georefid:2002-073207SEDIS 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=2002-0732072002-01-01publicationgeorefid:2002-073207Keller, GertaPrinceton University, Department of Geosciences, Princeton, NJ, United StatesauthorAdatte, ThierryUniversity of Missouri-Columbia, United StatesauthorStinnesbeck, WolfgangUniversity of Neuchatel, SwitzerlandauthorAffolter, MarkUniversity of Karlsruhe, Federal Republic of GermanyauthorSchilli, LionelUniversidad Autonoma de Nuevo Leon, MexicoauthorLopez-Oliva, Jose GuadalupeauthorGeological Society of America (GSA), Boulder, CO, United StatespublisherdocumentHardcopyIn: Koeberl, Christian (editor), MacLeod, Kenneth G. (editor), Catastrophic events and mass extinctions; impacts and beyond356145-161The discovery of as many as 4 spherule layers within 10 m of pelagic marls below the sandstone-siltstone complex and Cretaceous-Tertiary (K-T) boundary in the La Sierrita area of northeastern Mexico reveals a more complex K-T scenario than previously imagined. These spherule layers were deposited within pelagic marls of the Mendez Formation; the oldest layer is as much as 10 m below the K-T boundary. The marls are of latest Maastrichtian calcareous nannofossil Micula prinsii zone and planktic foraminiferal zone CF1 (Plummerita hantkeninoides) age; the latter spans the last 300 k.y. of the Maastrichtian. The oldest spherule layer was deposited near the base of zone CF1 and marks the original spherule-producing event. This is indicated by the presence of a few marl clasts and benthic foraminifera that are frequently surrounded by welded glass, and many welded spherules with schlieren features, indicating that deposition occurred while the glass was still hot and ductile. It is possible that some, or all, of the three stratigraphically younger spherule layers have been reworked from the original spherule deposit, as suggested by the common marl clasts, terrigenous input, reworked benthic and planktic foraminifera, and clusters of agglutinated spherules. These data indicate that at least one spherule-producing event occurred during the late Maastrichtian and provide strong evidence for multiple catastrophic events across the K-T transition.completedStratigraphyalgaebenthic taxaburrowsC-13/C-12carbonCenozoicChicxulub CraterChondrites ichnofossilsclastscoastal environmentCretaceousDeep Sea Drilling ProjectDSDP Site 525Foraminiferageochemical anomaliesichnofossilsInvertebrataIPODiridiumisotope ratiosisotopesK-T boundaryLa SierritaLeg 74lower PaleoceneMaestrichtianmass extinctionsMendez FormationMesozoicmetalsMexicomicrofossilsnannofossilsnortheastern MexicoPaleocenepaleoclimatologyPaleogenepaleohydrologypaleotemperaturepelagic environmentplanktonic taxaPlantaeplatinum groupProtistareworkingschlierenSenonianspherulesstable isotopesstratigraphic boundarysubtidal environmentTertiaryUpper Cretaceousupper Maestrichtianurn:org.iodp:exp:74urnlargerWorkCitationcampaignurn:org.iodp:exp:74:site:525urnlargerWorkCitationstudyurn:org.iodp:exp:74urnlargerWorkCitationcampaignEnglishgeoscientificInformation2.59072.5908-29.0415-29.0414