georefid:2006-077746georefid:2006-077737SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.2973/odp.proc.sr.198.102.2005<gco:CharacterString>An early late Paleocene event on Shatsky Rise, Northwest Pacific Ocean (ODP Leg 198); evidence from planktonic foraminiferal assemblages</gco:CharacterString>2006-01-01publicationgeorefid:2006-077746doi:10.2973/odp.proc.sr.198.102.2005Petrizzo, Maria RoseUniversita di Milano, Dipartimento di Scienze della Terra, Milan, ItalyauthorTexas A&M University, Ocean Drilling Program, College Station, TX, United StatespublisherdocumentDigitalIn: Bralower, Timothy J., Premoli Silva, Isabella, Malone, Mitchell J., Arthur, Michael A., Averyt, Kristen B., Bown, Paul R., Brassell, Simon C., Channell, James E. T., Clarke, Leon J., Dutton, Andrea, Eleson, Jason W., Frank, Tracy D., Gylesjo, Susanne, Hancock, Haidi J. L., Kano, Harumasa, Leckie, R. Mark, Marsaglia, Kathleen M., McGuire, Jennifer, Moe, K. T., Petrizzo, Maria Rose, Robinson, Stuart A., Roehl, Ursula, Sager, William W., Takeda, Kotaro, Thomas, Deborah, Williams, Trevor, Zachos, James C., Proceedings of the Ocean Drilling Program; scientific results; extreme warmth in the Cretaceous and Paleogene; a depth transect on Shatsky Rise, Central Pacific; covering Leg 198 of the cruises of the drilling vessel JOIDES Resolution; Yokohama, Japan, to Honolulu, Hawaii; Sites 1207-1214; 27 August-23 October 2001198A pulse of intense carbonate dissolution occurred during the early late Paleocene at 58.4 Ma. A prominent 5- to 25-cm-thick dark brown clay-rich calcareous nannofossil ooze was found on Shatsky Rise at Sites 1209, 1210, 1211, and 1212 during Ocean Drilling Program Leg 198. The layer corresponds to the lower part of planktonic foraminiferal Zone P4 and coincides with the evolutionary first occurrence of the nannolith Heliolithus kleinpellii, an important component of late Paleocene assemblages and a marker for the base of Zone CP5. The clay-rich layer contains common crystals of phillipsite, fish teeth, and phosphatic micronodules and corresponds to a prominent peak in magnetic susceptibility that probably reflects these high amounts of detrital and authigenic materials. Detailed quantitative analysis of planktonic foraminiferal assemblages across the clay-rich nannofossil ooze layer shows that fundamental changes in faunal composition occurred before, during, and after deposition of the clay-rich ooze. Planktonic foraminifers in the clay-rich layer are characterized by a low-diversity, largely dissolved assemblage dominated by representatives of the genus Igorina (mainly Igorina tadjikistanensis and Igorina pusilla). Conversely, Igorina albeari, morozovellids, acarininids, globanomalinids, subbotinids, and chiloguembelinids are common below the clay-rich layer, almost disappear within it, and reappear in low abundances above the clay-rich layer. These changes in faunal compositions are likely a response to a change in carbonate saturation that caused increased dissolution on the seafloor owing to the shoaling of the lysocline and the carbonate compensation depth.completedStratigraphyassemblagesbiostratigraphybiozonescarbonate compensation depthCenozoicForaminiferaInvertebrataLeg 198microfossilsNorth PacificNorthwest PacificOcean Drilling ProgramPacific Oceanpaleo-oceanographyPaleocenepaleoenvironmentPaleogeneProtistareconstructionShatsky RiseTertiaryupper PaleoceneWest Pacificurn:org.iodp:exp:198urnlargerWorkCitationcampaignEnglishgeoscientificInformation157.1500162.460031.340037.4800Available only on CD-ROM in PDF format and on the Web in PDF or HTML; includes appendixapplication/pdfunknownSEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContacthttp://www-odp.tamu.edu/publications/198_SR/VOLUME/CHAPTERS/102.PDFdownload