Saturday, January 02, 2010

Rock Piles at Outlooks

Observations accumulate into patterns and ideas form slowly. I have been reporting examples of "chambered cairns" (see here for an example from Framingham) and two weekends ago, in Berlin, I walked up to a ridge with a fine southeastern view to find a chambered cairn and a site very obviously located in relation to the view outward (see here) . Thinking back to some of the other recent "chambered cairns", some were at nice outlooks and some were not. At the same time, some of these "cairns" are rectangular, others were elongated ovals. So these are not simple monolithic ideas; rather I am seeing some hints of commonality, some hints of themes that I hope will become more real and more valid over time. I previously only posted a video of the Framingham "chambered cairn" example. Here are a couple of other pictures of it. This is an isolated rock pile on a small piece of the Sudbury Valley Trustees land on Doeskin Hill. Note the view to the south:and the note the hollow in the center of the structure (from one side):(and from in 'front'):
* * *
But I don't actually want to write about chambered cairns so much as about large rectangular piles that top a ridge and look outward. (It is just that a lot of examples of such seem to be chambered.) The nice weather after Christmas gave me a chance to do some exploring. What with the find in Berlin, and the Framingham example (also an outlook), my interest was drawn back to Oak Hill [Oak Hill is the long ridge following the western edge of the valley of Beaver Brook (north to the Nashua) and Elizabeth Brook (south to the Assabet), a valley followed by Rt 495 as it loops around the northwestern edge of the Boston area. This is the area associated to the Boxborough Esker, as written about in Manitou. The geology of Oak Hill is layers of schist, standing on edge. This makes for steep ups and downs. With the easy commute via waterways and with its steep slopes ideal for watching the sky or a distant horizon, it is no wonder that this ridge contains the highest density of rock pile sites around here. It is the main reason I can go out weekend after weekend and continue to find new sites. ] Oak Hill is one long outlook - a ridge with excellent views to the east, running for miles through Littleton, Boxborough, Harvard, Bolton, and Berlin. As I looked over the topo maps I figured it might be worth exploring more directly around the Harvard University Observatory on Oak Hill. I found several small sites over the course of a couple of walks there. On one walk I started near "A", found a rock pile (shown under new snow a few posts previously), then continued into the woods, skirting the edges of an orchard (indicated by green dots on the map). There are lots of big sites in this area, so I was skirting the fringes looking for other smaller sites and I came to a small site at "B". This site consists of a long broken down rock pile on top of a low ridge, looking eastward a short distance to three separate rock-on-rocks. First I noticed the rock-on-rocks, then the smeared out remnants of a larger pile at the top of the small ridge there:
video
Here is a view uphill:And a view downhill:[A nice snow started falling and I was relieved to be on foot]

The size of the component rocks in this smeared-out pile are significant. They match the sizes used in the Framingham examples, and the Berlin examples. This same rock sizes appear in one of two examples from a subsequent walk. The main significance is how different it is from another pile discussed below.

Last weekend I managed to get FFC out of Carlisle for a short walk downhill from the Harvard U. Observatory. He knows people everywere and we ended up parking at the house of a friend-of-friend on Cleeves Hill Rd, and accessing the woods directly behind the house. Almost immediately we got up to the top of the ridge, and almost immediately located a large broken down rock pile (at "C") that was definately at an overlook, definately made from similar sized component rocks. To me, this feels a lot like these chambered cairns discussed earlier.
Note the view eastward:
Note the size of the component rocks - overall largish. So the attributes worth noting are:
  • good view eastward
  • rectangular and large ~25' sides
  • large component rocks but not too large to carry
Another smaller pile was just over the curve of land 20 yards to the side:

Contrast that with what else we found up there on Oak Hill. At "D" we came across something that was quite different and just enough like field clearning to make me unsure. This was a big 20 yards long berm at the crest of a ridge made mostly of smaller component rocks.
Actually the pile was hooked around like a "J" with the long berm as the main stem of that letter.
video
At one end of the berm was loose dumped rocks, suggesting a practical agrarian reason for this pile. At the other end of the pile, a single white rock, suggesting a ceremonial reason for this pile. Note that the component rocks are small and that this is quite a different beast from the outlook piles shown earlier. Sometime contrast with some "other" helps clarify differences between types of rock piles. This large hooked berm is unlike the rest, but at the same time similar to other berms I have seen: some in Lexington and Waltham [reminds me a little of Whipple Hill], some in Littleton [reminds me of John Hanson Mitchell's "Serpent Mound" at Sarah Doublet] and one in Princeton overlooking Watchusett Reservoir. [Sorry there are no better pictures.] As we returned from that high point, there were several other beaten down structures made from similar small component rocks. Seems to me that the rock harvesting mechanism is a significant classifyer of a type of rock pile. Since these component rocks seem to have come from a similar mechanism, located near to it, it makes sense to group these with the large berm. Here was another berm-like structure forming the edge of the ridge.And here was a small rectangular pavement of cobbles in a bit of a hollow along the wall. So, some rather diverse structures up near "D" which cannot be completely disassociated from practical agrarian purposes, even though the large hooked berm is quite interesting and comparable to berms in other places. The sites at "B" and "C" may be candidates for a new site classification involving ridge crests and outlooks.


After that nice day, the weather got colder, I got in one more walk, then it started snowing again, which it is doing now.

1 comment :

Chris Pittman said...

Fantastic post. I think developing some kind of formal classification system for these sites is necessary to further our understanding of how these sites were used.