099.74
20EF67-1724.6532.48013.74037.000.39000.41010.94.571.0399.49
21EF67-1724.6531.281.4212.64038.650.3700008.143.520.7996.02
22EF67-1724.6530.510.5311.71040.140.501.5600.3905.702.550.5893.59
23EF67-1724.6535.510.2512.58028.350.257.4600.51011.182.980.6799.07
24EF67-1724.6535.06013.25039.440.401.840.67006.434.180.94101.27
25EF0069-1743.638.667.0613.150.568.95018.41001.0011.000.150.0398.94
26EF8057-1572.338.667.2613.471.079.37018.13001.1310.380.200.0599.67
27EF0066-171738.81011.79030.9505.170009.722.780.6399.22
28EF0066-171734.320.3512.57034.360.435.120006.701.890.4395.74
29EF0066-171738.440.3712.57028.0207.4600010.021.670.3898.55
30EF0066-171733.42011.17032.6803.660009.603.270.7493.8
31EF0056-1568.733.42016.48033.810.53000010.832.770.6397.84
32EF0056-1568.738.570.9811.13029.3207.3000010.613.740.84101.65
33EF0056-1568.739.60012.32025.00011.010009.872.780.63100.58
34EF0056-1568.736.73010.15029.3307.4800010.644.651.0598.98
35EF0056-1568.743.1909.54022.86012.740008.342.280.5198.95
Table 7. Compositions of accessory grains of apatite in the eastern portion of the Oktyabrsky ore deposit.
Table 7. Compositions of accessory grains of apatite in the eastern portion of the Oktyabrsky ore deposit.
#SampleP2O5SiO2Ce2O3La2O3FeOCaONa2OFClO≡FO≡ClTotal
(wt.%)
F
(apfu)
Cl
(apfu)
OH
(calc.)
1EF0035-1534.142.94000054.89000.690.000.1698.620.000.191.81
2EF0035-1534.141.960.360.200054.5100.981.260.410.2898.570.510.351.13
3EF0035-1534.141.66000.26053.48006.970.001.58100.530.001.950.05
4EF0035-1534.142.46000054.7901.623.000.680.68100.510.830.830.34
5EF0035-1534.142.37000054.8101.313.760.550.85100.850.671.040.29
6EF0035-1534.140.95000053.23006.870.001.5599.500.001.950.05
7EF0035-1534.141.680.34000.7354.53001.990.000.4598.820.000.561.44
8EF0035-1534.140.7600.5000.7752.89006.830.001.54100.210.001.930.07
9EF0035-1534.142.140.79000.4455.0601.371.130.580.26100.100.710.310.98
10EF0035-1534.141.3800.830053.38006.490.001.47100.610.001.820.18
11EF0035-1534.140.830.6000053.13005.840.001.3299.080.001.660.34
12EF0035-1534.141.730.81000.8954.9001.690.870.710.2099.980.870.240.89
13EF0035-1534.142.28000 54.48006.550.001.48101.830.001.810.19
14EF0035-1553.7542.000.5100054.4602.921.451.230.3399.781.500.400.10
15EF0035-1553.7541.910.43000.5755.4900.293.530.120.80101.300.150.980.87
16EF0035-1553.7542.550.3900055.0000.985.340.411.21102.640.501.450.05
17EF0035-1553.7542.28000055.24006.740.001.52102.740.001.850.15
18EF0035-1553.7543.56000056.7903.150.541.330.12102.591.570.140.28
19EF0040-1706.441.040000.4253.55006.110.001.3899.740.001.730.27
20EF0040-1706.442.180.41000.3554.7102.710.441.140.1099.561.390.120.48
21EF0040-1706.442.99000054.9302.530.801.070.18100.001.290.220.49
22EF0040-1706.440.990.3200053.13006.440.001.4699.420.001.820.18
23EF0040-1706.440.56000052.82006.560.001.4898.460.001.880.12
24EF0043-1748.441.960.360.1900.7853.070.340.763.360.320.7699.740.400.940.66
25EF0043-1748.441.860.390.4700.7553.380.3804.090.000.92100.400.001.150.85
26EF0043-1748.441.520.620.5300.4552.620.340.253.870.110.8799.220.131.090.78
27EF0043-1748.440.740.620.3500.9852.500.1305.930.001.3499.910.001.680.32
28EF0061-1603.343.010000.4955.0902.430.451.020.10100.351.240.120.63
29EF0061-1603.342.830000.654.4102.680.541.130.1299.811.370.150.48
30EF0061-1603.342.480000.554.0903.230.581.360.1399.391.660.160.18
31EF0061-1603.342.140000.5154.8103.140.641.320.1499.771.610.180.21
32EF0062-1591.341.660000.5853.94004.170.000.9499.410.001.180.82
33EF0065-1714.841.910.3600054.3900.743.450.310.7899.760.390.960.65
34EF0065-1714.841.630.410.610053.3801.861.220.780.2898.050.980.340.68
35EF0065-1714.841.470.60000.6853.7401.902.400.800.5499.450.990.670.34
