Fossilised wood

Darwin first encountered fossilised wood on the island of Chiloé, and later made significant finds high up in the Andes. He lyrically compared the snow-white forest of 50 still-standing, petrified trees, near the summit of the Uspallata Range, to ‘Lot’s Wife’ from the Biblical story, and was able to draw several significant conclusions. He realised that the same process of ‘permineralisation’ had operated both in the far distant and relatively recent geological past, and that the trees at Uspallata had to have been below sea level when they became fossilised, and then raised gradually up with the mountain chain. For Darwin, fossilised wood was evidence of the past history of the region: ‘I can show that this grand chain consisted of Volcanic Islands, covered with luxurious forests; some of the trees, one of 15ft in circumference, I have seen silicified & imbedded in marine strata.’