Bulletin Mineralogie Petrologie

Dolníček Zdeněk, Velebil Dalibor, Gebouský Milan

Ročník 32, číslo 2 (2024), strana 160-176

DOI: https://doi.org/10.46861/bmp.32.160

Mýtinka, Krušné Hory Crystalline Complex, Bohemian Massif, skarn, epidote, amphibole

Two types of skarns and associated mineral veins were sampled at the Mýtinka - Vysoká skarn site near the Měděnec village (Krušné hory/Erzgebirge Mts., Czech Republic) and studied by means of BSE imaging and electron microprobe analyses. The Type I skarns composed mainly of garnet, epidote, and amphibole clearly prevail at the study site. In contrast, Type II skarn formed by garnet, biotite, and ca. 30 vol. % of magnetite is scarce. The mineral veins cutting skarn are composed of epidote, amphibole, albite, biotite, phengitic muscovite, chlorite, quartz, calcite, and K-felspar. The minerals from skarns and veins show the same chemical composition suggesting their coeval origin. In terms of mineral classification, garnets are represented exclusively by grossular (even in case of magnetite-rich skarn), amphiboles by magnesiohornblende, edenite, magnesiohastingsite and actinolite (often potassic and fluorian varieties are present), biotite by phlogopite, chlorites by ripidolite, clinochlore and pennine, epidote-group minerals by epidote, clinozoisite and allanite-(Ce). A predominance of Mg-endmembers of minerals suggests for a Mg-rich protolith of skarns, which was likely dolomite marble or crystalline dolomite. Both these carbonate rocks are tightly spatially associated with skarns at the study site. The newly found skarn-hosted gahnite probably represents a relic mineral originating from metacarbonate protolith; a Zn-rich spinel was formerly described from calcite dolomite at the study site. Accessory titanite hosted by skarn contains in places a high proportion of CaAlSiO₄F component (up to 33 mol. %), which is the highest content reported from skarns of the Krušné hory Mts., and small contents of Sn (up to 0.007 apfu). The input of K, Sn, F, and Fe could indicate a source of skarnization fluids in the granitoid rocks.

Abstrakt (PDF) - 187.49KB
Fulltext (PDF) - 2.77MB

Anders E, Grevesse N (1989) Abundances of the elements: Meteoritic and solar. Geochim Cosmochim Acta 53: 197-214. https://doi.org/10.1016/0016-7037(89)90286-x

Bau M, Möller P (1992) Rare earth element fractionation in metamorphogenic hydrothermal calcite, magnesite and siderite. Miner Petrol 45: 231-246. https://doi.org/10.1007/bf01163114  

Bauer ME, Seifert T, Burisch M, Krause J, Richter N, Gutzmer J (2019) Indium-bearing sulfides from the Hämmerlein skarn deposit, Erzgebirge, Germany: evidence for late-stage diffusion of indium into sphalerite. Miner Deposita 54: 175-192. https://doi.org/10.1007/s00126-017-0773-1

Bayliss P (1975) Nomenclature of the trioctahedral chlorites. Can Mineral 13:178-180.

Bureš K (2021) Zabezpečení 2 DD „Štola JD č.2“ (č.o.2788) a „Dolní Halže 1“ (č.o.2789) v k. ú. Horní Halže. MS archiv GIS-GEOINDUSTRY, s.r.o., 1-274

Burisch M, Gerdes A, Meinert LD, Albert R, Seifert T, Gutzmer J (2019) The essence of time - fertile skarn formation in the Variscan Orogenic Belt. Earth Planet Sci Lett 519: 165-170 . https://doi.org/10.1016/j.epsl.2019.05.015

Cathelineau M (1988) Cation site occupancy in chlorites and illites as a function of temperature. Clay Miner 23: 471-485. https://doi.org/10.1180/claymin.1988.023.4.13

Dolníček Z, Kovář M, Ulmanová J (2020) Axinit a doprovodné minerály z lokality Jezuitský rybník východně od Golčova Jeníkova (moldanubikum, Česká republika). Bull Mineral Petrolog 28(2): 437-453. https://doi.org/10.46861/bmp.28.437  

Korges M, Weis P, Lüders V, Laurent O (2020) Sequential evolu­tion of Sn-Zn-In mineralization at the skarn-hosted Hämmer­lein deposit, Erzgebirge, Germany, from fluid inclusions in ore and gangue minerals. Miner Deposita 55: 937-952. https://doi.org/10.1007/s00126-019-00905-4  

Kotková J (1991) Skarns of the central part of the Krušné hory Mts. - mineralogy, geochemistry and their implications for the skarn origin. Věst Ústř Úst Geol 66: 215-232

