Descripción de requisitos estándar IEEE 830

1_{Jiří Sejkora,} 1,2

Ivo Macek,

1_{Pavel Škácha,} 1,3_{Petr Pauliš,} 4

Vlastimil Toegel

1 _{Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, Praha 9, CZ-193 00,}

Czech Republic; #[email protected]

2 _{Dept. of Geological Sciences, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic} 3 _{Smíškova 564, Kutná Hora, CZ-284 01, Czech Republic}

4 _{Medlov 251, CZ-783 91, Uničov, Czech Republic}

Key words: Hg selenides, Tl selenides, Cu selenides, EPMA data, Zálesí deposit, Czech Republic

INTRODUCTION

The abandoned small uranium deposit Zálesí is situated near the southern margin of the Zálesí settlement, about 6.5 km SW of Javorník in the Rychlebské hory Mountains, Czech Republic. The deposit was discovered during the regional uranium exploration and mined from Galleries I. - III. on five levels at vertical intervals 50 m. Over 400 t of uranium was worked-out there during 11 years (1958- 1968). The studied samples were collected on the mine dumps in the area of outcrops of the Pavel structure during several past years.

GEOLOGY

Thirty hydrothermal veins and two stockworks are hosted by the folded and metamorphosed Paleozoic sequence of the Strónia Group belonging to the Orlice- Snieznik crystalline complex. The primary mineralization of the deposit originated in three mineralization stages - uraninite, arsenide and sulphide and can be classified

as close to the so-called "five-element" formation (U-Ni-Co-As-Ag). Majority of the primary Se mineralization is related to the uraninite stage, the occurrence of Bi selenides (ikunolite - laitakarite) in bismuth of the arsenide stage was found sporadically only (Fojt et al. 2005). The primary and supergene Se mineralization of this ore deposit were recently studied by Fojt, Škoda (2005), Pauliš et al. (2006), Sejkora et al. (2004, 2006, 2011, 2012), and Topa et al. (2010).

METHODS OF STUDY

Polished samples mounted in the epoxy resin were studied using the ore microscope Nikon ME600L (National Museum, Prague) and the quantitative chemical data were collected with the electron microprobe Cameca SX100 in the wavelength dispersive mode (National Museum, Prague).

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Tiemannite is abundant in the studied

samples; it forms grains up to 1 mm in size; association with hakite, eukairite, klockmannite, Ag-Cu-Tl selenides and molybdomenite was observed. Tiemannite usually contains minority contents of Cu (up to 0.10 apfu; 2.27 wt %). Empirical formula: (Hg0.99Cu0.02)Σ1.01(Se0.98S0.01)Σ0.99.

Hakite was found as rare irregular

grains up to 100 μm in tiemannite aggregates; umangite and molybdomenite were also found in the association. Empirical formula:

(Cu9.21Ag0.39)Σ9.60(Hg1.97Zn0.03)Σ2.00(Se12.93S 0.09)Σ13.02.

Ag-Cu-Tl selenide forms very rare

irregular grains up to 80 μm in size in association with eukairite, umangite and tiemannite. Its chemical composition is not directly corresponding to any known mineral phase in Cu-Tl-Se system (bukovite, crookesite, sabatierite). Its metals/Se ratio (1.77) is close to sabatierite (Cu6TlSe4) but it differs in significant Ag

contents (10.80-14.91 wt. %). The determined Ag contents correlate negatively with both Tl and Cu. Empirical formula: Cu4.99Ag1.09Tl0.95Se3.98.

Eucairite occurs as grains up to 100

μm in association with Ag-Cu-Tl selenide, umangite, tiemannite and molybdomenite. It contains minor contents of Tl up to 0.24 wt%. Empirical formula: Cu1.01Ag1.03Se0.96.

Klockmannite forms irregular grains

up to 200 μm in tiemannite aggregates. It usually contains minority contents of Ag (up to 0.06 apfu; 4.32 wt %) and Hg (up to 0.02 apfu; 2.74 wt %). Empirical formula: (Cu0.98Ag0.02)Σ1.00(Se0.96S0.04)Σ1.00.

Umangite was found as irregular

grains up to 100 μm in size which partly replaces older eukairite and Ag-Cu-Tl selenide; tiemannite was also observed in the association. Empirical formula: Cu3.00(Se1.98S0.02)Σ2.00.

Acknowledgements: Research of the selenide mineralization is financially supported by the grant 14-27006S of the Czech Science Foundation.

REFERENCES

FOJT, B., DOLNÍČEK, Z., KOPA, D., SULOVSKÝ, P. & ŠKODA, R. (2005): Paragenesis of the hypogene associations from the uranium deposit at Zálesí near Rychlebské hory Mts., Czech Republic.

Čas. Slez. Muz. Opava (A), 54, 223-280.

(in Czech)

FOJT,B. & ŠKODA, R. (2005): Bi4Se3 and

ikunolite-laitakarite from the uranium deposit Zálesí near Javorník, the Rychlebské hory Mts. Acta Mus.

Moraviae, Sci. geol. 90, 99-107. (in Czech)

PAULIŠ, P., ŠKODA, R. & NOVÁK, F. (2006): Demesmaekerite from uranium deposit Zálesí in the Rychlebské hory Mts. (Czech Republic). Acta Mus. Moraviae,

Sci. geol. 91, 89-95. (in Czech)

SEJKORA, J., PAULIŠ, P. & MALEC, J. (2004): The supergene selenium mineralization at the uranium deposit Zálesí, the Rychlebské hory Mts. (Czech Republic). Bull. mineral.-petrolog. Odd.

Nár. Muz. (Praha), 12, 174-179. (in

Czech)

SEJKORA, J., ŠKODA, R. & PAULIŠ, P. (2006): Selenium mineralization of the uranium deposit Zálesí, the Rychlebské hory Mts., Czech Republic. Miner.

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SEJKORA, J., MAKOVICKY, E., TOPA, D., PUTZ,H.,ZAGLER,G.& PLÁŠIL,J. (2011): Litochlebite, Ag2PbBi4Se8, a new selenide

mineral species from Zálesí, Czech Republic: description and crystal structure.

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SEJKORA, J., PLÁŠIL, J., LITOCHLEB, J., ŠKÁCHA, P. & PAVLÍČEK, R. (2012): A selenide association with macroscopic umangite from the abandoned uranium deposit Zálesí, Rychlebské hory Mountains (Czech Republic). Bull. mineral.-petrolog.

Odd. Nár. Muz. (Praha), 20, 187-169. (in

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TOPA,D., MAKOVICKY, E., SEJKORA, J. & DITTRICH,H. (2010): The crystal structure of watkinsonite, Cu2PbBi4Se8, from the

Zálesí uranium deposit, Czech Republic.

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