Obsidian may hold the key to a mysterious ancient city

Archeologists tend to uncover puzzling questions along with ancient artifacts, and so it was when a team from the University of Chicago discovered a long-vanished city, about 6,000 years old, in eastern Syria.

But the city wasn’t where it should have been.

“A hundred years of scholarship taught that urban life began farther south, in Mesopotamia,” said Clemens Reichel of the university’s Oriental Institute, referring to the ancient name for Iraq. And unlike the cities in that area, Hamoukar isn’t on a waterway.

Now Reichel thinks he has found a crucial piece of the puzzle: obsidian. The piece of shiny volcanic rock he held in his office recently still had an edge that felt sharp enough to shave with.

Over several excavating seasons, his team recovered hundreds of finely fashioned obsidian cutting tools in Hamoukar -- industrial equipment for a preindustrial age. Large deposits of obsidian were known to have existed just north of Hamoukar, in what is now Turkey.

Reichel theorizes that raw material was imported by the inhabitants of Hamoukar, sharpened and honed by artisans and shipped downstream to Mesopotamia. Food presumably was imported with the profits.

When Reichel and his colleagues first reported their excavations, beginning in 1999, what was most impressive wasn’t the contents of the site but its size and dramatic evidence of its fate. Six hundred square meters of ruined city walls and buildings testified to a flourishing urban center that had been abruptly destroyed about 3500 BC.

Amid evidence of a massive fire, the city was littered with missiles designed to be flung with a sling. Hamoukar’s demise was violent. Some invading force destroyed it in an early instance of the kind of street-by-street combat now engulfing Iraq.

“In archeology, we can only say something is the oldest until the next discovery,” Reichel said. “But so far, it’s the earliest example we have of a theater of urban warfare.”

Archeologists are fascinated by the evolution of cities, noted Guillermo Algaze, a professor at UC San Diego. Cities are where the human species took a great leap forward.

For thousands of years, humans lived in small groups, living by hunting and subsistence agriculture. Then came what archeologists call the urban revolution, as substantially larger groups formed, specialized trades appeared, and commerce and writing developed.

Scholars long assumed that cities emerged in Mesopotamia about 6,000 years ago, spread up the Tigris and Euphrates river valleys to the larger Middle East, then to Greece, Rome and Western Europe.

But the excavations at Hamoukar revealed a city at least as old as its supposed predecessors far to the south.

This development to the north was puzzling. Rivers provide drinking water and a natural avenue of commerce, so Hamoukar seems an unlikely site for a city.

But a city flourished there. “We asked ourselves why.”

If obsidian is the answer, it also might account for the city’s demise, perhaps at the hands of a commercial rival or former customers who wanted the obsidian market for themselves.

Algaze thinks the Oriental Institute team is on to something. But, as often happens in archeology, a new hypothesis leads to new questions. If Hamoukar reached the brink of civilization, why did that honor eventually go to the people of Mesopotamia?

“The north went down the drain; the south took off,” Algaze said. “Why? That’s question of the hour.”