Not just subduction but also erosion. Outside of dedicated digging efforts like deep mines or such, the fossils we find today are the ones close to the surface that are almost eroded and will be gone soon (on geologic timescales). There is a nice curious droid video on the topic whether a humans if they went extinct tomorrow, wouldn't create a fossil record similar to dinosaurs, simply because we've been on planet earth for a too short period. ▶ this video > What we have to remember is that they existed for over 165 million years, 3300 times longer than modern humans have been around and the number of creatures that lived in that time frame alone, not including very small insect-sized ones must be in the trillions. However, only a tiny number of those would have been in the right conditions to be quickly covered in sediment and then fossilized. Then millions of years later they happen to be exposed on the surface at just the right time before they are eroded away for us to find them. The latest estimate is that the total number of modern humans to have ever existed over the 50,000 years we have been around is about 107 billion. But 50,000 years is a very small slice of geological time and all of our 5000 years of recorded history would be a fraction of that, and the last 200 years or so since the industrial revolution, a tiny fraction of that again, maybe a razor-thin sliver of a darkened layer somewhere in the dozens of kilometers of limestone, siltstone, and shale of the future
in “Freshly made plutonium from outer space found on ocean floor” · View on HN