Fig. 3From: Coloring mechanisms of ancient buried wood: Japanese cedar trees excavated from the foothills of Mt. ChokaiInfrared photoacoustic spectra in the 2000–800 cm−1 region for (a) modern Japanese cedar (heartwood, black solid line), (b) UW1-1 (heartwood, red solid line), (c) UW1-2 (sapwood, blue solid line), and (d) UW2 (heartwood, green solid line)Back to article page