Rare earth element enriched birnessite in water-bearing fractures, the Ytterby mine, Sweden

Microbial Communities Inhabiting a Rare Earth Element Enriched Birnessite-Type Manganese Deposit in the Ytterby Mine, Sweden

“…Characterization of the YBS by IR-and EPR-spectroscopy, analysis of concentrations and isotopic signatures of carbon and nitrogen, sequential extraction procedures and lipid analysis indicated the presence of about 1.8% carbon, one third of which was organic (Sj€ oberg et al, 2017). In a previous study by Sj€ oberg et al (2017), a microbial origin of a major fraction of the manganese oxide precipitation was suggested by the EPRspectroscopy: none of the metals appeared to be present as metal-organic or humic bound species. The organic matter was predominantly hopanoids, and the presence of C 31 to C 35 extended side chain species was a distinct indication of bacterial presence.…”

“…The maximum age of the YBS is 60-70 years, assuming that accumulation started when the tunnel was constructed. The elemental composition of the YBS (excluding oxygen, carbon and silicon) was 82% Mn, 13.5% Ca and 2 §0.5% REE +Y, with all other metals being less than 2% in total (Sj€ oberg et al 2017). The dominant mineral phase was a birnessite-type phyllomanganate, as evidenced by XRD, with minor fractions of quartz, plagioclase and calcium carbonate (likely arising from the underlying bedrock and underlying mineralized calcium carbonate precipitate).…”

“…(E and F) Occasionally bubbles of various sizes sometimes with a metallic luster are observed on the surface of the YBS. embedded in these microstructures and suggest that the celllike shapes occur within specific laminae (Sj€ oberg 2017;Sj€ oberg et al 2017). ).…”

“…The Ytterby mine, once a quartz and feldspar mine, known for the discovery of scandium, yttrium, tantalum and five of the rare earth elements (REE), was recently found to host a REE+Y enriched Mn deposit denoted YBS, Ytterby black substance (Sj€ oberg et al 2017). Elemental analysis and phase analysis by XRD indicate that the dominant phase is a birnessite-type Mn oxide with low Fe content but with traces of organics.…”

“…Poorly crystalline birnessite-like phyllomanganates often represent the initial phase precipitated by bacteria and fungi during microbially mediated Mn oxidation (Hansel and Learman 2016). Electron paramagnetic resonance (EPR) spectroscopy indicates a microbial origin of a large fraction of the manganese oxide precipitates (Sj€ oberg et al 2017).…”