Growth condition of quartz crystals at the Zhelannoe deposit in the Nether-Polar Urals: Evidence from fluid and solid inclusions

Abstract

The topography of various faces of quartz crystals indicates that the late growth of rock crystals occurred at a relatively slow rate, by the layer by layer mechanism activated by screw dislocations. The capture mechanism of gas-liquid inclusions by quartz at the deposit is identified, and gas-liquid and solid inclusions are examined in various quartz populations. The temperature of the mineral-forming processes is evaluated from the homogenization temperatures of the inclusions. Distinct quartz populations are determined to be formed under similar physicochemical conditions, at temperatures no higher than 260°C, which increased from earlier to later quartz populations. The quartz veins were produced by solutions of sodic-hydrocarbonate composition. The geochemical environment in which mineral-forming processes occurred at the Zhelannoe deposit was generally poor in fluid, and the inclusions are dominated by water and usually contain no more than 10 wt % carbon dioxide, strongly subordinated amounts of nitrogen and carbon monoxide, and no identifiable methane amounts.