LATE CRETACEOUS CARBON-ISOTOPE STRATIGRAPHY IN EUROPE - CORRELATION AND RELATIONS WITH SEA-LEVEL AND SEDIMENT STABILITY

Upper Cretaceous (Upper Cenomanian to Lower Coniacian) stable carbon i sotope stratigraphy of German hemipelagic marls (borehole Dresden-Blas ewitz), pelagic carbonates (quarries Salzgitter-Salder and Sohlde), an d of two Turonian to Santonian pelagic sections in the northern Alpine Helvetic Zone, supplemented by published carbon isotope data (Kent, s outhern England; Gubbio, Italy), are used for correlations of northern temperate (boreal) and Tethyan sections. General carbon isotopic tren ds are different in pelagic and hemipelagic carbonates, probably in re sponse to the input of terrestrial organic carbon to the inner shelf c arbon reservoir (including sediments). The global component in the car bon isotope stratigraphy is best recorded in pelagic carbonates. Suffi cient biostratigraphic control is present to correlate all sections ac ross facies boundaries and between the two biogeographic provinces. Hi atuses produce breaks in the gradual carbon isotopic trends and their duration can be estimated relative to complete sections. A broad delta (13)C minimum straddles the Turonian-Coniacian boundary at the propose d boundary stratotype Salzgitter-Salder, with its center about 0.5-1 m below the biostratigraphic reference level (first occurrence of C. ro tundatus Fiege sensu Troger non Fiege). Increases and maxima of pelagi c delta(13)C values occur during phases of sediment accumulation. Decr easing pelagic delta(13)C values and minima characterise phases of sed iment erosion. The amplitudes of these stratigraphic fluctuations may indicate the intensity of sediment reworking. Changes in the sediment accumulation/erosion ratio and accompanied carbon isotopic variation m ay be related to short-term sea-level fluctuations and their effect on fine-grained sediment stability. (C) 1997 Elsevier Science B.V.