Dear Lisa Bröder and co-authors,

Thank you for your reply to the comments of the two reviewers. I think that you have appropriately addressed most of the reviewer's concerns in your response letter and I am looking forward to seeing the comments incorporated in a revised version of your manuscript.

One request that has been sort of made by both reviewers is a better highlight the specialty of the Siberian Arctic Shelf as a location and depositional environment (general comment reviewer 1; comment 4 reviewer 2), and more specific the processes that take place during land-sea transport of terrigenous OC. Please make sure that the revised manuscript elaborates on this, and considers the differences(?) in transport between active and passive margins.

Thanks for submitting your work to Biogeosciences.

Best regards,
Francien Peterse

Dear Lisa Bröder et al.

Thank you for submitting a revised version of your manuscript. I think you have handled most of the reviewer's comments well. There are a few final (minor) comments that I would like you to address, listed below. Line numbers refer to the version with track changes.

Best,
Francien Peterse

- L76-78: The order of words seems a bit off to me. Please check the phrasing.
- L301: input of young autochtonous material is not supported by the stable carbon isotopic signature – please specify how.
- Comment 4 of reviewer 2: I still think this is a valuable comment. Please specify that the transport times reported by Keil et al. (2004) are for an active margin, and should be taken here as a minimum.
- Add the contribution of the reviewers to the acknowledgements.
- Table 1: have d13C measurements done in duplicate? If so, what was the error, and what value is displayed here in the table (average)? What is the precision of the measurement, i.e. can you report d13C values with this amount of significant numbers?

Dear Lisa Bröder et al,

I have evaluated the changes made in response to my last set of comments and I am happy to inform you that I have accepted the manuscript for publication in Biogeosciences.

All the best,
Francien Peterse