Averaged probability density functions for different sample types
a, b, Averaged probability density functions for different sample types (Extended Data Fig. 3, Supplementary Note 5 and Supplementary Data 1). a, Samples susceptible to inbuilt age. Light blue, whale bone (n = 1, uncorrected for marine reservoir effect); red, wood (n = 17); brown, burnt wood (n = 7); black, charcoal (n = 22). b, Short-lived samples. Light green, turf or sod from the Norse buildings (n = 4); olive, outermost rings and twigs from Norse-modified wood (n = 4). c, Wiggle-matched probability density functions for the last growth ring of each wood item. Dark green, 4A 59 E3-1; navy, 4A 68 J4-6; orange, 4A 68 E2-2.