Characterisation of differential mixing of foraminifera and bulk carbonate in NE Atlantic sediments.

• Published in: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• Main Authors: Brown, L., Cook, G.T., Mackenzie, A.B., Naysmith, P., Anderson, R., Thomson, J., Nixon, S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2000
• Subjects: Rockall Plateau; North East Atlantic
• Online Access: http://nora.nerc.ac.uk/id/eprint/158257/; https://doi.org/10.1016/S0168-583X(00)00389-X

Radiocarbon age offsets between foraminifera and bulk carbonate samples were investigated in a sediment core from the western Rockall Plateau in the North East Atlantic. Within the surface mixed layer (SML), foraminifera (forams) ages were significantly younger than those of the bulk sediment at corresponding depths. Below the SML, no significant offset was observed between the two, which is in contrast to previous studies. The absence of an offset below the SML may be the result of advective biological mixing dominating over diffusive mixing in the SML, or the foram size fraction being below the threshold at which size selective mixing becomes active. Within the SML, the sampling strategy may bias the collection of forams towards the youngest specimens at each depth.