Reply to the comment on "Implications of diagenesis for the isotopic analysis of Upper Miocene large mammalian herbivore tooth enamel from Chad" by L. Jacques, N. Ogle, I. Moussa, R. Kalin, P. Vignaud, M. Brunet and H. Bocherens [Palaeogeography, Palaeoclimatology, Palaeoecology 266 (2008) 200-210]

n their comment to our recent paper (Jacques et al., 2008), Zazzo et al. (2009-this issue) provide a correction regarding some technical features of one of the isotopic mass spectrometers used in our comparative study. It appears that the system used to purify CO2 in Saskatoon was a dual inlet (DI) and not a continuous flow (CF) as mistakenly stated. As this system was considered as reliable as the other CF used in the comparative study, Zazzo et al. (2009-this issue) infer that the isotopic ratios previously measured on heavily contaminated material from a late Miocene Chadian site, Toros Ménalla (TM), with another DI are reliable as well. Our reply will re-evaluate the comparison between CF and DI systems in the light of the correction for the system used in Saskatoon, and discuss the claim that previous isotopic measurements made on Chadian material reflect biogenic signatures and were not affected by oxide contamination.