An Archaic Mexican Shellmound and its Entombed Floors ed. by Barbara Voorhies (review)

This monograph is the eightieth entry into the UCLA Costen Institute of Archaeology’s monograph series. More specifically, this archaeological site report is an overview of an excavation comprised of entries analyzing various aspects (faunal, lithic, ceramic, geochemical) of a site and how those entries contribute to a larger research question. In a typical site report, one can find an overarching narrative examining the “big picture,” but mostly these reports are very technical descriptions of field work, data collection and observation, and lab analyses. Oftentimes when cracking their covers after having had my interest piqued by a neat-looking artifact or site photograph, I would find my eyes glazed over and my mind awash in tables, graphs, and artifact counts, not to mention unfamiliar disciplinary debates. Then, I would most likely place it back in the pile. Yet, as someone who maintains a personal and teaching interest in Mesoamerica, if I were to do the same to Barbara Voorhies’ monograph, then my knowledge of the debates and discoveries in pre-historic Mexico would not be current. For cultural-historical geographers or cultural ecologists, especially those using geophysical proxies with archaeology data, An Archaic Mexican Shellmound is a relevant read to better conceptualize the long block of human prehistory known as the Archaic Period (8,000-2,000 BCE).

The archaeological site described within this volume is a shellmound, an anthropogenic heap composed of mollusk shells, sediment, and other debris. This shellmound formed over a period of 600-800 years in the late Archaic (approximately 3,000 BCE – 2,200 BCE) on the southern Pacific coast of what is today the Mexican state of Chiapas. The so-called Tlacuachero Site is as an island 125 meters wide and 7 meters high in a tidal mangrove forest. Of particular interest to the authors are floors within the shellmound, representing human occupations and thus windows into the lifeways of the late Archaic. This period in Mesoamerica is especially notable because of the massive economic and social changes that occurred locally within the Chantuto culture and across the region represented by increasing sedentism, greater social complexity, and a transition from wild-based to domesticated foods.

The larger project of Voorhies and her colleagues is to provide a more nuanced depiction of this important transitional period in Mesoamerican prehistory. This research seeks to complicate the simplistic assessment of life before villages and cities as mere hunting and gathering. Additionally, this book contributes to a larger debate regarding the formation processes of shellmounds across the Americas, from the US southeast to northern California to southeastern Brazil. The highly detailed work on the stratigraphy, chronology, and artifact assemblages by the authors points out that determining how shellmounds formed is a more knowable and therefore more instructive research question than theorizing why they formed. Knowing the processes of how these shellmounds formed more precisely reflects the social changes that the late Chantuto people experienced.

To make these arguments, Voorhies and project archaeologists contribute 11 concise, well-written chapters. After a site introduction, an analysis of the stratigraphy and chronology locates the site and its formation in its appropriate temporal setting (Chapter 2). In the chapter that follows, the post-Archaic occupation is analyzed through ceramic artifact assemblages, indicating the use frequency of the site during times of more complex societies (Chapter 3). Chapters 4 through 7 focus on the buried floor features themselves, first by describing them and the sampling methodology used, followed by floor geochemistry and micro-artifact analyses. These floor features were clearly activity areas where food processing and consumption took place. One of the most intriguing discoveries was that the floors were not composed of clay as previously believed but of hydroxylapatite, which likely formed from the introduction of calcite from ash or shell (or both) transformed through reaction with phosphates deposited by human activities. Chapter 7 examines phytolith...