Thermoluminescence Dating Studies of Lake Cores from Alaska

Glenn W. Berger gwberger@dri.edu  (Principal Investigator current)

Abstract    

     This award is in support of one element of paleoclimatology from Arctic
     Lakes and Estuaries (PALE).  Arctic lakes are recognized as valuable
     repositories of paleoenvironmental proxy information (e.g. fossil pollen,
     sediment chemistry) that is important for paleoclimatological studies. 
     However, beyond the usual 30-40 ka limit of radiocarbon dating, dating control
     needed form the interpretation of such fossil pollen records is presently
     unavailable.  Preliminary, single-analysis thermoluminescence (TL dating
     results have been obtained for one Arctic lake core (Squirrel Lake) to test the
     capability of TL dating for such Arctic sediments, but some results are
     ambiguous.  This award outlines TL dating and other tests(e.g. measurement of
     TL emission spectra) designed to assess the cause of these ambiguous,
     preliminary results for some samples for the Squirrel Lake core.  The proposed
     dating experiments will refine the limitations and usefulness of TL sediment
     dating procedures for Arctic lake sediments, provide the first
     "radiometrically" dated record beyond 30-40 ka for Arctic lakes, and provide a
     firmer basis for future application of TL dating to long-core (0-200 ka)
     sediment records for circumpolar Arctic lakes.