CONTRIBUTIONS OF GEOARCHAEOLOGY TO MESOAMERICAN STUDIES

A survey of the Mesoamerican geoarchaeological literature published from 1990 to the present—in celebration of Ancient Mesoamerica’s first 20-year katun anniversary—shows the full spectrum of small, focused projects to broad-range programs. Some scholars defend subdisciplinary boundaries and only do their research as physical science. Others combine natural with social science investigations, and some delve well into the humanities. I suggest here that the more successful programs are the latter because I believe the human experience in ancient Mesoamerica does not fit neatly into one or two of our Western disciplinary categories. Hopefully the next katun can be characterized by more open inquiry including the fullest range of scholarship from the natural sciences, through the social sciences, and embracing the humanities. The growth of new “bottom-up” approaches and post-structural theory—often including agency, practice theory, and resistance—help broaden inquiry and therefore bode well for the next katun. Rapp and Hill (2006:1) provide a useful definition of geoarchaeology as “the application of any earth-science concept, technique, or knowledge base to the study of artifacts and the processes involved in the creation of the archaeological record.” Geoarchaeology is now recognized as a legitimate subfield of inquiry, with textbooks (Dincauze 2000; Goldberg and Macphail 2006; Rapp and Hill 2006; Waters 1992), the journal Geoarchaeology published since 1986, and advanced courses taught in many universities. The subfield includes topics such as the natural aspects of archaeological site formation and preservation, stratigraphy, sedimentation, erosion, reconstruction of ancient environments and climates, natural-cultural disasters and their aftermaths, resilience to unanticipated stresses, geochemistry, natural materials as resources, determining sources of materials in sites, ceramic and lithic petrography, dating, remote sensing, and geophysical exploration. Rapp and Hill (2006:273–275) are determinedly and exclusively scientific, but I argue here that avoiding the humanistic is unfortunate. I believe the more successful geoarchaeological research projects in Mesoamerica are those that do not stop at academic boundaries, but rather seek relevant data and insights from the full range of physical sciences, social sciences, and the humanities. Even the hallowed journal Science recently reported the beginnings of multidisciplinary research in geophysical disasters that highlight mythology, oral history and religion of native peoples, in addition to scientific geophysical and geoarchaeological components (Krajic 2005). And volcanologists in Costa Rica, at the southernmost end of Mesoamerica, are beginning to explore how eruptions may have affected ancient peoples and become preserved in legend (Alvarado and Soto 2008). Significant human events, be they crises or successes, rarely occur within the tight boundaries of a traditional Western scholarly subfield. EARLY STUDIES Geology as a discipline developed about a century before archaeology, and archaeologists in the late nineteenth and early twentieth centuries adopted geological concepts such as type fossils (archaeologists’ “diagnostic” artifacts), uniformitarianism, stratigraphy, and relative dating. They were also aware of context, as nineteenth-century European scholars found handaxes in ice-age gravels associated with extinct megafauna, finally followed by somewhat similar discoveries at Paleoindian sites in the American Southwest and in Mesoamerica. Early archaeologists were not shy about borrowing theory and methods from geology, and thus it would be difficult to find a significant Mesoamerican research project conducted during recent decades that did not incorporate some aspects of geology. During the second half of the twentieth century Mesoamerican archaeologists were increasingly exploiting geological techniques such as quantitative dating, petrography, and instrumentation to determine sources of materials such as obsidian and jade and methods to reconstruct past environments (Rapp and Hill 2006; Waters 1992). They were gaining sophistication in understanding modes of emplacement of various natural and anthropogenic sediments and the numerous natural processes that affect sites after abandonment. THE PRESENT KATUN : 1990–2009 The katun to which I am referring is not an actual Maya katun but, rather, the completion and celebration of a katun-length period of 20 years of publication of the journal Ancient Mesoamerica. This article is organized geographically from northwest to southeast. Space limitations obviate comprehensive coverage. Rather, topics and examples must suffice.