Southeast Atlantic ODP1262 Upper Paleocene/Lower Eocene Isotope Data Zachos, J.C.; McCarren, H.; Murphy, B.; Röhl, U.; Westerhold, T. Zachos, J.C. McCarren, H. Murphy, B. Röhl, U. Westerhold, T. carbon cycle earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,composited,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,carbonate,null,per mil,null,paleoceanography,null,null,N,bulk sediment) earth science/paleoclimate/paleoceanography (delta 13C,carbonate,null,per mil,null,paleoceanography,null,null,N,bulk sediment) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 1262>LATITUDE -27.186>LONGITUDE 1.577) The upper Paleocene and lower Eocene are marked by several prominent (>1‰) carbon isotope (d13C) excursions (CIE) that coincide with transient global warmings, or thermal maxima, including the Paleocene-Eocene Thermal Maximum (PETM). The CIE, which are recorded mainly in marine sedimentary sequences, have also been identified in continental sequences, occurred episodically, and yet appear to be paced or triggered by orbital forcing. To constrain the timing and scale of the CIE relative to long-term baseline variability, we have constructed a 4.52 million year (myr) long, high-resolution (~3 kyr) bulk sediment carbon isotope record spanning the lower Eocene to upper Paleocene (C25r-C24n) from a pelagic sediment section recovered at ODP Site 1262 in the southeast Atlantic. This section, which was orbitally-tuned utilizing high-resolution core log physical property and geochemical records, is the most stratigraphically complete upper Paleocene to lower Eocene sequence recovered to date. Time-series analysis of the carbon isotope record along with a high- resolution Fe intensity record obtained by XRF core scanner reveal cyclicity with variance concentrated primarily in the precession (21 kyr) and eccentricity bands (100 and 400-kyr) throughout the upper Paleocene-lower Eocene. In general, minima in d13C correspond with peaks in Fe (i.e., carbonate dissolution), both of which appear to be in phase with maxima in eccentricity. This covariance is consistent with excess oceanic uptake of isotopically depleted carbon resulting in lower carbonate saturation during periods of high eccentricity. This relationship includes all late Paleocene and early Eocene CIE confirming pacing by orbital forcing. The lone exception is the PETM, which appears to be out of phase with the 400-kyr cycle, though possibly in phase with the 100-kyr cycle, reinforcing the notion that a mechanism other than orbital forcing and/or an additional source of carbon is required to account for the occurrence and unusual scale of this event. STUDY NOTES: Bulk sediment carbon and oxygen isotope record for the composite sections from Ocean Drilling Program Holes 1262A, B, and C. ODP Site 1262: 27°11.160'S, 1°34.620'E, 4755m water depth NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Zachos, J.C. Investigator : McCarren, H. Investigator : Murphy, B. Investigator : Röhl, U. Investigator : Westerhold, T. 2012-07-10 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/13134 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/zachos2010/zachos2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/zachos2010/zachos2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/zachos2010/zachos2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/zachos2010/zachos2010.txt English https://www.ncdc.noaa.gov/paleo/study/13134 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/zachos2010/zachos2010.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/zachos2010/zachos2010.txt Zachos, J.C., H. McCarren, B. Murphy, U. Röhl, and T. Westerhold. 2010. Tempo and Scale of Late Paleocene and Early Eocene Carbon Isotope Cycles: Implications for the Origin of Hyperthermals. Earth Planet. Sci. Lett., Vol. 299, pp. 242-249. doi:10.1016/j.epsl.2010.09.004 START YEAR: 56600000 cal yr BP * END YEAR: 52100000 cal yr BP 1.577 -27.186 1.577 -27.186