New Diggings Town

Among The Rocks

The narration, for which we are indebted to Phito, of part of the experiences of Solon the Athenian law-giver in Egypt, was for many centuries considered fabulous in its relation of the disappearance of the vast Island of Atlantis beneath the ocean. We respect the noble character of the Athenian sage too much to suspect him of misrepresentation, but the Egyptian hierarch, with whom we are less acquainted, might be supposed capable of disseminating travelers' stories, in regard to which, moreover, the priesthood were possibly themselves deceived. Modern thinkers are inclined to believe that the supposed fable carries with it some elements of truth. It is not easy to follow the almost shadowy story of a lost land with such precision as to establish its identity with this continent, but the position assigned to Atlantis by the Egyptians favors the idea, to which modern investigation is inclined, that our own America must have been known to the ancients way back in remote antiquity, and that its submersion beneath the waves had been recorded in curiously preserved traditions ; but we cannot pretend to determine what era in the upbuilding of this continent may have been indicated by that semi-apocryphal storv.

Geology tells us of upheavals from the depths of the sea, to which we are able to trace an island now known to science as the Island of Wisconsin, which appeai'ed at about the same time with several other islands, comprising parts of the Appallachian Ranges, and of New York, as well as probably other parts of the land now being covered with a population of millions, governed and to be governed by the United States of America.

The cooling and contraction of the globe is credited with having diminished its diameter by about 180 miles, and a diminution so great might easily account for the fatal depression of Atlantis ; but that shrinkage occurred at a time when human life was not possible. The popular reader will not so readily perceive how the inevitable continuance of the same process would account at a later date for the resurrection of the land which we now inhabit. The chief geologist of Wisconsin, Mr. T. C. Chamberlin, tells with a simple eloquence, which science advanced as his cannot always command, the story of the rocks upon which the greatness of this nation is securely builded ; and, in trying to embody the main facts of the earth's revelation in this history, we shall endeavor to follow in the footsteps of the eminent Professor, though with the modesty and diffidence of a learner, venturing to deal with presentations which have tasked the powers of masters whose dictum is accepted by the world of learning.

The first cooling, whose catastrophe may have been attended by the submergence of Atlantis, if we may imagine a race of Salamanders rejoicing in extremes of temperature, was a comparatively general reduction of warmth and bulk, in which the earth's surface was sufficiently ductile or clastic to participate without fracture; but later, when the superficial coating of our molten globe had become more rigid, nature was constrained to Avork by other methods ; the granite rocks, incapable of contraction, otherwise, in such a degree as would meet the changing conditions of the body which they enfolded, and subjected to pressures, compared with which, the vastest applications of mechanic force by human agency, sink into insignificance, bent under the ocean until the outer shell touched the shrunken kernel ; and then ths semi-rigid envelope, heated in every particle by the compression, changed and wrinkled its mighty form, projecting its peaks above the surface of the ocean as a series of granitic islands, whose shores sloped more or less declivitously toward the depths of the sea. There are folds in the strata, observable to-day, which indicate the long-continued application of a power capable of creasing and bending adamant just as irresistibly as the hand of man may crumple paper.

Could we suppose an Alexander Selkirk possible on our inhospitable Island of Wisconsin, he would look abroad upon a limitless but comparatively shallow sea, in which, possibly, was yet no sign of lite, vegetal or animal, and his island home would necessarily present to him a bleak and desolate rock, without shrub, grass, soil or insect, if we may assume that the uplifted crystalline mass had not commenced its process of disintegration.

The phenomena of building anew the Western Hemisphere can be studied in Wisconsin as advantageously as on any part of this continent, and the writing on the wall of rock is so clear and precise that the wayfarer, even though a fool, may not err if he will patiently unravel the legend which the globe offers for our acceptance. Strong winds, dashing waves, evaporation and precipitation, with some chemical conditions of the atmosphere that helped to disintegrate the exposed surface of rock more rapidly than would be possible now, acting upon stone similarly compacted, gave back to the ocean a vast aggrega'e of detritus worn from peak and precipice by those unceasing forces, to form the vast deposit of sandstone now known as the Potsdam, which ranges according to the convolutions of the sub-oceanic surface upon which it lodged, in thickness from a few feet to more than one thousand feet. The superimposed layers have each their own revelation to make clear ; some of them in fossils .which the human eye can readily decipher ; others in forms so minute that the microscope is needed to unlock its mysterious message from a world possibly pre-Adamite.

