More on rock pile half-life and site classification and chronology

Speaking (here) of damaged rock piles and estimating site age by the amount of the damage, or the proportion of damaged piles at the site (something I called rock pile half-life in these articles [you need to scroll down]), it is not such a crazy idea when construed statistically over a wide number of similar sites in a restricted region like east central Massachusetts. Take, for example, marker pile sites with triangular rock piles of which we have many examples, enough to comprise a legitimate statistical sample. And suppose, reasonably, that these are manifestations of a culture that existed in a limited part of the past - a time frame whose limits we want to estimate - or at least place in chronological order with other types of sites. It is certainly true that individual sites will have experienced different amounts of damage depending on later land use. If they were in an open field (I am thinking Manana Island) they might not get too quickly damaged. If they were subject to falling branches and trees, they might be more damaged. But over a large sample of sites the local differences in land use would average out in a restricted region. If you had a reasonable sample size for a different type of site, these same local variabilities would apply to them. To make a long story short: If over a collection of sites of one type there is more damage (on average) than for a collection sites of another type; then it is perfectly reasonable to conclude the more damaged sites are older. In this regard, there is no question that rock piles with hollows are significantly older than triangular rock piles.

I can almost create chronology now for these different types of rock piles:

• piles with hollows and tails
• piles with hollows and no tails
• piles with hollows, no tails, and in proximity to "ski-jump" shaped piles, evenly spaced and in lines.
• Evenly spaced triangular rock piles in lines and grids - with viewing platform or high point.

I like visual representations:For what it is worth these are also sort of regional:

• Rock piles with hollows and tails (A) are from Carlisle to northern Fitchburg.
• Rock piles with hollows and no tails (B) are from Leominster to Boylston to Hopkinton
• Rock piles with hollows and outlying ski jumps (C) are from Upton to Holliston
• Triangular rock piles (D) are pretty much everywhere.
  

I wonder how much of this is actually correct?