A foraminiferal biostratigraphy of the Campanian and Maastrichtian chalks of the United Kingdom

Foraminiferal biozones and their relationship to the lithostratigraphy of the Chalk Group of southern England

“…Hart 1973;Carter and Hart, 1977;Hart et al, 1989), although hyaline gavelinellids began a phase of diversification at this time, in the form of Lingulogavelinella and Gavelinella (Berthelina). Gavelinella was split into several genera by Revets (1996Revets ( , 2001, although he did not consider their phylogenetic relationships through time as had, for example, Price (1977), Swiecicki, (1980), Edwards (1981, Swiecicki (1987, 1988). These authors clearly demonstrated that biostratigraphically useful evolutionary lineages could be recognised in Gavelinella, several of which were thrown into disarray by Revets" concepts.…”

The lithostratigraphy and biostratigraphy of the Chalk Group (Upper Coniacian to Upper Campanian) at Scratchell's Bay and Alum Bay, Isle of Wight, UK

“…This section is also only accessible at the very lowest tides and 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 consequently there is a small gap between the sections logged at Scratchell"s Bay by the survey team and with those logged by one of us (MAW) on the southern side of Alum Bay beneath the Palaeogene unconformity. Data from other sources (Swiecicki, 1980;Gale, pers comm. 2008) demonstrates that the stratigraphical gap between the BGS logs is small and represented by 30-35m of strata.…”

“…Presumably Brydone refers here to the obvious stratal condensation in what we now call the Seaford Chalk Formation and the so-called "Flintless Belt" in the Newhaven Chalk Formation, amongst other differences compared to the stratotype sections in Sussex. Since these early descriptions of the section no further significant study was undertaken until Swiecicki (1980). His unpublished PhD thesis included Scratchell"s Bay as one of 27 sections of Campanian and Maastrichtian chalk from which he developed foraminiferal biozonal schemes that he related to the macrofaunal biozones.…”

“…The eastern half of Scratchell"s Bay, for the most part exposing the Seaford Chalk Formation (middle-Coniacian to middle-Santonian) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 was not included in that thesis. The relationship of these zones to those adopted by BGS (British Geological Survey) are given in Wilkinson (this issue) The complete scheme for the highest Chalk Group strata beyond that exposed on the Isle of Wight equates with the benthonic foraminiferal biozones B1 to B7 of Swiecicki (1980 , Fig 2.1), and was developed utilising sections in East Anglia and two wells in the North Sea. At Scratchell"s Bay and Alum Bay the macrofaunal correlation utilised in the Swiecicki PhD was derived from the work of Rowe (1908) and Brydone (1914) together with additional macrofaunal material identified by C J Wood (formerly of the BGS) for the author.…”

“…Montgomery (1994) and Montgomery et al (1998) compare the magneto-stratigraphy of Scratchell"s Bay and Culver Down. Hart et al (1989) published a small-scale outline section for both Alum Bay (Upper Campanian) and Scratchell"s Bay (Santonian to late Campanian only) but this appears to be a further presentation of the section utilised by Swiecicki (1980 A complete manuscript lithological log from the Palaeogene unconformity in Alum Bay around the Needles promontory and into Scratchell"s Bay was kindly provided by Professor Andy Gale (pers. comm., 2008).…”