Chromium- and nickel-rich micas and associated minerals in listvenite from the Muránska Zdychava, Slovakia: products of hydrothermal metasomatic transformation of ultrabasic rock

Abstract

The Cr-Ni-rich micas, Ni-Co sulphide phases and associated minerals occur in a small body of listvenite, an extensively altered serpentinite, in Lower Palaeozoic paragneisses near Muránska Zdychava village in Slovenské Rudohorie Mts. (Veporic Superunit, central Slovakia). The main rock-forming minerals of the listvenite are magnesite, dolomite and a serpentine-group mineral, less frequently calcite, quartz and talc. Accessory minerals of the listvenite include Cr-Ni--rich micas, chromite, and Ni-Co-Fe-(Cu-Pb) sulphide minerals (pyrite, pyrrhotite, pentlandite, millerite, polydymite, violarite, siegenite, gersdorffite, cobaltite, chalcopyrite and galena). The micas from the Muránska Zdychava listvenite (Cr-Ni-rich illite to muscovite and Ni-dominant trioctahedral mica) contain the highest Ni concentrations ever reported in the mica-group minerals (up to 22.8 wt. % NiO or 1.46 apfu Ni). The Cr concentrations are also relatively high (up to 11.0 wt. % Cr 2 O 3 or 0.64 apfu). contents, the latter two typical of ultrabasic rocks. The more advanced alteration stage shows lower SiO 2 , but higher content of volatiles (c. 35 wt. % of LOI) bound in carbonates and hydrated silicate minerals. Based on geochemical and mineralogical characteristics, the studied listvenite body originated during three principal evolutionary stages: (1) peridotite stage, (2) serpentinization stage, and (3) hydrothermal-metasomatic stage (listvenitization). The listvenite origin was probably connected with Alpine (Late Cretaceous) late-orogenic uplift of the Veporic Superunit crystalline basement and retrograde metamorphism; we assume P-T conditions of the final listvenite stage at ~200 MPa and up to 350 °C. The NE-SW and NW-SE trending fault structures played a key role during the process of listvenitization as they channelized the CO 2 -rich fluids that transformed the serpentinized peridotite into the carbonate-quartz listvenite.

Tetrahedrite-(Ni), Cu6(Cu4Ni2)Sb4S13, the first nickel member of tetrahedrite group mineral from Luobusa chromite deposits, Tibet, China

“…These mineral assemblages and temperature range are very consistent with our case (Fig. 2) and similar to the P-T conditions (350 °C, 0.20 GPa) of Muránska Zdychava listvenite assumed by Ferenc et al (2016). For the further alteration, the SLZT structure from the southern part of Kangjinla district plays a key role during the process of listvenitization as it could be the channel of the CO2-rich fluids that transform the serpentinite into the carbonate-quartz listvenite.…”

Native antimony emplaced by methane‐rich hydrothermal fluid in an orogenic fault‐zone

“…The early mineral associations in the Lapa deposits are typical of a CO 2 ‐rich environment, and the high flux of H 2 O–CO 2 was therefore preeminent, as in most orogenic gold deposits (Goldfarb & Groves, ). CO 2 ‐rich carbonatation (listvenitization) occurs at high temperatures of around 290°–350°C (Ferenc, Uher, Spišiak, & Šimonova, ). Production of CH 4 has been described during serpentinization peaks between 200° and 315°C (McCollom & Bach, ) and therefore might become dominant only after the cessation of the CO 2 flux, at a lower temperature.…”

Mechanisms and conditions of Ti and Cr incorporation in mantle phlogopite: the results of atomistic simulation

“…The data of atomistic modeling for Cr incorporation of into phlogopite are consistent with the literature data as well. An exception is the high Cr 2 O 3 content (up to 6.54 wt %) reported for trioctahedral Ni-bearing micas from listvenite (Ferenc et al 2016). The limited miscibility detected for the substitution mechanism VI (Mg 2+ ) + IV (Si 4+ ) = VI (Cr 3+ ) + IV (Al 3+ ) provides Cr 2 O 3 accumulation up to 5.5 wt % (Table 5).…”

“…Ferenc et al (2016) point to the predominant role of the schemes VI (R 2+ ) + IV (Si 4+ ) = VI (Cr 3+ ) + IV (Al 3+ ) и 3 VI (R 2+ ) = 2 VI (Cr 3+ ) + VI (□), where R 2+ are divalent cations. At the same time, the described micas contain the high Al 2 O 3 concentrations (up to 23 wt %), which cannot be realized, if Cr is incorporated via the scheme 3 VI (R 2+ ) = 2 VI (Cr 3+ ) + VI (□); according to this scheme, at a content of ~ 6.5 wt % Cr 2 O 3 , the concentration of Al 2 O 3 will not exceed 12.1 wt %.…”