Suppose the State cut through to the level of Lake Michigan, east from the Mississippi River in Grant County, we find the formations which prevail throughout Wisconsin, and .ar beyond its borders, always attesting the regularity with which Dame Nature prosecutes her designs. The Lower Magnesian limestone gives us the first record of life found in this region, hitherto, after the disintegrated gneiss or granite had in some degree solidified beneath the waters as sandstone, and the thickness of that stratum is remarkably even throughout our imagined cutting ; the limestone following the form of the underlying rock, and having suffered bui littk from abrasion, protected as it must have been by its coverlet and base of supplies, the sea. Elsewhere this formation is much less regular in depth, as it follows the contour line preceding its deposit, and lies irregularly. Grant River has cut down into this bed of limestone at about 350 feet above the level of Lake Michigan, but the banks of the Father of Waters reveal the same formation at an elevation of about 200 feet. Our supposititious section runs east and west through the county of Grant about seven miles north of Lancaster, crossing the head-waters of Platte River.

Next above the Lower Magnesian limestone, we find St. Peters sandstone, so called from one of its best exposures, which has evidently suffered from abrasion in many parts of its surface, and is found cropping out on the Mississippi banks as well as on the sides of Grant River, though still far below the Platte. Trenton lim.estone, moderately rich in fossils, attests an era in which life had risen to more various formations, beautiful as though some cunning and skilled artist, with an unbounded wealth of resource, had fashioned and imbedded them to minister in after ages to the aesthetic sense in man. The head-waters of the Platte cut through and into this formation, which reaches an elevation little more than oOO feet on the Mississippi at our imagined line, but is found at an altitude of nearly 500 feet on Grant River, our base line being always the level of Lake Michigan. Galena limestone follows next in order, and the name is significant at once as to its place of first identification, and as to the valued minei'al with which it was charged. The stratum has been abraded in many localities until it fails even to put in an appearance; as for instance, at our imagined line bisecting the bank of the Mississippi, but east of that point the stratum asserts itself, cut through with greater or less pertinacity by streams that have long since found a grander channel. That deposit caps the ranges in the vicinity of Grant River, and further east along the head-waters of the Platte, rising east of that point to an elevation of about 700 feet on the eastern boundary line of the county.

The fact that this region did not suffer from glacial denudation and was not enriched by morainic drift, gives to our line of bisection special value in ascertaining readily the surface contour of the land before that era of refrigeration, allowing always for erosion by the atmosphere and rains and rivers. For that reason, we will follow another imagined bisection of the county due north and south, near the eastern boundary. North of the center of the line, the Potsdam sandstone rises above the level of Michigan Lake, and gradually ascends to an elevation of about four hundred feet, not far from the northern limit of the county, descending thence by denudation to about three hundred feet at the boundary. Although this sandstone is not rich in fossils, it would be folly to assume that life was not plentiful on this planet while this vase stratum was being deposited ; the more sensible conclusion is that the stratum was not well adapted to the preservation of the forms of life which passed into its keeping. The Laurentian rocks, upper and lower, which constituted the first Island of Wisconsin, were sedimentary, and their formation must have preceded the sandstone mentioned by a term which human investigation has never yet defined; yet the Laurentian rocks hold within their embrace many evidences which are satisfactory to men of scientific attainments, that vitality of a low order preceded their deposition, and some fossils have been found in America and in Europe, which, it is claimed, set that question forever at rest. Some careful investigators doubt the organic character of the alleged fossils, and we are not prepared to decide, where doctors disagree ; but, inasmuch as our supposed section of Grant County does not reveal the systems of rocks named from their great developments in the valley of the St. Lawrence, we will proceed with our brief disquisition on the strati actually found in that region, which we endeavor to describe. Wisconsin River has cut its course through the Potsdam sandstone, and numerous streams of less dimensions have left their marks in unmistakable characters, hewn out of the same body, which is entirely denuded of all such overlying strata as may elsewhere be found. The same order of succession as has been noted in the line east and west - Lower Magnesian limestone, St. Peters sandstone, Trenton limestone and Galena limestone in the same relative position - is still observable, but superimposed upon these we find preserved in the Platte Mounds, at an elevation not less than seven hundred feet above the level of Lake Michigan, the formation known as Cincinnati or Hudson River shale, capped by a remnant of Niagara limestone. Blue River has its course bottomed on St. Peters sandstone, while Trenton and Galena limestones form the superincumbent layers, and this regularity in the movements of natural forces enables the student to apply himself, with much economy of resource, to unfold the wealth of mineral possessions, which, in our own time and in the near future, will become the heritage of the human family.

