Skip to main content
    • Aa
    • Aa

Enhanced Age Resolution of the Marine Quaternary Record in the Arctic Using Aspartic Acid Racemization Dating of Bivalve Shells

  • Glenn A. Goodfriend (a1), Julie Brigham-Grette (a2) and Gifford H. Miller (a3)

Aspartic acid (Asp) racemization occurs at a significantly higher rate than isoleucine epimerization and consequently provides better temporal resolution of Arctic marine deposits (from Alaska, Spitsbergen, and Baffin Island). Heating experiments (at 100°C) on the bivalves Mya and Hiatella show the Asp racemization rate decreases with increasing D/L values, as is typical for biogenic carbonates. Based on these experimental racemization rates and rates determined from racemization of samples radiocarbon dated to ca. 10,000–12,000 yr B.P., activation energies for Mya and Hiatella are estimated to be 30.6 and 30.0 kcal/mol, respectively, for Asp racemization, and 29.0 and 29.5 for isoleucine epimerization. Analysis of a time series of Plio–Pleistocene Hiatella from the north coast of Alaska shows that last-interglacial mollusks can be readily distinguished from modern samples by Asp but not by isoleucine. D/L Asp values indicate a younger age for the Fishcreekian transgression than does isoleucine epimerization. For Spitsbergen, D/L Asp shows a slight age difference (ca. 12,000 yr) between two units of the “episode B” interstadial and suggests that the age of these units may be closer to 65,000 than to 80,000 yr B.P., two possible ages suggested by other evidence. The age of the Loks Land Interstadial on Baffin Island is likely to be greater than that indicated by radiocarbon ages. Within deposits from each region, D/L Asp values are less variable among individual shells than isoleucine epimerization values. This may indicate better reliability of Asp for geochronology.

Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

G. H. Miller S. Funder A. de Vernal , and J. T. Andrews (1992). Timing and character of the last interglacial-glacial transition in the eastern Canadian Arctic and northwest Greenland. In “The Last Interglacial-Glacial Transition in North America” ( P. U. Clark and P. D. Lea , Eds.), pp. 223231. Geological Society of America Special Paper 270, Boulder, CO.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Quaternary Research
  • ISSN: 0033-5894
  • EISSN: 1096-0287
  • URL: /core/journals/quaternary-research
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Abstract views

Total abstract views: 16 *
Loading metrics...

* Views captured on Cambridge Core between 20th January 2017 - 28th March 2017. This data will be updated every 24 hours.