georefid:2004-011512georefid:2004-011510SEDIS 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.186.106.2003<gco:CharacterString>Middle Miocene to Pleistocene diatom biostratigraphy of the Northwest Pacific at sites 1150 and 1151</gco:CharacterString>2003-01-01publicationgeorefid:2004-011512doi:10.2973/odp.proc.sr.186.106.2003Maruyama, ToshiakiYamagata University, Department of Earth and Environmental Sciences, Yamagata, JapanauthorShiono, MasamichiCarnegie Institution of Washington, United StatesauthorTexas A&M University, Ocean Drilling Program, College Station, TX, United StatespublisherdocumentDigitalIn: Suyehiro, Kiyoshi, Sacks, I. Selwyn, Acton, Gary D., Acierno, Michael J., Araki, Eiichiro, Ask, Maria V. S., Ikeda, Akihiro, Kanamatsu, Toshiya, Kim, Gil Young, Li, Jingfen, Linde, Alan T., McWhorter, Paul N., Mora, German, Najman, Yanina M. R., Niitsuma, Nobuaki, Pandit, Benoy K., Roller, Sybille, Saito, Saneatsu, Sakamoto, Tatsuhiko, Shinohara, Masanao, Sun, Yue-Feng, Proceedings of the Ocean Drilling Program, scientific results, Western Pacific geophysical observatories; covering Leg 186 of the cruises of drilling vessel JOIDES Resolution; Yokohama, Japan, to Yokohama, Japan; sites 1150 and 1151, 14 June-14 August 1999186Late Neogene biostratigraphy of diatoms has been investigated from two sites occupied during Ocean Drilling Program (ODP) Leg 186 off the coast of northeast Japan. A unique aspect of ODP Leg 186 was the installation of two permanent borehole geophysical observatories at the deep-sea terrace along the Japan Trench. The Neogene subsidence history of the forearc was documented from both Sites 1150 and 1151, and Quaternary to middle Miocene (16 Ma) sediments represent a nearly continuous stratigraphic sequence including numerous ash records, especially during the past 9 m.y. Diatoms are found in most samples in variable abundance and in a moderately well preserved state throughout the sequence. The assemblages are characterized consistently by age-diagnostic species of Denticulopsis and Neodenticula found in regions of high surface water productivity typical of middle to high latitudes. The Neogene North Pacific diatom zonation divides the Miocene to Quaternary sequences fundamentally well, except that the latest Miocene through early Pliocene Thalassiosira oestrupii Subzone is not applicable. Miocene and late Pliocene through Pleistocene diatom datum levels that have been proven to be of great stratigraphic utility in the North Pacific Ocean appear to be nearly isochronous within the level of resolution constrained by core catcher sample spacing. The taxonomy and stratigraphy of previously described species determined to be useful across the Miocene/Pliocene boundary have been investigated on the basis of the evolutionary changes within the Thalassiosira trifulta group. The biostratigraphically important forms belonging to the genus Thalassiosira have been illustrated with scanning electron micrographs.completedStratigraphyalgaeassemblagesbiostratigraphybiozonesCenozoicdiatomsJapan TrenchLeg 186marine sedimentsmicrofossilsmiddle MioceneMioceneNeogeneNorth PacificNorthwest PacificOcean Drilling ProgramODP Site 1150ODP Site 1151Pacific OceanPlantaePleistoceneQuaternarysedimentsSEM dataspecies diversityTertiaryThalassiosiraWest Pacificurn:org.iodp:exp:186urnlargerWorkCitationcampaignurn:org.iodp:exp:186:site:1150urnlargerWorkCitationstudyurn:org.iodp:exp:186urnlargerWorkCitationcampaignurn:org.iodp:exp:186:site:1151urnlargerWorkCitationstudyurn:org.iodp:exp:186urnlargerWorkCitationcampaignEnglishgeoscientificInformation143.2000143.200038.450039.1100Includes appendix; available only on CD-ROM in PDF format and on the Web in PDF or HTMLapplication/pdfunknownSEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContacthttp://www-odp.tamu.edu/publications/186_SR/VOLUME/CHAPTERS/106.PDFdownload