Dear Dr. Zhang,
Thank you for submitting a revised draft of your manuscript “Amelioration of marine environments at the Smithian-Spathian boundary, Early Triassic”.
You have dealt well with the reviewers’ concern and I can provisionally accept your manuscript for publication in Biogeosciences. However, there are a few remaining issues, which I ask you to address before the paper goes to press.

1.Both reviewers complained about insufficient background on your calculation of sediment flux rates. You simply refer to a citation in the caption of Fig. 3, which is insufficient, especially because the cited paper is not open access and thus cannot be read by everybody. Please add a paragraph on flux rates to your methods section in which you describe the basic procedure. Does your method consider the scaling law of sedimentation rates as described by Sadler (1981, J. Geol. 89 569-584) and several other authors?
2. Both reviewers also complained about the stratigraphic correlations in Fig. 1. You added some text to the caption to make clear that conodont zonation in the West Pingdingshan section is well established. Nevertheless it still appears from the figure that your conodont finds were used to establish the zonation, which is misleading. I figure that all data in the Pindingshan section are from the literature and hence I understand that no lithological column is provided. But why then the conodont occurrences? Please revise this figure giving more space for the section studied here, remove conodont occurrences in the West Pingdingshan section (just show the colored zones), and remove the colored zones from the Shitouzhai section (just show the dashed markers). This is just a suggestion and you may find a better solution but a revision is necessary. Please also correct instances of NV. instead of Nv.
3. You seem to use covariation and correlation as interchangeable, which is not quite correct. Correlation is covariation adjusted for the standard deviations of x and y. As you seem to always report correlation coefficients (r) rather than covariation, you should use the term correlation throughout.

Looking forward to receiving your revised draft soon

Best regards

Wolfgang Kiessling

Dear Dr. Zahng,

Thanks for making those final corrections. The manuscript is ready for production now, with only one exception.
In spite of your discussion on the terminology of covariation and correlation I must insist that you use "correlation" at least when you report correlation coefficients such as in lines 234, 277, 284. Covariation may be understood but it's a different thing. You can leave covariation in other instances, although I don't understand why you would wish to do so.

Thank you for submitting your work to Biogeosciences

Wolfgang Kiessling