Radiation Holds Key To Inca Riddle

[Nakharar]

Radiation holds key to Inca riddle

 

By Mary Ann Albright, Corvallis Gazette-Times

 

Corvallis Gazette Times, OR

March 27 2005

 

An Oregon State University researcher is using modern technology to

unravel the mysteries of an ancient South American culture.

 

The Inca empire marked momentous state occasions with a ritual called

capacocha. These ceremonies linked the capital of Cuzco to remote

Inca provinces through the sacrifice of children and the burial of

precious objects.

 

OSU researcher Leah Minc used neutron activation analysis to identify

the compositional elements of 15th century pottery found in several

sacred burial sites. Establishing the artifacts' makeup allowed her

to pinpoint their origins, and ultimately to better understand the

capacocha.

 

The findings were published in the March issue of the Journal of

Anthropological Archaeology and illustrate the possibilities of

archaeometry, a field that applies scientific analysis to

archaeology.

 

"This study gives us a whole different perspective on ancient

societies," Minc said. "It was exciting to be able to shed light on

an ancient ritual in a way that no other technology would allow."

 

Minc came to OSU last summer from the University of Michigan, where

she conducted these analyses. When the University of Michigan closed

its radiation center, Minc looked for a new institution with the

capabilities her research required.

 

The OSU Radiation Center "has a lovely reactor," Minc noted. "All of

this requires the artifacts be placed in the neutron flux of a

nuclear reactor."

 

Steve Reese, acting director of OSU's Radiation Center, explained as

simply as he could how neutron radiation analysis works:

 

"You insert the sample into the reactor and bombard it with neutrons

that activate the sample. The elements in the sample absorb the

neutrons and become radioactive. You look at the radiation they emit,

and that tells what atoms are present."

 

Minc looks at the types and quantities of trace elements in a sample

to determine its geographic origin based on its chemical

"fingerprint" or "signature."

 

By applying this procedure to the Inca pottery, Minc determined that

both imperial and provincial people contributed to the burial gifts.

She compared samples from five sites, mostly in Peru and Argentina.

 

Contrasting the raw materials used to make the different ceramic

vessels allowed Minc to demonstrate that all of these sacrificial

burials were part of the capacocha ritual. The geographical scope of

the ceremony supports archaeologists' belief that imperial Inca

leaders used the ritual to link the political heartland of Cuzco to

outlying provinces.

 

Minc spent several years on this project, but OSU's resident

archaeometrist has plenty of other cultures she wants to study. One

current venture uses analysis of late Bronze Age Armenian pottery to

examine that society's market system and trade routes.

 

Reese says Minc's work will add to the radiation center's prestige,

attracting more research grants and funding.

 

Prior to Minc arriving and beginning an archaeometry program, OSU

primarily used neutron activation analysis for geochemical analysis,

Reese explained. He believes Minc's work opens up new possibilities

for the university's radiation technology.