Expanding Dendroarchaeology into Northern Mexico

University Of Arizona, Tucson AZ

Investigators

Abstract

With support of the National Science foundation, Dr. Ronald Towner and his colleagues will conduct archaeological tree-ring research at prehistoric cliff dwellings in the remote Sierra Madre of northern Sonora, Mexico. These spectacular structures rival the more famous cliff dwellings of US Southwest in size and construction techniques, but have received virtually no attention from scientists. Our team of US and Mexican dendrochronologists and archaeologists will collect tree-ring samples and archaeological data from these enigmatic structures in order to (a) develop an absolutely dated annual tree-ring sequence for northern Mexico and (b) generate baseline archaeological information, such as detailed site maps, for the previously undocumented cliff dwellings. The development of absolutely dated tree-ring sequences in the area will be a major advance toward providing Christian calendar dates for many archaeological sites in northern Mexico. Such a breakthrough will help historians, archaeologists, and anthropologists delineate important aspects of the development and decline of complex societies in Mexico, such as Casas Grandes, and illuminate aspects of the interaction between prehistoric societies in the US Southwest and northern Mexico. By dating the rooms and structures, it will be possible to study the behaviors and social organization of the site inhabitants and, on a larger scale, examine issues such as migration, trade, and the transfer of technologies and ideas between prehistoric groups in northern Mexico and the southwestern United States. In addition, the baseline archaeological data will provide important information relevant to current and future research questions and management decisions by the Mexican government regarding these irreplaceable pieces of their national patrimony. The project will also help Mexican scientists learn tree-ring sample collection techniques, thus enabling them to conduct future research at sites in northern Sonora and Chihuahua. Finally, the project tree-ring samples themselves contain important environmental information. The many tree species used in the cliff dwellings are different than those found in the United states and exhibit different growth patterns. These patterns are a result of somewhat different climatic regimes in northern Mexico and will help in identifying climatic relationships between the US Southwest and northern Mexico. The absolutely dated ring sequences, therefore, will contribute significantly to future studies of past hemispheric climatic variability and models of short- and long-term weather phenomena such as the southwestern monsoons, El Nino, and La Nina.