Great Barrier Reef 5000 Year Mollusc Amino Acid Racemization Data Kosnik, M.A.; Hua, Q.; Jacobsen, G.E.; Kaufman, D.S.; Wüst, R.A. Kosnik, M.A. Hua, Q. Jacobsen, G.E. Kaufman, D.S. Wüst, R.A. earth science/paleoclimate/others (Rib Reef>LATITUDE -18.48>LONGITUDE 146.88) Radiocarbon-calibrated amino acid racemization ages of 250 individually dated Tellina shells from two sediment cores are used to quantify molluscan time averaging with increasing burial depth in the shallow-water carbonate lagoon of Rib Reef, central Great Barrier Reef, Australia. The top 20 cm of sediment contain a distinct, essentially modern assemblage with a median age of only 5 yr. Sediment between 20 and 125 cm are age-homogeneous and significantly older than the surface sediment (median age 189 yr). Shell age distributions within layers indicate that the top 125 cm of lagoonal sediment is thoroughly mixed on a subcentennial scale. Shell size is an important correlate of shell half-life and an important determinant of the inferred age of sedimentary layers. These results illustrate the importance of bioturbation in these environments, indicate that age estimates in this depositional setting are sensitive to specimen choice, and document a size-dependent bias in death assemblage formation. STUDY NOTES: D/L aspartic acid, glutamic acid, and serine (Amino Acid Racemization [AAR]) in Tellina casta from sediment cores from Rib Reef, Great Barrier Reef, Australia NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Kosnik, M.A. Investigator : Hua, Q. Investigator : Jacobsen, G.E. Investigator : Kaufman, D.S. Investigator : Wüst, R.A. 2014-07-23 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/16994 https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2007gbr/kosnik2007gbr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2007gbr/kosnik2007gbr.xls https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2007gbr/kosnik2007gbr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2007gbr/kosnik2007gbr.xls English https://www.ncdc.noaa.gov/paleo/study/16994 https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2007gbr/kosnik2007gbr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/aar/kosnik2007gbr/kosnik2007gbr.xls Matthew A. Kosnik, Quan Hua, Geraldine E. Jacobsen, Darrell S. Kaufman, and Raphael A. Wüst2007Sediment mixing and stratigraphic disorder revealed by the age-structure of Tellina shells in Great Barrier Reef sedimentGeology359811-81410.1130/G23722A.1http://geology.gsapubs.org/content/35/9/811.abstract START YEAR: 5000 cal yr BP * END YEAR: 0 cal yr BP 146.88 -18.48 146.88 -18.48