Occam’s Razor is going to be coming in handy

The fun with radiocarbon dates continues.  I did manage to get a proposal off to a client, make some preparations for the summer field season and take care of the usual admin sorts of things.  Otherwise, I was working on the C14 dates.

It was slow going, in part because I read French much more slowly than I do English, and I was working my way through the Blumer compendium of St. Lawrence dates, which requires looking in at least 3 places to figure out how to evaluate the dates.  In some cases, one also has to go to other books to look at what the original excavator recorded (or didn’t).  Thank goodness for the American Museum of Natural History and their very nice downloadable PDFs (although the link seems troubled at the moment) of their Anthropological Papers.  I had a couple of them on my hard drive, which saved me a trip to get the actual books.

Anyway, St. Lawrence is going to be quite a mess.  There are a lot of whale and walrus dates, and Dumond  has calculated a correction for them by paired dating with terrestrial plants.  The only problem is that the whales in St. Lawrence are the same stock as the whales they catch here, and whalebone C14 doesn’t turn over very fast (a couple of decades at least) so they average the ∂C13 over that period.  That means that the correction factor for those whales should be the same anywhere in their range.  We’ve worked on it here for the Nuvuk graves, and the correction factor that works is much smaller.  I’m guessing walrus ingest relatively huge amounts of old carbon and skewed the calculations…

There was a very nice evening sky on the way home.

Sky from NARL. It was actually brighter, but this exposure shows the colors best.

Wrestling with dating

That’s what I’ve been doing lately.  No, not that kind of dating.  I’ve been wrestling with how old sites are, combined with the catching up after travel and working on taxes and other forms, it’s kept me busy enough that blogging kept coming in second to sleep.

I got started on this because I agreed to write a chapter for a forthcoming handbook of arctic archaeology dealing with Western Thule to Late Precontact in Northern & Western AK.  The northern part was fairly easy, since this is where I have been working for years, and I know the literature inside out, and am responsible for most of the C14 dates in that time frame, as it turns out (a lot of the major sites here were excavated before C14 dating was invented) but I needed to brush up a bit on the more southern parts of the area, I felt.  When I started doing that, I realized that terminology was a bit fuzzy (early investigators tended to think the entire sequence had to be present, and to call things, say, “Birnirk” because they thought there must be Birnirk, rather than because there were any diagnostic (types or designs only found in one culture) Birnirk artifacts at the site.

Then it became clear that people were using some artifact types as “index fossils” without being clear that they were really only in use for a limited time period.  So if they found such an artifact in a feature, they assumed the feature was used at the same time as all other features with that artifact in them.  Fairly recent C14 dating of some such artifacts has shown that some are pretty good to use, and others were being made for hundreds of years, so they aren’t really much help.

There is a pretty good dendrochronological (tree ring) series for the southern part of the area, due to Lou Giddings‘ pioneering work.  This has enabled people to date wood, although in some cases the possibility of wood reuse seems not to have been considered thoroughly, and only one log dated in a feature.  Then artifacts and artifacts assemblages (groups of artifacts often found together) found in that feature have been dated from the dendro date, and similar assemblages have been assumed to be about the same age.

Add the fact that there are a number of beach ridge complexes  in the area (Cape Krusenstern, Cape Espenberg), which develop over time.  Once people figured that out, it was a logical (and frequently correct) assumption that maritime-adapted people would choose to live on the ridge closest to the ocean.  From there, it was only a short step to deciding that all features on a particular ridge were fairly close in age.  In fact, as people have started doing more C!4 dating, and understanding how to interpret the dates better, it’s clear that isn’t the case.

As you can see, it’s not a pretty picture.  Add the tendency of earlier researchers to conflate time periods (as they understood they) with archaeological cultures, and things get really confusing.  Since this is a handbook, which one assumes is meant to be around for a while (although come to think of it, the Encyclopedia of Marine Mammals, in which I have a co-authored article, is in a 2nd edition less than seven years after the original came out), one would like to write an article that will not be rendered obsolete immediately.

So….  I’ve been going through the literature actually looking at the details of dates given for sites, dendro, C14 or otherwise, and am evaluating them on 9 different criteria to try to winnow out dates that are really reliable to base the chronology on.  That doesn’t mean other sites/features won’t be mentioned, but it does mean I’ll avoid putting hard dates on them, or using them as a basis to date yet other sites.

This is not fun.  I just hope it’s productive.

18th Arctic conference–Part 4 (Day 2-AM)

This penultimate chapter is a bit belated, to say the least, due to holidays, much travel and associated presentations, and proposal preparation.  However, there were some very interesting papers on the final day as well, and I decided I needed to get this written before yet another conference happened.  And I needed a break from final tweaking of the PowerPoint for said conference.

