Figure 2. XRD scans for Sample 3-5, measured using Co K radiation ( = 1.7903). The upper panel shows the bulk sediment. The lower panel shows a separate from this sediment, which has a grain size of 63- to 250-µm and a density of >2.8 g/cm³. Gray bands represent the expected position of calcite peaks. Prominent peaks are seen at these angles for the bulk sediment but are nearly completely absent from the separate, demonstrating that the separation protocol effectively concentrates aragonite (see Table 2).