Mineral Composition and Geochemical Zoning of Bottom Sediments in the Pobeda Hydrothermal Cluster (17°07.45′ N-17°08.7′ N Mid-Atlantic Ridge)

The paper presents the mineral and chemical compositions of carbonate, metalliferous, and ore-bearing sediments developed within the Pobeda ore cluster based on the materials of stations 37L244g, 37L245g, and 37L184k by the chemical, optical, electron microscopic, electron probe, and X-ray methods. The compositions are compared with those of background biogenic carbonate sediments developed beyond the hydrothermal cluster. The results revealed that the hydrothermal activity zone is marked by various types of mineral and geochemical zoning: (1) increase in the ore element concentration downward the sediment section leading to a downsection change of carbonate sediments by the ore-bearing variety (St. 37L184k); (2) layer-by-layer enrichment of sediments with ore components (St. 37L244g); and (3) confinement of concentration zones to the roof, middle part, and bottom of sedimentary deposits (St. 37L245g). The relationship of various types of mineral and geochemical zoning with the physical and chemical parameters of interstitial waters in the metalliferous and ore-bearing sediments is considered.