re: #33 austin_blue
Why? Tectonics won’t affect that kind of coffin. The concept is that the coffins will be subducted with other ocean sediments and recycled into the upper mantle, where the radioactive elements in place in the first place
Not really. Anything you just dump into a trench at a subduction boundary will end up being scrapped off into the sedimentary melange as the heavier oceanic basaltic plate is dragged under. It will likely be deeply buried but it is very unlikely that it will actually end up going for the long plunge into the mantle.
Tectonic melanges are interesting geologic assemblages and are typified by high pressure/low temp metamorphism (blue schist-glaocophane).