Albian calcareous nannofossils from the Gault Clay of Munday’s Hill (Bedfordshire, England)
Abstract. Abundant and diverse Middle and Upper Albian nannofossil assemblages are present in the Gault Clay exposed at Munday’s Hill, Bedfordshire, England. The section was deposited between the first appearance datums of Tranolithus orionatus and Eiffellithus turriseiffeli. This interval can be further subdivided, using the last appearance of Braloweria boletiformis and the first appearances of Axopodorhabdus albianus, Owenia hilli sp. nov. and Eiffellithus monechiae sp. nov.
The presence of Braloweria boletiformis, Ceratolithina hamata and Gaarderella granulifera, only at this and other north-west European localities, defines a unique endemic nannofloral province. Low latitude species are present throughout the studied section and first and last appearance datums of species are nearly synchronous, both at Munday’s Hill and in other areas. This indicates continuous marine connections between Munday’s Hill and low latitude areas through the Mid and Late Albian.
Abundance patterns of high latitude nannofossils, primarily Repagulum parvidentatum and Seribiscutum primitivum, suggest that relatively cold waters dominated in the Munday’s Hill area near the base of the Middle Albian. The abundance of high latitude taxa gradually decreased towards the end of the Middle Albian, but temporarily increased at the base of the Upper Albian. The abundance of high latitude taxa was relatively low throughout the lower half of the Upper Albian and intermediate to low in the upper half of the Upper Albian.
Two new genera, Braloweria gen. nov. and Owenia gen. nov., and two new species, Owenia hilli sp. nov. and Eiffellithus monechiae sp. nov., are described.