Vanadian and chromian garnet- and epidote-supergroup minerals in metamorphosed Paleozoic black shales from Cierna Lehota, Strazovske vrchy Mountains, Slovakia: crystal chemistry and evolution

BAČÍK, Peter, Pavel UHER, Petra KOZAKOVA, Martin STEVKO, Daniel OZDIN a Tomáš VACULOVIČ. Vanadian and chromian garnet- and epidote-supergroup minerals in metamorphosed Paleozoic black shales from Cierna Lehota, Strazovske vrchy Mountains, Slovakia: crystal chemistry and evolution. Mineralogical Magazine. London: MINERALOGICAL MAGAZINE, 2018, roč. 82, č. 4, s. 889-911. ISSN 0026-461X. Dostupné z: https://dx.doi.org/10.1180/minmag.2017.081.068.

Základní údaje

• Originální název: Vanadian and chromian garnet- and epidote-supergroup minerals in metamorphosed Paleozoic black shales from Cierna Lehota, Strazovske vrchy Mountains, Slovakia: crystal chemistry and evolution
• Autoři: BAČÍK, Peter (703 Slovensko, garant), Pavel UHER (703 Slovensko), Petra KOZAKOVA (703 Slovensko), Martin STEVKO (203 Česká republika), Daniel OZDIN (703 Slovensko) a Tomáš VACULOVIČ (203 Česká republika, domácí).
• Vydání: Mineralogical Magazine, London, MINERALOGICAL MAGAZINE, 2018, 0026-461X.

Další údaje

• Originální jazyk: angličtina
• Typ výsledku: Článek v odborném periodiku
• Obor: 10406 Analytical chemistry
• Stát vydavatele: Velká Británie a Severní Irsko
• Utajení: není předmětem státního či obchodního tajemství
• WWW: Full Text
• Impakt faktor: Impact factor: 2.210
• Kód RIV: RIV/00216224:14310/18:00106727
• Organizační jednotka: Přírodovědecká fakulta
• Doi: http://dx.doi.org/10.1180/minmag.2017.081.068
• UT WoS: 000452015500008
• Klíčová slova anglicky: garnet supergroup; goldmanite; epidote supergroup; mukhinite; allanite-(La); black shales; Cierna Lehota; Western Carpathians; Slovakia
• Štítky: rivok
• Příznaky: Mezinárodní význam, Recenzováno

Anotace

Silicate minerals enriched in V, Cr and Mn including garnets and epidote-supergroup members, in association with amphiboles, albite, hyalophane, titanite, chamosite, sulfides and other minerals occur in Devonian black shales near Cierna Lehota in the Straovske vrchy Mountains, Slovakia. The garnets have high concentrations of V, Cr and Mn (up to 17 wt.% V2O3, <= 11 wt.% Cr2O3 and <= 21 wt.% MnO) and several compositional types. Vanadian-chromian grossular (Grs 1) usually preserves primary metamorphic oscillatory zoning. whereas solid solutions between goldmanite (Gld 2A,B), V- and Cr-rich grossular and spessartine (Grs 2A,B, Sps 2) form irregular domains or crystals with variable zoning. Dominant substitutions in the garnets include CaMn1 and (V,Cr)Al-1, resulting in coupled Ca(V,Cr)Mn1Al1. Epidote-supergroup minerals occur as abundant anhedral crystals with variable compositional zoning. Nearly all crystals have a complete zoning sequence beginning with REE-rich allanite-(La), followed by mukhinite and by V- and Cr-rich clinozoisite to mukhinite and V- and Cr-poor clinozoisite. In common with garnets, the epidote-supergroup minerals are enriched in V, Cr and Mn (<7 wt.% V2O3, <5 wt.% Cr2O3 and <3 wt.% MnO). Lanthanum is the dominant REE (up to 11.5 wt.% La2O3) in allanite-(La). The composition of epidote-supergroup minerals is controlled by REEFe2+(CaAl)(1), REEMg(CaAl)(1), REEMn2+ (CaAl)(1) and REEFe2+ (CaFe3+) substitutions introducing REE, together with VAl1 and CrAl1 substitutions. The negative Ce and slightly positive Eu anomalies displayed in chondrite-normalized patterns and enrichment in V, Cr and Mn are ascribed to the geochemical properties of the protolith. The minerals investigated exhibit multi-stage evolution: (1) presumed low-grade greenschist-facies metamorphism; and (2) development of V- and Cr-rich zones in both garnet- and epidote-supergroup minerals which result from late-Variscan contact metamorphism due to granitic intrusion of the Suchy Massif. Decreased temperature following the metamorphic peak probably resulted in the formation of REE-, V- and Cr-poor clinozoisite and secondary garnet.