From the writings and tracings of Prof. Chamberlin, we are permitted to supplement our scanty delineation of tlie State, as represented in the geological features of this region, by adding a general though brief description of the State as a whole, and of the upheaval and formations that have contributed the material bases of our national wealth.

We have delineated the shallow sea that ebbed and flowed, obeying the impulses of the moon, where the State of Wisconsin now reposes in beauty and excellence, the loved home of a thrifty and prosperous people, but we will return to that point in our narrative, the better to present the picture of that upheaval to the popular mind. The sediment to which we are indebted for the Laurentian rock, is estimated to have been much more rapid in deposition than similar processes to-day, and a thickness of 30,000 feet is claimed by scientists as only a small remainder of a more vast formation, contributing its quota to the crust of the earth. Beneath the sea, this sediment accumulated in horizontal strata under circumstances that favored metamorphic action, the results of which are still visible. The time came when heat and lateral pressure, such as we have already mentioned, re-arranged the folds of the earth's mantle and began to prepare a dwelling-place for man. That nucleus of a nation may be called, for our own convenience, the Island of Wisconsin. The character as well as the position and form of that rock, was probably changed in the act of upheaval, so mighty were the forces therein engaged. The sediment had been changed into crystalline rocks, widely dissimilar from the later sandstone, although compacted of the same elements. Thus we stand, as it were, in the presence of the Archgean or ancient rocks, otherwise known as the Azoic. The wonderous changes through which this metamorphic rock passed in attaining the eminence of an island in those seas, might well be supposed capable of obliterating all signs of vital organization, but, in other rocks which seem to be identified with this formation, it is asserted, with some authority, that fossils have certainly been found, and our investigations have hitherto been too narrow and restricted to entitle us to say with authority that there are no fossils in the Laurentian formation here. It is not possible to define accurately the extent of that island won from the domain of Neptune, but it is assumed to have filled a large area in the northern central part of our State, stretching beyond into the Upper Peninsula of Michigan. This was the primeval base upon which was to be erected an empire of the people, sacred to liberty and right. Other islands, at remote distances, were perhaps upheaved at the same instant with our own, to be banded together in one vast continent, for the noblest ends possible on earth, when the Laurentian era should have taken its place away back in the remotest antiquity with which life has been identified. We have no data whereby we can determine the altitude of these islands, upon which the rain descended and the floods came, beating with tempestuous violence ; but, apart from the strata forced into positions almost approaching the perpendicular, and from which the cap or connecting fold has been abraded, we have the deep and wide-spread deposits of the Huronian period to tell us of the mountainous elevations from which that sandy detritus must have been torn away by wind-storms, rain, the beat of countless waves, and the never-ceasing disintegrating power of the chemic constituents of the atmosphere. We have, thus, our island lifting its head toward heaven, and the elements tearing down the inaccessible mountain peaks, to bridge the chasms and convert that island, with others widely scattered, into the broad expanse of prairie, mountain, valley, cataract, lake and river, which is to-day the world's wonder. Science may yet enable us to read this exquisite story of the earth as the home prepared for man, with fuller appreciation. It is not easy to imagine that"! on an island thus builded, there could have been any form of vegetable life at the outset ; but, in the sea around its base, if we may judge from the carbonaceous matter incorporated with the deposits, there must have been an abundant marine flora, and, in the limestone accretions we find evidence of higher organizations. Life was in the waters surrounding our island, and the Great Artificer of the Uni\"erse was, through His laws, compelling the least of His animate creatures to prepare the way for their superiors in the army of being. Perhaps this statement of the case may savor of dogmatism, but we argue the presence of life in the waters from the limestone deposits left in testimony, as well as from the fact that the Laurentian rocks, which antedated this era by unnumbered centuries, are not certainly and entirely barren of fossils. The shales, sandstones and limestones of this period of deposition, aggregated many thousand feet in depth ; and, in due time, these also were upheaved and metamorphosed in that process, as the Laurentian had been, into crystalline and semi-crystalline rocks, known to us by various names and innumerable uses in the civilization by which we are surrounded. The Huronian rocks are compacted of quartzites, crystalline limestones, slates, schists, diorites, quartz-porphyries and other forms of metamorphic sediment. Graphite is the resultant from carbonaceous deposits, and magnetite, hematite and specular ores tell of the forms of life by which such means of wealth are brought within our ken ; the last-named deposits are so great as to give the name of the ironbearing series to this upheaval. These several strata, contorted and folded by pressure and heat, added largely to the circumference of the island, from whose shores and heights they had been gathered, and the ceaseless activities of nature paused not one instant in preparing new formations. The nearest approach to a mountain in our State, is the upturned edge of the Huronian upheaval, which stretches for sixty miles, crossing Ashland County, bearing within its rampart a belt of magnetic schist through nearly the whole length of Penokee Range. The Menominee iron-bearing scries, which extends into the northern part of Oconto County, is another important topographical and mineralogical feature in the Huronian formation- Barron

