Diverse chemical markers
According to Mc Arthur and al. (1993), the marine report 87Sr/86Sr decreases of 0.70775 in Cénomanien in 0.70730 in average Turonien before increasing by quasi-linear way until values superior to 0.70775 at the beginning of Maastrichtien.
The curve LOWESS (McArthur, on 2001) serves as reference to the works concerning the isotopes of the strontium in stratigraphy. Well, for example, data supplied by drillings on the tray of Ontong Java put back on this curve (BBralower and al ., on 2004