FollowupTo: sci.archaeology I haven't yet got hold of the current Science issue, but today
From: email@example.com (Michael L. Siemon)
I haven't yet got hold of the current _Science_ issue, but today's
(Tuesday's) NY Times has some further information:
"The most revealing evidence has come from Tell Leilan, where
Dr. Weiss has been excavating for 14 years and finding succes-
sive layers of ruins going back some 8,000 years. For several
millenia, this was a small village established by some of the
world's first farmers. Around 2600 B.C.E., it suddenly expanded
sixfold to become the city of Shekhna, with 10,000 to 20,000
inhabitants. They lived in the middle of a land of rainy
winters, dry summers and a long growing season for wheat and
barley, much as it is today.
"All the more reason the kings of Akkad, or Agade, ... reached
out and conquered places like Tell Leilan about 2300 B.C.E. The
region became the breadbasket for the Akkadian empire...
"...for years archeologists puzzled over the 300-year gap in
human occupation of Tell Leilan and neighboring towns, beginning
in 2200 B.C.E. It occurred to Dr. Weiss that since no irrigation
works had been uncovered there, the region must have relied on
rain-fed agriculture, as is the case there today, in contrast to
the irrigated farming in southern Mesopotamia. A severe drought,
therefore, could be disastrous to life in the north.
"The idea was tested by Dr. Courty, using microscopic techniques
she pioneered in a scientific specialty, soil micromorphology.
By examining in detail the arragenment and anture of sediments
at archeological sites, it is possible to reconstruct ancient
environmental conditions and human activity.
"One of the first discoveries was a half-inch layer of volcanic
ash covering the rooftops of buildings at Tell Leilan in 2200 B.C.E.
All ash falls leave distinctive chemical signatures. An analysis
by Dr. Guichard traced the likely source of this potassium-rich
ash to volcanoes a few hundred miles away in present-day Turkey"
[hah! that's what I had guessed.]
"Since the abandonment of Tell Leilan occurred at the same time
and the climate suddenly became more arid, volcanic fallout was
first suspected as the culprit... But from their knowledge of
recent volcanoes, scientists doubted that the eruptions could
have perturbed the climate over such a large area for 300 years.
"And there seemed no doubt that the drought lasted that long, Dr.
Courth said. In the surrounding countryside at Tell Leilan and
elsewhere, she examined a layer of soil nearly two feet thick and
lying just above the volcanic ash. This layer contained large
amounts of fine wind-blown sand and dust, in contrast to the
richer soil in earlier periods. Another telltale sign was the
absence of worm holes and insect tracks, which are usually present
in soils from moister environments.
"This was strong evidence, the researchers reported, of a 'marked
aridity induced by intensification of wind circulation and an
apparent increase' of dust storms in the northern plains of Meso-
"It was during the 300-year desertification that archives of the
southern cities reported the migration of barbarians from the
north and a sharp decline in agricultural production, and showed
an increasing number of names of people from the northern tribes,
mainly the Amorites.
"According to the evidence of the sediments, rain in more abundance
returned to northern Mesopotamia in 1900 B.C.E. and with it the
tracks of earhtworms and the rebuilding of the deserted cities.
Over the ruins of Shekhna... rose a new city named Shubat Enlil...
The builders were Amorites."
The Times reports:
"Other archeologists said the theory was plausible and appeared
to provide the first logical explanation for the Akkadian downfall...
In an article accompanying the report in _Science_, Dr. Robert McC.
Adams, secretary of the Smithsonian Institution and an anthropolo-
gist specializing in Mesopotamia, cautioned that Dr. Weiss and his
colleagues had not thoroughly established the link between climate
and the empire's fall. He questioned whether such widespread and
persistent drought could be inferred from local soil conditions
at a few sites. 'It will demand of other people in the field to
either refute it or replicate it with their own work.' Dr. Adams
said of the theory. 'And the only way to get people to pick up
that challenge is for Weiss to stick his neck out. I applaud it.'"
The Times also has a nice sidebar (and accurate, as far as I can tell!) on
the surrounding chronology, from the appearance of Akkadian, through the
rise of Agade and on to the (Amorite ruled) Babylon of Hammurapi's dynasty.
Michael L. Siemon "We honour founders of these starving cities
firstname.lastname@example.org Whose honour is the image of our sorrow ...
email@example.com They built by rivers and at night the water
-standard disclaimer- Running past the windows comforted their
E-Mail Fredric L. Rice / The Skeptic Tank