36EF0065-1714.841.540.39000.4953.2000.753.920.320.8999.090.391.100.50
37EF0066-1726.0542.53000054.8502.851.711.200.39100.351.460.470.08
38EF67-1707.841.380.601.070052.320.440.802.990.340.6899.090.420.840.73
39EF67-1707.840.050.681.0200.8451.320.630.652.970.270.6797.600.350.860.79
40EF67-1724.6542.07000.50.9853.2402.551.751.070.4099.121.320.490.19
41EF0069-1743.641.410.730.840.380.3652.540.321.453.090.610.7099.430.760.860.38
42EF0069-1743.641.360.730.8000.5752.500.340.973.120.410.7199.280.510.880.61
43EF0069-1743.641.800.581.0001.0053.0000.443.710.190.84100.510.231.040.73
44EF0069-1743.641.930000.9153.210.390.384.800.161.08100.380.201.340.46
45EF0069-1757.842.670000.6454.5803.510.311.480.07100.161.790.080.13
46EF0069-1757.842.480000.5854.7903.400.371.430.08100.101.740.100.16
47EF8057-1572.343.17000054.3002.051.740.860.39100.001.050.480.47
48EF8057-1572.343.150.34000.4554.7201.322.480.560.56101.340.670.680.65
49EF8057-1572.342.410.3200053.930.270.983.940.410.89100.550.511.090.41
50EF8057-1572.341.450.58000.453.140.360.664.470.281.0199.770.341.250.40
51EF0057-1590.541.820.17000.4853.2403.430.211.440.0597.861.790.060.16
52EF0062-1615.442.8500.640053.730.532.970.701.250.16100.011.520.190.29
53EF0066-171742.670000.5054.6703.470.761.460.17100.441.770.210.03
Note: The formula proportions of F and Cl are based on 25 O atoms; values of OH (calc.) are estimated as 2 − (F + Cl) apfu assuming the full site occupancy.
Table 8. Compositions of grains of monazite-(Ce), thorite-coffinite, thorianite and uraninite in the eastern portion of the Oktyabrsky ore deposit.
Table 8. Compositions of grains of monazite-(Ce), thorite-coffinite, thorianite and uraninite in the eastern portion of the Oktyabrsky ore deposit.
#Sample P2O5SiO2ThO2UO2Ce2O3La2O3Pr2O3Nd2O3Sm2O3Gd2O3Dy2O3Al2O3PbOFeOCaOTotal
(wt.%)
1EF0040-1706.4Mnz-Ce29.54013.22029.4320.9907.490000000100.67
2EF0040-1706.4 31.070.470032.9615.114.1513.831.531.260.550000.71101.64
3EF0062-1597.4 32.130.770034.4718.252.889.39000000.940.8599.68
4EF67-1707.8 26.26019.57027.9513.562.679.300000000.6099.91
5EF0065-1714.8Thr5.2514.8068.3705.552.3301.89000001.961.44101.59
6EF0065-1714.8 5.4514.3867.4706.213.0101.47000002.071.23101.29
7EF67-1707.8 2.2924.5654.2601.660000003.6503.45089.87
8EF67-1724.65 0.7617.5953.7223.64000000000.411.93098.05
9EF67-1724.65 017.3751.9825.30000000001.012.68098.34
10EF67-1707.8Tho0091.293.900000000000095.19
11EF67-1724.65Urn00093.74000000003.100096.84
# P
(apfu)
SiThUCeLaPrNdSmGdDyAlPbFeCaΣ
1 Mnz-Ce1.000.000.120.000.430.310.000.110.000.000.000.000.000.000.000.96
2 1.010.000.000.000.460.210.060.190.020.020.010.000.000.000.031.00
3 1.030.000.000.000.480.260.040.130.000.000.000.000.000.030.030.97
4 0.940.000.190.000.430.210.040.140.000.000.000.000.000.000.031.04
5 Thr0.220.740.7700.100.040.000.030.000.000.000.000.000.080.08-
6 0.230.720.7700.110.060.000.030.000.000.000.000.000.090.07-
7 0.091.100.5600.030.000.000.000.000.000.000.190.000.130.00-
8 0.040.960.670.290.000.000.000.000.000.000.000.000.010.090.00-
9 00.960.660.310.000.000.000.000.000.000.000.000.020.120.00-
10 Tho0.000.000.960.040.000.000.000.000.000.000.000.000.000.000.00-
11 Urn0.000.0000.980.000.000.000.000.000.000.000.000.040.000.00-
Note: The atomic proportions of monazite-(Ce), labeled Mnz-Ce, and thorite (Thr) are based on four oxygen atoms pfu, and those of thorianite (Tho) and uraninite (Urn) are based on O = 2 apfu.
Table 9. Compositions of grains of a zirconolite-type mineral (Y-rich, unnamed) in the eastern portion of the Oktyabrsky ore deposit.
Table 9. Compositions of grains of a zirconolite-type mineral (Y-rich, unnamed) in the eastern portion of the Oktyabrsky ore deposit.
