Scientific Article
previous document  unige:27858  next document
add to browser collection
Title

Genesis of high-sulfidation vinciennite-bearing Cu-As-Sn (+/-Au) assemblage from the Radka epithermal copper deposit, Bulgaria: evidence from mineralogy and infrared microthermometry of enargite

Authors
Ramboz, C.
Bailly, L.
Bogdanov, K.
Published in Canadian Mineralogist. 2004, vol. 42, no. 5, p. 1501-1521
Abstract The Radka deposit is one of the largest Cu–Au epithermal deposits related to Late Cretaceous volcanic arc-type magmatic activity in the Panagyurishte ore region, central part of the Srednogorie zone, Bulgaria. The mineralogical and geochemical features of a vinciennite-bearing Cu–As–Sn (± Au) assemblage at Radka show very similar characteristics to those in other vinciennite-bearing high-sulfidation epithermal deposits worldwide. The assemblage consists of enargite, Cu-excess tennantite, chalcopyrite, gold, vinciennite, colusite, and minor covellite, within a gangue of barite, illite, and quartz. A detailed electronmicroprobe study of vinciennite and associated minerals reveals the heterovalency of Cu and Fe. New data on the composition of vinciennite sheds light on aspects of its crystal chemistry, such as incorporation of Cu2+ and Fe3+ and Sn4+ Ge4+ substitution, and leads us to propose a new empirical formula: Cu+8Cu2+2Fe3+3(Fe,Cu)2+(Sn,Ge)4+(As,Sb)5+S162–. Infrared microthermometry of enargite-hosted fluid inclusions provides constraints on the conditions of deposition of this unusual assemblage in the context of the evolution of the magma-related ore-forming system at Radka. The assemblage was formed by oxidized and slightly acid fluids, with a dominantly magmatic signature, high fugacity of sulfur and intermediate salinity (about 10 wt.% eq. NaCl) at a temperature of about 275°C. In view of the geology of the Radka deposit, its mineralogical and geochemical peculiarities, ore textures, type of hydrothermal alteration and the character of the fluids, we interpret the deposit as a deep part of a high-sulfidation epithermal mineralization, possibly genetically related to a porphyry copper system.
Keywords VincienniteEnargiteMineralogyInfrared microthermometryFluid inclusionsEpithermalSrednogorieRadkaBulgaria
Identifiers
Full text
Article (Published version) (1.2 MB) - document accessible for UNIGE members only Limited access to UNIGE
Other version: http://canmin.geoscienceworld.org/content/42/5/1501
Research group Mineral Resources and Geofluids
Citation
(ISO format)
KOUZMANOV, Kalin et al. Genesis of high-sulfidation vinciennite-bearing Cu-As-Sn (+/-Au) assemblage from the Radka epithermal copper deposit, Bulgaria: evidence from mineralogy and infrared microthermometry of enargite. In: Canadian Mineralogist, 2004, vol. 42, n° 5, p. 1501-1521. https://archive-ouverte.unige.ch/unige:27858

208 hits

0 download

Update

Deposited on : 2013-05-15

Export document
Format :
Citation style :