THERMOLUMINESCENCE DATING OF AN ARCTIC LAKE CORE FROM ALASKA

Eight samples were selected from a 14 m core record from Squirrel Lake in the Alaskan Arctic for fine-grain, partial bleach thermoluminescence (TL) dating. Nine radiocarbon (C-14) ages were available for comparison. Three TL ages of 8.8 to 11.6 ka in the upper 2.5 m do not exceed calendar-corrected C-14 ages, suggesting that zeroing of light-sensitive TL in the detrital feldspars has been effective enough in this depositional environment to allow accurate dating of deeper core samples of similar sedimentology. TL ages of 60-65 ka for two samples in the 4.9-7 m depth range are consistent with an 'infinite' C-14 age of > 38.6 ka at 5.8 m. TL ages from 83+/-11 to 125+/-31 for three samples in the depth range 11-13.5 m suggest that this core record encompasses the last interglacial period (80-130 ka). These first TL ages for sediments from an Arctic lake core demonstrate the potential of the method for providing a directly measured chronology beyond the radiocarbon dating range in the climatically sensitive Arctic regions.