Литосфера (Apr 2020)
Prospects for identifying the Mississippi Valley type deposits in the North-East of Russia
Abstract
Research subject. The Mississippi Valley type deposits make up about a third of the global balance of lead and zinc reserves, resources and production. Additionally, silver, antimony, arsenic, barium, bismuth, cadmium, cobalt, gallium, indium, mercury, molybdenum, nickel and thallium can be present in the ores of these deposits. In the North-East of Russia, the Mississippi Valley type of deposits is poorly represented. In this work, we investigate the deposits of the Sardana ore cluster of the Republic of Sakha (Yakutia) and individual deposits of the Magadan region. Materials and methods. The article discusses the results of previous scientific research and new data on the geochemical features, isotopic composition of ores and geological and structural conditions for the formation of the Sardana cluster deposit. In addition, the potential for identifying stratiform lead-zinc deposits is associated with favourable geodynamic conditions in the region, as well as with the refinement and adaptation of the forecast-search model of MVT deposits for the North-East of Russia. Results. The mineralogical and geochemical features of the rocks and ores of the Sardana cluster deposits, the morphology of ore bodies, their zoning elements, as well as isotopic ratios indicate that the ores are likely to be of the Mississippi Valley type with the onset of ore deposition at early diagenetic and catagenetic stages. The distribution of rare elements indicates a significant role of superimposed metamorphism of the host carbonate-terrigenous strata in the deposition of the ores of producing stages. Conclusion. The potential possibility of increasing the mineral and raw material base of lead and zinc is associated with the identification of sedimentary basins with a stagnant anoxic regime of carbonate accumulation in the immediate vicinity of the development areas of rift complexes, as well as with the presence of other critically important forecast-search signs. In addition to the well-known Killakh metallogenic zone, Tuora-Sis and Orulgan metallogenic taxa located in the north of the Republic of Sakha (Yakutia) with known stratiform manifestations of lead and zinc belong to such areas.
Keywords
