Hollows in Rock Piles - a discussion

[Photos by Tim Fohl, of Whipple Hill, Lexington]

P says:
We have seen numerous examples of large rock piles which have a scooped-out place on their upper surface; and we have debated (at least Tim and I have) whether this might be an architectural feature (a deliberate seat or nest to sit in) or if it corresponds to vandalism where someone started to dig a hole into the rock pile.

Here is some evidence in favor of it being vandalism not architecture:

I went back to take other photos of the rock pile I featured in last week's "Rock Pile Picture of the week". I noticed that the retaining wall is very well formed all the way around the pile except directly below the scooped-out hollow that is visible in the middle of the photo I sent. At that one spot below the hollow (mostly blocked by a tree trunk at the lower left of the photo) the retaining wall was broken down and the larger rocks scattered a few feet away from the pile. If the hypothesis is "architecture" then it does not seem too good an explanation for messing up a nice retaining wall in one spot. On the other hand if the hypothesis is vandalism then this almost predicts that the retaining wall would be damaged near where other damage occurred. It certainly provides a clear rationale for such damage. To me this says that vandalism is a better explanation than architecture for what we see exemplified here.

These hollows are quite common and I rarely see a large pile which does not already have one. A classic example is John Hansen Mitchell's "Turtle Mound" which he writes about in "Tresspassing" and which is located just uphill from the corner of Nagog Hill Rd and Fort Pond Rd in Littleton. That rock pile has a hollowed scoop. Another classic example is a large mound of cobbles over the reservoir which Bruce MacAlleer showed me in Weston [I think Tim has also seen this one]. It seems likely, if one accepts the "vandalism" explanation, that somebody vandalised a lot of piles and did it pretty systematically. From this we can draw some other conclusions: one is that digging up rock piles must have been part of a standard activity known to a group of people (we see it at widely different places from Weston, to Stow, to Littleton).
C says:
The widespread folk belief that rock piles contain burials and grave goods, rather than any actual recovery of such goods, might also account for vandalism.

N says:
Vision quest sites in Ontario and elsewhere north of the border (and here, too?) often consisted of stone lined pits in the ground, rather than the U-shaped prayer seats found in the far West and Canada. If I'm not mistaken, these hollowed-out features are called Pukaskwa pits or oracle grots. You might consider this possibility for the scooped out pits in rock piles.


T says:
I think some of these scooped out places are part of the original design. They are seen in a wide variety of places. There is a whole complex of mounds with scooped hollows at Perch Lake near the St Lawrence. They are being studied by Juliann Van Nest of the NY Museum. A picture is attached. The big mound at Whipple Hill has a scooped top and several "seats" in the sloping sides. These are quite regular and show no signs of disorderly spill from digging into the structure. There is a good example of a dug into structure on the Conant Land and the stones are scattered around the base fairly obviously.