Location Taken: Cahokia Mounds State Park, Collinsville, Illinois
Time Taken: November 2012
To continue from yesterday’s discussion about Cahokia, this is another fascinating example of technological might found at the site: woodhenge!
Yes, woodhenge. Think stonehenge but with wood. At least it’s not carhenge.
And technically, it’s a replica. The problem with woodhenge is that, well, it’s made out of wood. Wood rots and weathers away fairly quickly. The only reason we even know woodhenge existed was that rotting posts changes the chemical composition of the dirt it’s sunk into, so archeologists could find and map these ancient wooden circles.
Yes, plural, they made several. There’s a whole series of varying sizes of circles of wooden posts marked into the earth. Every single one has posts perfectly lined up for marking solstices and equinoxes, so just like stonehenge, this was likely used for tracking the movement of the sun.
Given how important it was to maximize the output of the fields that surrounded the city, knowing exactly what time of year it is is crucial to keeping the city fed. When the sun rose at a certain point along the circle of woodhenge (probably marked with a post), it was time to break out the seed corn and get planting! Another post would warn you that winter was close enough to worry about frost, and you’d rush to get the last of the harvest in. And so on.
These days we use calendars to keep track of such things, and growing zone graphs on the back of seed packets. It’s much the same concept, really. And while we’re using a lot of wood for paper to print the calendars and graphs on, at least we don’t have to worry about the posts rotting away.
