Sortable silt of sediment cores GC-01A from Gulf of Cadiz

For sortable-silt 83 samples were analysed in the fraction <63 micron. In these, organic matter was eliminated with 33% of hydrogen peroxide (H2O2) and carbonates removed with 0.2N hydrogen chloride (HCl). Then, samples were dispersed with 0.5% Na-hexametaphosphate (Calgon) and ultra-sonicated for 2 minutes. Prior to grain-size analysis in a Sedigraph Micromeritics III Plus, samples were homogenised by stirring in a magnetic plate for 30 minutes. The grain-size distribution was acquired in the interval 10-63 micron, assumed to have non-cohesive behaviour during transport and deposition (McCave et al., 1995), at the IGME. The sortable silt mean of the carbonate-free 10-63 micron interval is designated as SS (McCave et al., 1995). The percentage of sortable silt (SS%), i.e. % (10-63 micron)/<63 micron, is also a key parameter obtained from Sedigraph analyses. Dry-density required for the grain size distribution calculation was measured by using a pycnometer Micromeritics Accupy 1330.