I recently came across a newspaper account of an archaeological investigation undertaken in 1887 in which an excavator was hired by the Ohio Archaeological and Historical Society (now the Ohio Historical Society)"to sink a hole in the bottom of the moat." According to the newspaper account, the excavation revealed that the ditch had been lined with "a fine gravel and cobble stone" that presumably would have enabled it to hold water. Unfortunately, the results of this excavation were never published formally and I have been unable to find any field notes or other records in the OHS archives that would allow this account to be substantiated. (For whatever reason, I don't take it for granted that everything published in a newspaper is an established fact.)
The interior ditch is an important element of the architecture of the Great Circle. None of the other major earthworks at Newark had one, so the builders didn't need to dig a ditch in order to build an enclosure. So they made a conscious decision to put a ditch inside the Great Circle. It must have been important and one reason for it may have been to create a barrier of water appropriate for certain kinds of ceremonies that the Hopewell conducted here and not at the other earthworks.
Kenneth Tankersley, archaeologist at the University of Cincinnati, and U.C. graduate student Emily Culver are conducting research at the Great Circle to answer this important
question. They extracted a series of sediment cores from the ditch to see if they could identify soil layers consistent with water having been present. Culver reported the preliminary results of these investigations in her Masters thesis.
According to Culver, there is evidence for an "anthropogenic [human-made] buried soil placed as a ditch lining" at a depth of between 1.3 and 1.5 m below the current surface. X-ray diffraction analysis of the different layers in the soil cores indicates that calcite and other water soluble minerals are absent from the layers above the inferred ditch lining. According to Culver, this is due to the presence of water in the ditch from the time of its construction through the historic era. By the time Atwater visited the site, sometime prior to 1820, several generations of tree's roots and burrowing animals had punched enough holes in the lining to allow the water to begin to seep out of the ditch.
Culver argues that the water-filled ditch may have had both practical and symbolic functions. It may have provided drinking water during a dry climate episode, while serving as a social or religious expression of separation.
Whatever the correct interpretation for why the Hopewell created architectural barriers of both earth and water at some enclosures, knowing that the Great Circle's ditch did, indeed, once hold water is an important discovery that changes how we understand this amazing site and how it was related to the larger complex of earthworks of which it was but one part – and the only part with a water-filled ditch.
Brad Lepper
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7 comments:
Incredibly interesting! We should ask her to present her research at the Newark Earthworks Center. I'd love to know more!
Water is used to determine level, of course, no "ceremony" needed. Ancient astronomy sites often have such water features or are near a water body serving the same function.
"Ceremony" seems to be the present-day substitute for "We just don't know, but will never admit ignorance."
Brad,
First of all, the notion that a lining of “fine gravel and cobble stone” would retain water is nothing short of absurd. When the Ohio canals were built, it was specified that the canal prism be lined with puddled clay, not gravel, for this very reason.
Secondly, as you know, the Newark Great Circle lies on an elevated alluvial plain of sand and gravel, specifically Ockley silt loam. The A and B horizons are typically moderately to strongly acidic, and naturally percolating surface waters have removed calcareous matter (i.e., “calcite,”) to a depth of 70 inches, more than 1 ½ meters. It has nothing to do with tree roots or groundhogs “punching holes” in some water-impervious layer.
I’ve seen standing in water in such prehistoric “moats,” especially after a recent rain; but the water quickly drains through the topsoil and disappears. I suspect it always has and always will.
This would seem to be a case of a graduate student being unduly influenced by her thesis advisor, in this case one who elsewhere has given ample evidence that he has water on the brain. Ms. Culver’s thesis is not yet available on the web, as UC seems to be a bit behind with processing them, but I look forward to reading it.
Jim
James L. Murphy
Jim,
Thanks for your comments. Your points are well-taken, but I am impressed by two factors. First, there is Atwater's reference to a considerable amount of water in the ditch in 1820. In nearly 25 years of close observation, even after heavy snow melt and rain, I have never seen any water standing in any portion of the Great Circle's ditch.
Second, the lining of the ditch was described in an 1887 newspaper account as "macadamized or guttered with a fine gravel and cobble stone." This sounds a lot like the linings at the bottom of the ditches at Fort Ancient, some of which still hold water in spite of the best efforts of the Civilian Conservation Corps to drain them.
If water played such an important role in the Hopewellian architecture of Fort Ancient, why not at Newark's Great Circle as well?
I agree that the case for water in the Great Circle's ditch has not been made. To do so, I think we need to excavate a trench into the ditch to expose a larger portion of the alleged lining to evaluate its original capactiy for water retention.
Brad,
You know better than to take Atwater’s observations at face value; but if you do, consider them in their entirety. What Atwater actually says is that the water in the Great Circle ditch was especially noticeable on the side of the circle adjacent to a 150-200 acre pond that had formed only very recently (some speculate it was a result of the New Madrid earthquake of 1811) and “sometimes reaches to the very walls of” the Great Circle. This certainly suggests that any water in the “moat” was a Historic phenomenon and rather quickly disappeared as we know the “Great Pond” did.
Also, you seem to presuppose the existence of a “lining” to the ditch and then look for it. You well know, too, that if you excavate anywhere at the Newark Earthworks you eventually reach glacial outwash gravels; if, as early investigators seem to have done, you quit digging at this point, of course you have what looks like a “layer.” If you keep digging you will have a long way to go, as this “layer” in the vicinity of Newark is hundreds of feet in thickness.
You are certainly correct that excavation of an extensive portion of the ditch would reveal more than a few soil cores.
Jim
Jim,
First of all, I disagree that we can be sure the large pond at Newark was a recent feature. In an unpublished manuscript in the archives of the American Antiquarian Society James and Charles Salisbury (1862) wrote that they observed the trenches dug to drain the pond. They described layers of peat and marl at its bottom. That sounds more like a very ancient kettle lake to me. Its level certainly did fluctuate in historic times, though it's extremely unlikely that the New Madrid earthquate had anything to do with it. (You should know better than that.)
Second, I wouldn't go digging with the presumption that a lining existed, but to test explicitly the proposition that such a lining existed. (To paraphrase Einstein, "I don't want to find a prepared surface, I just want to know whether or not there was one.") And I think I could tell natural glacial gravels from a prepared surface. But, just in case, if I was going to undertake such an excavation, I would be sure to do so in partnership with a geologist/soil scientist.
Brad:
Squier and Davis (1848), who predate even the Salisbury brothers, refer to "a large natural pond" but add that "Previous to the earthquake of 1811… it is said but little water was contained in the basin; after that event it rose to the depth of ten feet and retained that level until the drainage took place."
We can quibble over how deep the water was before Atwater's time but his observation that the water in the ditch was deeper adjacent to the pond goes far to suggesti a non-anthropogenic explanation of why there was water in the trench at that time and not later (and, I would suggest, maybe not earlier, either).
Jim
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