Archaeologists have finally cracked what all those stones were for submerged beneath Lake Huron. At www.sciencenews.org/blog/science-ticker/lake-huron-holds-9000-year-old-h… … a reference to stones laid out in a linear fashion that were found a couple of years ago underneath the waters of Lake Huron. Caribou and other game was driven into a centralised 'killing zone' according to an article in PNAS April 28th 2014
The same story is fleshed out at http://popular-archaeology.com/issue/03012014/article/9-000-year-old-car… …. underwater archaeologists discovered mysterious rock structure on a ridge beneath Lake Huron – which was human made. One of them consists of two parallel rock lined paths used to funnel game into an 8m wide lane – preceded by a V shaped fan structure set above the lane. It seems hunters became aware caribou and other ungulates had a tendency to follow linear features – and constructed the linear structures to take advantage of this and entice them into what was a killing zone. Lots of similar structures have survived in the Arctic zone but in more temperate climes traces of them are lost.