In an earlier posting (17 July), I mentioned that often we're able to just see the archaeological site (or portion of it) and tell right away what it is. But most of the time it isn't quite so easy, and I thought I would dedicate a posting (or maybe two) to how we actually go about finding these sites.Our archaeology survey team just wrapped up four days of work on the east side of Onekotan Island looking for prehistoric sites in order to get information on when people were living on this island. Much of the east side of the island is dominated by Blakiston Bay, which is a pretty forbidding stretch of coastline (see photo).
Volodya Golubtsov and Dima Chvigian head towards camp on a foggy day at Blackiston Bay Beach, Onekotan Island
First off there's the cliff. It is an eroding deposit of pyroclastic flow 50-75 m thick. What that means is that sometime thousands of years ago (there have been a couple of different deposition events over the past 20,000 years, with the most recent one 5500 years ago or so), one of the two volcanoes on the island (Krenitsyna on the south end of the island, and Nemo on the north end of the island) sent out a raging torrent of super-heated ash and rock-depositing the 50-75 m of material in a single event. Next there's the beach itself. Nice enough, as beaches go-a few glass floats here and there, nice black sand, etc. But it's only about 20 m wide, and gets swept clean during extreme high tides and big storms (remember the cliffs?). And then there's the wide open Pacific Ocean acting as a source for waves, which were only a piddly 2 m high when we were there and that made the beach too dangerous for us to land on. Never mind the possibility of tsunamis in the area-I don't even want to think about that!
In any case, people lived here. Prehistorically and historically. But they tended to put their homes up on the tops of the headlands at either end of the bay. And that's why we wanted to look there.
So how do we find these sites? If there isn't already a surface exposure of sediment, the main thing we have to go on is pits and depressions on the surface of the ground. Often, these pits and depressions are the long-weathered footprints of semi-subterranean houses, or, more simply, pit houses. Pit houses were constructed by first excavating out a circular or sometimes rectangular pit into the ground. Then it would have been covered over with a frame of driftwood (sometimes whalebone, too). And, finally, the frame would be covered over with skin and/or sod to make a cozy little house, with a smoke hole in the top center, and some combination of side and/or top entryways.
OK. So that's a pit house. People who lived here prehistorically lived in pit houses. And we walk around and try to find the pits that are left behind (in a terminological flip-flop, we call them house pits).
Sometimes we can see their outlines in the vegetation. But sometimes we find them literally by falling into them. You can't see your feet or the ground when you are walking in grass waist-high or higher. And you can't see the slight rise formed by the wall of the pit. And you can't see the 0.5-2 m drop into the bottom of the pit! So in you go, head over heels into the soft grass. And you've found a house pit!
The trick with looking for house pits in the Kuril Islands is that the islands were host to intensive military occupation preceding and during WWII. So the occupying forces (first the Japanese, followed by the Russians) set up defensive gun emplacements and bunkers in the places where they would be the most effective for defense. Yep, you guessed it.:. on the headlands. Right where the house pits are supposed to be located.
So now we've got a problem. First off is the destruction of the prehistoric sites through the construction of the military features (which also included miles and miles and miles of foot trenches, which zigzag all over the coastlines of the Kuril Islands). But there is also the problem of there being lots of different kinds of pits out there besides just house pits.
Sometimes the military features are easy to identify. Like the one we visited near our campsite on Onekotan. There was a very obvious trench that zigged and zagged along the edge of the bluff, and it ended in a circular depression looking out over the bay. It also had empty rifle casings lying in and around it (see photo).
Dr. Michael Etnier holds up a spent rifle cartridge in his right hand while sitting in a military bunker on Mussel Cape, Onekotan Island. (Photo courtesy of Natasha Slobodina)
So that's easy. And sometimes the military pits are really large (6 m X 6 m), which is much larger than most house pits, which tend to be 2-4 m maximum dimension. But there are lots of in-betweens, and archaeologists have discussions that go back and forth several times before we make a field identification of what we think it is.
But that's probably not good enough. What if somebody back in the past decided to make a really big pit house? If we looked at its footprint hundreds or thousands of years later, we might decide it was a military feature-and we'd be wrong.
So instead of making what is little more than an educated guess, we take a small, but hopefully somewhat representative, sediment sample from inside the depression using a 1.5 cm soil probe. We can't do an excavation every time we find a depression-we can't afford the time, and it wouldn't be ethical (nor is it allowed by our permit!). But our soil probe brings up all sorts of good sub-surface samples, including bones, flakes (by-products of stone tool production), and, if we're lucky, charcoal.
If we don't get any artifacts or charcoal, we can't really test the hypothesis that a particular depression is a house pit. Maybe it is, but we missed? But if we get artifacts, that's pretty good support for the hypothesis-especially if the artifacts are likely to be prehistoric (i.e., flakes, rather than iron fragments or glass). And if we get charcoal, then we can use that for radiocarbon dating to see how old it (the charcoal) is. Of course, there are lots of assumptions and limitations built into radiocarbon dating. But at least it gives us something to work from.
OK. I've babbled on a lot about house pits. And it's time for me to shuffle off to the galley for dinner, which is likely to be either fresh cod or halibut, since the crew members caught several of them today!
Bon Apetita!
--Dr. E.
Next Posting: Surprising results from "archaeological survey as an afterthought" on Makanrushi Island, plus some interesting developments in the fish count!