Fig. 3: Compositional maps of iron oxide & filament clusters.
From: Microbial biosignature preservation in carbonated serpentine from the Samail Ophiolite, Oman
A Transmitted light image and accompanying EDS maps of iron oxide precipitates containing numerous entwined filamentous structures. EDS data show enrichment of C correlated to Fe. The C enrichment is inversely correlated with Ca, indicating that the enriched C signal does not appear to be due to aragonite. B, upper) View of NanoSIMS (NS) mapping area (white dashes) imaged in transmitted light (left) and SEM backscatter detection (right). Note that the SEM view shows the extent of surface-exposed iron oxides and filaments (indicated by blue arrow) measured by NanoSIMS. In transmitted light, the filaments are difficult to distinguish due to the dense accumulation of iron oxides. B, lower) NanoSIMS ion maps of carbon, nitrogen, and phosphorous associated with iron oxide and filament cluster. The blue arrow points to Type A filaments that have been further revealed by the sputtering process. The field of view for each ion map is 40 μm x 40 μm, and brighter features correspond to higher total ion counts per pixel as shown by the lower scalebar.