Leake BE, Woolley AR, Arps ChES, Gilbert MCh, Grice JD, Hawthorne FC, Kato A, Kisch HJ, Krivovichev VG, Linthout K, Laird J, Mandarino JA, Maresch WV, Nickel EH, Rock NMS, Schumacher JC, Smith DC, Stephenson NCN, Ungaretti L, Eric JW, Whittaker EJW, Youzhi G (1997) Nomenclature of amphiboles: report of the Subcommittee on Amphiboles of the International Mineralogical Association, Commission on New Minerals and Mineral Names. Can Mineral 35: 219-246. https://doi.org/10.1127/ejm/9/3/0623

Lee SG, Lee DH, Kim Y, Chae BG, Kim WY, Woo NCh (2003) Rare earth elements as indicators of groundwater environment changes in a fractured rock system: evidence from fracture - filling calcite. Appl Geoch 18: 135-143. https://doi.org/10.1016/s0883-2927(02)00071-9  

Lefebvre MG, Romer RL, Glodny J, Kroner U, Roscher M (2019a) The Hämmerlein skarn-hosted polymetallic deposit and the Eiben­stock granite associated greisen, western Erzgebirge, Germany: two phases of mineralization two Sn sources. Miner Deposita 54: 193-216. https://doi.org/10.1007/s00126-018-0830-4  

Lefebvre MG, Romer RL, Glodny J, Roscher M (2019b) Skarn formation and tin enrichment during regional metamorphism: The Hämmerlein polymetallic skarn deposit. Lithos 348-349: 105171. https://doi.org/10.1016/j.lithos.2019.105171

McLennan SM (1989) Rare earth elements in sedimentary rocks: influence of provenance and sedimentary processes. Rev Mineral 21: 169-200. https://doi.org/10.1515/9781501509032-010

Meinert LD (1992) Skarns and skarn deposits. Geosci Can 19: 145-162

Meyer N, Markl G, Gerdes A, Gutzmer J, Burisch M (2024a) Timing and origin of skarn-, greisen-, and vein-hosted tin mineraliza­tion at Geyer, Erzgebirge (Germany). Miner Deposita 59: 1-22. https://doi.org/10.1007/s00126-023-01194-8

Meyer N, Burisch M, Gutzmer J, Krause J, Scheibert H, Markl G (2024b) Mineral chemistry of the Geyer SW tin skarn deposit: understanding variable fluid/rock ratios and metal fluxes. Miner Deposita, accepted. https://doi.org/10.1007/s00126-024-01297-w.

Morimoto N, Fabries J, Ferguson AK, Ginzburg IV, Ross M, Seifert FA, Zussman J (1989) Nomenclature of pyroxenes. Can Mineral 27: 143-156. https://doi.org/10.1180/minmag.1988.052.367.15

Petrík I, Broska I, Lipka J, Siman P (1995) Granitoid allanite-(Ce) substitution relations, redox conditions and REE distributions (on an example of I-type granitoids, Western Carpathians, Slovakia). Geol Carpath 46: 79-94

Pouchou JL, Pichoir F (1985) “PAP” (φρZ) procedure for improved quantitative microanalysis. In: Armstrong JT (ed.) Microbeam Analysis: 104-106. San Francisco Press, San Francisco

Reinhardt N, Frenzel M, Meinert LD, Gutzmer J, Kürschner T, Burisch M (2021) Mineralogy and fluid characteristics of the Waschleithe Zn skarn - a distal part of the Schwarzenberg mineral system, Erzgebirge, Germany. Ore Geol Rev 131: 104007. https://doi.org/10.1016/j.oregeorev.2021.104007

Reinhardt N, Gerdes A, Beranoaguirre A, Frenzel M, Meinert LD, Gutzmer J, Burisch M (2022) Timing of magmatic-hydrother­mal activity in the Variscan Orogenic Belt: LA-ICP-MS U-Pb geochronology of skarn-related garnet from the Schwarzenberg District, Erzgebirge. Miner Deposita 57: 1071-1087. https://doi.org/10.1007/s00126-021-01084-x

Rieder M, Cavazzini G, D´yakonov YS, Kamenetskii VAF, Gottardi G, Guggenheim S, Koval´ PV, Mueller G, Neiva AMR, Radoslovich EW, Robert JL, Sassi FP, Takeda H, Weiss Z, Wones DR (1998) Nomenclature of micas. Can Mineral 36: 905-912. https://doi.org/10.1180/minmag.1999.063.2.13

Šrein V (1992) Skarny Krušných hor. MS, kandidátská disertační práce. Geologický ústav ČSAV, Praha.

Šrein V, Šreinová B (2000) Mineralogy of the skarns of the Bohemian part of the Western and Central Krušné Hory Mountains. Acta Montana A17(19): 67-108

Wiewióra A, Weiss Z (1990) Crystallochemical classifications of phyllosilicates based on the unified system of projection of chemical composition: II. The chlorite group. Clay Miner 25: 83-92. https://doi.org/10.1180/claymin.1990.025.1.09