Geochemical Fractions of Heavy Metals in Bottom Sediments of the Pobeda Hydrothermal Field, Mid-Atlantic Ridge (17°07′–17°08′ N)

We examined the distribution of Fe, Mn, Cu, Zn, and Pb in one core metalliferous, non-mineralized (background) carbonate sediments (located 69 km northwards), from Pobeda hydrothermal field. Mechanisms metal accumulation (12 samples) were evaluated based on sequential extraction geochemical fractions, including mobile (exchangeable complex, authigenic Fe-Mn hydroxides, sulfides), lithogenic (fixed crystalline lattices) forms. Maps element sediment components obtained using a scanning electron microscope equipped with an energy-dispersive spectrometry detector. In metalliferous sediments, according to X-ray diffraction data, main Fe mineral phase was goethite FeOOH (37–44% carbonate-free basis). The contents Mn reached 31.6 0.18%, respectively, whereas concentrations Zn 0.98, 0.36, 0.059%. coefficient enrichment relative background values varied 16 125 times. exception for which no increased recorded. Essential mass (up 70% total content) represented by residual fraction composed crystallized goethite, aluminosilicates, minerals derived bedrock destruction processes. Among geochemically 90–97% found form oxyhydroxides. same predominant host both (55–85%). A 40–96 % Cd, associated these fractions. sulfide amounted roughly 10% each metal. core, maximum metals their fractions recorded deeper intercepts, observation that might be attributed influence diffused fluids. Our data suggested are mostly accumulated contact zone underlying serpentinized basalts.