noaa-other-11199 Atlantic 2MYr Foraminiferal Amino Acid Racemization Data Kvenvolden, K.A.; Peterson, E.; Wehmiller, J.F.; Hare, P.E. Atlantic 2MYr Foraminiferal Amino Acid Racemization Data 2011-05-23 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/11199 Investigator K.A. Kvenvolden Investigator E. Peterson Investigator J.F. Wehmiller Investigator P.E. Hare earth science paleoclimate others geoscientificInformation 2000000 cal yr BP 40000 cal yr BP Complete 17 17.63 -74.4 -45.87 -3746 -2800 Ocean Atlantic Ocean North Atlantic Ocean V23-110>LATITUDE 17.63>LONGITUDE -45.87 Ocean Pacific Ocean North Pacific Ocean V12-122>LATITUDE 17>LONGITUDE -74.4 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Kvenvolden, K.A., E. Peterson, J. Wehmiller, and P.E. Hare. 1973. Racemization of amino acids in marine sediments determined by gas chromatography. Geochimica et Cosmochimica Acta, Vol. 37, Issue 10, October 1973, pp. 2215-2225. doi:10.1016/0016-7037(73)90100-2

Ratios of D- to L-amino acids in acid hydrolysates from foraminifera of two deep-sea cores from the Caribbean Sea and Atlantic Ocean increase with depth and consequently with age over a span from 40,000 to 2,000,000 yr. The changing ratios do not seem to follow first-order reversible rate laws. Valine, leucine and glutamic acid apparently racemize (isoleucine epimerizes) at slower rates than do phenylalanine, alanine, aspartic acid and proline. The general relative order for rates of racemization of total (free and bound) amino acids may depend on the electron-withdrawing capacity of the R substituents of the amino acids and on the rates with which the amino acids are naturally hydrolyzed. In contrast to the total amino acids, the free amino acids in these samples are more extensively racemized, probably as a result of various catalytic and hydrolytic reactions. Previous related work based on ion-exchange chromatography has considered only ratios of alloisoleucine to isoleucine. With the gas chromatographic method used here, D/L ratios of all common asymmetric amino acids can be estimated. Measurement of the extent of racemization of amino acids in marine sediments seems to provide the basis for a geochronological tool covering the last few million years. STUDY NOTES: Measurement of D/L values for nine amino acids from mixed foraminfera samples from sediment cores from Atlantic and Caribbean cores. Wehmiller, J.F. , 1971. Diagenesis of amino acids in fossil calcerous organisms. PhD dissertation, Columbia University, Dept. of Geology, New York. 329 pp.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kvenvolden1973forams/kvenvolden1973forams.txt GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kvenvolden1973forams/kvenvolden1973forams.xls USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11