The first paper was by Molly Odell, on economic change at  Mitksqaaq Angayuk between 3400-100BP.  The site, on Kodiak, seems to have had discontinuous occupations from Early Katchemak to the Russian occupation.  Molly focused on the fauna from a midden associated with an Alutiiq house.  The house seemed to have been occupied primarily by men, based on the artifacts.  The midden showed a change from a pre-contact mixed fishery (primarily cod but with significant amounts of salmon and small amounts of other locally available fish) to a fishery focused almost entirely on cod in the historic period.  Molly interprets this as a shift from a winter settlement to a cod-fishing camp, presumably staffed by men.

Jennifer Raff gave a paper on mitochondrial aDNA (ancient DNA) from the Lower Alaska Peninsula & Eastern Aleutians.  This is interesting, as there are disagreements about how/when various cultures in that area appeared, and whether or not they represent in situ (in place) developments or population replacements.  This work may help settle some of those questions.  Not to spoil any surprises, as this paper is being published, but both haplotypes A & D are well represented, and there is B from one site!

Rick Knecht, a fellow Bryn Mawr College PhD, gave a “just out of the field” talk about excavations at Nunalleq, a Yup’ik site in the Yukon-Kuskokwim delta.  The Yup’ik culture is quite well-known ethnographically, but almost no archaeology has been done in the area.  Nunalleq, for which there is a date of 1300BP (not sure if that’s calibrated or what it’s on or associated with) has extraordinary organic preservation at the moment, but is suffering erosion, which is accelerating due to permafrost melting and sea level rise.  The local community actually contacted the archaeologists in concern.  The 2010 season excavated a house, with lots of organic artifacts (rye grass matting, for example) present on the floor.  They think it might have been a men’s house, which are known for the Yup’ik from the ethnographic record, based on the low numbers of women’s artifacts recovered.  There was a burnt side room, with a large number of arrowheads present, which is possibly a result of conflict.  More work is planned.

Chistyann Darwent followed with a report on the 2010 work at Cape Espenberg, a beach ridge complex which is located near Kotzebue in the Bering Land Bridge National Preserve.  This project has been doing survey there for a couple of years and has surveyed and mapped extensively, especially the more recent periods.  They have actually been able to excavate several houses (one on each of the 3 Thule-age ridges) to a considerable extent.  One thing they discovered was that the surface mapping did not necessarily give a good picture of what was under the ground in terms of houses, side rooms and so forth.  One of the houses seems to have burned, although why is not yet clear.  They excavated an outdoor ceramic manufacturing area (inadvertently–it looked like part of the house from the surface).  The houses on the oldest and middle Thule ridges had Thule 2 harpoon heads associated with them, suggesting that they were fairly early.  The also found a copper eyed needle, slat armor.  The tunnel floor was lined with baleen.  The youngest house was of a type that was familiar to the project’s elder consultant, who had been in the US Army during the Korean War, since he’d grown up in a similar house.  It had lots of evidence for fishing.  The dates were a bit later than prior testing had led them to expect, the oldest around 1260-1400BP, the middle 1450-1650BP.

Justin Tackney gave a paper on mDNA (mitochondrial DNA) from Nuvuk, as well as presenting the new direct dates that Joan Coltrane has for the human remains. The results show a number of haplogroups hypothesized to be founders to modern Inuit populations all in one area, which is new.  In general, this supports a Thule expansion from North Alaska.

I got the slot before lunch, and gave a paper looking at the material culture of modern Iñupiat whaling.  I am using this as a way to approach what sort of evidence might be expected in archaeological sites of whalers, and where that evidence might be found.  Essentially, the modern case has a number of artifacts that are needed for whaling and nothing else, most of which have pre-contact equivalents.  The interesting thing is that they are generally not stored in the house, which implies that excavations focused on houses may not be able to address presence/absence whaling too well.

Papers and articles and PowerPoints, oh my…

Despite the fact that I am still in New York on vacation (except for things like on-line payroll and P-card reviewing and approving, which can’t wait), I’m taking a bit a of a break from reading mysteries and eating Christmas goodies to work on several things I have in progress.  I’m not going to be able to finish any of them, since I don’t have any books here for checking references, and most of the images I want to use are in the Aperture vault  on my computer back in Barrow.  However, I can do outlines, and get a fair bit of the text drafted before I get home, at least for some of them.

In order they are: 1) PowerPoint & accompanying paper on Iñupiat and Cold War Science for a conference in Munich, 2) encyclopedia article on Western Thule 1300-1750AD in North & Northwest Alaska (in 7000 words maximum!), 3)PowerPoint on Alaskan archaeological sites and threats to them from climate change as it has been observed to be occurring for a conference in Tromsø, Norway, 4) article I’m working on with Claire Alix and Owen Mason on Ipiutak at Nuvuk, 5)  encyclopedia article on Barrow sites (Nuvuk, Birnirk and Utqiagvik), 6) paper on ethnographic data on storage of whaling gear, and 7) a paper on whaling gear recovered from archaeological sites which are known to have had whaling taking place.

These all have places they are to go, and times they need to be there.  Nothing concentrates the mind like deadlines, except perhaps the threat of execution…

Piles of Wood

One of the great things about doing archaeology in the Arctic is that the preservation can be spectacular.  Artifacts often froze the winter after they were abandoned, and only thawed when they were excavated.  This means we get to find a lot of the bone, wood ivory and leather items that were undoubtedly part of most precontact people’s tool kits.  We don’t have to guess at what people were using or extrapolate from a few stone tools that did manage to be preserved; we can see it firsthand.

