Presented here is Dr. Tom King’s briefing to the expedition team members who will work under his supervision at the Seven Site during the upcoming expedition.
Here are some things that everyone planning to work at the Seven Site should
be aware of. A lot of it’s pretty basic, but I thought it would be well to
make sure we all understand one another.
Archaeology is all about context – the spatial relationships among things.
It’s from these relationships that we can reconstruct what happened in a given
location, how a given thing came to be where it’s found, which things got deposited
in the site before other things, and so on.
In traditional archaeology we’re very much concerned about both horizontal
and vertical relationships. At the Seven Site there’s not much to the vertical
dimension; everything is pretty much in the top 10 cm. or so of the site. So
in a way, what we do is a lot like crime scene investigation: where is the
(smoking) gun lying vis-à-vis the broken flowerpot; that sort of thing.
This is why we’re so careful about mapping, and plotting in the location of
each item found. We do this with varying degrees of anal-retentiveness, but
generally we want to record carefully where each thing is before we move it.
We’ve established a central “datum point” over which we set up a total station,
and we map everything in with reference to that point. We’ll supplement the
mapping with overhead Kite Aerial Photography and Pole Aerial Photography (KAP & PAP).
There are vertical relationships to be recorded, too. For example, by carefully
examining such relationships we were able to determine that a lot of small
clams were deposited on one small part of the site, then a layer of asphalt
siding was laid over them, and then some corrugated iron was laid on top of
the siding. We don’t know what kind of time passed between these incidents,
or why they occurred, but the fact that they were sequential might mean something,
so it’s good we were able to detect it.
Much of what we record on and recover from the Seven Site has no obvious relationship
to Earhart, or even to the putative castaway who may have been Earhart. Such
relationships may – or may not – emerge through later analysis, but no one
should expect “aha!” moments in the field. We didn’t recognize the probable
rouge in the field; we just recognized that it wasn’t coral or scaevola, and
therefore it was unusual so we kept and recorded it. Similarly, we didn’t recognize
the mirror fragments as mirror fragments in the field. In 2001 one of our team
had a lot of trouble understanding why it was so important to collect all the
fish and bird bones, and complained a lot about the time it took to do so.
But on analysis, the kinds of fish represented (the bird bone analysis isn’t
yet done) turned out to suggest that whoever was collecting and preparing the
fish was not following standard Pacific island norms – and so was probably
not an indigenous Pacific islander. That’s an important piece of data. It’s
the slow accumulation of such data that gives us a basis for testing our hypothesis.
So the bottom line is, we’ll be trying to record and map the locations of everything
we find.
There are some standard ways of doing archaeological fieldwork that we’ll be
adhering to, and some that we’ll be modifying in various ways. And there’s
some terminology we use that everyone ought to be familiar with.
We use the metric system; measurements are in meters, centimeters, and occasionally
millimeters.
We do not impose a metric grid system over the whole site. That’s often done
in archaeology, but it’s time-consuming, tedious, and generally a pain in the
behind when you’re working a site like the Seven Site, on a convoluted ridge
with lots of vegetation.
When we elect to concentrate on a particular location, however, we do lay down
a metric unit or units within which to work. This is usually a 1x1 meter or
2x2 meter square, or a 1x2 meter rectangle, or a combination of multiple such
polygons. Each square or rectangle (called a unit) is given a designator (examples
from 2007: “SL-3,” “WR-1”). Their locations are carefully mapped in, and we
then map in things we find within a rectangle by measuring from two perpendicular
sides.
We generally dig in 10 cm. levels, though in point of fact we seldom find anything
deeper than 10 cm.
Everything from a given level in a given unit (and sometimes from a sub-unit
– e.g. the NW quarter of Unit XB-7, 0-10 cm. level) is typically passed through
a sieve or screen (we call them screens, the Brits call them sieves), and kept
together in a labeled bag (or bags). It is critically important to label every
bag accurately, and keep the label intact (don’t let it get rubbed off). Surface
finds are also “tagged and bagged.”
Our screens are PVC rocker screens lined with ¼″ mesh hardware cloth. We have
1/8″ gauge inserts that we seldom use, but have on hand just in case.
Saying the material from a level is “passed through” the screen is a bit of
a misnomer, since the site is mostly coral rubble that just sits in the screen
and glares at us. We go through it by hand, throw out the rubble, pick out
the artifacts, and the little bit of humus that exists falls through.
We keep all “artifacts” – that is, things made by people, and many “ecofacts”
– that is, things created by nature. Of course, we don’t keep every chunk of
Scaevola bark, or every lump of coral or marine shell, but we do keep all bones,
turtle shells, etc.
