Discussion of “Ryazanian to Barremian mineral stratigraphy of the Speeton Clay in the U.K. southern North Sea Basin” Proceedings, Vol. 48, part 3, pp. 255–264, 1991

Abstract

J. W. Neale writes: I regret that I was unable to be present at the meeting at which this paper was read and would like to congratulate Dr Knox on an excellent, interesting and very useful addition to our knowledge of the Speeton Clay. The author rightly draws attention to the problem of the close correspondence between the succession above the Coprolite Bed at Speeton and the Cinder Bed in Dorset. Given the generally accepted stratigraphical reading of these two sections at different ends of the country he goes on to suggest that this difficulty might be resolved by postulating progressive migration of climatic zones and rejuvenation of southern source areas. In the light of recent work it is now possible to propose a much simpler explanation. Until 1963 one felt intuitively that the Coprolite Bed at Speeton and the Cinder Bed in Dorset were of roughly the same age and that their correlation could be regarded as a reasonable working hypothesis. However, as a result of Casey’s work (1963) in the south of England, the Cinder Bed was adopted as the Jurassic/Cretaceous boundary in non-marine facies and the earliest beds datable by ammonites at Speeton were shown to lie well up in the Ryazanian in comparison with the boreal continental successions. Recently Dr Su (Chinese Academy of Geological Sciences, Beijing) and I have been working on correlation in non-marine facies in Europe and China. In this connection we carried out extensive field work in 1989, collecting in southern England, ...