Archaeological applications of stable isotope analysis: subsistence and residential mobility in the Chao Valley of Peru

Jonathan D. Bethard, MADepartment of AnthropologyThe University of Tennessee

“For in the seemingly little and insignificant things that accumulate to create a lifetime, the essence of our existence is captured.”

– James Deetz (1977)

Research Goals

1) Utilize established isotopic methods to investigate diet and residential mobility at Santa Rita B

2) Define previously unreported isotopic ranges for the Chao Valley

Location of Site

Santa Rita B

N

CA3

CA3

Demographics from CA3Entierro Sex Age

1 F 15 – 18

2 M 25 – 30

3 ? 10 – 12

4 ? 5 – 9

5 ? 10 –12

8 M 35 – 40

9 M? 12 – 16

10 ? 8 – 10

11 ? 9 – 11

TOTAL n = 9

* AMS Dates: cal. AD 1030 - 1240

Entierro 2 Entierro 3 Entierro 9

Stable Isotope Analyses

• Human bones/teeth reflect the isotopic composition of consumed foods

– Collagen and apatite

• Carbon isotopes: differentiate type of consumed plants

• Nitrogen isotopes: differentiate terrestrial from marine protein sources

• Strontium isotopes: reflect geological bedrock and differentiate locals from non-locals

Materials and Methods

• Samples obtained during 2006/2007 field seasons

• Collagen: Ambrose (1990)

• Apatite: Balasse et al. (2002)– Finnigan MAT 252 mass spectrometer interfaced with an

Elemental Analyzer and Kiel III Device

• Sr purified following Pin and Bassin (1992)– Nu Plasma Inductively Coupled Plasma Mass

Spectrometer

Chao Valley Strontium• Petford and colleagues (1996)

– 0.704108 to 0.705710

N

Local Range (Santa Rita B):0.7050 – 0.7056

Local Range (Moche):0.7069 – 0.7087

Discussion

• 1) C/N isotopes are effective for evaluating diet– Maize-based agriculture

– Coastal location not a definite indicator of marine consumption

• 2) Sr isotopes are effective for characterizing mobility– ‘Local’ signature must be established first

– Useful for determining if non-locals are present

Future Directions

• Continue using carbon isotopes to investigate introduction of maize

• Investigate geography and marine resource exploitation

• Characterize other north coast Sr local signatures

Acknowledgements

• Dr. Stanley Ambrose

• Dr. Kelly Knudson

• Dr. Lori Baker

• Justin Glessner, MS

• UIUC and ISGS laboratory personnel

• Dr. Dan Weinand

• Prof. Marty Salter

• Dr. Ann Kronk

• National Institute of Culture – (Peru)

• Profs. Victor Vasquez and Teresa Rosales

• Dr. Jonathan Kent

• Dr. Catherine Gaither

The William M. Bass Endowment funded this research.