Over the next week I plan to post on Aniakchak art, research being done by my lab class, and new developments with the Hamline Village History project. Check back soon for this new stuff.

For now, I’ll just add some photographs of modern pectroglyphs and Inuksuit I took while walking along Artist’s Point in Grand Marais this last summer.

First of all, the fact that the debate continues means that some archaeologists find the Walker Hill lithics convincing, or at least exhibiting enough potential that they are unwilling to declare the location a non-cultural site.

A second issue raised in the listserv communications is that there are two distinct concerns about the site – research and preservation. Those of us who are interested in the site’s research potential can debate about this site until we retire. This debate is part of the scientific process. More importantly, no one is hurt if we are wrong. The only concern is that we eventually move forward our understanding of the past.

Those who must consider the preservation issues raised by the Walker Hill site face a much greater challenge. They do not have the luxury of waiting 10 years for the scientific debate to reach concensus.  Do they recommend preservation or not? Do they recommend continued field work? From a research perspective, the safest decision would be to preserve the site, just in case it turns out to be cultural. This decision, however, will cost people money. So there’s pressure to make the right call, and pressure to make the call right now.

The final issue raised in the CMA listserv that I found interesting were comments expressing disappointment that the debate has been so public (and to some degree personal). I disagree with both of these reactions. I have been impressed by the great care to keep the debate professional (especially compared to some of the really acrimonious debates in science). I think everyone agrees that the Leech Lake Heritage Sites Program archaeologists approached the site and the presentation of their results with due professionalism. They know that any pre-Clovis claim is going to be scrutinized. They know that every wall profile they record, every lithic they bag up, and every interpretation they make is going to be critically evaluated by a host of archaeologists. This is the price they pay for the bad luck of finding a potential pre-Clovis site. (Just ask Adovasio if he doesn’t sometimes regret choosing to dig at Meadowcroft.)

So clearly we need a debate, and this debate is going to be contentious. The question raised by some of the CMA listserv comments is whether we should keep this debate private. If you’re reading this, then you obviously know that I’m not in favor of a private debate. First of all, it’s too late. The site has been discussed all across the world. Second of all, I don’t think many people out there pay even the slightest attention to our debate, whether we keep it private or make it public. But people should at least know that a debate is raging and that this is normal scientific process and peer-review.

Ultimately, the only issue that really matters is determining whether Walker Hill is a cultural site or natural formation. So how do we move forward on this question? Attempts to distinguish artifact from geofact has a long history in archaeology (Barnes 1939, Peacock 1991). In fact, archaeologists working in Alberta just recently published a paper where they looked at flaked stone from a very similar geological context as the Walker Hill site (Gillespie et al. 2004). The Walker Hill excavators said that they are developing a similar protocol when they gave their presentation at the CMA meeting. So moving forward shouldn’t be difficult. It’s just going to take time. As a research archaeologist, I can wait for these results. Fortunately I don’t have to make any tough calls about preservation. Let’s hope that those who do have to make these decisions get it right.

Barnes, A.S. (1939) The Differences Between Natural and Human Flaking on Prehistoric Flint Implements. American Anthropologist 41:99-112.

Gillespie, Jason David,  Susan Tupakka, and Christine Cluney (2004) Distinguishing between naturally and culturally flaked cobbles: A test case from Alberta, Canada. Pp. 615-633, Vol. 19.

Peacock, Evan (1991) Distinguishing between Artifacts and Geofacts: A Test Case from Eastern England. Journal of Field Archaeology 18(3):345-361.

… there is no evidence that the Walker Hill site represents an early human occupation of Minnesota (pg 6).

Anfinson’s eight page statement includes discussion of the site’s stratigraphy, glacial history, and lithic finds. As Anfinson argues, the lack of indisputable artifacts from the site is troubling, but he considers most damaging to the claims about the site is its geological context.

In the end, the most convincing evidence that the site is not an early human occupation is the fact that a glacial geologist has suggested that a “high energy environment” (i.e., massive glacial outwash) produced the sediment layers that contain the “artifacts”. … Such environments have been shown to produce “naturefacts” that greatly resemble artifacts (pg 6).

Although discussion of the Walker Hill finds will probably continue, I think this is an important statement that should reign in some of the unfounded speculation. Minnesota, at least for now, needs to be taken off the pre-Clovis list. 

The paper presentation by Thor and colleagues provided many important details about the site setting, stratigraphy and lithic finds. The lithics were recovered from beneath a relatively thick (40 cm) deposit of aeolian sand. The lithic bearing horizon varies across the site. In some places it is a gravel lense and others it is a water-sorted sand deposit. The researchers were convincing in their argument that the lithic bearing horizon was an intact and sealed deposit, unlikely to contain significant mixing from upper soils.

They note that the site sits on one of the highest land surfaces in the area, and some distance from water (this is northern Minnesota though, the land of 10,000 lakes, so it’s hard to get too far from water). The glacial geology maps they showed indicate this setting was at the “confluence of a lot of glacial activity”. Given this geological complexity, it is not surprising that a variety of cherts, chalcedonies, jaspers, siltstones and other lithic materials are locally available.

