Geochemical data derived from an absolutely dated shell-based chronology for the Irish Sea

The identification in various proxy records of periods of rapid (decadal scale) climate change over recent millennia, together with the possibility that feedback mechanisms may amplify climate system responses to increasing atmospheric CO2, highlights the importance of a detailed understanding, at high spatial and temporal resolutions, of forcings and feedbacks within the system. Such an understanding has hitherto been limited because the temperate marine environment has lacked an absolute timescale of the kind provided by tree-rings for the terrestrial environment and by corals for the tropical marine environment. Here we present the first annually resolved, multi-centennial (489-year), absolutely dated, shell-based marine master chronology. The chronology has been constructed by detrending and averaging annual growth increment widths in the shells of multiple specimens of the very long-lived bivalve mollusc Arctica islandica, collected from sites to the south and west of the Isle of Man in the Irish Sea. The strength of the common environmental signal expressed in the chronology is fully comparable with equivalent statistics for tree-ring chronologies. Analysis of the 14C signal in the shells shows no trend in the marine radiocarbon reservoir correction (DR), although it may be more variable before ~1750. The d13C signal shows a very significant (R**2 = 0.456, p < 0.0001) trend due to the 13C Suess effect.

(Tables 1-2) Heavy mineral composition and median grain size of sediments obtained near 'Rote Kliff' west of Sylt, North Sea

The interpretation of 19 bore cores from the sea floor west of Rote Kliff (Isle of Sylt, North-Frisian Islands) gave information about the thickness of Holocene sand and the sediments below it; especially regarding their resistance to erosion in the area seaward of the beach-barrier. At the Same time, additional knowledge was obtained about the development of Sylt.

Dinoflagellates and pollen of the Brito-Arctic Igneous Province flora, ODP Hole 104-642E

Palynological studies of the intrabasaltic sediment layers in the lower volcanic series from ODP Leg 104 outer Voring Plateau Hole 642E Cores 102 through 109 indicated abundant pollen and rarer dinoflagellate cysts. The dinoflagellates belong to the Apectodinium hyperacanthum Zone and indicate an age equivalent to nannoplankton Zones NP9-lower NP10 around the Paleocene/Eocene boundary. The pollen and spore assemblage found here in 12 of the samples from the lower volcanic series is of well- preserved and distinctive specimens and contains unusual forms of pollen from the Taxodiaceae and the Hamamelidae. It has not been transported far from vegetation that was dominated by conifer forest with some ferns and deciduous arborescent angiosperms. Nearly identical assemblages are found elsewhere in the Brito-Arctic Igneous Province, in intrabasaltic sediments from eastern Greenland, the Faeroe Islands, the Isle of Mull, and Antrim (Northern Ireland), and above basalt at the Rockall Plateau. The assemblage is also present in sediments around the Paleocene/Eocene boundary in Spitsbergen. This pollen and spore flora is also associated with dinoflagellate cysts of the Apectodinium hyperacanthum Zone in the deposits from eastern Greenland, the Rockall Plateau, and Spitsbergen, suggesting that these are correlative. Assemblages of the same age from the North Sea, Denmark, and the London and Paris Basins are different. Paleobotanical evidence suggests a short survival of the intrabasaltic flora, and that all the deposits considered here are of about the same age. We propose that at around the Paleocene/Eocene boundary a distinct flora, named here as the Brito-Arctic Igneous Province (BIP) flora, occurred on the line of volcanicity stretching from Rockall to the Greenland Sea, and even to Spitsbergen. Geophysical evidence supports our view that the Rockall to East Greenland intrabasaltics are more or less contemporaneous, at about the Paleocene/Eocene boundary. However, the comparable pollen and spore assemblage in the Hebridean province, at Mull and Antrim, is from pyroclastics that may be a little older.