Though I don't like to admit it, I grew up in Michigan a quarter mile from Lake Huron. I also have thing for shipwrecks and stone circles like Stonehenge and Avebury. So what do the three factoids have in common? Water. The Great Lakes, shared by Minnesota (barely), Wisconsin, Illinois, Indiana, Ohio, Michigan, Pennsylvania, New York State and the provinces of Ontario and Quebec, are five of the top twelve largest bodies of freshwater in the world, and hold something like 22% of the world's fresh water. They're a little boggling to land-locked folks; you can't see across them in most places and they act more like seas than lakes, but without the daily tides and the salt; 350 million years ago, they were seas that left fossilized coral colonies called Petoskey stones. What you see now, though, is the remnant of glaciers that covered most of North America 10,000 years ago and gouged out those lake beds before filling them with meltwater.
The Great Lakes are deceptively deep and each has a personality of its own. Huron, the one I lived on, is a known ship swallower of oceanic proportions. Of the approximately 4,700 known shipwrecks (with an estimated six to ten thousand total) in the Great Lakes, more than a thousand ships, from ocean-going iron ore freighters to pleasure boats (and airplanes), have been documented as sunk in Lake Huron alone, a large number in the area known as Thunder Bay, just to the north of where I grew up. Lake Michigan, though, gets some of the fiercest storms. It's estimated that 3,000 ships lie in the sands of Lake Michigan.
But ships aren't the only things the waters of the Great Lakes have drowned. The lakes' mean levels rise and fall (PDF) in an approximately 20-year cycle that has to do more with annual snowfall than gravity, so houses and docks and boathouses have a tendency to disappear cyclically as well. Shoreline appears and disappears, is reshaped and eroded and built back up again; wetlands come and go. And as the glaciers pulled away, the lakes rose even more drastically than during this cycle until they reached their present levels, leaving being a number of isolated islands.
One of these islands is Big Beaver Island in Lake Michigan, home to Michigan's very own stone circle. Now there may be another, this one discovered underwater by Dr. Mark W. Holley of Northwestern Michigan College in Traverse City during the course of surveying the shipwrecks and other debris in Grand Traverse Bay. Ah, see? It all comes together: Michigan, shipwrecks, stone circles. Maybe I should clarify before you take a look at the photo of it at right. Don't expected Stonehenge, capital S. It's as much a stone alignment as a henge, which are circular or oval in nature. But standing stone arrangements come in numerous configurations, most of which seemed to have some kind of astronomical significance. Many, like the familiar Stonehenge near Salisbury, UK, were both grave sites and astronomical markers. One acoustics scientist, Rupert Till,has discovered that Stonehenge, at least, reflects music almost perfectly, "making the stone circle an ideal setting for listening to repetitive trance rhythms," as the Discovery News article points out. Rave on, Dude! Of course, whether that's actually what went on there is impossible to tell.
(That circle in the middle of the sonar photo above is an artifact of the imaging tool, a Kongsberg-Mesotech MS 1000 sonar,
which produces some eerily vivid images of underwater objects
(including a very spooky image of a downed plane on their home page) by
pinging soundwaves off them. From watching old submarine movies, I'm
used to seeing a sweeping green line with little blips on it as sonar
images, not something this high-def. That high definition is, of
course, thanks to software processing programs rather more
sophisticated than the echolocation sonar used in WWII subs. Unlike the
side-scanning sonar that's towed behind a surface vessel or sub that
can give wide, sweeping views of the seafloor, this is a more or less
stationary sonar dropped overboard to scan a circular area. Sound waves
blanket an area and the time they take to bounce back to the
transmitter/receiver tells you how high off the surface the objects
returning the sound are, as well as how dense they are, since different
materials absorb and reflect sound differently. The software is
calibrated for the type of surface that's being pinged, so harder
objects, like stones, form clearer pictures than the background sand,
Just what function North American stone circles had is still up for grabs; there are very few of them. What there are a lot of is medicine wheels, which may have served a similar function but have a very different design. What you're seeing here looks very similar to the remains of other medicine wheels across the Great Plains (left). What's doubly interesting about this particular set of standing stones is that one appears to have a picture of a mastodon with a spear in its side carved into it. Mastodon remains have not previously been found that far north, so this could be a significant find. There's some question about whether the stone really shows a mastodon, and it's hard to verify the fact since it's in 40 feet of water and covered in algae.
The truly mystifying thing about most stone circles is how the heck they got where they are. North American stone structures are generally made of rocks that could easily be carried by hand from the surrounding area, but European megaliths often weigh from several hundred pounds to several tons, and some of the stones were quarried hundreds of miles away. It's cases like this that really show up human ingenuity and give the lie to the idea that people in history were less sophisticated or dumber than we are. First, they've chipped this slab of bluestone (which describes the color more than denoting a particular type of stone in this case) out of a quarry 250 miles away in Wales. What now? Using gravity, bits of wood, and some rope, a former construction worker in Flint, Michigan shows you how to move two ton rocks with your bare hands:
This isn't exactly an unknown technique; the Egyptians probably used something like it to erect their obelisks, like the one now residing in London, or the one in New York's Central Park. When the Vatican wanted one moved from behind the sacristy of St. Peter's to the piazza in front, it took "900 men, 75 horses and untold numbers of pulleys and lengths of rope," and a lot of scaffolding. So Wally Wallington's feat is pretty impressive. The stones he's moving weight as much as a minivan. Of course, you could just go directly to the minivan itself.
I shudder to think what future archaeologists might make of Carhenge. Maybe it'll wind up underwater too, with a little luck, and rust can take its course. In the mean time, I wonder how a rave there might sound?