February 19, 2012

Sudan: Update on the dig

After scraping the mound with mattocks numerous times, we have
determined that there are “no more graves”. Well, one more that’s been
cleaned and needs to be recorded and excavated, which will result in
Anna or my going to site and spending two hours working and then six
hours sitting around “looking busy”. But don’t take the lack of
evident graves as an indication that we have exhaustively (however
exhaustingly) excavated the entire cemetery mound: Just because we
don’t see them doesn’t mean they’re not just a little bit deeper, a
little bit more covered by 4000 years of sand. The only way to find
guaranteed 100% of the graves would be to bulldoze the entire thing
and then check what turns up; however, we don’t have the time or
resources to do this, and it’s pretty destructive and thus a poor
archaeological method (although the British show “Time Team” would beg
to differ). As it is, there’s only a couple woman-hours left for the
physical anthropology work, which means most of this week will be
spent in the house, out of the wind, analyzing skeletons. We have 97
total, and a bunch of commingled remains we need to spend the better
part of a day sorting en mass.

Anna and I have done some preliminary analyses with about 2/3 of the
assemblage. (We use the word “assemblage” to describe an
archaeological collection from one site rather than “population”,
which implies a complete and coherent group. We don’t know if these 97
individuals are representative of the population from which they came,
and they definitely aren’t the totality.) While sitting in my tent one
day, hiding from the wind, I made a mortality profile in my notebook –
the way people did it before Excel made things terribly easy – which
shows the amount of dead individuals from each age group. Age is
difficult to estimate from skeletal remains, but there are some
methods we use that are easy to explain. The first is the appearance
of the pubic symphysis, the point where your pubic bones join. As
individuals age, the outline and texture of the join change. Some
researchers claim they can also use this to tell if a female has given
birth, but this is highly questionable. Another method is analyzing
the auricular surface, which is where your sacrum meets your pelvis.
This, too, experiences often-predictable changes with age. We can also
look for certain age-related diseases like osteoarthritis, the
prevalence of which increases with age. For children, we use dental
development, which is a lot more accurate than the methods used for
adults. Teeth form and erupt on a highly predictable schedule, from
milk teeth emerging at 9 months to wisdom teeth at 15-18. We can also
look at fusion of long bones: the middle of the bone grows separately
from the ends and fuses in the early or late teens (growing pains are
the result of the massive growth that takes place in early puberty
before they finally fuse). Since children experience so many changes
over a relatively short time, they are much easier to age, often to
within 12 or 24 months, and teenagers to within 3-4 years. As adults
are more difficult, we assign them to one of three categories: Young
Adult (20-35 years), Middle Adult (35-50 years), and Older Adult
(50+).

We found that most people in our cemetery assemblage were in the
“Child” and “Young Adult” categories – that is, most people in Kerma
times in this area died when they were 3-7 years old or 20-35. Fewer
people died in the range of 8-16, which is expected since that’s a
pretty healthy time: your immune system is fully developed and you’re
no longer susceptible to fatal childhood illnesses, and girls aren’t
exposed to the dangers of childbirth nor boys to hunting/farming/war
accidents. There were few people dying in the 35-50 group, probably
because they barely squeaked to 35; only one female was over 50, and
she was decked out in over 600 beads. When we analyzed the children
separately, we found that 0-5 was the most dangerous time, with over
half of child deaths occurring then. A mortality curve I made shows
that 83% of infants born into this assemblage could expect to survive
to their first birthday, then 50% to their second, 20% to their third,
down to 4% to their fifth. (However, it should be noted that we often
give ages like “2-3” or “3-5” and have only found two infants under 1
year, so the curve might be overestimating.) These figures fit
perfectly with what one should expect to see in any cemetery anywhere
in the world before 1850, which pleases me and Anna because it implies
we’ve done a pretty good job at determining age. (Sanitation,
pasteurization, and improvements in medicine in the early 19th century
drastically reduced child mortality. With antibiotics in the mid-20th
century, young adult mortality declined as well.) So, if your Kerma
kid made it to 5 years old, he or she could expect to live another 30
years or so, unless they were very lucky. That’s just the way it was.

 

Anyway, back to modern times. Yesterday we started packing up the
skeletons into boxes for transport. We pad the boxes with cotton from
old mattresses and then put in the bags of skeletons, with more
padding on the top and sides. We also try to leave air in the bags so
they’re a little cushioned, and always pack them with heavy legs on
the bottom and fragile skulls and teeth at the top. These will be
driven down to the Khartoum National Museum, where we will pack them
into metal trunks and send them air freight back to London. We are
also keeping lists of which skeleton goes into which box so we’ll know
if any disappear en route. Our final week here will be spent packing
up artifacts, counting beads, and closing up the house; we will
probably drive to Khartoum next Monday so we can have a day to unpack
and repack and another day to go to the souk (market) and the museum.
I’m saying now that nobody reading this is receiving any presents from
Sudan as there’s really nothing to buy, but you can will see the
wonderful pictures that my friends have taken, since I lost my
American adapter and my battery died. C’est la vie.

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