Tuesday, August 15, 2006

Anatomy of a kettle hole

Falmouth on Cape Cod is one of the only parts of the Cape where there are significant hills and valleys, and rocks - which were left there when the glaciar retreated . This is called glacial "morraine". One feature of the morraine is a number of deep holes left behind as large isolated blocks of ice melted down into the earth. These are called kettle holes and, on the Cape, they provide the majority of the steep slopes available in the landscape. Perhaps for this reason this is where the majority of the rock pile sites are found in the Falmouth area. Or perhaps it is because there is sometimes fresh water at the bottom of kettle holes.

For the last two summer vacations, every day I would head out in the morning to explore kettle holes, would find two or three small sites and would come home satisfied. Last summer I explored locations that had been previously mapped by Mavor and I am pleased to report that not one single site that he found did I find on my own and not one single site that I found did he find. This tells me something interesting, which is that there are more sites than you would think and that neither Mavor nor I had the correct exhaustive strategy for finding sites. He looked for alignments and I looked for kettle holes. More generally I just wandered around in the blueberries until my feet would find a rock pile. Anyway, and aside from that, it is still true that most rock pile sites in Falmouth are located in kettle holes. In some areas about one in three kettle holes has a site, so if you want to find sites just put in the time: go out and do the leg work.

Here is part of a site map Mavor made. He is a careful observer and mapped as accurately as he could, using a compass and pacing out distances. To be honest there are a number of piles I found which are not on this map (indicated by black dots) and a number of piles on the map which I did not see when I explored there. But aside from such minor quibbles, this is a reasonably good representation of the site. What is particularly noticeable on the ground is the curve of rock piles which seem to follow the contour on the right hand side of the map fragment. One has a definate sense of alignment, except the piles do not lie on a line but on a curve. Another thing that is very noticeable on the ground is a group of piles in a true line which are shown among the piles on the upper left of the map fragment. After exploring a number of other kettle holes I have come to realize that these features are often present at other kettle hole sites. In particular a curve of piles sweeps around the hole on the southern side of the hole, in part balanced by a cluster of piles near the bottom. At another hole [which I'll describe in more detail in a subsequent post] my recollection is that the piles were arranged something like this.
I am not as careful an observer or mapper as Mavor but it is my best guess. In addition, I should add that the southern sides of the holes happen to be the steepest sides of the holes leaving it ambiguous if one or both of these attributes ("southern" and "steepest") are important. To me there is a strong suggestion that these common features are related to sky watching. What are we watching? Where are we supposed to be standing? I don't know.

All the piles on the slope are supported boulder piles. But at the bottom there are always a few ground piles which seem to be different in nature and purpose. My guess it that these are burials but that sky watching from somewhere near the bottom was also important and perhaps supplemental to the burials.

Most kettle holes only have one or two piles. Usually they are ground piles near the bottom of the hole. In only a few cases is the site larger, including this "curve" of piles spiralling up the steepest side of the hole. I presume that this is a separate function from that of the ground piles.

I should also mention that I came across some kettle holes in Groton, MA and, with some curiousity, walked down into them to see if there were piles there, to see if Groton was anything like Falmouth. In fact there were the one or two ground piles near the bottom in these kettle holes as well but no spirally sweep of piles up the southern (steepest) side of the hole.

1 comment :

pwax said...

My guess is that these kettle hole curves of piles are related to what I have been calling "marker pile sites".