Molten sulphur-dominated fluids in the origin of a native sulphur mineralization in lacustrine evaporites from Cervera del Rio Alhama (Cameros Basin, NE Spain)

Abstract

During the regional and petrologic study of the Cameros Basin, vein deposits containing native sulphur, gypsum, quartz and rare sphalerite were found enclosed in lacustrine evaporites. The fluid inclusion study of the coeval quartz crystals revealed that the aqueous fluids were extremely scarce during vein formation. Surprisingly, die textural study, microthermometry and qualitative Raman analyses of these inclusions proved that the main fluid-trapped during vein formation was a mixture of molten sulphur and volatiles (N-2, CO2 and H2S). As far as we know, this is the first time that an almost pure sulphur-bearing fluid is described to occur in sulphur deposits. (C) 2000 Elsevier Science B.V. All rights reserved.