Histoky Of The Lead Eegion

County owes its deposits of pipestone to the same source, and they cover a large area. The Baraboo quartzite ranges in Sauk and Columbia, with detached outliers northeasterly throuo-h other counties, are conspicuous contributions from that formation, which has its most southerly exposure near Lake Mills, in the county of Jeiferson.

Before the Huronian strata were upraised, it is assumed that the crust of the earth was fissured in the Lake Superior region, and that a vast outflow of molten rock spread itself by successive eruptions at various intervals over an area more than 300 miles long by 100 miles wide, forming a series of trappean beds. Sometimes there were intervals between these molten streams, during which the ocean ransacked from the superimposed rock, the materials for beds of sand, gravel and clay, which are now present as sandstone, conglomerate and shale ; and, as though tenacious of the credit that belonged to its handiwork, the waves of the perturbed sea have left their ripple-marks in the stone to tell us that the forces of the centraffire were not allowed to assert themselves unchallenged by the ocean. When eruptions ceased entirely in that region, the sedimentary process went on accumulating until the series achieved a thickness which is stated in miles. The rocks which have been named as thrown up from within the earth's crust have undergone changes so great that their igneous character is almost obliterated ; the mineral ingredients have been metamorphosed by chemical action, so that we find iron chlorite and feldspar associated with quartz, prenite, calcite, laumontite, analcite, datolite, magnetite, native copper, silver, and occasionally other minerals, the rock being known as a melaphyr. Usually we find the upper portion of each bed composed of cells about the size of an almond (illed with the minerals that have been indicated, so that the rock is amygdaloidal. After the beds were deposited, the native copper was placed in the receptacles, where it is found to-day, by chemical action after changes in the rock had been initiated by similar means, and the silver found in that series is due to the same agency. Ashland, Bayfield, Burnett, Douglas and Polk Counties, in the northern section of the State, are remarkable for the presence of copper and silver bearing rocks, the metals being most plentiful in the amygdaloids and some conglomerates, but being found in the melaphyrs, sandstones and shales also. The Huronian rocks carried the copper-bearing series with them in their upheaval, and they are found with the same folds and Hexures. The Keweenaw Point range extends from the part of Michigan to which its name is ilue southwesterly through Ashland, Burnett and Polk Counties, in this State, the beds dipping toward Lake Superior northwesterly; but, in a parallel range, which is found in Bayfield and Douglas Counties, the beds dip at a less angle in the opposite direction. There was a " lost interval" after the upheaval of the Archaean rocks, the Laurentide hills of the early French explorers, the Laurentian of our time, which even now, after ages of erosion, can be traced on the north side of the St. Lawrence, from Labrador to Lake Superior, and still to the north a distance yet undetermined. The hills of this formation are seen 4,000 feet in height, and where the Saguenay makes its course toward the St. Lawrence there are clitTs that lift their heads fully 1,500 feet sheer from the water's edge. South of the range throufjh which the Saguenay runs, the Adirondack Hills stand an isolated mass 6,000 feet in altitude, a sentinel rock of the Laurentian system, rivaled by the newer formation - the White Mountains. The Lower Laurentian has no exposure in our State, but it is found in Newfoundland, New Brunswick, Nova Scotia, and, rarely, in Massachusetts and Maryland. Beyond the Atlantic the same rocks are identified in Norway, Sweden, the Hebrides and Bohemia, bearing with slight differences the same alleged but debatable fossils, the Eozoon Canadense, Bavaricum, etc., of a type still said to be extant. The Lougroynd groups of rocks in Shropshire and in Wales, with their equivalents in the Wicklow Mountains in L^eland, are probably Huronian rather than Laurentian. The exact equivalency of our Laurentian system with that of Canada and the provinces is not determined, but strong likelihoods point in that direction with increasing force. The "lost interval" indicates no idleness in nature, but a fi\ilure on the part of the geologist to follow her operations. We have elsewhere glanced at the wondrous activities that laid down the vast beds now known as Potsdam sandstone, and then upheaved them to their present and to still greater elevations. We can trace the formation here lying on the foot of an eminence which is gradually succumbing to

