Abstract

"Since the orthogenetic sequences of many of the planktonic as well as the benthonic Foraminifera are identical in both the type-Danian and the type-Maestrichtian one must conclude that these stages are contemporaneous (it has to be emphasized that 'Maestrichtian' in international sense embraces a much older series of rocks than the type- Maestrichtian of Dumont, the Tuff Chalk of Maestricht). Consequently, the planktonic foraminiferal break coincides with the Cretaceous-Tertiary boundary only when there is a gap in the orthogenetic record caused by a sedimentary gap; when there is no gap, the faunal change begins within the uppermost part of the Cretaceous (which includes the type-Danian)."

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