Geochemistry and electron spin resonance of hydrothermal dickite (Nowa Ruda, Lower Silesia, Poland): vanadium and chromium

Rok, strany: 2012, 241 - 252

Geochemical analyses for trace V and Cr have been done on a representative sample of a typical hydrothermal dickite/kaolinite filling vein at Nowa Ruda. The mineralogy of the sample is comparatively simple, dickite being the principal component (ca. 91 % of the total sample). Geochemical fractionation and inductively coupled plasma-optical emission spectrometry (ICP-OES) indicate that most (>90 % of total metal) of the V and Cr reside in the dickite. Electron Spin Resonance (ESR) shows that most (>70 %) of the V in the dickite structure is in the form of vanadyl (VO²⁺) ions. A high concentration of Cr³⁺ is also detected in this structure by ESR. The combination of geochemical and spectroscopic tools applied to VO²⁺ and Cr³⁺ allow one to specify the Eh (>0.4 V, highly oxidizing) and pH (L4.0, highly acidic) of the solution during the formation of dickite from the Nowa Ruda Basin. Substantial proportions of the V and Cr (as well as VO²⁺ and Cr³⁺) in the dickite structure were probably contained in an original hydrothermal acid water. We suggest that hot hydrothermal waters leached the surrounding varieties of gabbroids enriched in V and Cr for the dickite-forming solution. The results of this work have shown V and Cr are potentially reliable indicators for geochemical characterization of the physicochemical conditions of their formation. The bulk-rock V/Cr ratio in hydrothermal dickites and kaolinites from Nowa Ruda, Sonoma (California, USA), Cigar Lake (Saskatchewan, Canada) and Teslic (Bosnia and Hercegovina) is also briefly explored here as a potential tracer of redox state during their formation.

ISO 690:

I. Premovic, P., Ciesielczuk, J., Bzowska, G., G. Dordevic, M. 2012. Geochemistry and electron spin resonance of hydrothermal dickite (Nowa Ruda, Lower Silesia, Poland): vanadium and chromium. In Geologica Carpathica, vol. 63, no.3, pp. 241-252. 1335-0552. DOI: https://doi.org/10.2478/v10096-012-0020-8

APA:

I. Premovic, P., Ciesielczuk, J., Bzowska, G., G. Dordevic, M. (2012). Geochemistry and electron spin resonance of hydrothermal dickite (Nowa Ruda, Lower Silesia, Poland): vanadium and chromium. Geologica Carpathica, 63(3), 241-252. 1335-0552. DOI: https://doi.org/10.2478/v10096-012-0020-8