MacLeod, Kenneth G.; Huber, Brian T. (2001): The Maastrichtian record to Blake Nose (western North Atlantic) and implications for global palaeoceanographic and biotic changes. Geological Society of London, London, United Kingdom, In: Kroon, Dick (editor), Norris, Richard D. (editor), Klaus, A. (editor), Western North Atlantic Palaeogene and Cretaceous palaeoceanography, 183, 111-130, georefid:2001-079992
Abstract:
Widespread biological, geochemical and sedimentological shifts within the Maastrichtian are well documented, but data are limited for the low-latitude Atlantic. New observations from Ocean Drilling Program (ODP) sites located on Blake Nose in the subtropical western North Atlantic increase information concerning the Maastrichtian history of this critical region. Planktonic delta (super 18) O results suggest up to 6 degrees C of local surface water warming (or 4 per mil decrease in salinity) at the same time as most of the globe was cooling. Benthic delta (super 18) O and delta (super 13) C values of both planktonic and benthic taxa show little if any directional trend or excursions on long time scales; however, planktonic and benthic taxa exhibit strong delta (super 13) C and delta (super 18) O cycles (up to 0.8 and 0.6 per mil, respectively) across a short interval of high-resolution sampling. Other portions of the cores have not yet been studied at high resolution. The last occurrence of inoceramid shell fragments on Blake Nose matches previously documented global patterns, i.e. a mid-Maastrichtian extinction event that occurred later in low latitudes than in high southern latitudes. Models for Maastrichtian change seem to be converging on variation in intermediate to deep water ocean circulation as a unifying process. Blake Nose data are consistent with this conclusion, but demonstrate new regional patterns and emphasize the importance of precise and accurate chronostratigraphic correlation in understanding Maastrichtian change.
Coverage:
West: -77.0000 East: -76.0000 North: 30.3000 South: 29.3000
West: NaN East: NaN North: NaN South: NaN
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