The two reviews are thorough and complementary. They make it clear that this is valuable and high-quality dataset that should be published, but they raise a number of questions and points of concerns. The response of the authors to these reviews is comprehensive, and addresses or rebuts these concerns clearly and with reasonable arguments. With revisions to the manuscript as described by the authors, this submission will be a strong paper, well suited for publication in Biogeosciences.

Editorially, I am content with the authors responses to all the points raised by the two reviewers. I also have some comments myself, particularly about two of the figures. I make these as suggestions for consideration, rather than as editorial requirements.

Fig. 4 shows an ODV plot of 226Ra data. Is an ODV plot of Ba so visually similar that it is not worth plotting? It would be good, though, to consider adding an ODV plot of Ra/Ba. Variability in that ratio is important, as indicated by the fact that the abstract concludes on this point. Although ratios are visible in Fig 8 as profiles, it would be interesting to see if variation in this ratio is sufficiently cohesive to plot systematically on a section.

Similarly, in Fig 7, I was intrigued as to whether the Ba and Ra anomalies are ever sufficiently uncorrelated that anomalies in the Ra/Ba are observed relative to the OMP model. Perhaps a third panel on this figure to show Ra/Ba?
Also, on this figure, is it possible to show an assessment of the uncertainty next to the scale bar to aid interpretation? It is not immediately clear to the reader how strong a colour has to be before it can be taken as significant.

In general I found this an interesting and well-written manuscript, and I congratulate the authors on a careful piece of work. The resulting paper will make an excellent contribution to the GEOVIDE Special Volume.

Gideon Henderson
17th April 2018

Allowing author to make a final correction to figures

Thank you for making the additional changes to the two figures.

I look forward to seeing your interesting work in this special volume.