Ore mineralogy of Novo-Uchaly volcanogenic massive sulfide (VMS) deposit (South Urals)

The Novo-Uchaly VMS is one of the main ore objects currently being developed in the South Urals. It is a major source of copper and silver, the main source of zinc in Russia; along the way, Au is extracted, as well as a number of rare and critical/strategic metals (In, Co, Ni, Ga, Ge, Se, Te, etc.). During the field work, the authors collected a collection of samples taken from various areas of the ore deposit (recumbent, hanging side, wedging areas – the contact zone with host volcanites and dykes of gabbroids). Silver sulfosalts, cassiterite, and high-gallium mica (such as chlorite) and the fineness of native gold have been identified in ores for the first time using scanning electron microscopy (SEM) and X-ray spectral microanalysis (XMA). The article describes the mineral associations of ores and new minerals identified by the authors. The results of mass spectrometry with inductively coupled plasma in combination with laser ablation (LA-ICP-MS) for pyrite, sphalerite, chalcopyrite from various mineral associations and samples from different parts of the ore deposit are presented. It was found that pyrite is the main concentrator of gold, selenium and tellurium; their concentrations are especially high when local metamorphism occurs as a result of the temperature action of a thick gabbro dyke. Sphalerite contains high concentrations of cadmium and indium, as well as gallium and tin.