Southern Ocean Oligocene to early Miocene Paleoceanographic Data Anderson, L.D.; Delaney, M.L. Anderson, L.D. Delaney, M.L. earth science/paleoclimate/paleoceanography (barium excess,sediment,null,micromole per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (mineral matter,sediment,null,weight percent,null,paleoceanography,null,null,N,determined as total sediment % minus carbonate % minus biogenic silica %) earth science/paleoclimate/paleoceanography (manganese,sediment,null,micromole per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (biogenic silica,sediment,null,millimole per square centimeter per kiloyear,null,paleoceanography,null,null,N,mass accumulation rate) earth science/paleoclimate/paleoceanography (phosphorus,sediment,null,micromole per gram,null,paleoceanography,null,null,N,reactive) earth science/paleoclimate/paleoceanography (phosphorus,sediment,null,micromole per gram,null,paleoceanography,null,null,N,detrital phosphorus) earth science/paleoclimate/paleoceanography (age,null,null,radiocarbon year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (barium,sediment,null,micromole per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (barium excess,sediment,null,micromole per square centimeter per kiloyear,null,paleoceanography,null,null,N,accum. rate) earth science/paleoclimate/paleoceanography (phosphorus,sediment,null,unspecified unit,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (calcium carbonate,sediment,null,millimole per square centimeter per kiloyear,null,paleoceanography,null,null,N,accum. rate) earth science/paleoclimate/paleoceanography (calcium carbonate,sediment,null,weight percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (uranium,sediment,null,nanomole per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (biogenic silica,sediment,null,weight percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (aluminum,sediment,null,parts per million,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (mineral matter,sediment,null,gram per square centimeter per kiloyear,null,paleoceanography,null,null,N,terrigenous sediment mass accumulation rate determined as Total MAR - carbonate MAR - biogenic silica MAR) earth science/paleoclimate/paleoceanography (titanium,sediment,null,micromole per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 1090>LATITUDE -42.908333>LONGITUDE 8.9) Ocean Drilling Program (ODP) Site 1090, on the Agulhas Ridge in the South Atlantic sector of the Southern Ocean, is ideally located to capture changes in Southern Ocean circulation patterns. Using samples taken from cored sediments, we construct multiproxy records of productivity (biogenic barium (Baex), opal, and CaCO3 mass accumulation rates (MARs)), nutrient and organic carbon burial (reactive phosphorus (Pr) MARs), and redox conditions (U and Mn enrichments) to investigate hydrographic conditions associated with climatic shifts from the Oligocene through the early Miocene. Orbitally induced cyclicity in U and Mn enrichments (100 kyr) suggests shifts in deepwater characteristics. However, CaCO3 dissolution coincident with low U and Mn enrichments does not indicate low-oxygen, corrosive waters similar to modern conditions. These observations indicate that a well developed ""modern-type"" Antarctic Circumpolar Current (ACC) did not yet exist over the period from 30 to 20 Ma, with two potential consequences: The Southern Ocean was not functioning as a silica trap, permitting a broader distribution of silica that may have facilitated organic carbon burial in the ocean in general, and the lack ofa deeply mixing ACC may have facilitated organic carbon burial in the Southern Ocean. Both the relative (high opal MARs coincident with low CaCO3 MARs) and absolute (high Pr MARs) burial of organic carbon suggest a powerful mechanism for pCO2 drawdown. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Anderson, L.D. Investigator : Delaney, M.L. 2005-01-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/2628 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1090d-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2005b https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1090d-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2005b English https://www.ncdc.noaa.gov/paleo/study/2628 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1090d-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2005b Anderson, L.D. and M.L. Delaney. 2005. Use of multiproxy records on the Agulhas Ridge, Southern Ocean (Ocean Drilling Project Leg 177, Site 1090) to investigate sub-Antarctic hydrography from the Oligocene to the early Miocene. Paleoceanography 20(3), PA3011. doi:10.1029/2004PA001082 START YEAR: 29750964 14C yr BP * END YEAR: 20120856 14C yr BP 8.9 -42.908333 8.9 -42.908333