Professor Emeritus Dr. William Lovis, an environmental archaeologist, coauthored an article in Quaternary Science Reviews with Alan Arbogast, Professor of MSU Spatial, Geographic and Environmental Sciences, Dr. Kevin McKeehan of the US Geological Survey, and the late Dr. G. William Monaghan of Indiana University and Indiana University/Purdue University Indiana.
Their collective interdisciplinary research addresses the evolution of coastal sand dune systems along the eastern and northern shores of Lake Michigan, addressing one of Lovis’ primary interests in coastal archaeological site taphonomy and preservation.
“There are lots of archaeological sites right along the coast of Lake Michigan,” Lovis said. “And those sites are either preserved or not preserved, based on when the dunes are growing and when they are less active or quiescent.”
The question Lovis and his colleagues were trying to answer? What dynamic natural processes make the dunes active and what processes make them relatively inactive or “quiet” now?
The research team’s collective research focused on the movement, growth, and stabilization of dunes in the Lake Michigan coastal zone area. Preservation of ancient archaeological sites, some going back five thousand years or more, along dunes in the coastal zone isn’t always guaranteed, Lovis said.
“There is always this assumption that somehow, almost all the human occupation sites from all time periods in the past – the places where people lived, are going to persevere. But that’s not necessarily true. So, the results of this interdisciplinary research collaboration really do enlighten us quite a bit about what we can expect the past to yield to us today, and how best to manage that record.” Lovis said.
“If the dunes are formed during certain times and human occupation sites rapidly get covered by sand, then those sites are going to be preserved, and with the right techniques can be relocated. On the other hand, if anyone was living in a sand dune that was regularly being churned up and disturbed, then there’s very little evidence that might remain to reveal that anyone lived there.”
According to Lovis, the research he and his colleagues conducted was challenging as they had to comb through more than 75 years’ worth of data.
The research presented in QSR is a broad and robust meta-analysis of radiocarbon and optical dating of dune activation and quiescence cycles over the past 5000 or more years based on collaborative research between archaeologists and earth scientists.
“We collected and analyzed data from around the Lake Michigan basin in Michigan. Then, we pulled together all the archeological data and the geographical dune data, you know, the OSL or the optical age data, from the dunes and the radiocarbon data from archaeological sites. That’s what really makes this a very comprehensive and robust analysis.”
According to Lovis, this work is a rare example of the full integration of data derived from coastal archaeological sites and dune geomorphological research.
“We tried to solve a problem and answer some big questions that had been lingering for a long time, and we came up with what’s probably a pretty good model for people to test,” Lovis said.
“The sand in coastal dunes can be activated in a lot of different ways … it can result from a drought, or it can be the lake level getting lower,” Lovis added. “It can be because the process of isostatic rebound or “uplift”, as it is called, is bouncing the coastal landforms higher and moving the dunes away from the water and exposing the sand. There’s a complex relationship there that we were trying to decipher.”
Lovis said that, in the long run, “The real proof of this is going to be if other people can somehow either confirm, or potentially reject, some of the ideas that we came up with in the paper. But, so far, you know, this is the most robust analysis that’s been done of the area.”
The results of this multidisciplinary analysis provide a strong foundation through which archaeologists can understand where, when and why evidence of early human occupation is preserved in coastal dune contexts, and for coastal dune geomorphologists narrows down the range of possible hemispheric climate drivers impacting regional aeolian processes.
The article may be accessed at DOI: 10.1016/j.quascirev.2023.108042
