fig4

Figure 4. Example ²¹⁰Pb profiles. Horizontal dashed lines represent the bottom of the surface mixed layer (SML). Solid lines show the section of each profile to be used for the calculation of the sedimentation velocity. (A) A profile from a deep, coastal basin sediment. (B) A profile from a Zostera marina meadow, showing a deeper, more disturbed SML but clear decay with depth below the SML. (C) A profile where the core is too short or the sediment too disturbed to reach the decay depth, so no sedimentation velocity can be determined. (D) Inverted ²¹⁰Pb profile near-surface shows that older material has landed on top of newer; a sedimentation velocity can be determined below the slump, but the absolute age of the deep section is unclear. (E) A core with a slump of older material at mid-depth, above which regular accumulation seems to have resumed; SML may or may not be present; this rate would be uncertain relative to those in (A and B).