Dataset: Iron speciation in hydrothermal plume particles determined by synchrotron X-ray absorption spectroscopy of samples collected on R/V Atlantis cruise AT50-15 at the Juan de Fuca Ridge in 2023

Synchrotron microprobe X-ray absorption imaging and spectroscopy allows for the investigation of iron speciation at specific points on a filter-bound sample. Microprobe iron 1s X-ray absorption near edge structure (µXANES) spectra were collected on filter-bound hydrothermal plume particles at the hard X-ray microprobe beamline XFM (4-BM), National Synchrotron Light Source II (NSLS-II), Brookhaven National Laboratory. Data collection and analysis methods were similar to prior studies of particulate iron from deep-sea hydrothermal systems (Toner et al. 2009; Hoffman et al. 2020; Stewart et al. 2021). The monochromator energy was calibrated with a standard iron foil with the inflection point set to 7110.75 eV. Particles were located using X-ray fluorescence mapping followed by XANES spectra collection in fluorescence mode at a series of points for each filter-bound sample.