This is not always an unmixed blessing.  Arctic archaeology  sometimes suffers from an embarrassment of riches.

Boxes with wood from the Driftwood Feature (DWF).

In the past, archaeologists generally only saved the artifacts from a site.  Animal bones and soil were pretty much ignored, or at best documented in the field (there are a lot of excavated houses in the Arctic where the animal bones are still piled at the edge of the excavation where they were left decades ago).  As archaeological science advanced (radiocarbon dating began about 60 years ago) and people began to do more things with faunal (animal) remains and soil samples, people began to collect a lot more, and to bring it back to museums to save, on the assumption that one day someone would be able to do something informative with it.  The idea is still a good one in theory, but it is bumping up against various realities.  For one thing, in most areas these sorts of things require storage in climate controlled conditions or they will deteriorate and become useless.  They are often quite bulky compared to just the artifacts.  Most museums simply don’t have any place to put all this stuff!  Some of the better-funded places, like the Smithsonian Institution, have built large off-site storage facilities in areas where real estate is a bit less expensive, just to keep all this stuff.  But such places require operational funds and new staff, and that costs money too.  Most places can’t really afford that.  Some institutions have started charging for putting collections there, but there are problems with that as well.

So part of the new reality for archaeology is that we can’t keep everything.  The question is how to decide what to keep and what not to keep.  In general, the artifacts are kept.  No problem there.  The issue is how to deal with the other things.

It’s even more complicated for the Nuvuk project.  We have had several areas where massive amounts of organic material, with some artifacts and faunal remains mixed in, were encountered.  While one might normally choose to excavate this all in the field, in a couple of cases the areas were right at the erosion face, and could literally have vanished overnight.  Combine that with a very cold field situation, where mild hypothermia can dull excavators’ thought processes, it didn’t seem like that was the best plan, since it risked data in a variety of ways.  I decided to take tightly-provenienced (with very accurate information on where they were from) bulk samples, which can then be processed in the lab, where it is warm and we have good lighting, magnifying lenses and water to wash the dirt and gravel off so we can get a good look at everything.  If excavators recognize an artifact in the field, it gets recorded there, but the idea is that we’ll find the less obvious ones in the lab.

Contents of one bucket shot laid out on a tray.
A closer look

One of the areas with a massive amount of organic material was what we called the Driftwood Feature.  This level is about 1 meter (39 inches) below the Thule graves.  It was actually permanently frozen, and therefore everything organic was in great shape.   It looks like there was an Ipuitak dwelling (maybe there were more that had already eroded–we don’t know) on a ridge near the ocean.  Sometime between 300-400 AD there was a huge storm, which washed all sorts of things (driftwood, bark, marine invertebrates, shellfish, peat, etc.) up onto the beach, all the way up to where the people were living.  It left what is called a strand-line.  It looks like they either left in a hurry and didn’t come back, or didn’t survive, since a number of artifacts were still there. The strand-line continued along what had been the beach ridge, and we wanted to see if there was any evidence of more human activity besides the one dwelling.  Because there was so much wood, and a number of the artifacts at the dwelling had been wood, we had a needle in a haystack problem, with the haystack about to fall into the ocean (which it did the next winter).  So we bulk sampled.

Close-up of the Ipiutak layer at DWF. We excavated many square meters of this!

Now we are going through some of the bulk samples.  I’ve been very lucky to have Dr. Claire Alix, a French scholar who specializes in Arctic driftwood and its use by humans, involved with the project since the very early days.  She was based in Fairbanks, Alaska, for many years, but has recently gotten a teaching and research position at the Sorbonne in Paris.  This is wonderful, since Claire is a great person & really deserves it, but it certainly complicates the logistics of her research on this wood!

Dr. Claire Alix in the Nuvuk Lab

Claire arrived on this morning’s plane, and is already hard at work going through samples from 2009 which were excavated after she left the field.  She is looking for all worked (altered by people) items, picking out things that we can’t yet identify for further examination, and recording amounts & types of wood, bark, and other identifiable organics.  The non-worked identified material is then being lab discarded.  I’ve got the computer map up and color-coded so Claire can look at it when she needs to, Laura is unwrapping the samples, and I’ll probably end up doing the data entry in the catalog.  She leaves again on Wednesday night, and won’t be back in the US until sometime after January, so we’ve got a lot to do, and not much time to do it.

Claire and Laura hard at work.
Lab discards--on closer examination they turned out not to be cultural.

Later this fall we are going to start going through soil samples and so forth.  We hope to be able to reduce the volume they take up.  Some of that will be done by separating the actual sample material of interest from the gravel matrix.  Where that isn’t possible (for example with large logs or whalebone) we will have to sub-sample, retaining only a portion of the total sample volume.  Otherwise, we’re going to run out of room.