Dear Authors,
First of all I apologize for the long delay to replying to you after the 2 reviews and your reviews' comments. As co-editor in chief of Climate of the Past, I decided to take over editor Liping Zhou who missed to reply you several time, in agreement with my colleagues co-editors in chief.
In such circumstances, I am following both reviewers' decision requesting a major revision of your manuscript. Therefore I invite you to submit a seriously revised version by following very carefully the reviewers' comments and suggestions, as they are both willing to review your revised version.
Thanks you for submitting your results to Climate of the Past
ALl the very best
denis-didier Rousseau
Climate of the Past co-editor in chief

Dear authors,
Many thanks for the revised version that both former reviewers checked and appreciated. I am therefore pleased to accept your revised manuscript provided some very last minor revision that reviewer 2 requires and that I repeat here.

- page 2, lines 25-30. Acidobacteria are only some of the potential producers of brGDGTs.
- page 8, lines 10-13. Isoprenoid GDGTs are likely not detected (rather than absent) in a majority of samples.
- page 12, lines 5-9. In order to conclude about in situ brGDGT production, the brGDGT concentrations should be expressed in microg/g of organic carbon (and not in microg/g of dry sediment).
- pages 18-19. Paragraphs 5.5 and 5.6 should be merged as they are directly linked.

Thank you once more for choosing Climate of the Past to publish your interesting results.
Looking forward to read other papers from your group in CP
All the very best
denis-didier Rousseau
Climate of the Past co-editor in chief