#SampleNb2O5TiO2ZrO2ThO2UO2Y2O3Ce2O3Nd2O3Sm2O3Gd2O3Dy2O3Er2O3Yb2O3FeOCaOTotal
(wt.%)
1EF00401706.4030.6833.502.222.169.651.171.851.010.671.611.2509.584.84100.19
2EF0040-1706.4029.6733.271.314.576.200.400.6200.3500.670.738.126.3792.28
3EF0061-1603.33.9928.7433.350.89010.501.933.571.061.180008.744.0798.02
4EF0069-1743.61.9927.7735.588.552.093.771.150.79000005.725.9393.34
5EF0066-1717028.7134.811.1508.902.793.521.110.681.6201.179.513.7197.68
6EF0066-1717029.5734.541.3108.832.643.580.800.561.3901.229.493.7497.67
7EF0066-17173.4927.2432.161.701.3611.861.712.441.161.372.1001.439.392.78100.19
8EF0066-17171.7028.5732.760.90012.471.522.961.111.291.8400.849.103.0698.12
9EF0066-17171.9731.4834.741.1807.203.913.160.790.2100.510.548.495.4199.59
10EF0066-17171.9330.0135.121.080.365.514.712.670.770.390.500.610.719.175.2698.80
# Nb
(apfu)
TiZrThUYCeNdSmGdDyErYbFe2+Ca
1 0.003.052.160.070.060.680.060.090.050.060.070.050.001.060.69-
2 0.003.132.280.040.140.460.020.030.000.030.000.030.030.950.96-
3 0.242.872.160.030.000.740.090.170.050.100.000.000.000.970.58-
4 0.132.962.460.280.070.280.060.040.000.000.000.000.000.680.90-
5 0.002.952.310.040.000.650.140.170.050.060.070.000.051.080.54-
6 0.003.012.280.040.000.640.130.170.040.050.060.000.051.080.54-
7 0.212.762.120.050.040.850.080.120.050.120.090.000.061.060.40-
8 0.102.902.160.030.000.900.080.140.050.110.080.000.031.030.44-
9 0.123.082.200.030.000.500.190.150.040.020.000.020.020.920.75-
10 0.122.992.270.030.010.390.230.130.040.030.020.030.031.020.75-
Note: The formula proportions were calculated on the basis of 14 oxygen atoms pfu.
Table 10. Reflectance values, measured in air, for a zirconolite-type mineral (Y-dominant, unnamed) from the Oktyabrsky ore deposit.
Table 10. Reflectance values, measured in air, for a zirconolite-type mineral (Y-dominant, unnamed) from the Oktyabrsky ore deposit.
Λ, nmR, %R, %R, %R, %
44013.814.113.513.2
46013.814.113.513.2
48013.714.113.413.1
50013.614.013.313.0
52013.613.913.213.0
54013.513.813.212.9
56013.513.713.112.9
58013.413.713.112.8
60013.413.713.112.8
62013.413.613.112.8
64013.313.513.012.7
66013.213.513.012.7
68013.213.413.012.7
70013.213.413.112.7
72013.213.413.112.8
Table 11. Compositions of grains of argentopentlandite, hessite, acanthite and sopcheite in the eastern portion of the Oktyabrsky ore deposit.
Table 11. Compositions of grains of argentopentlandite, hessite, acanthite and sopcheite in the eastern portion of the Oktyabrsky ore deposit.
#Sample PdFeNiAgCuSTeTotal (wt.%)Pd (apfu)FeNiCuAgΣMeSTe
1EF0057-1590.5Sop25.320033.870040.8099.993.000.000.000.003.96-0.004.04
2EF0061-1603.3 26.320033.930041.90102.153.060.000.000.003.89-0.004.06
3EF0035-1546.2Apn034.9623.6210.19031.750100.520.005.043.240.000.769.037.970.00
4EF0042-1722.3 039.2417.2413.30031.470101.250.005.682.380.001.009.067.940.00
5EF0061-1603.3 036.1219.4912.751.3531.870101.580.005.212.670.170.959.008.000.00
6EF0063-1744.3 038.6016.3412.69031.51099.140.005.682.290.000.978.938.070.00
7EF0069-1757.8 036.8918.7212.84031.950100.400.005.362.590.000.978.918.090.00
8EF0069-1757.8 036.4020.4413.00032.110101.950.005.222.790.000.978.988.020.00
9EF0069-1757.8 034.9327.656.89033.020102.490.004.853.660.000.509.017.990.00
10EF0040-1706.4Hes00060.500036.0496.540.000.000.000.002.002.000.001.00
11EF0043-1764.3 00061.590038.41100.000.000.000.000.001.961.960.001.04
12EF044-1801.05 00059.780037.8097.580.000.000.000.001.951.950.001.05
13EF0063-1744.3 00062.730037.27100.000.000.000.000.002.002.000.001.00
14EF0063-1744.3 00062.700037.78100.480.000.000.000.001.991.990.001.01
15EF0066-1726.05 00063.740037.91101.650.000.000.000.002.002.000.001.00
16EF0062-1597.4Aca00085.83013.70099.530.000.000.000.001.951.951.050.00
Note: These formulae were calculated for a total of 11 apfu for sopcheite (Sop) and 3 apfu for hessite (Hes) and acanthite (Aca).
Table 12. Compositions of grains of Au-Ag alloy minerals in the eastern portion of the Oktyabrsky ore deposit.
Table 12. Compositions of grains of Au-Ag alloy minerals in the eastern portion of the Oktyabrsky ore deposit.
