My brain loves to pretend that this is what happened for millions of years, but the truth is that it turns into dust and "dirt." Things still weather and get broken. Even stone turns to sand. But it takes longer than we're currently used to and the particles don't get processed. But this same event that the parent linked led to all our coal as well as an important niche that modern fungi hold today (they existed back then, but couldn't process the lignin. Interesting thing, there's a term called "evolutionary radiation" and this was one of the largest periods of time for this, but it is not related to the radiation in the context of Chernobyl.