We record all “features” – that is, concentrations of things that may represent
human activity. Some examples of features we’ve recorded are:
“Clambushes.” Clambush is a term we made up for clusters of Tridacna (“giant”)
clam valves, clearly the remains of someone’s clambake. We’ve found two, creatively
labeled Clambushes 1 and 2.
“Shell scatters.” We’ve found only one of these so far; it’s a scatter of small
“butter clam” (Anadara sp.) valves, also probably the remains of a meal.
“Birdbone scatters.” As the term implies, these are scatters of bird bones.
“Corrugated iron features.” Sheets of corrugated iron, reduced to rust on the
ground.
We also record the locations and characters of such natural features as living
trees, dead trees, pits, swales, irregularities in the ground surface, etc.
We systematically scan the surface of the site with metal detectors, as well
as visually.
In 2007 we also scanned about half the surface of the site using the Clauss/King
Unpatented Daylight Ultraviolet Scanner (UDUS). Bones and teeth fluoresce in
UV light. It worked, but didn’t reveal any human bones or teeth, and is very
tedious to use. It was necessary to rake the surface in advance of UDUS scanning.
What I’ve just described is our standard way of doing business at the Seven
Site. We propose this year to do things a little bit differently, as described
below.
We have four goals at the Seven Site in 2010:
- Make sure we’ve characterized the geography of the site correctly – that its
components don’t extend beyond the area we’ve cleared of vegetation
and examined;
-
Examine the entire site in much greater detail;
- Collect a more comprehensive body of information on features and artifacts;
and
- Make a particular effort to collect material that might present recoverable
DNA, and GUARD AGAINST ITS CONTAMINATION!
The site presents some serious physical challenges, notably:
- It’s covered with Scaevola, a truly nasty shrub, which must be cut and removed;
it’s hard to remove because wherever you try to put it, there’s
more Scaevola growing.
- Much of what we’re interested in is right on or very close to the
surface, easily disturbed by walking around on it, dragging Scaevola over
it, etc.
- The top 3-5 cm. of the site is a sort of pavement of coral gravel, a
deflated surface through which the smaller-grained material has sifted.
As a result, artifacts and features tend to be hard to see even though
they’re virtually
on the surface, and almost always in the top 10 cm. of the “soil” (There really
isn’t any soil; it’s coral rubble with patches of humus and
fire features).
In the past we’ve cleared the Scaevola off areas of the site (dragging it to
clearings where it could be piled, or just throwing it deeper into the bush),
done systematic metal detecting, ultraviolet light scans, and raking, and excavated
selected locations (mostly fire features) employing standard archaeological
methods. I think we now understand the site well enough to take a somewhat
different approach.
This approach will be destructive: I propose to turn over essentially the entire
surface of the site. This is an inherent problem in archaeology: we destroy
what we study.
As soon as we arrive on the island and get a boat into the lagoon, I propose
to move a team to the Seven Site to begin clearing Scaevola at the NE corner
of the area we cleared in 2007 (which will certainly have grown up again, but
appears from recent satellite imagery to have grown up rather lightly). It
should take us about two days to clear the 2007 area. We’ll carry the cuttings
back into the Buka forest NW of the clearing and pile it there (first carefully
checking the debris-pile site to make sure we’re not covering something up).
We won’t necessarily stick to the limits of the area cleared in 2007; the basic
idea is to clear an area about 30 meters wide running along the crest of the
ridge that bisects the site. Needed technology will include pneumatic loppers,
chain saws or other brush cutters, knives, and trimmers.
As soon as the cutters have cleared an area of about 10x30 meters, I propose
to peel two people off to cut in from the ocean side to a location 30 to 50
meters SE of the 2007 cleared area. Having reached the ridge (along a path
of least resistance plotted in satellite imagery), this team will clear a good
broad swath back to the 2007 clearing, enabling us to make sure that the site’s
features don’t extend any farther along the ridge than we’ve mapped.
By about Day Three on the site, while the exploratory cutting team is cutting
SE of the cleared area, we should be able to get to work on actually “excavating”
the site. I figure that we’ll stake out a line perpendicular to the ridgeline
and running right across it, near the NW end of the clearing. Along this line
I figure we can deploy about 7 team members, each responsible for about 5 meters
of the line. We’ll also need to set up the total station surveying instrument
over Datum 3, the most convenient of our datum points to use in mapping along
the ridge. We’ll hold 2 or 3 screens (sieves) in readiness. One team member
will serve as Evidence Manager (EM), making sure that anything that might have
DNA on or in it is collected with sterile gloves, and that all bags are correctly
labeled with provenience data. |