The Paleocene Working Group was commissioned by the International Subcommission on Paleogene Stratigraphy in 1993 to define Global Stratotype Sections and Points (GSSP’s) for the bases of the Selandian and Thanetian stages. After 14 years of research, a meeting was held in Zumaia (Spain) in June 19-20, 2007. The meeting was attended by 23 scientists, including a majority of the scientists that participated in the founding meeting in 1993 in Göteborg, Sweden (Schmitz, 1994). After constructive discussions the attending scientists held a vote that gave the unanimous result that the GSSP’s for the Paleocene stages shall be placed in the Zumaia section in Spain. The Danian/Selandian boundary is placed at the base of the Itzurun Formation in the Zumaia section at San Telmo Beach. The Selandian/Thanetian is placed at the base of magnetochron 26n in the same section. A detailed voting document for the International Subcommission on Paleogene Stratigraphy was prepared by Schmitz et al. The proposal was approved by the International Subcommission on Paleogene Stratigraphy, by the International Commission on Stratigraphy, and ratified by the International Union of Geological Sciences in September 23, 2008.

References:

Schmitz B., Pujalte V., Molina E., Monechi S., Orue-Etxebarria X., Alegret L., Apellaniz E., Arenillas I., Aubry M.P., Baceta J.I., Berggren W., Bernaola G., Caballero F., Clemmensen A., Dinarès-Turell J., Dupuis Ch., Heilmann-Clausen C., Hilario, A., Knox R., Martín-Rubio M., Ortiz S., Payros A., Petrizzio M.R., von Salis K., Speijer R., Sprong R., Steurbaut E. & Thomsen E. (2011). The global boundary stratotype sections and points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages at Zumaia, Spain. Episodes 34, 220-243.