The Science Museum of Minnesota’s 2010 Ranelius site project at Spring Lake
Posted by Ed Fleming on Sunday, May 30
The 2010 Ranelius site archaeological project has two main components. First, we are analyzing the collection from the Science Museum’s 1954 and 1955 excavation. This involves an in-depth examination of the field notes and maps, re-cataloging the artifact collection, and analyzing the various artifact classes (stone tools, ceramics, plant remains, bone materials) to place them into chronological context and draw conclusions about external relationships. When was the site occupied, which cultural groups were there, and how did the people living at the Ranelius site relate to others and the history of the region? These questions carry over into the second main component of research.
The second component is a new expedition of field research into the site. Beginning this week, we will conduct a geophysical survey of about two acres of the site. Geophysical survey applies several methods to examine differences in the geological deposits beneath the surface. Variations in the sub-surface geology can potentially reveal human-made deposits. Ground penetrating radar (GPR) and electrical resistivity identifies areas of high or low resistance. Low resistance areas can indicate the location of ancient storage pits. Areas where a pit had been dug and then refilled in ancient times will still be less compacted than the surrounding areas. High resistance areas might reveal a compacted house floor, a wall or foundation (which is unusual from pre-contact times in the Upper Midwest), or a cobble-lined pit. Magnetometry reveals differences in the magnetic signatures of the sub-soil. Burned areas (like a fire pit) will have a different magnetic signature than their immediate surroundings. Used in combination, these three methods can put a spotlight on specific parts of the site that have particular types of ancient cultural remains.
Now, while a geophysical survey does reveal differences in the sub-surface geology, it does not tell us that what these differences mean. These anomalies MIGHT be the remains of what people left behind a thousand years ago, but they also might be natural. To understand what the geophysics means requires excavation. We will look at the results of the geophysical survey and select for excavation several anomalies that appear to be cultural. The geophysics will guide our excavation strategy. Because of this, we will not be digging blind. We will be targeting specific parts of the site that have a good chance of containing archaeological materials for study. This is called ground-truthing the geophysics. Once we dig, we can then assume that other features that appear in the geophysics across the site are similar to the ones we excavate, and then draw conclusions about the layout of the site and gain a better understanding of the whole area surveyed. The artifacts uncovered through the excavation of site features will also tell us when these features were used and who used them - also details that the geophysics alone cannot tell us.
All data from the 1954/1955 excavation and the 2010 project is being held in a geographic information system (GIS). This is a database that holds all information about the locations of all archaeological and natural features of the site. A GIS is useful for discovering relationships between these aspects of the site.
The results of this research will be reported through this blog, a final report submitted to the Minnesota Historical Society as a requirement for the grant that funds the project, and an article in the Minnesota Archaeologist - the local, public journal for archaeological studies in and around Minnesota.
When we are finished with the project this fall we should have a better understanding of when the Ranelius site was occupied, who was there, how the site was used over time, and the relationships between the people who lived there and other communities across the broader region of southeastern Minnesota. We will also have a better understanding of the importance of the Mississippi River to the people living along it during the period of about 700 A.D. and 1400 A.D. Furthermore, we will have a better understanding of Native American people who made this landscape their homes during this period. Finally, and importantly, we will be helping all of you learn the rich and deep history of Mississippi River.