#SampleAuAgCuTotal (wt.%)Au (at.%)AgCu
1EF0035-1534.158.2642.560100.8242.857.20.0
2EF0035-1534.157.9941.49099.4843.456.60.0
3EF0035-1534.158.0941.53099.6243.456.60.0
4EF0035-1534.162.9538.360101.3147.352.70.0
5EF0042-1722.366.8433.510100.3552.247.80.0
6EF0042-1722.355.7844.04099.8241.059.00.0
7EF0043-1748.441.3360.720102.0527.272.80.0
8EF0043-1748.445.8154.490100.3031.568.50.0
9EF0043-1764.370.6828.69099.3757.442.60.0
10EF0043-1764.370.0231.550101.5754.945.10.0
11EF044-1801.0573.1425.94099.0860.739.30.0
12EF044-1801.0560.2238.23098.4546.353.70.0
13EF044-1801.0573.6625.50099.1661.338.70.0
14EF0061-1603.372.8326.25099.0860.339.70.0
15EF0061-1603.373.1428.850101.9958.141.90.0
16EF0061-1603.370.1029.23099.3356.843.20.0
17EF0061-1603.370.4229.49099.9156.743.30.0
18EF0062-1597.4098.98098.980.0100.00.0
19EF0062-1597.460.5841.460102.0444.555.50.0
20EF0062-1597.4099.88099.880.0100.00.0
21EF0062-1597.40100.550100.550.0100.00.0
22EF0062-1597.40101.710101.710.0100.00.0
23EF0062-1597.40100.860100.860.0100.00.0
24EF0062-1597.4098.46098.460.0100.00.0
25EF0062-1597.4099.81099.810.0100.00.0
26EF0063-1744.360.4839.920100.4045.354.70.0
27EF0065-1713.339.6159.261.74100.6125.970.63.5
28EF0065-1713.3098.74098.740.0100.00.0
29EF0065-1713.352.7444.85097.5939.260.80.0
30EF0065-1713.334.3466.980101.3221.978.10.0
31EF0065-1714.858.9040.38099.2844.455.60.0
32EF0065-1714.862.0639.510101.5746.253.80.0
33EF0066-1726.052.8895.11097.991.698.40.0
34EF67-1724.65099.22099.220.0100.00.0
35EF67-1724.6525.5573.71099.2616.084.00.0
36EF67-1724.6524.9875.960100.9415.384.70.0
37EF67-1724.650100.620.28100.900.099.50.5
38EF0069-1757.873.1824.921.2999.3959.737.13.3
39EF0069-1757.874.9825.940100.9261.338.70.0
40EF0069-1757.873.1226.37099.4960.339.70.0
Note: The atomic proportions were calculated for a total of 100 at.%.
Table 13. Compositions of grains of altaite and members of the galena-clausthalite series in the eastern portion of the Oktyabrsky ore deposit.
Table 13. Compositions of grains of altaite and members of the galena-clausthalite series in the eastern portion of the Oktyabrsky ore deposit.
#Sample PbFeTeSeSTotal
(wt.%)
Pb
(apfu)
FeTeSeSS + Se + Te
1EF0040-1706.4Alt62.45036.842.040101.33 0.980.000.940.080.001.02
2EF0040-1706.4 63.22038.0100101.23 1.010.000.990.000.000.99
3EF0040-1706.4 61.94037.980099.92 1.000.001.000.000.001.00
4EF0040-1706.4 61.71038.160099.87 1.000.001.000.000.001.00
5EF0043-1748.4 58.141.8236.830096.79 0.930.110.960.000.000.96
6EF0043-1748.4Gn85.55001.1813.27100.00 0.980.000.000.040.981.02
7EF0043-1764.3Cth-Gn74.0301.2121.251.8298.31 1.030.000.030.780.160.97
8EF0061-1603.3 87.00003.0710.97101.04 1.050.000.000.100.850.95
9EF0061-1603.3 82.520014.065.88102.46 1.050.000.000.470.480.95
10EF0063-1744.3Gn86.1400011.7997.93 1.060.000.000.000.940.94
11EF0065-1714.8 87.6200012.0399.65 1.060.000.000.000.940.94
12EF0066-1726.05 82.411.7105.099.7598.96 1.000.080.000.160.760.93
13EF67-1707.8 83.851.9902.2811.0199.13 1.000.090.000.070.850.92
14EF0069-1743.6 85.6800014.32100.00 0.960.000.000.001.041.04
15EF0069-1757.8Gn-Cth78.8900.6914.375.8499.79 1.010.000.010.490.490.99
16EF0069-1757.8Gn88.930 012.78101.71 1.040.000.000.000.960.96
17EF0069-1757.8Gn-Cth80.8400.8113.875.90101.42 1.030.000.020.460.490.97
18EF0069-1757.8 79.7300.9514.625.20100.50 1.040.000.020.500.440.96
19EF0069-1757.8Gn87.7300012.43100.16 1.040.000.000.000.960.96
20EF0069-1757.8Cth-Gn81.5000.3412.036.45100.32 1.050.000.010.410.540.95
Note: The atomic proportions are based on a total of 2 atoms per formula unit, apfu. The label Alt is altaite, Gn is galena, and Cth is clausthalite.
Table 14. Compositions of grains of pyrrhotite and troilite in the eastern portion of the Oktyabrsky ore deposit.
Table 14. Compositions of grains of pyrrhotite and troilite in the eastern portion of the Oktyabrsky ore deposit.
