Abstract
Inland and coastal dune fields of North America contain important geomorphic and stratigraphic records of environmental change that can be tied to shifts in late Quaternary climate, particularly during the Holocene. Additionally, the affinity of early Americans and aeolian dune fields is well documented (e.g. Holliday, 2001), providing archaeologist sites to investigate the early peopling of North America. The Geoarchaeology of Lake Michigan Coastal Dunes is the second volume in the Michigan Environmental Research Series, edited by James A. Robertson, a staff archaeologist within the Michigan Department of Transportation (MDOT). The first volume of the series, which some readers may find interesting, is by Monaghan and Lovis (2005).
The present volume begins with an introduction aimed at providing important context to archaeological studies within dunes. This context includes basic background information on dune field activation and evolution in relation to changing climate. The chapter outlines some basic research design such as site selection and field data collection. Chapter 1 could be lightly skimmed by the experienced scientist. However, this basic background information is crucially important for novice researchers and the general public, as much of the text in later chapters relies on an understanding of these concepts.
Chapter 2 provides a historical and interpretive perspective of Lake Michigan coastal dune archaeological sites by highlighting key research since the early 1900s. Although some site investigations predated the 1960s, most of the significant research in the Lake Michigan Basin took place in the 1960s and 1970s. Significant research included the University of Michigan Museum of Anthropology 1962–1963 survey, the Michigan State University 1972–1973 survey and excavation, and the detailed studies of several sites – each of these sites are briefly described within the chapter.
Aeolian processes, dune formation and modification and dune activation and stabilization cycles are described in Chapter 3. The information provided on these topics is cursory, yet sufficient for the text. A brief historical perspective of coastal dune research is also provided. The chapter concludes by providing new chronological control of dune formation from the northern part of the Lake Michigan Basin. The new chronology suggests a cyclic nature of dune formation that dates to c. 5 ka BP. Unlike previous dune studies, the ages provided in this report suggest that dune activity was not directly driven by lake-level fluctuations associated with the Nipissing transgression and regression. Instead, dunes appear to have been formed episodically with major building episodes between c. 3.5 and c. 2 ka BP and a rebuilding episode after c. 1 ka BP.
Chapter 4 discusses the relationships between dune formation, lake levels and human settlement within the Lake Michigan Basin. In particular, the authors highlight the timing of major lake transgressions and regressions, including high water levels from c. 6 to c. 4.5 ka BP, low water levels between c. 4 and c. 3.5 ka BP and cyclic high and low water levels within the last 2000 years, which the authors contend relate to major global climate change events (e.g. the Mediaeval Warm Period and ‘Little Ice Age’).
Six new dune archaeological sites that were investigated between 2006 and 2008 are described in Chapter 5. Like in previous chapters, each site is described in terms of location, stratigraphy, chronology and regional context. Information from each site has helped contribute to the overall larger-scale patterns of dune formation within the Lake Michigan Basin.
Chapter 6 provides a summary, a discussion and a synthesis on the data described in previous chapters. Particular emphasis is given to the chronology of dune formation and modification and the environmental/climatological factors responsible for dune formation in the Lake Michigan Basin. The chapter also presents a spatio-temporal model of coastal dune formation, in which dune formation events are related to a lagged response to coastal erosion as well as to other extrinsic climatological factors, such as storms and drought.
Finally, Chapter 7 is a case study in which local land managers are tasked with identifying landscapes and dune areas to be managed to varying degrees in proximity to a major roadway. The authors use their interpretations from previous chapters to identify specific areas to be put under land management. This chapter is relatively short, but provides a useful guide directed to the general public and the MDOT engineers/scientists in matters concerning the true complex nature of these dune systems.
Following the main text are three appendices. Appendix A details the chronological methods employed including optically stimulated luminescence (OSL) sampling and dating techniques. Appendix B is a table of all radiocarbon and OSL ages reported in the text. Finally, Appendix C provides detailed archaeological site descriptions.
Overall, the book is written by three respected scientists with several decades of experience researching the topic. Furthermore, the scientific reasoning behind the data presented is sound, including the sampling and dating methods of the chronological data. The effort of the authors to condense such large quantities of data in a succinct text is also appreciated. The text likely has a limited audience, which the authors themselves acknowledge as MDOT scientist/engineers, archaeologists, earth scientists, park interpreters, land managers and the general public. Nevertheless, those interested parties will find great quantities of useful data and contextual synthesis.
Perhaps the most important contribution of this compilation is the collection and dissemination of geographical, chronological, stratigraphic and anthropological data associated with dune landscapes in Michigan. As the authors note throughout the text, data from individual sites provide important local information. However, the larger-scale questions of changing regional environments can only be answered through regional synthesis of all data. Other researchers in the fields of aeolian science have recognized the importance of compiling data for regional synthesis, and similar projects aimed at compiling data on dune fields have been undertaken in the Great Plains (Halfen and Johnson, 2013) and, more particularly, by the research team of the International Union for Quaternary Research (INQUA) Global Digital Database and Atlas of Quaternary Dune Fields and Sand Seas (Lancaster, 2011).