This doctoral dissertation research project will examine possible linkages between climate change and prehistoric societies in the Cuenca Oriental, an area of interior drainage in the eastern Trans-Mexican Volcanic Belt. Drought has been invoked to explain the abandonment of many areas of Mesoamerica, but direct evidence is only available for a handful of sites, and non-climatic explanations often have been proposed. This doctoral dissertation research project will focus on development of a multi-proxy record of human occupation and Holocene climate change from Aljojuca and Alchichica, two maar lakes located near Cantona, an archaeological site in the northeastern part of the Cuenca Oriental. During the late Classic period, Cantona was one of the largest cities in the Americas, but the site was abandoned several hundred years later, possibly as a result of drought. The doctoral student will develop a record of Holocene climate change by analyzing the fossil pollen content, stable isotope composition, and sediment chemistry of sediment cores from Aljojuca and Alchichica. Pollen slides will be scanned for corn pollen as an index of agricultural activity in the area. These data will help reconstruct the timing of past changes in climate as well as the history of human settlement in the region. The Aljojuca core has already been recovered by an international scientific team from the National Autonomous University of Mexico and the GFZ German Research Center for Geosciences. Radiocarbon dating reveals that the core spans approximately 6,200 years.
This dissertation project will produce two new high-resolution, well-dated paleoenvironmental records from the eastern Trans-Mexican Volcanic Belt. These records will improve basic understanding of the timing of Holocene climate change in the region, especially the history of Mexico's summer rainfall regime. The project therefore will contribute to interdisciplinary debates in archaeology and geography about the role of climate change as a factor influencing human societies. The project will strengthen international collaborations among scientists in Mexico, Germany, and the U.S. Results will be disseminated through a variety of media for scholarly and public audiences, and they will be used in educational activities and lesson plans for undergraduate and K-12 students. As a Doctoral Dissertation Research Improvement award, this project will provide support to enable a promising student to establish an independent research career.