" the tooth and razure of oblivion," except as its remains are preserved as particles of quartz in the new stratum. Again we see some harder projection of the old rock detached from the main island, which yet lifted its head in solemn self-assertion, and breasted the angry billows, impatient of their endeavor to reduce its elevations to the common level ; and yet again we meet some great bowlders, typical of the empire foretold in Scripture, compacted of brass and of clay ; there the harder components remain, dismounted from their eminences by the erosion of feet of clay in the softer material upon which they depended, and the sands of the sea shore reverently surrounded them with their legions of defenders, to retain them where they are found in our era, still distinguishable as mementoes of the age of giant rocks, which built for man a temple not made with hands.

Life was an ever-present element in this formation, but the earlier sandstones are not rich in well-defined fossils, although they give us lithographic illustrations and actual casts of the shells in which living beings built themselves in from the elements. Limestones and shales, interstratifying the sandstone, mark where some sheltered spot temporarily favored the establishment of a cemetery, upon which the sands once more advanced, burying the dead out of the sight of generations that had never dreamed of the mysteries of existence. The red sandstone of Lake Superior is due to the action of the sea upon the iron and copper-bearing series of rocks of whose qualities we have spoken ; away from that region we find a broad, irregular belt reaching almost around the Archaean island, a rude crescent of light-colored sandstone, won by the Avaves and winds and rains from porphyries, quartzites and granite, either of which would, in our more conservative age, be able to hold its own against oxygen for centuries unless frost came in to help the demolition.

