A Falmouth Kettle Hole and a Hypothesis about Marker Piles

A few years ago Mavor gave me copies of his topo maps for the Falmouth area - fragments of the larger map - and, over time, I have been able to match the features on his fragments to known landmarks on bigger maps, to see how to get to the places. Over time, I located most of his sites but there was one I could not figure out, showing four rock piles near the notation "chamber". Working harder at map matching before coming down to the Falmouth area this summer, I figured out where this spot was and realized it was a kettle hole site I knew about. But I never found four rock piles (I remembered two or three) and the notation "chamber" was intriguing since it was mentioned several times in Manitou that there were no stone chambers on the Cape. So I went to take another look at the site and, in the end, found 12 rock piles in the kettle hole as well as the "chamber" nearby.

A couple of personal comments. First, it is gratifying that both Mavor and I missed the majority of the rock piles. Another is that the four piles he found were in a line and evenly spaced in a pattern which, over and over again, appears in his writing as being part of a larger scale alignment of features and piles that can stretch a quarter of a mile or so across the landscape. In fact, following this line of piles across the highway, there is indeed another cluster of rock piles in another kettle hole. But I am pretty sure that is not it, at all.The picture shows the kettle hole: a bowl-like valley created (we are told) by uneven melting of glacial ice. At the top of the western slope were two prominent boulders, and on the eastern and northeastern slopes were twelve evenly spaced piles forming a typical example of what I call a "marker pile site", or a "grid" of piles. Four in a row (actually five) do point as Mavor indicated but there are several other lines and directions present and a different explanation is suggested.

Here is a view from the bottom of the hole up towards the boulders:
Note how flat the slope is.

And here is a view back down towards the piles from the top of the western slope:The piles would all be visible from here, if not for the foliage, and they are arranged in a way that covers the entire opposite slope.

It occurred to me that the boulders were part of the site, so I climbed up to them to look around and found a damaged rock pile and a rock-on-rock up there, somewhat confirming that this is part of the "site":Here are some of the rock piles, hidden in the blueberry bushes:
These are pretty big, somewhat rectangular, and thoroughly smeared out. Which says to me that they are pretty old. Let me put it this way: several pairs of well-trained eyes missed these completely. Here's what you get, a view of three rock piles in a line, but who would know:
A Hypothesis:
Standing at the bottom of the kettle hole, and looking up the slope towards the boulders, I could see that the slope was very even and flat (but not level) below the boulders and I could see that the setting sun would graze the slope evenly and, inevitably, would cause shadows of the boulders to project down the slope and over against the opposite sides. Inevitably those shadows would have to pass over the rock piles as the sun sets. Could it be that the rock piles are evenly spaced because a certain fixed number of days have elapsed since the shadow crossed one pile; and now the sunset shadow falls across a new pile? Could this be a simple calendar mechanism?
In this version of the sketch, looking southwest, the sun sets further to the right in summer time, and sets further to the left in winter. I invite the reader to think what happens to the channel of light between the two shadows as the winter solstice approaches.

Perhaps I can get out there more often. A little more time-lapsed observation would confirm this.