Barron County, Wisconsin - Chapter 2: Geology, 1922

The land area of Barron county shares with the rest of the central plain of the United States a geological history which reaches unmeasured ages into the past.

The molten, seething mass of chaos cooled into an earth crust of solid rock. The mist and vapor condensed and formed great oceans, which covered large portions of the earth's crust.

Not once, but many times was the central plain of the United States thus covered, the sea sometimes joining the Gulf of Mexico with the Atlantic Ocean. For a part of the time at least, the waters were warm.

Upon the rocky bed of these successive seas was slowly deposited a sand¬ stone formation nearly a thousand feet thick, and upon the sandstone forma¬ tion was still more slowly deposited a limestone formation some three or four hundred feet thick.

Later, an uplift of this sea bottom occurred and the upper beds of sand and limy material, compacted into solid sandstone and lime stone, were raised hundreds of feet above the sea level by interior volcanic pressure, and be¬ came a part of the continent of North America. The great interior sea, which connected the Gulf with the Arctic Ocean was forced to recede, leaving the stony skeleton of the continent high and dry.

Upon the rocks thus exposed swept wind and rain and storm and ice. Frost and heat worked their disintegrating forces. Wild rushing streams tore on their mad way.

In Barron county the top layer of limestone was entirely weathered and eroded away, except in the extreme southwestern corner. There the surface rock is the Lower Magnesian limestone or as the geologists call it, the Prairie du Chien group of the Ordovician period.

The limestone being eliminated, the sandstones underneath were left as the surface rock over a greater part of Barron county. This is called by geologists the Potsdam or St. Croixan sandstone of the Cambrian period.

In Doyle township, parts of Cedar Lake and Sumner townships, and very small portions of Stanley and Rice Lake townships, this Potsdam sandstone has likewise been eliminated, and the surface rock consists of Pre-Cambrian or crystalline rock (granite, quartzite and trap rock). In this area are in¬ cluded a series of hard quartzite ridges. These quartzites were originally a lower standstone, and were changed into hard quartzite by the great heat developed by molten rocks thrown up from underneath. These ridges in the eastern part of Barron and the western part of Rusk counties are known by geologists as the Barron Hills. Several of these ridges reach elevations of 1,500 to 1,600 feet above the sea level, the lower land surrounding the highest of these ridges having a varying altitude between 1,100 and 1,300 feet.

Thus the crystalline rocks underlie all of the county and are exposed on the surface in the eastern part. Over these crystalline rocks throughout most of the county lies the Potsdam sandstone, and is exposed here and there in various places. Over the sandstone in the extreme southwestern part of the county lies the Lower Magnesian limestone, and is here and there exposed on the surface.

The rocky base of the county being thus formed, a soil, called residual soil, was formed by the decay of the bed rock. Upon this residual soil were laid down glacial deposits.

For some cause, yet unknown, the climate of northern North America became cold - probably as cold as southern Greenland is at present. The precipitation which now falls mainly as rain fell in the form of snow, and even the summers were so cold that this snow did not all melt, but accumulated in enormous quantities. The piling up of the snow was particularly great in Canada, including Labrador and the region west of Hudson Bay, the centers from which the glaciers moved outward. Year after year and century after century the snow continued to accumulate here and in northern Europe, and also in the higher mountains all over the world. The snow on both sides of Hudson Bay is believed to have become several thousand feet deep. Its own weight, and possibly slight melting in summer, compressed the snow into ice, and under the tremendous weight of this ice the bottom layers were so pressed upon that they were forced to flow outward - especially southward where the temperature was milder and where melting along the margin of the glacier took place during the warmest months of the year. The movement of the glacial ice was very slow, possibly only a few yards or a few rods a year, as is now the case with the great glacier which covers Greenland.

Soil and loose rock became frozen into the glacier and were slowly moved along with it. The glacier moved over hills and low mountains, through val¬ leys and across plains, removing everything that was movable, scouring and grinding the rocks over which it passed, deepening some valleys, rounding off hills and other eminences, and carrying along a prodigious amount of rock waste in the form of clay, sand, rock fragments and bowlders. Much of this debris was ground fine and forms the present soil. The hardest rocks resisted the grinding and are now found scattered over the surface of the ground as glacial bowlders, some of which weigh many tons.

In Canada the work of the glacier consisted mainly in the removal of all loose material. There large areas are almost entirely bare rock whose grooved and polished surfaces show plainly the prolonged scouring action of the glacier. In the region now included in our northern states the ice did some eroding, but its most important work was that of depositing materials. The load of rock waste which the ice carried was spread unevenly over the sur¬ face of our northern states and now forms the soil and many of the hills of these states. As time is reckoned in geology the glacial period ended only yesterday. Many evidences suggest that the glacier melted away in this region not over 50,000 to 60,000 years ago. The glacial period, as a whole, lasted hundreds of thousands of years. It was not a time of continuous cold, how¬ ever, but rather an alternation of several cold periods - during which the snow accumulated and the ice moved southward - and warmer, interglacial periods - during which the ice melted and the southern margin of the glacier receded toward the north - at least receded from the section of the continent including Wisconsin.

The glacial period was brought to an end by the gradual change of climate. The earlier glaciers had pushed their way as far south as the present Ohio and Missouri rivers. The last advance was not so far.

The earlier advances are known as the Illinoian, Iowan, Kansan and pre- Kansan. Their deposits are spoken of collectively as older drift. The older drift overlies most of Barron county.

