(Table 2) Concentrations of particulate chemical elements in waters of the Pechora Sea

Mineralogy of suspended matter from surface and bottom waters has been studied at two sites in the Barents Sea. Along with terrigenous minerals, particulate matter samples contain authigenic mineral phases of iron and manganese oxyhydroxides. Mn-feroxyhite, Fe-vernadite, goethite, and proto-ferrihydrite have been identified in samples from the surface waters, whereas birnessite and non-ferruginous vernadite have been found in samples from the bottom waters. Formation of suspended manganese minerals in the bottom waters is explained by an additional Mn supply from underlying reduced sediments during their early diagenesis and oxygen depletion in the near-bottom nepheloid layer. Bacteria are supposed to take part in the authigenic mineral formation.

本研究针对巴伦支海两处站位的表层与底层水体悬浮颗粒物开展了矿物学研究。除陆源矿物（terrigenous minerals）外，颗粒物样品中还赋存铁、锰羟基氧化物（iron and manganese oxyhydroxides）类自生矿物相（authigenic mineral phases）。表层水体样品中检出锰铁氧羟基物（Mn-feroxyhite）、含铁水锰矿（Fe-vernadite）、针铁矿（goethite）以及准水铁矿（proto-ferrihydrite）；底层水体样品中则发现水钠锰矿（birnessite）与无铁水锰矿（non-ferruginous vernadite）。底层水体中悬浮态锰矿物的形成机制可解释为：早期成岩作用（early diagenesis）阶段，下伏还原沉积物向水体提供额外锰供给，同时近底雾状层（near-bottom nepheloid layer）内发生氧耗竭过程。研究认为细菌参与了该类自生矿物的形成。