Ann Arbor on Ice
There are also massive hunks of granite, gneiss, and limestone in the former gravel pit at the Fox Science Preserve near Delhi. Abandoned more than forty years ago, the mine is being recolonized by various plants, mosses, fungi, algae, and lichens. This landscape offers us a possible vision of Ann Arbor as it looked 11,000 years ago, after the scouring retreat of the glacier and the return of living things.
Other gravel mines dot the area, most of them now abandoned. Sepulchers to industry, these pits used to be hills containing deposits of gravel and sand that were mined for local construction. (Gravel from Olson Park and the Fox Science Preserve was used to build I-94.) These hills--known as kames--were created when glacial melt poured heavy sediments like sand and gravel into holes, crevices, and other openings in the ice; lighter sediments such as clay and silt were carried off by the water. Further melting of the glacier eventually dropped the sorted accumulation in heaps on the ground. One kame still stands in the Ruthven Nature Area, at the northeast corner of Huron Parkway and Geddes Rd.