#SampleFeNiSTotal
(wt.%)
Fe
(at.%)
NiFe + NiS
1EF0035-1534.160.01038.7798.78 47.00.0047.053.0
2EF0035-1534.160.33040.33100.66 46.20.0046.253.8
3EF0035-1546.260.63039.1499.77 47.10.0047.152.9
4EF0035-1546.260.750.7839.98101.51 46.30.5746.953.1
5EF0035-1553.7560.710.4239.35100.48 46.80.3147.152.9
6EF0035-1553.7560.54039.3999.93 46.90.0046.953.1
7EF0035-1553.7560.93039.33100.26 47.10.0047.152.9
8EF0040-1706.463.44036.3899.82 50.00.0050.050.0
9EF0040-1706.463.41035.9399.34 50.30.0050.349.7
10EF0040-1706.463.38036.68100.06 49.80.0049.850.2
11EF0042-1722.361.85039.14100.99 47.60.0047.652.4
12EF0042-1722.361.54038.3899.92 47.90.0047.952.1
13EF0043-1748.462.79038.25101.04 48.50.0048.551.5
14EF0043-1764.360.23039.3099.53 46.80.0046.853.2
15EF0043-1764.360.72039.46100.18 46.90.0046.953.1
16EF0043-1764.360.41038.0898.49 47.70.0047.752.3
17EF044-1801.0560.690.8338.64100.16 47.10.6147.752.3
18EF0061-1603.360.900.6239.35100.87 46.80.4547.352.7
19EF0061-1603.360.28039.94100.22 46.40.0046.453.6
20EF0062-1591.363.45036.84100.29 49.70.0049.750.3
21EF0062-1591.360.32038.3298.64 47.50.0047.552.5
22EF0062-1591.364.37036.11100.48 50.60.0050.649.4
23EF0062-1597.461.751.7835.5299.05 49.31.3550.649.4
24EF0062-1597.464.37036.52100.89 50.30.0050.349.7
25EF0062-1597.463.54036.76100.30 49.80.0049.850.2
26EF0063-1744.362.05038.59100.64 48.00.0048.052.0
27EF0063-1744.363.78036.91100.69 49.80.0049.850.2
28EF0065-1713.364.20036.84101.04 50.00.0050.050.0
29EF0065-1714.863.41036.63100.04 49.80.0049.850.2
30EF0065-1714.864.34036.67101.01 50.20.0050.249.8
31EF0066-1684.464.07036.90100.97 49.90.0049.950.1
32EF67-1712.060.500.7539.67100.92 46.40.5547.053.0
33EF0069-1743.663.14036.7199.85 49.70.0049.750.3
34EF0069-1743.663.93036.80100.73 49.90.0049.950.1
35EF0069-1743.663.35036.65100.00 49.80.0049.850.2
36EF0069-1757.861.020.7139.51101.24 46.80.5247.352.7
37EF0069-1757.860.680.7940.30101.77 46.10.5746.753.3
38EF8057-1572.363.66036.68100.34 49.90.0049.950.1
Note: The atomic proportions were calculated for a total of 100 at.%.
Table 15. Compositions of grains of pentlandite in the eastern portion of the Oktyabrsky ore deposit.
Table 15. Compositions of grains of pentlandite in the eastern portion of the Oktyabrsky ore deposit.
#SampleFeNiCoCuSTotal
(wt.%)
Fe (apfu)Ni CoCu ΣMS
1EF0035-1534.132.0034.400033.83100.234.404.500.000.008.908.10
2EF0035-1546.230.5536.181.76033.38101.874.164.690.230.009.087.92
3EF0035-1546.229.8535.492.17033.03100.544.124.660.280.009.067.94
4EF0035-1553.7531.8735.910033.24101.024.374.690.000.009.067.94
5EF0035-1553.7530.3836.360033.39100.134.194.780.000.008.978.03
6EF0035-1553.7531.0137.320033.31101.644.234.850.000.009.087.92
7EF0040-1706.437.0930.070033.53100.695.083.920.000.009.008.00
8EF0040-1706.435.8928.941.15033.4499.424.973.810.150.008.938.07
9EF0042-1722.333.8133.280033.47100.564.644.350.000.008.998.01
10EF0042-1722.333.0033.581.04033.29100.914.534.380.140.009.047.96
11EF0042-1722.333.3631.991.46033.24100.054.614.200.190.009.008.00
12EF0043-1748.436.9330.230034.11101.275.023.910.000.008.938.07
13EF0043-1748.437.7528.740033.80100.295.183.750.000.008.938.07
14EF0043-1764.332.0133.451.45033.62100.534.404.370.190.008.968.04
15EF0043-1764.332.2734.910033.87101.054.414.540.000.008.948.06
16EF044-1801.0530.8533.492.18032.1498.664.344.490.290.009.127.88
17EF044-1801.0531.1834.571.82033.20100.774.294.520.240.009.057.95
18EF0061-1603.330.4836.230033.66100.374.194.740.000.008.938.07
19EF0061-1603.330.6234.81.55033.42100.394.224.560.200.008.988.02
20EF0062-1591.337.2927.4402.0933.86100.685.103.570.000.258.938.07
21EF0062-1597.436.2528.6400.8733.0098.765.063.800.000.118.978.03
22EF0062-1597.436.8829.270032.9099.055.143.880.000.009.027.98
23EF0062-1597.435.9727.6902.3933.3499.394.993.660.000.298.948.06
