Late Albian ammonite biostratigraphy of the Kirchrode I borehole, Hannover, Germany
Abstract The ammonite biostratigraphy of the 245 m of sediments of Late Albian age traversed in the Kirchrode I (1/91) boring, situated in the south-eastern suburbs of the City of Hannover (Lower Saxony basin), is described. Correlation is made with the Actinoceramus (‘Birostrina’) bivalve-biostratigraphy in the part of the core of early Late Albian age and with the Inoceramus (Inoceramus) lissa-Aucellina gryphaeoides succession above. The earliest sediments of Late Albian age are of late Dipoloceras cristatum Subzone age with a good representation of the Hysteroceras orbignyi Subzone and an incomplete representation of the Hysteroceras varicosum Subzone. A notable feature of the succession is the presence of a considerable thickness (ca. 164 m) of sediments of Callihoplites auritus Subzone age. Sediments of Stoliczkaia dispar Zone age indicate the representation of the Mortoniceras (Mortoniceras) rostratum, Mortoniceras (Durnovarites) perinflatum and Arrhaphoceras (Praeschloenbachia) briacensis Subzones. The ammonite fauna of the borehole is listed and the ammonite biostratigraphy of the clay sediments traversed is discussed. A brief comparison is made with other surface and borehole sections in northern Germany and elsewhere and the more cosmopolitan Tethyan elements of the fauna are indicated and discussed.