Overall, the manuscript can be accepted after minor revisions, following the suggestions and corrections made by the reviewers. Both reviewers provided valuable suggestions and I can see that you followed these suggestions in the author´s response and the draft of the revised version. Please note that some references are given in the text, which are not listed in the reference list.

- Hayes et al. 2010
- Dawson 1991
- Bacchetta et al. 2008
- Chenon et al. 2003
- Mantecca et al. 2007
- Fort et al. 2001
- Franzini et al. 1975
- Leoni and Saitta 1976
- Marianelli and Sbrana 1998
- Niewkoop and Faber 1956
- Gogh and Neff 2003

Please add these references when submitting the revised version.

Best regards,

Bernd Wagner

The manuscript can be pubished after technical corrections. However, there are is huge number of technical corrections, which need to be addressed.
- Please check the manuscript carfully for English grammar and wording. There seem to be quite a number of minor flaws in the English. Although copy-editing is mandatory, you may avoid a lot of questions, when reveiving the proof.
- Please note also that the references are not complete or information is missing. For example, the years are missing in several references (but check all references for completeness, as also other information is missing)
- Please use the wording Lake Ohrid instead of Ohrid lake or lake Ohrid
- Please check the spelling of Xenopus laevis (laevis not in capitals)
- line 116: provide reference for ASTM 1998
- lines 164 and following: what is NH3 e NH4? Do you mean NH3 and NH4?
- line 170: K is the ?
- line 249: greigite