The waters of the great continental rivers are solid and opaque, the fine sediment rides near the surface and absorbs all light. There are no dancing diamonds of sunlight in these streams, the sky is muted with clouds of silt and ashes of people, the mud glazes lightly on the edges. There are few stones or boulders here in the heartland, just solid soil suspended in the flow, delivered to the banks along its way to the deep Gulf of Mexico. Delivered, the silt swirls with the gulf coast fishes and comes to rest on the dark ocean floor while the light sparks high above with blue to the sky.
Yet few stones are there in the rivers, small stones are riding the deepest channels of these large, wide rivers, deep in the hydrodynamic equations under the surface. The stones are lifted from their source, suspended for miles of steady rate, and they drop from the flow according to formulas of speed, decent, and curve. There are few gravel bars along the river’s edge, and one is just north of the confluence on the Mississippi, filled with the small tumbled stones of the continent.
It is called the Chain of Rocks, and it’s a long, gentle bar of small stones along the river. Fishermen fish, a grandfather and his boy, sitting on overturned buckets in the shade. Household trash and a porcelain toilet are dumped in the rutted parking lot. But rock hunters know this is the spot, one of the few where stones gather from the muddy stream.
When I went there with my father, I gathered handfuls of shiny, milky stones, knicks out of time from a thousand eras of geology, plucked from the strata and brought along for the ride. Each stone is different, a medley of origins, each can be traced to a hundred different locations on the massive continent this river drains. These are not local rocks, these are rocks from the journey, mementos of passing scenes.
While scanning and sorting the way rock hunters do, I found a prize, a large fossilized vertebra — a bone that had turned to stone, a huge old mammal with a large spine made with three wings and a hole in the center. The hole was now crammed with mud and rocks, and the creature once walked the continent long before the humans, for to be fossilized means to be very, very old.
Maybe this beast walked and grazed upon the high north of the Canadian shield, in between the ages of ice, along the shield where the earth's oldest stone is exposed. The animal died, it was picked clean and scattered, the bones weathered and washed away to be buried so deeply for so long that the minerals of bone could be exchanged with the minerals of stone. It rose to the surface again and has been moving slowly downstream, resting and rising and settling and tumbling with the sediment loads until it landed there in a moment of rest in the Chain of Rocks.