South China Sea ODP1148 Neogene Benthic Foraminiferal Isotope Data Tian, J.; Zhao, Q.; Wang, P.X.; Li, Q.Y.; Cheng, X. Tian, J. Zhao, Q. Wang, P.X. Li, Q.Y. Cheng, X. earth science/paleoclimate/paleoceanography (delta 13C,Cibicidoides sp.,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (lightness,sediment,null,dimensionless,null,paleoceanography,null,null,N,L* on CIE scale) earth science/paleoclimate/paleoceanography (delta 18O,Uvigerina sp.,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,radiocarbon year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (gamma radiation,sediment,null,count per second,null,paleoceanography,null,null,N,natural radiation signature) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 1148>LATITUDE 18.836>LONGITUDE 116.566) General global cooling over the Neogene has been modulated by changes in Earth's orbital parameters. Investigations of deep-sea sediment sequences show that various orbital cycles can dominate climate records for different latitudes or for different time intervals. However, a comprehensive understanding of astronomical imprints over the entire Neogene has been elusive because of the general absence of long, continuous records extending beyond the Pliocene. We present benthic foraminiferal d18O and d13C records over the past 23 Ma at Ocean Drilling Program Site 1148 in the northern South China Sea and construct an astronomically tuned timescale (TJ08) for these records based on natural gamma radiation and color reflectance data at this site. Our results show that a 41 ka cycle has dominated sediment records at this location over the Neogene, displaying a linear response to orbital forcing. A 100 ka cycle has also been significant. However, it is correlated nonlinearly with Earth's orbital variations at the 100 ka band. The sediment records also display a prominent 405 ka cycle. Although this cycle was coherent with orbital forcing during the Oligocene and the early Miocene, it was not coherent with Earth's orbital variations at the 405 ka band over the whole Neogene. Amplification of Northern Hemisphere and Southern Hemisphere glaciation since the middle Miocene may be responsible for this change in sedimentary response. Our benthic foraminifera d18O and d13C records further exhibit amplitude variations with longer periods of 600, 1000, 1200, and 2400 ka. Apparently, these cycles are nonlinear responses to insolation forcing. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Tian, J. Investigator : Zhao, Q. Investigator : Wang, P.X. Investigator : Li, Q.Y. Investigator : Cheng, X. 2008-07-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/6415 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1148-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tian2008 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1148-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tian2008 English https://www.ncdc.noaa.gov/paleo/study/6415 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1148-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tian2008 Tian, J., Q. Zhao, P. Wang, Q. Li, and X. Cheng. 2008. Astronomically modulated Neogene sediment records from the South China Sea. Paleoceanography, 23, PA3210. START YEAR: 23103000 14C yr BP * END YEAR: 0 14C yr BP 116.566 18.836 116.566 18.836