AMS radiocarbon dating of organic fractions from varved lake sediments: an empirical test of reliability

摘要: Replicate cores of annually laminated (varved) sediments have been used to test the accuracy and precision chronologies lake sediment accumulation over last 1000 years, based on AMS 14C measurements. The internally consistent results show that in case soft-water studied (Kassjon, northern Sweden), all organic fractions include aquatic components give significantly older dates than expected. Only single terrestrial macrofossil fine, unidentified residual particulate fraction provide close true age sediments. also discrepancies for some are not constant time. may arise from carbon reservoir effect within ecosystem, resuspension focusing marginal material into deepest part or combination these processes. More work is needed ‘age’ varve-dated a range types.