THE RELATIVE STRATIGRAPHIC POSITION OF THE FORAMINIFERAL AND BELEMNITE STANDARDS FOR THE CAMPANIAN MAASTRICHTIAN BOUNDARY

The two most commonly used biostratigraphic standards for the Campanian-Maastrichtian boundary are the appearance of the belemnite Belemnella lanceolata (Schlotheim) and the disappearance of the planktic foraminiferan Globotruncanita calcarata (Cushman). The first is a boreal standard, the second tethyan. The assumption that the two coincide is false. In Mississippi the disappearance of G. calcarata is the same eustatic peak of sea-level which in north Germany lies near the top of the Nostoceras polyplocum Zone, within boreal nannofossil Zone CC/B22. This places the foraminiferal standard somewhere between 1.3 and 3.5 m.y. older than the belemnite standard. The belemnite standard is at or close to the appearance of Gansserina gansseri (Bolli) in Mississippi.