georefid:2009-020475SEDIS 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=10.1130/G25193A.12009-01-01publicationgeorefid:2009-020475doi:10.1130/G25193A.1Newkirk, Derrick R.University of Florida, Department of Geological Sciences, Gainesville, FL, United StatesauthorMartin, Ellen E.authorGeological Society of America (GSA), Boulder, CO, United StatespublisherdocumentHardcopyGeology (Boulder)37 (1)87-90Changes in circulation associated with the shoaling of the Isthmus of Panama and the Caribbean carbonate crash in the Miocene were investigated using Nd isotopes from fossil fish teeth and debris from two sites in the Caribbean Basin (Ocean Drilling Program Sites 998 and 999) and two sites in the eastern equatorial Pacific (Sites 846 and 1241). The total range for epsilon (sub Nd) values measured from 18 to 4.5 Ma in the Caribbean is -7.3 to 0. These values are higher than Atlantic water masses (approximately -11) and range up to values equivalent to contemporaneous Pacific water masses, confirming that flow into the Caribbean Basin was composed of a mixture of Pacific and Atlantic waters, with an upper limit of almost pure Pacific-sourced waters. Throughout the Caribbean record, particularly during the carbonate crash (10-12 Ma), low carbonate mass accumulation rates (MARs) correlate with more radiogenic epsilon (sub Nd) values, indicating increased flow of corrosive Pacific intermediate water into the Caribbean Basin during intervals of dissolution. This flow pattern agrees with results from general ocean circulation models designed to study the effect of the shoaling of the Central American Seaway. Low carbonate MARs and high epsilon (sub Nd) values also correlate with intervals of increased Northern Component Water production and, therefore, enhanced conveyor circulation, suggesting that the conveyor may respond to changes in circulation associated with shoaling of the Central American Seaway. Reduced Pacific throughflow related to shoaling of the seaway led to a gradual increase in carbonate preservation and more Atlantic-like epsilon (sub Nd) values following the carbonate crash.completedStratigraphyAtlantic Oceanbiochemistrycarbonate sedimentsCaribbean SeaCenozoicCentral American SeawayChordataCocos RidgeColombian BasincorescurrentsEast PacificEquatorial PacificgeochemistryisotopesIsthmus of PanamaLeg 138Leg 165Leg 202marine sedimentsmetalsMioceneneodymiumNeogeneNorth Atlanticocean currentsOcean Drilling ProgramODP Site 1241ODP Site 846ODP Site 998ODP Site 999Pacific Oceanpaleo-oceanographypaleocirculationpaleogeographyPiscesrare earthssedimentationsedimentation ratessedimentsshoalingSouth PacificSoutheast PacificteethTertiaryVertebrataurn:org.iodp:exp:138urnlargerWorkCitationcampaignurn:org.iodp:exp:165urnlargerWorkCitationcampaignurn:org.iodp:exp:202urnlargerWorkCitationcampaignurn:org.iodp:exp:202:site:1241urnlargerWorkCitationstudyurn:org.iodp:exp:202urnlargerWorkCitationcampaignurn:org.iodp:exp:138:site:846urnlargerWorkCitationstudyurn:org.iodp:exp:138urnlargerWorkCitationcampaignurn:org.iodp:exp:165:site:998urnlargerWorkCitationstudyurn:org.iodp:exp:165urnlargerWorkCitationcampaignurn:org.iodp:exp:165:site:999urnlargerWorkCitationstudyurn:org.iodp:exp:165urnlargerWorkCitationcampaignEnglishgeoscientificInformation-90.4906-78.4422-3.054919.2923With GSA Data Repository Item 2009019