Specialists Team Up for an Israeli Dig
IN a few weeks, Steven Weiner will be setting up his portable laboratory inside a cave on Mount Carmel, south of Haifa. He'll be helping a team of archaeologists piece together what life was like 60,000 years ago. Although some archaeologists might say a chemist like Dr. Weiner has no place on a dig, he is showing that his craft has many applications outside the lab. ``The Kebera cave excavation began in 1982,'' Ofer Bar-Yosef says, now a professor at Harvard University. He is one of the two organizers of this French-Israeli expedition. In 1983, the expedition uncovered a 60,000-year-old ``almost complete burial of a Neanderthal man,'' he says.
Dr. Bar-Yosef expects other finds at Kebera to support the theory that ``modern-looking hominoids'' evolved in Africa more than 100,000 years ago and slowly spread to Europe and Asia.
The project includes four physical anthropologists, three archaeologists, two geologists, and one archaeolozoologist. According to Bar-Yosef, having a wide range of professionals makes for better archaeology. ``Questions can be asked and sometimes even resolved at the same time that the field work is taking place,'' he says.
Bar-Yosef met Weiner during his year-long appointment at the Weizmann Institute here. Weiner agreed to use his lab - a three-hour trip from the cave - to provide same-day analysis of mineral samples dug up at the cave. On most archaeological expeditions, samples are sent out to a laboratory for analysis: The results often don't come back for many months.
Inside the Kebera cave, the archaeologists found many animal bones in one location and none in others. Did the ancient inhabitants of the cave actually put bones only in one place, or were there bones throughout the cave that were later dissolved by running water?
To answer that question, archaeologists look for calcite, a yellowish mineral that dissolves in water. Any running water that would dissolve bones would also dissolve the calcite, so finding calcite without bones in a particular spot means that there were never bones in that place.
His first summer on the project, Weiner recalls, the archaeologists brought 50 samples back to his lab: None had any calcite. But that didn't mean that there wasn't any in the cave - it just meant that there wasn't any calcite in the samples.
``The second season, I decided the only way to solve the problem was to take the lab to the cave,'' Weiner says. Having the lab in the cave would let the archaeologists test many more samples; it would also let them use the results of the tests to decide where to dig.
The tool he took with him was his infrared spectrometer. By measuring how an unknown sample absorbs light at different frequencies, the instrument can identify the presence of different chemical compounds. Advances in computers and optics have enabled manufacturers to build spectrometers weighing less than 20 pounds.
Last summer, the question of calcite was resolved in three days, and the on-site lab started attacking other problems.
Bar-Yosef says this expedition is likely to be a model for others. ``For many years, interdisciplinary research in archaeology was just lip service,'' Bar-Yosef says. But now, others are setting up digs that will use professionals performing on-site laboratory analysis.