Comments on "Estimating the impact of early diagenesis on isotope records in shallow-marine carbonates: A case study from the Urgonian platform in western Swiss Jura" by A. Godet et al. [Palaeogeography Palaeoclimatology Palaeoecology 454 (2016) 125-138]

A recent paper by Godet et al. on Urgonian carbonates from the Swiss Jura concluded that diagenesis may hinder chemostratigraphic correlations of deep- to shallow-water facies. Although we agree with this conclusion we question their arguments and interpretations. These authors correctly identified diagenesis as the key factor, but we question the timing of events in their paragenetic sequence. In particular, they reported the leaching of originally calcitic oolitic cortices but failed to discuss this puzzling feature properly. In addition, the backbone of their argument is the stratigraphic correlation of a specific sequence from three dominantly shallow-water sections together with a basinal reference section. However, a reliable alternative biostratigraphic framework shows that this attempt of long-distance correlation might be erroneous.