Dear Dr Schönfeld,

We have now received your final manuscript and response letter to the reviewers. You adressed all points raised by the reviewers convincingly and your revisions to the paper add an extra value to the manuscript.

I have minor comments that you will have to adress with a new version of the manuscript before it can be accepted:
- I wonder why the title contains reference to the Pleistocene (and not only the Holocene) as the OMZ sediments from the Peru margin that you consider in your study are mostly from the Holocene, aren't they? The point of your paper is to compare the OAE2 of the Cretaceous with present characteristics of the OMZ, and it would be good to show it in your title. If the reference to the Pleistocene is made to include the Last Glacial Maximum, then you could insert it in the title as well, but you'd better keep it simple.
- Line 21 of your abstract (page 1). you say that oxygen levels, flux of organic matter and benthic life are "well known". Please remove well known. There are controversy on the flux deposited and its fate in the sediment, and oxygen levels (at the nanomolar level) are still questionned. You could replace by "well studied".
- Line 24 of abstract replace "were" by "are".
- page 17 line 14-19: a remark was made by reviewer 2 which was not answered in your reply on the "20% export flux", and if it applied at the time of OAE2. In your paper, you wrote a "20% burial efficiency", and the reviewer was wrong in his remark but please provide more arguments in the text why this value was chosen for burial efficiency. Furthermore, when dividing burial flux by burial efficiency, you obtain the deposition flux (or rain rate of organic carbon), which is different from the export flux. Please change export flux to deposition flux (or rain rate).
- page 17 line 19-21: The meaning of the sentence (Therefore, it is conceivable...) is unclear to me, and its relation to the previous sentence also. Please clarify the link between "thick section of lamination" and "redeposition due to near-bottom turbulence".

Please consider these points carefully, make the necessarry alterations in your manuscript and send a reply to these comments. Your paper should be accepted rapidly if your are convincing.

Best regards,

C. Rabouille, invited editor for Biogeosciences

Dear Authors,

Thanks for your revisions which adress most of my remarks. I agree with all of your answer except one which is the change of title.

To me, the interesting heart of your paper is the comparison between present day processes and the Cretaceous OAE-2. In fact, you refer to this question in both your abstract
"Particular emphasis is put on the comparison of Holocene OMZ sediments from the upwelling area off Peru with deposits of Cretaceous Oceanic Anoxic Event 2 from the Moroccan shelf"
and at the end of your introduction
"Sedimentary features similar to those found in Cretaceous strata were observed in deposits underlying Recent OMZs, where bottom-water oxygen levels, the flux of organic matter, and benthic life are well studied. Their implications for constraining past bottom-water oxygenation are addressed in this review."

Therefore, I would advise you that you change your title to "Records of past mid-depth ventilation: Cretaceous Ocean Anoxic Event 2 vs RECENT oxygen minimum zones" instead of Quaternary which is correct basically, but far from your main objective. This objective is to start with actual sediment features of the OMZ and extrapolate to OAE.

Please take this comment in consideration, and revise your paper accordingly,

Best regards,

C. Rabouille