Definition of a global boundary stratotype section and point for the Campanian/ Maastrichtian boundary by Odin, G, Hancock, J, Antonescu, E, Bonnemaison, M, Caron, M, Cobban, W, Dhondt, A, Gaspard, D, Ion, J, Jagt, J, Kennedy, W, Melinte, M, Néraudeau, D, Von Salis, K, Ward, P