The latest advance of glaciers in this region is known as the Wisconsin stage of glaciation. It covered only a part of Barron county. The edge of one great lobe of ice, called the Chippewa lobe, rested along the northeast border of the county, and the edge of another, called the St. Croix or Superior lobe, rested along the northwestern and western boundary of the county.

As the ice along the margins of the various lobes melted, terminal moraines, as they are called, were built up. These moraines are ranges of hills of glacial deposits extending for miles over the country. They mark the positions where the ice front stopped for a while, while ice from the rear advanced, melted, and dropped its load of drift, as it is called, consisting of sand, gravel, broken rock and bowlders.

The ground moraine is glacial drift that has been spread out somewhat evenly as contrasted with the terminal moraine which is heaped up in ranges of hills or in ridges. Outwash material is composed of assorted sand and gravel that streams washed from the melting glacier and deposited over the low ground.

Superimposed on the older glacial drift of the county in various places are the alluvial or river deposits. The alluvial deposits of this region consist mainly of gravel and sand and form level tracts of variable width in the valleys. Some time during the past, between the formation of the earliest and latest glacial deposits, there was a time of extensive valley filling in this area, presumably caused by a general depression of the land. The rivers and streams of that time were unable to carry the landwash brought down from the upland slopes and were forced to deposit large amounts of sand and gravel along their courses.

The loess consists of fine loam or silt which overlies the bedrock and glacial drift in various places. It is usually from one to five feet thick and is found mainly on the uplands and slopes, and occasionally in the valley bot¬ toms. The loess very probably mainly owes its origin to the action of wind in recent geologic times, probably during the time of one of the later glacial stages. The loess is free from stone or other rock material too large to be transported by wind action.

The top soil of the county consists of mineral and organic material. The mineral portion of the soil originates through the disintegration and weather¬ ing of the stony material and the surface formations of the land. The organic portions originate through the decay of animal and vegetable matter living upon and within the soil.

The various geographic forms of the land, the valleys, the hills and the plains, are the result of the rains and rivers, the glaciers and the wind act¬ ing through a long period of time.

The high hills and ridges were carved into their present reliefs in the bedrocks by the erosive work of rains and streams in an earlier geological age. The ridges along the eastern boundary of Barron county were formed as hills long before the age of the Potsdam sandstone. ' They were subsequently buried under the beds of sandstone, as noted, and in a later period were again uncovered by erosion.

Many of the swells of land in Barron county are the result of an uneven depositing of the glacial material. Some are merely the higher land left after the rivers of the present age have scooped out valleys in between.

The terminal moraines in Barron county consist of billowy hills asso¬ ciated with swamps and lakes, and have a usual width of from two tb six miles. These undulating hills usually reach a height of 50 to 100 feet above the surrounding lower land.

The temporal moraine of the Chippewa valley ice lobe extends in this region from the vicinity five or six miles north of Stanley westward to the Jim Falls on the Chippewa river, then turns to the north and passes along the border of Rusk and Barron counties, crossing the northeast part of Barron county in the region of Red Cedar lake.

From the vicinity of Haugen there is another belt of moraine formed by the edge of the St. Croix Valley or Superior ice lobe, extending through the vicinity of Cumberland, Turtle Lake, Clear Lake and New Richmond.

The origin of the rivers and valleys is closely connected. The valleys were carved out of the surface of the land by the erosion of the rivers and streams that flow through them. The rains that fall upon the land surface flow off the slope and tend to gather into rills and to wash out gullies as illustrated upon every hillside after any considerable shower. The gullies grow into ravines, the ravines grow into valleys by the simple work of run¬ ning water. By constant erosion the valleys lengthen and broaden out, and the area between the valleys becomes narrower and narrower.

Falls and rapids are common features in this region. They are usually developed in the valleys when the stream crosses from a more resistant rock to a less resistant one, the softer rock wearing away, and making the depres¬ sion to which the water drops from the surface of the harder rock.

Lakes may be formed anywhere where there is a hollow capable of hold¬ ing water. Except where the progress is delayed by men's improvements, the lakes of Barron county are gradually filling up.

A special feature of the geology of Barron county is the catlinite, or pipe stone, as it is called, which outcrops in quarries in the southeast quarter of ihe southeast quarter of section 27, and the northeast quarter of section 34, township 35, range 10 (Doyle), and section 3, township 34, range 10 (Sumner).

During one of the early geological periods, when, as already mentioned, a sea covered nearly all the land of the western continent, there is supposed * to have remained uncovered a Y-shaped territory called the Laurentian island, the right arm of which it is believed reached from the Lake Superior district in a northeasterly direction to Labrador. The left arm extended in a northerly direction toward Hudson Bay. The base reached southward into northern Wisconsin. The Y-shaped tract of high land was doubtless not continuous land, but more likely a succession of islands.

As the surface of earth's crust cooled, the condensation of vapors already mentioned, must have caused heavy and almost unceasing rains, which re¬ sulted in filling the lowest places, the accumulation of the water causing them to sink still lower, and crowding up other portions into mountain chains. Be¬ sides mountain building, these incessant rains played another important part in Nature's great drama by causing the softer portions of the newly formed, rocky surface of the unsubmerged land to disintegrate and to be carried down by the streams, the lightest materials being carried farthest from the shore, and forming a fine grained clay mud.

On the western side of the Laurentian island was thus deposited in thin layers a fine aluminous clay, impregnated with sufficient iron to give it a dark, rich, red color. As ages passed this clay was transformed into "catlinite" or "pipestone", and its principal place of deposit in Wisconsin is in Barron county.

Geological research is still being conducted in this region, and the re¬ sults are from time to time being published under state auspices. In this article merely the briefest review of general conditions hag been given.