Recent Geological History

The surface geology that determines the shape of the Millers watershed was predominantly formed during the last major deglaciation of the Great Lakes, between 16,000 and 10,000 years ago. Over this period of 6,000 years the Lake Erie and Saginaw glaciers retreated and then advanced, pushing up the Ft. Wayne and Defiance end moraines, that underlie the western extent of Ann Arbor and some of Ypsilanti (refer to the 1982 Quartenary Geology maps below).

As the ice retreated in Lake Erie and Saginaw Bay, the lake shorelines extended much deeper into the current northeast and southeast lower Michigan peninsula land mass than they do today. The dark green area on the 1982 Quartenary Geology map is lacustrine (lake) clay and silt, indicating that this was once a large, slow moving body of water where very small particles like clay and silt had time enough to settle out of the water.

According to Russell and Leverett (1915), the ancestral Huron River came into being during the build up of the Ft. Wayne moraine, but successively occupied a larger portion of its basin as the ice retreated to the east. The Huron River was a glacier meltwater drainageway that entered ancient Lake Erie near what is now Ford Lake (See Ann Arbor watershed geology map).

The Millers Creek watershed to the north is part of the Defiance end moraine, while the southern portion of the Millers Creek watershed may have once been part of the Huron River (see large extent of glacial outwash sand and gravel and postglacial alluvium surrounding the present Huron River location).

Above is a 1947 aerial photograph of the Millers Creek Watershed. Some watershed areas were not included in the original photograph. The creek watercourse and its tributaries are highlighted in blue. In this pre-Huron Parkway era, most of the watershed land use was agricultural and in some instances, creek tributaries have been created or straightened for draining the land.

Click here for a glossary of terms used in this article.

References

1. I.C. Russell and F. Leverett. The Ann Arbor Quadrangle: U.S. Geological Survey Folio 155. 1915.
2. Kunkle, G.R. "Lake Ypsilanti: A probably late pleistocene low-lake stage in the Erie Basin," Journal of Geology, 71:72-75, 1963.