georefid:2001-015236SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2001-015236<gco:CharacterString>Stability of subtropical sea surface temperatures during the Cenomanian-Turonian boundary deep water and high latitude warming event</gco:CharacterString>1999-01-01publicationgeorefid:2001-015236Huber, Brian T.Smithsonian Institution, National Museum of Natural History, Department of Paleobiology, Washington, DC, United StatesauthorNorris, Richard D.Woods Hole Oceanographic Institute, United StatesauthorLeckie, R. MarkUniversity of Massachusetts, United StatesauthorGeological Society of America (GSA), Boulder, CO, United StatespublisherdocumentHardcopyIn: Anonymous, Geological Society of America, 1999 annual meeting31 (7)251The Cenomanian/Turonian boundary interval (CTBI) at ODP Site 1050 (30 degrees 6'N, 76 degrees 14'W) yields an unusually well-preserved oxygen and carbon isotope profile for sediments of this age. Our study reveals that extinction of the deep-dwelling planktic foraminifer genus Rotalipora and Globigerinelloides bentonensis occurs at a level where middle bathyal waters increased from 15 to 19 degrees C, which is warmer than any other time during the Cretaceous and Cenozoic. The intermediate water warming may have caused a breakdown in the vertical structure of the water column, and could explain the extinction of the deeper dwelling planktic taxa. This warming event has also been identified from oxygen isotopic records of deep-sea planktic foraminifera in the southern high latitudes and is consistent with paleontological evidence for extreme warmth in the Arctic. On the other hand, sea surface temperature estimates based on planktic foraminiferal d18O values from Site 1050 (corrected for the modern day salinity gradient) remain steady throughout the CTBI, varying between 23 to 26 degrees C, which is within the range of subtropical SSTs today. Co-occurrence at Site 1050 of volcaniclastic sediments with the warmest benthic foraminiferal paleotemperatures supports previous speculation that there was a substantial increase in global volcanism and atmospheric pCO2 outgassing across the CTBI. If increased pCO2 was the primary mechanism driving the middle Cretaceous supergreenhouse then we must explain how heat was transported from the tropics to the poles with enough efficiency to maintain a latitudinal thermal gradient profile that was nearly flat.completedStratigraphyAtlantic OceanC-13/C-12carbonCenomanianCretaceousdeep-sea environmentextinctionForaminiferageothermal gradientheat flowInvertebrataisotope ratiosisotopesLeg 171Blower Turonianmarine environmentMesozoicmicrofossilsNorth AtlanticO-18/O-16Ocean Drilling ProgramODP Site 1050oxygenpaleoclimatologypaleotemperatureplanktonic taxaProtistasedimentsstable isotopesstratigraphic boundarytropical environmentTuronianupper CenomanianUpper Cretaceousvolcaniclasticsurn:org.iodp:exp:171BurnlargerWorkCitationcampaignurn:org.iodp:exp:171B:site:1050urnlargerWorkCitationstudyurn:org.iodp:exp:171BurnlargerWorkCitationcampaignEnglishgeoscientificInformation-76.1400-76.140030.060030.0600