FORAMINIFERAL RESPONSE TO MID-CENOMANIAN (UPPER CRETACEOUS) PALAEOCEANOGRAPHIC EVENTS IN THE ANGLO-PARIS BASIN (NORTHWEST EUROPE)

We have analysed the sedimentology, macrofossil event horizons (includ ing pulse faunas) and foraminiferal succession (SO samples) from an 8 m succession in the upper Lower and lower Middle Cenomanian (Upper Cre taceous) al Folkestone, Southeast England. Comparative sedimentologica l analysis of successions in southern and northeastern England indicat es the presence of three hierarchies of cycle: 20 kyr productivity (ch alk-marl couplets) cycles attributed to the Milankovitch precession cy cle; 100 kyr sea-level cycles attributed to the Milankovitch eccentric ity cycle; and Myr cycles attributed to longer-term sea-level cycles. Previously recognised macrofossil pulse faunas occur preferentially at the bases of the 100 kyr eccentricity cycles, We analysed the foramin iferal fauna across the Lower-Middle Cenomanian boundary at Abbott's C liff, Folkestone, in great detail (80 samples in 8 m). The foraminifer al succession is also intricately related to the 1 Myr sea-level, and 100 kyr eccentricity cycles, Changes related to the long-term cycles i nclude variations in the abundance of the benthic foraminifera Tritaxi a, Gyroidinoides, Lingulogavelinella and Dororhia, and an increase in benthic diversity in the transgressive deposits, Changes related to th e 100 kyr eccentricity cycles include: the presence of Rotalipora ex g r. reicheli in the lower part (and rarely upper part) of cycles, the a bundance of planktics (both absolute and relative) in the middle to up per part of cycles; an increase in the proportion of Gavelinella berth elini and G. reussi in the upper part of cycles. We present a stratifi ed water column model to explain the changes related to the 100 kyr sc ale cycle. (C) 1998 Elsevier Science B.V.