Two referees thoroughly evaluated the manuscript, and the authors answered to the comments; sometimes with having different opinion. I encourage the authors to also consider some of the more general comments of reviewer #1. These comments are mainly related to better guide the reader through the manuscript (i.e. be more specific with pointing out individual objectives and how they were achieved) and to compare the findings with other studies. These comments will help to improve the manuscript and are essential.
Regarding the combined presentation of results and discussion, the authors can keep the structure as is. However, in its current form, the authors miss presenting a more general discussion by combining the individual results. Therefore, I recommend emphasizing more the combined interpretation of isotope and geochemistry data. At the same time, the manuscript should not get too long, and therefore, I also encourage the authors to focus on the most important pionts.
Further, I don’t agree to the answer on just changing the title “Concluding remarks” into “Summary”. The authors should give a clear take home message and make conclusions.

Substantial rewriting of the manuscript is required and also some authors’ comments need to be revisited. Therefore, I am happy to reconsider the manuscript after major revisions were done. A revised version of the manuscript can be uploaded.

Dear authors,

the same referees evaluated the revised version of the manuscript; please note that one of the reports is attached as pdf file. The referees pointed out that the manuscript was improved, and the authors answered most of the comments in detail. However, there is still one technical issue (redundant figures in main text and SI) and some statistical measures should be given. More importantly, it is absolutely required to include a thorough discussion and place your results into context; also to exisiting literature. If the latter point is not considered properly in the revised version, the manuscript cannot be accepted for publication in HESS.
I am looking forward receiving a revised version of the manuscript.

Christine

The authors followed the reviewer suggestions and included statistics as well as a more thorough disucssion. Therefore, the manuscript can be accepted for publication. Thank you for considering HESS.