Fig. 1: µXRF and µXAS results.
From: Deep anoxic aquifers could act as sinks for uranium through microbial-assisted mineral trapping
a U µXRF map of a calcite crystal from Äspö HRL. The area outlined with a dashed line was used for U LIII-edge XANES measurements (estimated ~20 ppm U13, on the right y-axis - relative signal intensity scale); b U LIII-edge µXANES spectra of Äspö-calcite, U(IV)-calcite11 and U(VI)-calcite20. The energy shift between U(IV) and U(VI) references is ~1.6 eV. Marked on the spectrum of ‘U(VI)-calcite’ with I and II are spectral features characteristic to uranyl(VI) species; c Magnitude of the Fourier-transformed EXAFS (black solid line) and best fit (colored rhombs) for the “Äspö-calcite” and single scattering paths for the fitted shells (see further details in SI and Supplementary Fig. 2c, d for k3 -weighted and the real part EXAFS data).
