Extended Data Figure 1: Permafrost sample locality details.
From: Fifty thousand years of Arctic vegetation and megafaunal diet
a, Radiocarbon dating chronology for the main section at the Main River site, Russia, from which nearly all Main River samples are derived. b, View of the 2009 Duvanny Yar exposure, northeast Siberia. c, yedoma sandy silt in upper c. 12 m of the exposure at Duvanny Yar exposure, northeast Siberia. A large syngenetic ice wedge (top centre) within the yedoma is truncated by a thaw unconformity at a depth of c. 1.9 m below the ground surface, marking the maximum postglacial thaw depth after deposition of the yedoma had ended. People shown for scale, with DNA sediment sample holes to the right of the person on right. d, Calibrated radiocarbon date distributions plotted against depth above river level at Duvanny Yar exposure, northeast Siberia. Although there are some finite dates below ∼20 m, the general curve shape suggests the radiocarbon dating limit occurs at about this level. e, f, The two Svalbard sites at Colesdalen (e) and Endalen (f).
