Dissertation: The Role of Cerros de Trincheras in Prehistoric Agricultural Strategies of Northern Mexico and the Southern Southwest

University Of New Mexico, Albuquerque NM

Investigators

Abstract

Under the direction of Drs. Wirt Wills and Robert Hard, Mr. Gerry Raymond will collect data for his doctoral dissertation. For many years archaeologists have recognized the presence of "cerros de trincheras" (terraced hillsides) in the late prehistoric Southwest. Research indicates that they served multiple functions and that people both lived on them and used the terraces as agricultural fields. Recently however similar features have been discovered in the state of Chihuahua Mexico which are significantly earlier than their northern counterparts and which date to the Archaic period, over 3,000 years ago. The discovery of fragments of maize and other domestic plants in the terrace soil demonstrates that the inhabitants were practicing agriculture at a time and place where hunting and gathering had been believed to be the sole source of subsistence. Mr. Raymond will conduct archaeological research at a newly recognized group of cerros de trincheras in Chihuahua to determine how they functioned. Because little is known about this group, he will conduct test excavations to recover cultural material as well as charcoal, faunal and botanical remains. These will permit age determination by radiocarbon dating and also provide information on the range of subsistence resources. Mr. Raymond also wishes to understand why relatively large amounts of labor were expended to build such terraces and why residents did not rely on less labor intensive flat ground farming. Based on analyses from later U.S. counterparts, he postulates that individual terraces create separate microenvironments with unique moisture characteristics based on slight differences in runoff catchment. Some terraces, he believes were better watered than others and in variable semi-arid rainfall conditions, productivity among terraces would vary from year to year based on unpredictable rainfall level. Thus terracing would serve a risk minimizing function. Using a geographic information system to display and correlate data, he will map terraces, measure their slope, catchment area and geological context and determine whether observed variation meets his prediction. He will also set the individual terraced hillsides into a larger geographic context to learn how they functioned in a broader ecological/subsistence context. The research is situated within a theoretical framework of optimum foraging theory. This work is important for several reasons. The existence of Archaic cerros de trincheras was completely unexpected and significantly changes archaeologists understanding of the development of agriculture and the shift from hunting and gathering to farming over a wide region in the U.S. Southwest and Mexico. Mr. Raymond's work will add a new set of cases to a very small and inadequate sample. The research will provide new insight into how these features functioned and provide data of interest to many scientists. It will also assist in training a promising young scientist.