Thoughts on archiving older general posts

I was wondering if there was a way to archive much older inactive threads (maybe which have not been contributed to for over 2 year for instance) as recently there have been a few 9 or 10 year old posts which new visitors to the site are dragging up from the distant past and even answering the original questions which are no longer valid.     It is muddling up the newer posts as we sift through the out of date threads and would be better if these old posts were archived.     Just a thought although I'm not convinced that anyone in authority to action things are even going to read this  !!        worth a try at least :)     Have changed the title as don't expect the changes can be done without a lot more sifting to eliminate the  2 - 10 year old general posts which don't offer help topics.