Eau Claire County, Wisconsin - Chapter 1: The Island Op Wisconsin, 1914

assert with positiveness that ages ago the area tliat is now the north central portion of Wisconsin and the upper peninsula of Michigan was an island of great altitude. They trace the physical history of Wisconsin back even to a state of complete submergence beneath the waters of the ancient ocean." "Let an extensive but shallow sea covering tlie whole of the present territory of the state be pictured to the mind," suggests the eminent geologist, T. C Chamberlin, "and let it be imagined to be depositing mud and sand as at the present day. The thickness of the sediment was immense, being measured by thousands of feet. In the progress of time, an enormous pressure attended by heat was brought to bear upon them laterally or edgewise by which thej' were folded and crumpled, and forced out of the water, giving rise to an island, the nucleus of Wisconsin. The force producing this upheaval is believed to have arisen from the cooling and contraction of the globe. The foldings may be imaged as the wrinkles of a shrinking earth." The climate was tropical, incessant showers crumbled the soil on top and the ocean waves crumbled the sides. This erosion through unnumbered ages began to level the mountainous island till the sediment washed down on all sides, cut down the height and added to the area. Thus as the altitude was cut down, the area expanded. Soon little outlying islands or reefs were formed that in time became attached to the parent isle. Ages passed, the crust of the earth yielding to the tremendous pressure beneath, opened into fissures which were pierced by masses of molten rock holding the elements which later chemical processes have converted into rich mineral ledges. Thus by continued upheavals and erosions, the surface and the length and breadth of this ancient island of Wisconsin was subjected to constant change. After the upheavals that resulted in deposits of iron and copper, and accumulations of sandstone miles in thickness, came a great period of ero- sion. To the disintegrations thus washed into the water were added immense accumulations of the remains of marine life. The casts of numerous trilobites found in Wisconsin are relics of this age. Immense beds of sandstone with layers of limestone and shale were formed. The waters acting on the copper and iron of the Lake Supei'ior region gave the sandstone deposit there its tint of red. On the southern end of the island, the sandstones lack this element and they are to this day light colored.

Next came the great ice age. One monster stream of ice plowed along the eastern edge and hollowed the bed of Lake Michigan ; another scooped out Lake Superior and penetrated into Minnesota, Avhile between these prodigious prongs of ice one of lesser size bored its way along Green Bay and do-mi the valley of the Fox. When warmer days came, the glaciers melted and the water filled numerous depressions scooped out in the early irresistible progress of the vast masses. Thus were foi'med the 2,000 or more lakes that make of Wisconsin a summer paradise. The warmth that melted the ice to water also brought forth the vegetation to cover the nakedness of the land, the forests grew, and "man came upon the scene."