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The Jurassic succession of Denmark is largely confined to the subsurface with the exception of exposures on the island of Bornholm in the Baltic Sea. In East Greenland, in contrast, the Jurassic is extensively exposed. Comparison of basin evolution in the two regions, which now occur on two separate plates, thus relies on highly different datasets. It is possible nevertheless to construct an integrated picture allowing testing of hypotheses concerning basin evolution, regional uplift, onset and climax of rifting, relative versus eustatic sea-level changes and sequence stratigraphic subdivision and correlation. On a smaller scale, it is possible to compare the signatures of sequence stratigraphic surfaces as seen on well logs, in cores and at outcrop and of sequences recognised and defined on the basis of very different data types. Breakdown of the successions into tectonostratigraphic megasequences highlights the high degree of similarity in overall basin evolution and tectonic style. An important difference, however, lies in the timing. Major events such as late Early - Middle Jurassic uplift, followed by onset of rifting, basin reorganisation and rift climax were delayed in East Greenland relative to the Danish region. This has important implications both for regional reconstructions of the rift system and for the understanding and testing of classical sequence stratigraphic concepts involving eustatic versus tectonic controls of basin evolution and stratigraphy.

Abstract: The climate of the mid to Late Cretaceous was probably one of the warmest of the Phanerozoic, but by the late Maastrichtian distinctly cool high latitude regions had developed. Studies from low latitude sites have demonstrated that the late Maastrichtian cooling was punctuated by two pulses of warming, but the response of nannoplankton to climatic fluctuation in the mid to high northern latitudes is not well documented. A high-resolution nannofossil study was undertaken on subsurface chalk sections of Denmark which provide a stratigraphically complete record of late Maastrichtian sedimentation of nannofossil ooze in an extensive mid to high latitude carbonate province. The quantitative nannofossil data from cored sections through the upper Maastrichtian chalk reveal subtle but significant shifts in taxa interpreted as having been sensitive to temperature fluctuations (Arkhangelskiella cymbiformis, Kamptnerius magnificus, Lucianorhabdus cayeuxii, Nephrolithus frequens, and Watznaueria barnesiae), and indicate two late Maastrichtian warming events correlatable with those of low latitude records, and a decrease in surface water temperatures in the latest Maastrichtian. [ABSTRACT FROM AUTHOR]