24EF0063-1744.333.3532.141.41033.42100.324.594.210.180.008.998.01
25EF0063-1744.334.7931.721.17033.05100.734.784.150.150.009.087.92
26EF0065-1713.336.9226.7303.4633.45100.565.083.500.000.428.998.01
27EF0065-1714.836.5429.6401.1433.42100.745.013.870.000.149.027.98
28EF0065-1714.836.0831.020033.31100.414.964.060.000.009.027.98
29EF0065-1714.836.7629.930033.41100.105.063.920.000.008.988.02
30EF0066-1684.438.7528.410.95033.68101.795.263.670.120.009.047.96
31EF0066-1684.438.4728.650.80033.97101.895.203.690.100.008.998.01
32EF0066-1684.438.3027.260033.4298.985.323.600.000.008.928.08
33EF0066-1726.0532.0133.860033.5399.404.444.470.000.008.908.10
34EF67-1724.6526.2440.081.38033.22100.923.615.250.180.009.047.96
35EF67-1724.6526.8139.330032.2498.383.795.280.000.009.077.93
36EF67-1724.6527.0440.071.34033.54101.993.685.190.170.009.057.95
37EF0069-1743.639.7125.880032.3197.905.603.470.000.009.077.93
38EF0069-1743.638.9327.950034.08100.965.303.620.000.008.928.08
39EF0069-1757.831.5335.631.51033.73102.404.274.590.190.009.057.95
40EF8057-1572.341.6124.081.26034.21101.165.643.110.160.008.928.08
Note: The atomic proportions are based on a total of 17 atoms per formula unit, apfu.
Table 16. Compositions of grains of members of the kotulskite-sobolevskite series in the eastern portion of the Oktyabrsky ore deposit.
Table 16. Compositions of grains of members of the kotulskite-sobolevskite series in the eastern portion of the Oktyabrsky ore deposit.
#SamplePdTeBiSbTotal
(wt.%)
Pd
(apfu)
TeBiSbTe + Bi + Sb
1EF0035-1534.138.5429.1229.841.5099.00 0.970.610.380.031.03
2EF0035-1546.237.378.8252.371.44100.00 1.030.200.730.030.97
3EF0040-1706.444.0929.2225.45098.76 1.080.600.320.000.92
4EF0040-1706.440.7931.3828.400100.57 1.000.640.360.001.00
5EF0040-1706.441.2032.2027.490100.89 1.000.650.340.001.00
6EF0042-1722.339.1514.9644.572.51101.19 1.020.330.590.060.98
7EF0043-1748.440.2124.2935.500100.00 1.020.520.460.000.98
8EF0043-1748.437.5510.9551.790100.29 1.030.250.720.000.97
9EF0043-1748.438.5316.8444.58099.95 1.020.370.600.000.98
10EF044-1801.0537.3912.8650.400100.65 1.010.290.700.000.99
11EF044-1801.0538.029.2754.960102.25 1.030.210.760.000.97
12EF044-1801.0539.2212.3747.343.73102.66 1.020.270.630.080.98
13EF0061-1603.341.3838.2420.390100.01 0.990.760.250.001.01
14EF0061-1603.340.3634.2425.400100.00 0.990.700.320.001.01
15EF0061-1603.344.9455.8500100.79 0.981.020.000.001.02
16EF0061-1603.340.9223.5936.820101.33 1.030.500.470.000.97
17EF0062-1591.342.8721.4035.730100.00 1.090.450.460.000.91
18EF0062-1591.338.1225.6133.85097.58 0.990.560.450.001.01
19EF0063-1744.339.2111.5149.280100.00 1.060.260.680.000.94
20EF0063-1744.337.487.5753.202.02100.27 1.030.170.750.050.97
21EF0066-1684.439.9629.8129.32099.09 1.000.620.370.001.00
22EF0066-1684.441.8634.3122.88099.05 1.020.700.280.000.98
23EF0066-1726.0537.418.2254.840100.47 1.040.190.770.000.96
24EF0066-1726.0537.7510.0254.200101.97 1.020.230.750.000.98
25EF67-1712.037.9418.0645.560101.56 1.000.400.610.001.00
26EF67-1712.037.757.6953.472.70101.61 1.020.170.740.060.98
27EF67-1724.6540.0326.3231.22097.57 1.030.560.410.000.97
28EF0069-1743.639.8620.8540.830101.54 1.020.450.530.000.98
29EF0069-1743.639.1822.1238.41099.71 1.020.480.510.000.98
30EF8057-1572.339.5123.6437.350100.50 1.010.500.490.000.99
31EF8057-1572.339.5617.8242.630100.01 1.040.390.570.000.96
Note: The atomic proportions are based on a total of 2 atoms per formula unit, apfu.
Table 17. Compositions of grains of members of the moncheite-merenskyite series, michenerite and froodite in the eastern portion of the Oktyabrsky ore deposit.
Table 17. Compositions of grains of members of the moncheite-merenskyite series, michenerite and froodite in the eastern portion of the Oktyabrsky ore deposit.
