History of Oakland County Michigan a narrative account of its historic progress, its people, its principal interests / compiled from the official records of the county, the newspapers and data of personal interviews, under the editorial supervision of Thaddeus D. Seeley.

HISTORY OF OAKLAND COUNTY

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Later, I will speak of the melting back of these glaciers, but here I
want to help the reader to account for the irregular and discordant stratification that all have noticed so often in sand and gravel banks in this
county. It can largely be accounted for by recalling that the glaciers in
receding, and perhaps in advancing, with their burden of ground up rock
and debris would leave depressions, pools, hollows and dammed up valleys, and that the rains, winds and waves, and the streams of water flowing in and out of such depressions would assort and stratify the sands,
clays and gravels the same as they do now in like situations. Often the
rims of these hollows were worn away slowly by the gradual deepening
and wearing down of their outlets, or quickly by floods or other causes;
and then the stratification would begin anew under different circumstances and in a different situation. Is there any wonder then that in
a small gravel pit the stratification may be so discordant, tipped and
varied that we are puzzled to account for it in detail?
The soil of Oakland county has been transported very largely from
the northeast. This is established both by the detached fossils and
minerals, as well as the fossiliferous boulders we find scattered over the
county. Pieces of iron ore, copper and other minerals, as well as corals,
brachiopods and other fossils, are often found. The corals are sometimes called by the finders petrified "wasp nests" or "honeycomb," and
are very common in our drift. All the above are still found northerly
of us in Canada, in places in solid bed rock.
These glaciers swept over all Michigan and to, and in some places
beyond, the Ohio river. The last great ones that crossed this county
ended in northern Ohio and Indiana, and left there and in southern Michigan a great terminal moraine of earth, rock and debris, which accounts
for the hilly country of Hillsdale county in Michigan, and in some of
the counties in northern Indiana and Ohio.
Glacier streams or lobes, like other streams, generally follow depressions and valleys, although ultimately they may leave a hill where a valley
existed before. Geologists are now agreed that a number of great glacial
sheets swept down from the north, covering the northern states east of
Minnesota and north of the Ohio river. These glacial sheets succeeded
each other at different periods far apart. To distinguish them geologists
have differentiated and named those known, as the Kansas, Iowa, Illinois
and Wisconsin Glacial Sheets, and have determined that they came in the
order in which they are above mentioned. The Wisconsin, the last of
those great glacial sheets, passed over Michigan, including this county.
This great ice sheet included numerous subordinate glacial lobes, two of
which concern this county and largely shaped its present surface conditions. Both came from the northeast and in all probability originated in
the vicinity of Hudson's Bay, in Canada. They traveled over this county
in a southwesterly direction.
One of them, known as the Saginaw ice lobe, or glacier, came down
Saginaw bay and swept south across our state. Its left bank or moraine,
as the geologists call it, passed down the "Thumb" and across Huron,
Sanilac, Tuscola, Lapeer, Genesee and Oakland counties, and farther
south to and beyond Hillsdale and western Lenawee. The right or western moraine of the other, the Maumee ice lobe or glacier, which termin