Paleomagnetism and biostratigraphy of sediments from Souther
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TitlePaleomagnetism and biostratigraphy of sediments from Southern Ocean ODP Site 744 (southern Kerguelen Plateau): Implications for early-to-middle Miocene climate in AntarcticaAbstractNew paleomagnetic results from lower-to-middle Miocene samples from Ocean Drilling Program (ODP) Holes 744A and 744B, cored during ODP Leg 119 on the southern Kerguelen Plateau (Indian Ocean sector; Southern Ocean), provide a chronostratigraphic framework for an existing and under-utilized paleoclimate archive during a key period of Antarctic climate and ice sheet evolution. Site 744 is strategically positioned for high-latitude paleoceanographic and paleoclimatic studies because it lies within the southern domain of the Antarctic Circumpolar Current (ACC) and in proximity to the large and active Lambert Glacier-Amery Ice Shelf drainage system of the East Antarctic Ice Sheet. Magnetostratigraphic results were reported previously for this site, but technical difficulties and limited sampling prevented confident correlation of the magnetic polarity record with the geomagnetic polarity timescale. Our results, which are constrained by new semi-quantitative analyses of diatom assemblages and radiolarian first and last appearance events that are evaluated within a regional Southern Ocean biostratigraphic dataset through Constrained Optimization (CONOP) model runs, permit significant refinement of previous age models for the lower-to-middle Miocene sequence recovered at Site 744 (spanning the interval from  . 21 to 13.7. Ma). An extended record of sediment accumulation, with average sedimentation rates of  . 0.7-0.9. cm/kyr, is interrupted by a series of hiatuses in the middle Miocene. These disruptions in sediment supply, or erosional events, could mark a local response of north-south fluctuations in the location and/or strength of the Antarctic Circumpolar Current during transient glacial events within the Mid-Miocene Climate Optimum (MMCO;  . 17 to 14.45. Ma). With the enhanced age control provided by this study, combined with a refined chronostratigraphy for the underlying upper Eocene to Oligocene strata, Site 744 becomes a good candidate for future high-resolution stable isotope and microfossil paleoecological work, which will further elucidate the late Paleogene and early Neogene paleoenvironmental history of the Southern Ocean. Copyright 2013 Elsevier B.V.AcknowledgementsWe thank the IODP for granting permission to work on the studied cores and IODP personnel at the Gulf Coast Repository for assistance with sampling. The IODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. IODP is supported by NSF, Japanś MEXT, ECORD, and the Peopleś Republic of China, Ministry of Science and Technology. This research was conducted in parallel with the investigation of the ANDRILL AND-2A drillcore in the western Ross Sea, which was supported by NSF through a Cooperative Agreement 0342484 with the University of Nebraska--Lincoln, which supported a portion of the graduate research of R. Farmer. Parts of this work benefitted from funding from the Italian National Antarctic Research Program (PNRA) to FF. Reviews and comments by Andrew Roberts, Matt Olney, an anonymous reviewer and the Guest Editor Ramon Egli helped to improve the manuscript.
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1st AuthorFlorindo, F.AuthorFlorindo, F.Farmer, R.Harwood, D.Cody, R.Levy, R.Bohaty, S.Carter, L.Winkler, A.Year2013JournalGlobal and Planetary ChangeVolume110Pages434-454DOI10.1016/j.gloplacha.2013.05.004URLhttps://www.scopus.com/inward/recor.....9f81ad4b3511c77ace4db9c24KeywordsAntarcticaCONOPKerguelen plateauMiocenePaleoclimatesPaleomagnetism, Constrained optimizationGeomagnetismGlaciersIsotopesOcean currentsSediments, Biostratigraphy, biostratigraphychronostratigraphygeoaccumulationgeomagnetic fieldice sheetice shelfmicrofossilMiocenepaleoecologypaleoenvironmentpaleomagnetismsediment analysissedimentation, Antarctic Circumpolar CurrentIndian OceanKerguelen PlateauSouthern Ocean, Bacillariophyta, rank3Author KeywordsAntarcticaCONOPDiatom biostratigraphyKerguelen PlateauMiocenePaleoclimatePaleomagnetism
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TypeArticleCitationFlorindo, F., Farmer, R., Harwood, D., Cody, R., Levy, R., Bohaty, S., Carter, L. and Winkler, A. (2013). Paleomagnetism and biostratigraphy of sediments from Southern Ocean ODP Site 744 (southern Kerguelen Plateau): Implications for early-to-middle Miocene climate in Antarctica. Global and Planetary Change, 110: 434-454 IdentifierFlorindo2013Relevancerank3
Winkler, A., Paleomagnetism and biostratigraphy of sediments from Souther , [Florindo2013]. Antarctica NZ, accessed 19/08/2026, https://adam.antarcticanz.govt.nz/nodes/view/63492, 10.1016/j.gloplacha.2013.05.004