The Accumulation of the REE by Bacterial Fe Oxyhydroxide

Abstract The current study was focused on Fe oxyhydroxides from the north-western part of the East-European platform. Modern-day Fe oxyhydroxides of bacterial origin demonstrate an enhanced concentration of rare earth elements (up to 1200 ppm), compared to samples without iron bacteria. The 143 Nd/ 144 Nd ratio in bacterial Fe oxyhydroxide has the value from 0.511532 to 0.512588 and corresponds to the geochemical signature of the waters, oxyhydroxides precipitated from. Samples of iron hydroxides from Quaternary and recent continental ore deposits with different Nd and Sr isotope composition were used for the laboratory reduction of Fe 3+ up to emergence of magnetite ( T ~ 1000°C). 143 Nd/ 144 Nd and 87 Sr/ 86 Sr ratios in the newly formed mineral phases show insignificant discrepancy with parent iron ore. The persistency of Sm–Nd and Rb–Sr isotope systems in the process of bog iron ore experimental melting permits it’s applying to paleoenvironment reconstructions and archaeometry.