#Sample PtPdTeBiSbTotal
(wt.%)
Pt
(apfu)
PdPt + PdTeBiSbTe + Bi + Sb
1EF0042-1722.3Mch023.7534.0038.743.1699.65 0.000.960.961.140.790.112.04
2EF0042-1722.3 19.1912.0820.2146.483.15101.11 0.480.551.030.771.080.131.97
3EF0043-1764.3Mon39.33032.2028.470100.00 1.020.001.021.280.690.001.98
4EF044-1801.05Mch024.1228.9246.95099.99 0.001.001.001.000.990.002.00
5EF044-1801.05 024.9930.1945.580100.76 0.001.021.021.030.950.001.98
6EF0061-1603.3 024.8130.2546.050101.11 0.001.011.011.030.960.001.99
7EF0061-1603.3Mrk028.8361.3110.850100.99 0.001.011.011.790.190.001.99
8EF0057-1590.5 030.0171.6500101.66 0.001.001.002.000.000.002.00
9EF0061-1603.3Mch025.4729.8747.150102.49 0.001.031.031.000.970.001.97
10EF0061-1603.3 024.4429.3545.76099.55 0.001.021.021.020.970.001.98
11EF0062-1597.4Mon30.667.7642.6720.100101.19 0.710.331.041.520.440.001.96
12EF0065-1713.3 38.06035.6025.46099.12 0.980.000.981.400.610.002.02
13EF0065-1714.8 39.03038.9123.360101.30 0.970.000.971.480.540.002.03
14EF0065-1714.8 38.37035.4126.270100.05 0.980.000.981.390.630.002.02
15EF0065-1714.8 37.98032.9531.130102.06 0.970.000.971.290.740.002.03
16EF0069-1743.6 37.132.4342.9919.110101.66 0.890.111.001.580.430.002.00
17EF0069-1743.6 37.871.7243.3317.830100.75 0.920.080.991.600.400.002.01
18EF0069-1743.6 37.31031.2030.27098.78 0.990.000.991.260.750.002.01
19EF0069-1743.6 38.12032.3231.200101.64 0.980.000.981.270.750.002.02
20EF044-1801.05Fro021.82079.100100.92 0.001.051.050.001.950.001.95
21EF044-1801.05 021.53080.920102.45 0.001.031.030.001.970.001.97
22EF0063-1744.3 7.8717.16072.86097.89 0.220.881.100.001.900.001.90
Note: The atomic proportions for moncheite (Mon), merenskyite (Mrk), michenerite (Mch) and froodite (Fro) are based on a total of 3 atoms per formula unit (apfu).
Table 18. Compositions of grains of members of the paolovite (Pd2Sn)-unnamed (Pt,Pd)2Sn series and of unnamed Pd6Sn2As in the eastern portion of the Oktyabrsky ore deposit.
Table 18. Compositions of grains of members of the paolovite (Pd2Sn)-unnamed (Pt,Pd)2Sn series and of unnamed Pd6Sn2As in the eastern portion of the Oktyabrsky ore deposit.
#Sample PtPdAuSnSbAsTotal
(wt.%)
Pt
(apfu)
PdPd + PtAuSnSbAsSn + Sb + As
1EF0035-1546.2Plv-Unamed (Pt, Pd)2Sn5.4359.36032.113.190100.090.091.901.990.000.920.090.001.01
2EF0035-1546.2 7.2157.80032.611.72099.340.131.882.000.000.950.050.001.00
3EF0040-1706.4 064.27036.1800100.450.001.991.990.001.010.000.001.01
4EF0043-1764.3 064.05036.5900100.640.001.981.980.001.020.000.001.02
5EF0043-1764.3 1.9862.59035.280099.850.031.972.000.001.000.000.001.00
6EF044-1801.05 4.4860.53034.980099.990.081.932.000.001.000.000.001.00
7EF044-1801.05 4.5959.87035.5400100.000.081.911.990.001.010.000.001.01
8EF0061-1603.3 063.75036.230099.980.001.991.990.001.010.000.001.01
9EF0061-1603.3 064.90036.2200101.120.002.002.000.001.000.000.001.00
10EF0063-1744.3 11.9451.86033.270.490.4197.970.221.741.960.001.000.010.031.04
11EF0063-1744.3 5.5257.99033.470096.980.101.912.010.000.990.000.000.99
12EF0065-1713.3 19.9248.38031.8900100.190.371.652.020.000.980.000.000.98
13EF0065-1713.3 065.31036.5200101.830.002.002.000.001.000.000.001.00
14EF0065-1714.8 15.2853.35031.3700100.000.281.782.060.000.940.000.000.94
15EF0065-1714.8 46.1826.11027.700099.990.991.032.020.000.980.000.000.98
16EF0065-1714.8 25.2141.59033.2000100.000.481.471.950.001.050.000.001.05
17EF0066-1726.05 064.94036.2900101.230.002.002.000.001.000.000.001.00
18EF67-1707.8 39.2432.06026.440097.740.831.252.080.000.920.00 0.92
19EF67-1707.8 064.49035.5100100.000.002.012.010.000.990.00 0.99
20EF0035-1546.2UN Pd6Sn2As065.39027.9906.2199.590.005.93 0.002.270.000.800.00
21EF0043-1748.4 68.11021.64010.25100.000.006.01 0.001.710.001.280.00
22EF0061-1603.3 68.96022.7108.46100.130.006.12 0.001.810.001.070.00
23EF67-1724.65 67.740.7124.1607.51100.120.006.07 0.031.940.000.960.00
24EF67-1724.65 66.581.0024.5607.1299.260.006.04 0.052.000.000.920.00
25WDS 0.2265.761.2024.3007.5899.060.015.97 0.061.980.000.980.00
Note: The atomic proportions for members of the series of paolovite (Plv) to unnamed (Pt, Pd)2Sn are based on a total of 3 atoms per formula unit (apfu). Compositions of unnamed Pd6Sn2As were recalculated on the basis of a total of 9 apfu. Analysis #25 represents results of the test (i.e., repeat analysis) performed using a mode of wavelength-dispersive spectrometry (WDS). The presence of essential amounts of Au was thus confirmed.
