georefid:1999-027851SEDIS 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=1999-0278511991-01-01publicationgeorefid:1999-027851Dersch, MichaelaUniversitaet Giessen, Institut fuer Geowissenschaften und Lithosphaerenforschung, Giessen, Federal Republic of GermanyauthorStein, RuedigerauthorSpringer International, Berlin, Federal Republic of GermanypublisherdocumentHardcopyGeologische Rundschau80 (3)535-556Detailed sedimentological investigations were performed on sediments from DSDP-Site 594 (Chatham Rise, east of NZ) in order to reconstruct the evolution of paleoclimate and paleooceanographic conditions in the Southwest Pacific during the last 6 million years. The results can be summarised as follows: 1. High accumulation rates of biogenic opal and carbonate and the dominance of smectites in the clay fraction suggest increased oceanic productivity and an equable dominantly humid climate during the late Miocene. 2. During Pliocene times, decreasing contents of smectites and increasing feldspar/quartz ratios point to an aridification in the source area of the terrigenous sediments, culminating near 2.5 Ma. At that time, accumulation rates of terrigenous components distinctly increased probably caused by increased sediment supply due to intensified atmospheric and oceanic circulation, lowered sea level, and decreased vegetation cover. 3. A hiatus (1.45 to 0.73 Ma) suggests intensified intermediate-water circulation. 4. Major glacial/interglacial cycles characterize the upper 0.73 Ma. During glacial times, oceanic productivity and terrigenous sediment supply was distinctly increased because of intensified atmospheric and oceanic circulation and lowered sea level, whereas during interglacials productivity and terrigenous sediment supply were reduced. 5. An increased content of amphiboles in the sediment of Site 594 indicates increased volcanic activities during the last 4.25 Ma.completedStratigraphyAustralasiaCenozoicChatham RiseDeep Sea Drilling ProjectDSDP Site 594IPODLeg 90marine geologymarine sedimentsMioceneNeogeneNew ZealandPacific Oceanpaleo-oceanographypaleoclimatologyPleistocenePlioceneQuaternarysea-level changessedimentary petrologysedimentsSouth PacificSouthwest PacificTertiaryWest Pacificurn:org.iodp:exp:90urnlargerWorkCitationcampaignurn:org.iodp:exp:90:site:594urnlargerWorkCitationstudyurn:org.iodp:exp:90urnlargerWorkCitationcampaignGermangeoscientificInformation140.0000180.0000-40.0000-20.0000