The Walker finds are mostly pebbles, 2-3 cm in diameter, with some edge flaking. Thor and colleagues suggest these were scrapers, possibly used in the manufacture of wood and bone tools. (I believe this interpretation is based on edge morphology and not use-wear analysis.) There are no formal tools in the assemblage, no bifaces (although at least a few items have bifacial modification on an edge), and overall very little diversity. I looked at a number of their recovered flakes, including several jasper taconite flakes found in close proximity to each other, but saw none that appear to be from bifacial tool production or retouch – with one exception. The exception is a small flake of Hudson Bay Lowland chert that had multiple dorsal flakes scars and a distinct striking platform. I would not hesitate to identify this flake as cultural if I had found it while surveying for sites.

This small flake highlights the most obvious issue with the Walker Hill site – the essential absence of any indisputable artifacts. The question raised in the discussion following their presentation was why did the site’s occupants not manufacture any formal stone tools? Humans all over the world at this time were making exquisite bifacial and blade tools. Clovis, Dyuktai, Solutrean, even Chesrow complexes all include many items of indisputable human origin. The researchers’ reply that the Walker Hill occupants may have relied on bone and wood projectile technology because of the poor quality of northern Minnesota lithic materials is unconvincing given that later occupants of the region manage to chipped some decent tools from these same crappy rocks.

Perhaps the most pressing question I heard raised yesterday had to do with the geological context of the lithic bearing horizon. The water-sorted sands and gravel lenses identified by Thor and colleagues suggest fast flowing water formed these deposits. The key question is whether the modified lithics are coming from the aeolian soils or the fluvial soils? A high energy, flowing water environment could be the real culprit behind the Walker Hill materials and not some intrepid hunters living on the glacial margins.

My final thought on the Walker Hill site is that despite the impression made by recent press accounts, Thor and colleagues are approaching their investigation with due caution and skepticism. They are inviting the critical review of professional archaeologists, geologists, and other specialists. And they are marshaling multiple lines of evidence (soils, phytoliths, micro remains, etc) so that the question of the Walker Hill finds will eventually be answered to the satisfaction of most of us.

Although the Walker Hill discussion was of obvious importance, there were several other presentations that I found very interesting. Issues related to cultural resource management was a common theme in many of the papers, including the need for greater collaboration between archaeologists and local government planning agencies, improved site location data, and greater access to electronic records.

Kent Bakken’s presentation on lithic raw material use was the only regional analysis from the first day of papers. Kent’s presentation represents a major revision to his extremely useful, encyclopedic raw material paper from 1995. His new model on chronological patterns in raw material use offers considerable insight into changes in settlement patterns, territorial boundaries, and social interaction throughout Minnesota prehistory.

One comment made by Kent, almost in passing, needs further consideration by Minnesota’s archaeology community. Kent’s study clearly required an enormous data set drawn from the work of many different archaeologists and research programs. His comment that raw material type was the only attribute he found consistently recorded, however, suggests that a similar regional approach to the study of other data sets would be nearly impossible if based on existing records. I think Kent’s study illustrates the potential of a regional approach to archaeological analysis, but we as a community need to have a lengthy conversation about data standards, terminology, and open access to records if we want to expand beyond lithic raw materials.

The site was discovered as part of a CRM project undertaken prior to the construction of a new road near Walker, Minnesota. Unfortunately it sounds like the construction may go forward despite the potential importance of this find.

Minnesota archaeologists generally do not dig beneath glacial deposits because of the assumption that most areas of the state were uninhabitable until after the final retreat of the ice. The Leech Lake Heritage archaeologists would have probably never even found the site had it not been for an odd twist of events.

While investigating the path of the road, archaeologists came across a pit they thought might be related to the fur trade, said Thor Olmanson, director of the Leech Lake Heritage Sites Program and tribal archaeologist. But they quickly discovered that the pit was a 1960s child’s play fort, complete with a cap gun and other toys. Nevertheless, they dug down several feet below the pit’s floor, and they found a fragment of stone believed to be from toolmaking. That “was very puzzling,” Olmanson said, “so we decided to keep digging to see what was going on there.”

I love the idea that forty years ago some kids built a fort directly on top the oldest site in the state, and that’s why we archaeologists were lucky enough to find it.

The newspaper account includes photographs of two artifacts. The most convincing is described as an “axe-like” tool. It looks to me like a chunk of TRS (Tongue River silica) with some flakes removed from one edge. TRS is a common chipped stone raw material found in glacial deposits throughout western Minnesota. (Update: I had a chance to see this object and it’s actually siltstone).

(photo from StarTribue 1/11/2007)

Unfortunately, the photographic evidence is not sufficient to say whether this is a human-manufactured tool or simply a busted rock. On-the-other-hand, I know Thor and some of the other archaeologists mentioned in the newspaper account. I trust that the years of digging in northern Minnesota have made them very competent at telling artifacts from geofacts. I just wish they had an indisputable tool to show us. Where’s the blade core or bifacial point? That’s what I want to see. Hopefully we will soon be able to get our hands on the archaeology report from this project. Then we can add Minnesota to the Pre-Clovis map!

At about 9000 years old, the Browns Valley site is one of the oldest burials in North America. Barbara assisted with the repatriation and reburial of this individual in 1997. Bruce is working with a cast made of the skull prior to reburial. This collaboration of art and science is going to give us a new look at a very old face. I plan to post updates as this project progresses.