Decorative marbles from the Krkonoše-Jizera Terrane (Bohemian Massif, Czech Republic): provenance criteria

Abstract

Marbles from western part of the Krkonoše-Jizera Terrane (northern part of the Bohemian Massif) have been studied to obtain mineropetrographic and chemical reference data for provenance studies. Samples from six different quarries were analysed by mineralogical-petrographic and geochemical methods (optical microscopy, Xray diffraction, stable isotope ratio analysis, cathodoluminescence, bulk magnetic susceptibility). Petrographic characteristics permit a distinction between fine-grained to medium-grained marbles from the Jizera Mts (amphibolite metamorphic facies) and fine-grained marbles from the Ještěd Mts (low-grade greenschist facies). The samples studied are mainly calcitic, with the exception of those from Raspenava in which dolomite is abundant in two types. The mineralogical composition of the insoluble residues is clinochlore ± serpentine ± tremolite ± diopside ± pyrite + magnetite in case of the locality Raspenava and clinochlore + muscovite ± quartz ± pyrite ± rutile ± haematite in case of the localities from the Ještěd Mts. d 13 C and d 18 O variations in primary and secondary carbonate phases allow to distinguish genetically different carbonate veins and permit quarry separation in one case (Raspenava, Jizera Mts). The d 13 C and d 18 O values of the groundmass range from -1 to +3% and from -8 to -20% (PDB), respectively. The d 13 C and d 18 O values of secondary carbonate veins decrease to -3% and reach more negative values up to -26% in case of d 18 O. The fabric of cathodomicrofacies allows the distinction between calcite and dolomite, except three localities (Pilínkov, Horní Hanychov, Jitrava-rose type) with majority of quenchers (high content of iron in carbonate). The genetically different calcite is characterised by a pale and dark orange luminescence distribution. Serpentine, tremolite, forsterite, opaque minerals and quartz have no luminescence and very dull luminescence, respectively. The majority of studied marbles exhibits low values of the bulk magnetic susceptibility, with the exception of those from Raspenava rich in magnetite.

Methodology of analytical study for provenance determination of calcitic, calcite–dolomitic and impure marbles from historical quarries in the Czech Republic

“…3E). Rašovka marble (Krkonoše-Jizera Terrane) exhibits similar fabric as regards the cathodomicrofacies and, in addition, oscillatory zoning is present [23]. The zoning in carbonates represents an important identification mark in the studied marbles.…”

“…Values for marbles from the Krkonoše-Jizera Terrane (Raspenava e Rašovka) are taken from Ref. [23]. 7.…”

Cathodoluminescence of iron oxides and oxyhydroxides

“…Traditionally, CL imaging has been used in the analysis of silicate, phosphate, and carbonate minerals, while for other minerals, among which are Fe oxides and oxyhydroxides, the method has been considered inapplicable due to much poorer self-luminescence (Frimmel, 1997;Šťastná and Přikryl, 2009;Črne et al, 2014). Moreover, even low concentrations of Fe are documented to effectively quench CL emission of otherwise highly luminescent minerals (Barker et al, 1991;Tarashchan and Waychunas, 1995).…”