Just read that the oldest known wooden structure predates modern humans by 200,000 years

I stumbled on a paper about the Kalambo Falls excavation in Zambia and found out those logs with cut marks are from 476,000 years ago, way before Homo sapiens even showed up. How do archaeologists even date wood that old without it rotting to dust?

2 comments

2 Comments

king.aaron1mo ago

Huh, "wooden structure predates modern humans" is wild enough without the preservation question. They date it by looking at the sediment layers around the wood where it was buried, and the wood itself gets preserved when it's waterlogged in a bog or riverbank for hundreds of thousands of years. So it's not rotted to dust because it's been soaked in that wet, oxygen-free environment the whole time.

casey_lane731mo ago

Whoa, hang on @king.aaron, I gotta respectfully disagree a bit here. I mean, yeah, waterlogging can preserve wood for a long time, but hundreds of thousands of years? That's a stretch in my book. Most wood in those anaerobic bog conditions still breaks down slowly or gets crushed by sediment over tens of thousands of years, let alone 500,000. I've seen studies where even well-preserved bog wood from way more recent ice ages is super fragile and fragmented, not a whole structure you can easily date. Plus, dating based on sediment layers around the wood is tricky, those layers can get mixed up or shifted by ancient floods and stuff. Your mileage may vary, but I'm skeptical that any wood could hold up that long in one piece, even in a perfect oxygen-free spot.