Table 19. Compositions of grains of members of the atokite-rustenburgite series, niggliite, naldrettite, zvyagintsevite, plumbopalladinite and palladium antimonides related to mertieite-II in the eastern portion of the Oktyabrsky ore deposit.
Table 19. Compositions of grains of members of the atokite-rustenburgite series, niggliite, naldrettite, zvyagintsevite, plumbopalladinite and palladium antimonides related to mertieite-II in the eastern portion of the Oktyabrsky ore deposit.
#Sample PtPdAuSnPbSbBiTeAsTotal
(wt.%)
Pt
(apfu)
PdAuPd + Pt
(+Au)
SnPbSbBiTeAsSn + Sb
(+Bi + As)
1EF0065-1714.8Ato-
Rsb
48.4428.072.4121.0800000100.001.421.500.072.991.010.000.000.000.000.001.01
2EF0065-1714.8 48.4230.26021.3200000100.001.391.600.002.991.010.000.000.000.000.001.01
3EF0065-1714.8 41.5735.75022.6800000100.001.151.820.002.971.030.000.000.000.000.001.03
4EF0069-1743.6Nig63.660033.2503.09000100.001.030.000.001.030.890.000.080.000.000.000.97
5EF0063-1744.3 63.550036.4500000100.001.030.000.001.030.970.000.000.000.000.000.97
6EF0065-1714.8 58.920028.7802.589.7300100.010.990.000.000.990.790.000.070.150.000.001.01
7EF0042-1722.3Nld064.8000022.998.933.872.35102.940.002.020.002.020.000.000.630.140.100.100.97
8EF0069-1743.6Zv060.430039.570000100.000.002.990.000.000.001.010.000.000.000.000.00
9EF8057-1572.3 061.940038.880000100.820.003.020.000.000.000.980.000.000.000.000.00
10EF8057-1572.3 060.650036.81000097.460.003.050.000.000.000.950.000.000.000.000.00
11EF8057-1572.3Ppdn042.210058.050000100.260.002.930.000.000.002.070.000.000.000.000.00
12EF8057-1572.3 040.320058.30000098.620.002.870.000.000.002.130.000.000.000.000.00
13EF044-1801.05Met-II071.0704.69022.36002.35101.780.007.770.000.000.460.002.140.000.000.362.96
14EF0061-1603.3 070.9300025.11003.5899.620.007.960.000.000.000.002.460.000.000.573.04
15EF0061-1603.3 071.9000024.73002.98101.840.007.750.000.000.000.002.330.000.000.462.79
16EF0062-1591.3 069.8400029.6800099.520.008.020.000.000.000.002.980.000.000.002.98
17EF0062-1591.3 069.7300030.08000.76100.570.007.900.000.000.000.002.980.000.000.123.10
18EF0062-1591.3 068.8500029.39000.6798.910.007.930.000.000.000.002.960.000.000.113.07
19EF0062-1591.3 068.1100029.4300098.430.007.840.000.000.000.002.960.000.000.002.96
20EF0066-1726.05 068.7200030.28000.8699.860.007.840.000.00 0.003.020.000.000.143.16
21EF67-1724.65 070.2809.12016.48003.3099.180.007.930.000.000.920.001.620.000.000.533.07
22EF67-1724.65 067.15014.4011.41003.1296.080.007.820.000.001.500.001.160.000.000.523.18
Note: The atomic proportions of members of the series of atokite-rustenburgite (Ato-Rsb) and zvyagintsevite (Zv) are based on a total of 4 apfu, those of niggliite (Nig) are based on 2 apfu, naldrettite (Nld) on 3 apfu, and plumbopalladinite (Ppdn) on 5 apfu, and mertieite-II (Met-II) on a total of 11 apfu. Totals include the following values of minor elements: 1.31 wt.% Fe in analysis # 13, 2.23 wt.% Fe in analysis #15, and 0.89 wt.% Fe in analysis #19.
Table 20. Compositions of grains of sperrylite (Sb-bearing), majakite and unnamed Pd11Ge3As2 in the eastern portion of the Oktyabrsky ore deposit.
Table 20. Compositions of grains of sperrylite (Sb-bearing), majakite and unnamed Pd11Ge3As2 in the eastern portion of the Oktyabrsky ore deposit.
#Sample PtPdNiAsSbGeTotal
(wt.%)
Pt
(apfu)
PdNiAsSbAs + SbGe
1EF0035-1546.2Spy56.360041.471.41099.241.010.000.001.940.041.980.00
2EF0035-1546.2 57.860042.120.990100.971.030.000.001.950.031.980.00
3EF044-1801.05 <