georefid:2002-068165SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2002-0681652000-01-01publicationgeorefid:2002-068165Olsson, Richard K.Rutgers University, Department of Geological Sciences, Piscataway, NJ, United StatesauthorWright, James D.University of Tuebingen, Federal Republic of GermanyauthorMiller, Kenneth G.authorHemleben, ChristophauthorGeological Society of America (GSA), Boulder, CO, United StatespublisherdocumentHardcopyIn: Anonymous, Geological Society of America, 2000 annual meeting32 (7)145Carbon 13 values of benthic and planktonic foraminifera across the Cretaceous/Tertiary boundary (K/T) in New Jersey boreholes (ODP Legs 150X and 174AX) show the carbon isotopic shift across the K/T that indicates a reduction in oceanic primary productivity, the "Strangelove" ocean. Paleocene strata used in this study were deposited in a shelf setting (ca. 100 m paleodepth), which would have encompassed the photic zone and the deep chlorophyll maximum (DCM) layer. Carbon 13 values of Danian foraminifera are similar to the data of D'Hondt et al. (1998) that indicate organic flux to the deep ocean did not fully recover for over 3 million years. However, three observations are inconsistent with their hypothesis that organic flux recovered quickly in shallow environments. From our study on the New Jersey shelf, the overall calcium carbonate accumulation rate decreased, the mean ocean carbon 13 value did not significantly change, and the shelves did not go anoxic. The low carbon 13 values in shelf paleodepths may be due to lowered fertility and a thin DCM. Oxygen 18 values of Danian species indicate that they occupied a narrow range in the water column, suggesting a restricted DCM. The appearance of highly-efficient-feeding spinose planktonic foraminifera in the Danian may be an adaptation to these oligotrophic conditions. A marked change took place during the transition from the Danian to the upper Paleocene. The average size of planktonic foraminifera nearly doubled and the diversity of species doubled. Furthermore, oxygen 18 values show that a greater vertical range of the water column was used by individual species with shallow, intermediate, and deeper-dwelling habitats. We hypothesize that fertility of the oceans and the expansion of the DCM had returned to pre-K/T boundary levels on the shelf ca. 4 my after the extinctions and that the delay resulted either from reduced nutrient input from the continents or a different surface water mass structure.completedStratigraphyadaptationAtlantic Coastal PlainC-13/C-12calcium carbonatecarbonCenozoicchlorophyllCretaceousDaniandepositional environmentextinctionForaminiferahabitatInvertebrataisotope ratiosisotopesK-T boundaryLeg 150XLeg 174AXlower Paleocenemarine environmentmass extinctionsMesozoicmicrofossilsNew JerseynutrientsO-18/O-16Ocean Drilling Programorganic compoundsoxygenpaleo-oceanographyPaleocenePaleogenepigmentsplanktonplanktonic taxaproductivityProtistarecoveryshallow-water environmentshelf environmentspecies diversitystable isotopesstratigraphic boundaryTertiaryUnited StatesUpper CretaceousEnglishgeoscientificInformation-75.3500-73.530038.300041.2100New Jersey