Dear authors,

I would like to apologize for the delay in the reviewing process.

Both reviewers raised a number of concerns that prevents your ms from acceptation in its present form. From my own reading of the ms, and according to the reviewers reports, I identify two major blocking points:
1) in addition to new data of high quality, you should state clearly what is new compared to the previous work by Mitchell et al. (2008).
2) the carbon isotopic signal delivers some indications about how the carbon cycle was operating during an OAE. But I feel that, without combining it with the message carried by other proxies (such as Nd, see rev2), any interpretation remains highly speculative. Your section devoted to the long term evolution of the carbon cycle is obscure. You mention links between orbital parameters and climate extremes, themselves impacting the hydrological cycle, the weathering, and ultimately the carbon cycle. I think all of this should be rewritten, based on a more "physical" argumentation. As it stands, this section is confusing for the non-specialist reader. Improving its readability would enhance the impact of your contribution.
Beside these two points, rev 1 raised a number of technical questions that you should address in your revised ms (in line with your answers).
In summary, I encourage you to submit a revised version. It will go through a second round of reviews.

Best regards

Dear authors,

I'm glad to accept your contribution for publication in Climate of the Past. Your exhaustive answer to the reviewers is convincing, and the changes you bring to your ms largely improved it.

Best regards