Preliminary results from Bagratashen 1

I returned from Yerevan on Sunday night, having been forced to sprint to my last connection into Raleigh/Durham because Air France was unable to get the cargo hold open to release our baggage. This was my first experience with an Armenian spring, and there were some brisk days at ~3,000 feet (I'm usually there in the summer, when it can be broiling, particularly in the arid north where we work).

As I mentioned in my previous post, the goal of this trip was to conduct a preliminary analysis of the stone tools from Bagratashen 1 and, after having looked at them over the past two weeks, it appears as if they are going to be very interesting indeed. My colleague, Boris Gasparian, and I examined over 500 pieces from our excavations.

The Bagratashen 1 lithic material laid out for analysis.

While it's obviously going to take some time to sort out what's going on (not to mention additional excavations to recover a larger sample size−this stuff came from a small 6m² excavation), I can relate some observations:

• There's definitely (and unsurprisingly) Levallois technology represented. 
• We've got quite a few points and point fragments in the assemblage (over ten). What's interesting is that we have both unretouched and retouched Levallois pieces and non-Levallois pieces. So, MP folks used different techniques to produce stone tools with the same characteristic; i.e., pointy ends. I took some measurements on tip cross sectional area, which can, according to John Shea (2006) and others, help determine whether a point could have been used as an effective projectile (note that this attribute cannot say that a point definitively was used as such). A couple of these points look, at least in a general morphological sense, very similar to the elongated retouched points found in Levels 1 and 2 at Djruchula Cave (Georgian Republic) and Lower E at Hayonim (Israel). This is potentially significant for us, since we have yet to successfully date the Bagratashen 1 sediments and Djruchula and Hayonim have been dated to between about 300,000 and 150,000 years ago. We have to be careful here, though: morphological similarity does not necessarily mean temporal similarity, since technology, especially lithic technology, is subject to independent development. 
• Boris and I noticed that a number of the artifacts, most of which are dacite, display a "rotted" surface texture, and some even feel lighter, as if they've been leached somehow. Boris suspects that this may be related to thermal damage and, sure enough, another colleague of ours, Dmitri Arakelyan, told us that he has tossed dacite into fire before and it does indeed show this sort of modification. More systematic experiments are of course in order, but we may have some indirect evidence for fire at the site (whether its natural or anthropogenic is also another issue).
• Nearly all the pieces were covered by carbonate crust, likely imparted well after the materials had been buried. We recorded what face of each artifact was facing skyward before it was pulled out of the ground and, because carbonates tend to form on the "downward" faces of clasts, we should therefore get an idea of whether or not they moved around in the sediment post-depostionally.
• There also appears to be quite a bit of truncation going on. In essence, this means that after knocking off a flake, hominins chose to subsequently remove, either through a single, massive blow or finer retouch, one or both ends of the piece. Why one would bother to truncate a seemingly well-made flake is another question. One possibility is that this truncation provides a new platform for the removal of smaller flakes from the original piece. The knappers may have wanted to remove the old platform and/or the bulky bulb of percussion to artificially thin the piece, for instance. Whatever the reason, people were doing it at Bagratashen 1.

Alright, enough chatter, let's get to the analysis....

References:

Shea, JD (2006). The origins of lithic projectile technology: evidence from Africa, the Levant, and Europe. Journal of Archaeological Science 33, 823-846.