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RESEARCH PRODUCT

Reply on Comment by Longinelli (2013) on a revised phosphate-water fractionation equation.

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Longinelli (2013) contests the new phosphate–water oxygenisotopefractionation equationpresentedforfishteethin Puceatetal. (2010), and more specifically the pooling of the data of Puceatet al. (2010) with those of Longinelli and Nuti (1973b),performedto better constrain the regression parameters of the fractionationequation.Firstly, Longinelli (2013) criticizes that only 17 of the 24 datareported in Longinelli and Nuti (1973b) appear in Fig. 3. Doubtwas cast on whether the fish data of Longinelli and Nuti (1973b)were mixed with those of marine molluscs from Longinelli andNuti (1973a). Only oxygen isotope ratios of fish (Longinelli andNuti, 1973b) have been taken into account in Puceat et al. (2010),and all 24 data points were used for further calculation. The rea-sonwhyonly17samplesarevisibleinFig.3isthatonedatapoint(n° 18, following the sample identification of Longinelli and Nuti,1973b) plots outside the scale of Fig. 3 of Puceat et al. (2010),and that samples with identical oxygen isotope values plot oneach other (n° 1, 8 and 9; n° 2 and 3; n° 4, 5 and 6; n° 12and 15 following the sample identification of Longinelli and Nuti,1973b).Fig.1showsalldatapointsreportedbyLonginelliandNuti(1973b) with the original sample identifications so that the readerwill be able to identify easily every sample. The equation givenin Fig. 3 is that reported in Longinelli and Nuti (1973b), originally