Thanks, great answer. So it's not that sediments in the ocean can't be found so much as they don't stay around that long you'd find enough of it to be able to account for that massive glacial erosion event, due to tectonic movement?
So we still have ocean crust from when T. rex lived, for instance, but none from when trilobites lived, and definitely none from the time of these glaciations.
How mindblowing to imagine. We should make a simulation of the entire earth history where you could follow the atoms and molecules from the birth in stars to the forming of the earth and then through forming of continents, erosion, sedimentation, subduction, eruption as lava, etc. etc. Of course we only know a partial history of a fraction of material in these longterm cycles but still, it would be a nice way for our brains to get a moving simulation of all that science learned about the Earth System History. It would beat Google Earth or a planetarium or universe simulator. You could watch the neighbourhood you live in and follow it back in time for as far as we know.
Maybe this is the simulation.
Once the crust gets deeper in the mantle, eventually metamorphic phase transitions become the most important factor. In some seismic images, it looks like subducted slabs make it all the way to the core-mantle boundary (where they may contribute to the source of new mantle plumes).
For sure, I would love to have that simulation!
Still, it would be a cheap research project with big science returns like the Hubble Ultra-Deep Field, Dark Energy Survey or Sloan Digital Sky Survey did for cosmology.
Thank you for your answers, I now have a few weeks of science papers to read and follow up on.