Original paper

Aptian and Albian (Early Cretaceous) ammonites from glacial erratics of the Hamburg area, North Germany

Lehmann, Jens

Abstract

Early Cretaceous glauconitic sandstones form part of the well-established boulder association known in the German literature on glacial erratics as the “Ahrensburger Geschiebesippe”. Because ammonites are very rare in these sandstones, a small assemblage is described, based on material mentioned in several classical papers. The following taxa are recognized: Hypacanthoplites elegans, Hypacanthoplites jacobi, Aconeceras sp. juv. cf. A. nisus, Sanmartinoceras (Sinzovia) stolleyi (based on the original material of Oppelia (Adolphia) baltica Ernst, 1921, a nomen nudum) and Cheloniceras (Cheloniceras) cornuelianum. According to the ranges attributed to these taxa the stratigraphic interval represented is late Early Aptian to earliest Albian. This expanded stratigraphic range is in contrast to that of the rich boulder fauna recently reported from Wolgast-Hohendorf in northeast Germany (essentially Early Albian, Leymeriella acuticostata Subzone, in age). The origin of both boulder associations is assumed to be the southern part of the Danish-Polish Basin.

Keywords

albianammonitesaptianearly cretaceousglacial erraticsnorth germany