Microheterogeneity of element distribution and sulfur speciation in an organic surface horizon of a forested Histosol as revealed by synchrotron-based X-ray spectromicroscopy

► X-ray microscopy (μ-XRF) reveals microheterogeneity of element distribution in an organic soil. ► Diatoms, clay minerals, and sulfide precipitates can be identified at the (sub)micron scale. ► X-ray spectromicroscopy (μ-XANES) reveals microheterogeneity of S speciation in an organic soil. ► Inorganic and organic S species of different oxidation state coexist at the (sub)micron scale.