noaa-other-16996 Great Barrier Reef 5000 Year Mollusc Amino Acid Racemization Calibration Data Kosnik, M.A.; Kaufman, D.S.; Hua, Q. Great Barrier Reef 5000 Year Mollusc Amino Acid Racemization Calibration Data 2014-07-23 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/16996 Investigator M.A. Kosnik Investigator D.S. Kaufman Investigator Q. Hua earth science paleoclimate others geoscientificInformation 5000 cal yr BP 0 cal yr BP Complete -18.48 -18.48 146.88 146.88 Continent Australia/New Zealand Australia Rib Reef>LATITUDE -18.48>LONGITUDE 146.88 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

325 Broadway, E/NE31

Boulder CO 80305-3328 USA online ASCII Matthew A. Kosnik, Darrell S. Kaufman, Quan Hua 2008 Quaternary Geochronology 3 4 308-327 10.1016/j.quageo.2008.04.002 http://www.sciencedirect.com/science/journal/18711014/3

Numerical ages derived from amino acid racemization (AAR) geochronology are typically based on calibration curves that relate the extent of AAR to the age of independently dated specimens. Here, we compare options for developing calibration curves and quantifying age uncertainties using AAR data from 481 late Holocene shells, and AMS 14C analyses of 36 shells of four molluscan taxa (Ethalia, Natica, Tellina, and Turbo) collected from shallow sediment cores from a back-reef lagoon of the central Great Barrier Reef. The four taxa differed substantially in the quality of their geochronogical results. Explicitly including data from specimens alive at the time of collection improves calibration curves, but weighting numerical ages based on their uncertainty has no effect. Calibration curve statistics do not adequately assess calibration uncertainty. The relation between ages inferred from different amino acids is recommended for identifying aberrant specimens and quantifying the uncertainty of inferred ages. For this study, the AAR ages based on two amino acids (aspartic acid and glutamic acid) exceed 200 yr or 20% of their mean inferred age in ~15% of the specimens. Once these were removed, the mean age error (1sigma) for individual specimens based on two amino acids analyzed in duplicate subsamples ranged from 53 to 142 yr for Tellina and Turbo, respectively, or about a 30% age error for these relatively young shells. This compares favorably with analytical errors estimated at 50 yr or 5%. The presence of notable outliers undetectable using data from single amino acids emphasizes the importance of analyzing multiple amino acids. STUDY NOTES: Amino acid racemization (AAR) of Tellina, Ethalia, Turbo, and Natica shells from the Great Barrier Reef D/L aspartic acid and D/L glutamic acid in Tellina, Turbo, Ethalia, and Natica from sediment cores from the Great Barrier Reef, Australia are used to construct various calibration curves to find the best method for age estimation and determine outliers

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2008gbr/kosnik2008gbr.txt Text Data File; Great Barrier Reef Holocene Mollusc AAR Calibration Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2008gbr/kosnik2008gbr.xls Excel Data File; Great Barrier Reef Holocene Mollusc AAR Calibration Data USA/NOAA DIF Version 9.8.4 2019-03-27 2019-03-27