Fig. 3

Micro X-ray fluorescence element distribution maps of MNG 17001. (A) Optical photograph of the imaged area of MNG 17001. White spherules in the background are PET beads used for non-destructive fixation of the specimen during analysis. (B-G) Kα X-ray fluorescence maps of silicon (B), iron (C), calcium (D), phosphorus (E), arsenic (F), and yttrium (G), shown as grayscale images where dark tones denote low concentrations and light tones denote high concentrations. High concentrations of arsenic and yttrium in the PET beads in the background in (F) and (G) are artefacts. (H) Phosphorus and sulphur Kα peaks in X-ray fluorescence spectra of sediment (gray), matrix (blue), and bone (yellow), extracted from the areas in the element distribution map shown in (A). Note that the silicon Kα peaks of the sediment and the matrix are truncated and greatly extend the data range shown here. Spectra are normalized by background-matching at ~ 2.5 keV to allow for comparison. Scale bars: 5 mm