Nuclear analysis reveals secrets of Inca burial site


CORVALLIS - Researchers have applied a unique nuclear analytic technique to pottery found at an ancient burial site high in the Andes mountains, and believe that the girl buried at this site was transported more than 600 miles in a ceremonial pilgrimage - revealing some customs and rituals of the ancient Inca empire.

The findings are being published by scientists from Oregon State University in the Journal of Anthropological Archaeology.

On the highest peaks of the Andes, sacrificial burial sites have been discovered since the early 1900s. In one of them was the fully intact, frozen body of a girl who was sacrificed at age 15, called "The Ice Maiden," and buried more than five centuries ago along with various vessels - in what appeared to be one of the ritualistic ceremonies of that era.

"We examined the pottery, but not by comparing styles of vessels," said Leah Minc, coordinator of this research at the OSU Radiation Center. "We are using the sensitive, high precision technology of instrumental neutron activation analysis to learn about raw materials in artifacts.

"This provides a different part of the story than that obtained from DNA sampling of human remains," she added.

According to Minc, whose doctorate is in archaeology, the geochemical signature from the raw materials indicated the vessels were manufactured far away from the burial site, in the Inca capital.

The study offers insights into the origins of the children who were sacrificed in a key state ceremony called capacocha. This provides information about how imperial Inca statecraft linked the empire by sending representatives to remote mountaintops to perform religious rituals.

From samples of the pottery, this analytical technique created a series of radioisotopes and monitored their decay. It characterized trace elements, which scientists could then scientifically compare to those in ancient artifacts from other regions, as well as to pottery from contemporary sites in central Peru and northern Chile.

Neutron activation analysis is one of the advanced capabilities of the OSU Radiation Center's research reactor. Minc has helped OSU apply this technology to archaeological studies. "Archaeometry" can help unlock mysteries including the diet of prehistoric populations, from bone chemistry, and the authentic or fake status of an "ancient" artifact, researchers say.

The technology has regularly been used for research in engineering, medicine, nutrition, forestry, and geology.

OSU's Radiation Center is a leading facility in the use of ionizing radiation and radioactive materials. It serves institutions around the world, on everything from feasibility studies of experiments to safety evaluations, emergency response, and radioactive waste disposal.