Radiocarbon dates of the humic acid free fraction (HAF) and the humic acid fraction (HA) from bulk sediment samples of core Lz1021, Fryxell basin. All dates were calibrated into calendar years before present (cal. yr BP) using the calibration program CALIB 5.0 and the SHCal04 and INTCal04 data sets (Stuiver and Reimer, 1993; McCormac et al., 2004; Reimer et al., 2004), after subtracting a reservoir effect of 2475 yr (corr. yr BP), corresponding with the radiocarbon age of the surface sediment, from the radiocarbon ages (14C yr BP). Means and uncertainties were calculated from the lowest and highest dates at the 2sigma probability distribution.