Flotation versus dry sieving archaeobotanical remains: A case history from the Middle Horizon southern coast of Peru

Abstract

During excavations at the site of Casa Vieja located in the Peruvian coastal desert, archaeological plant remains were systematically collected to assess whether it is more productive and informative to sieve sandy sediments in dry environments or to process such samples by water flotation, a persistent methodological concern. At Casa Vieja, dual subsamples were collected and analyzed using both of these procedures. For dry, sandy sediment conditions, each processing strategy was found to yield a different view of the botanical remains. Dry sieving recovers more of the larger plant specimens whereas water flotation yields more of the smaller-sized material. These results should be incorporated into archaeological research designs in the future, especially for desert environments.

Keywords:

• archaeobotany
• Peru
• flotation
• dry sieving

No words can express our gratitude for the time, flawless commitment, and research acumen that Susana Arce, the Director of the Museo Regional de Ica and the Co-Director of excavations at Casa Vieja, brought and still brings to the project. She made much of this field and laboratory project a reality with support provided by José Cahuas, former Director of the Instituto Nacional de Cultura-Ica. José Cahuas and José Del Solar Celestino (an archaeology student who participated in our excavations) have both passed away since our excavations ended; they are sorely missed. We are grateful to the INC and their staff for support and help in providing the laboratory and storage facilities for the research collections especially despite the natural calamities that Ica has faced in recent years. Special thanks go to Asunción Cano E. of the Museo de Historia Natural Universidad Nacional de San Marcos, Lima, Peru for his advice and for supporting his former student José Eduardo Roqué Gamarra’s Master’s thesis research on our project. His studies resulted in the identification of screened excavation remains from Casa Vieja, and a comparative plant collection for the Ica River Valley that was used to help identify recovered archaeological taxa. The season report summarizing this project's work is titled Investigaciones de reconocimiento arqueológico en la parte baja del Valle de Ica (1988–1990), is housed within the Instituto Nacional de Cultura, and is referenced throughout the text as “A.G. Cook, personal communication.” Nancy Parrish also completed her Master’s thesis entitled “Gardens in the Desert: Palaeoethnobotanical Analysis from Casa Vieja, the Lower Ica Valley, Peru” in 2004 at George Washington University on the identification of ancient botanical remains from excavated soil samples from Casa Vieja and a preliminary comparison between flotation and dry sieving methods. We also thank all those who contributed to the success of this project including Lisa De Leonardis who laid out the site grid and helped initiate surface survey, David Clark who prepared and trained students to do flotation in the field, and Guillermo (Piro) Morón whose dedication and skills as a field archaeologist are evident in the field maps on which our GIS was based. In Washington D.C., Jeff Splitstoser provided his graphic design expertise most evident in the overall map of the region. Special thanks go to Kenneth Chiou for his advice and aid with the figures. In Berkeley, Laura Perez, Alan Farahani, and Nico Tripcevich helped us with constructing the GIS database. This research would not have been possible without the generous support of the John H. Heinz III Foundation, a six month Lecturing/Research Fulbright Grant, and several Catholic University Faculty Research grants.

Katherine L. Chiou (M.A. 2009, University of California, Berkeley) is a doctoral candidate in the Department of Anthropology at the University of California, Berkeley. Her research focuses on Moche (a.d. 200–800) households and cuisine on the North Coast of Peru.

Anita G. Cook (Ph.D. 1985, SUNY Binghamton) is Professor of Anthropology at the Catholic University of America. She conducts archaeological research in the Central Andes on early empires with a special focus on ritual, religion, and politics as revealed through portable material culture, architecture, and symbolic media.

Christine A. Hastorf (Ph.D. 1983, UCLA) is Professor of Anthropology at the University of California, Berkeley. She is known for her contributions to paleoethnobotany, agriculture, meaning and the everyday, food studies, political economy, ritual in middle range societies, and the Andean region of South America.