Not sure it will because it's a very short time period that plastics have existed geologically speaking and the time periods found in rock/soil/ice are generall

Not sure it will because it's a very short time period that plastics have existed geologically speaking and the time periods found in rock/soil/ice are generally pretty imprecise until we can relate them to something like tree rings that show precise year cycles where there's a large event like a fire that shows up in both the rock/soil layer and in trees. Generally without large anchoring events like that the best we get is very large time frames for events and mostly in relation to other events in the local area where you can measure forwards and backwards (up and down in the rock formation) relative to other events.