Dating rock piles

Dating rock piles is both the most important and the least important thing to do. If rock piles are recent - and I believe many are - then finding out their age might be a disappointment. From that point of view, dating the rock piles won't be your "smoking gun". But on the other hand it would be great if someone demonstrates a pre-colonial age for a rock pile here in New England. I think they have demonstrated middle woodland ages for rock piles in the south. If anyone knows about or has a suggestion on how to date a rock pile or a rock pile site, please leave a comment. Here are some possibilities. If you can explain any of them, it would be much appreciated. OSL - Optically Stimulated Luminescence. Surface Polish - how do you date that? Lichenometry - in some form. Pollen analysis - looking for chestnut pollen. C14 analysis of organic material from within or below the pile. The methods used to date ceramics or rocks which have been heated.