There was no great upheaval after the Potsdam sandstone had been deposited, hence it lies horizontally upon the abraded bed of the underlying crystalline stratum, neither crumpled nor metamorphosed by heat and pressure, only slightly arched toward the center of the State. The weight of superincumbent beds, and the cementing action of waters carrying lime and iron in solution, which have percolated through this formation, have largely increased its density; but the ripple marks, cross-laminations, worm burrows, and other indications of action and life on a sandy beach are clearly traceable, and its thickness varies from the fine line which defined its limit on the shore of the island down into the depths where it formed an aggregate of perhaps a thousand feet. All the later formations take their place above the Potsdam sandstone, which may be reached by boring in any part of the State, beyond the bounds of the Archaean core. This is a fact of vital importance, because a water-bearing rock can be calculated upon with absolute certainty, and the layers of limestone and shale which interstratify the mass are of great value in arresting the flow of water and turning it surfaceward. The formation of limestone, never arrested while life endures, comes now once more within our region of observation, and the deposit ranges from fifty to two hundred and fifty feet in thickness. The horizontality of the sandstone was not perfect, and the irregularities of the foundation were filled by the limestone as it settled down and solidified under oceanic pressure. There were places Avhere the substratum showed a rise and fall of nearly one hundred feet within quite a limited area, but the limestone itself is remarkable for an appearance aptly described as follows : The limestone and the interstratified beds mentioned earlier were magnesian or dolomitic, containing carbonate of magnesia in great quantity. There were quantities of silica in the deposit which sometimes are found as nodules of chert> and in other instances as quartz crystals ; this beautiful form of matter lines cavities which never saw the light until man quarried in the rock, and yet the exquisite loveliness of each crystal is perfected according to its law, as though the handiwork therein concealed had been one of the most costly adornments of a palace. Some metals appear in the mass, but they are of little value, and evidences of life herein are very scanty. Sea weeds, mollusks and a few other forms of being are scattered sparsely, save at intervals, where circumstances favored a more liberal contribution to our knowledge of the organisms that obtained in the earlier seas. Erosion has removed a large proportion of this rock, so that it is now jagged and irregular in the last degree, but, originally, it must have been a broad and regular band, contributing its quota toward increasing the island to the dimensions of a continent.

History Of The Lead Region

We cannot tell why the deposit of raagnesian limestone ceased, but the sandstone known as St. Peters comes next in order of succession, probably after an interval. This is a fine silicious sand, much desiderated in the manufacture of glass ; but it is deposited in small quantities, sometimes not enough to cover the inequalities of the limestone. The greatest thickness of St. Peters sandstone yet discovered does not exceed two hundred and twelve feet, and the average is less than one hundred. It is not a firm stone, having been imperfectly cemented, so that it disintegrates readily. Some organic remains have recently been found in this deposit, but they are few and far between, just sufficient to attest the presence of marine life and the agency of the ocean in triturating these fine grains of quartz. This belt, probably much reduced from its original dimensions, fringes the lower magnesian bed on the south, and covers but a small area. The absence of fossils may be accounted for in two ways : First, in the cutting and crushing action of the sandy particles, and next in their porosity - a quality to which we are indebted for the supply of many of our finest artesian wells, and from which numberless other such living fountains may be procured, as the flow of water is practically inexhaustible.

Trenton limestone deposits follow, indicating some changes in oceanic conditions, local or general, and, at the same time, a great deal of clay-like matter was being nlaced in position to be converted into shale, shells, corals and other organic debris, or their signs manual in the rock give positive evidence as to the origin of this limestone in the myriad lives that were capable of converting the particles held in solution by the seas into the osseous environment? of their own being. The limestone now deposited was very pure, not largely magnesian ; but, Avhen the clay predominated, a bed of shale, greater or less in extent, resulted. Sometimes these beds were so highly charged with carbonaceous matter that they burn readily, and no small portion of our petroleum comes from such formations. In the lead region, this deposit has sometimes been found rich in metals, but of course that condition is the outcome of chemical action and infiltration - not a characteristic found in the pure limestone stratum. The fossils in the Trenton limestone are abundant, and the stone, being susceptible of a very high polish, is valuable in an economic sense, as well as deeply interesting to the scientist on account of its archaeological revelations, as all the animal sub-kingdoms, except the vertebrates, are therein represented. This rock borders the St. Peters sandstone, and its greatest thickness hitherto observed is about one hundred and twenty feet.

The next formation is the highly magnesian Galena limestone, buff" or light gray in color, attaining a maximum thickness of about two hundred and fifty feet, and having a sub-crystalline structure. In the northeastern part of the State, the presence of shaly matter changes the color to a bluish or greenish gray ; but, in the southerly deposits, the bed is not aff"ected in that way. The presence of galena, or sulphide of lead, in this layer, in the southwestern part of the State more especially, has given its name and commercial value to this limestone. Zinc ore is abundant, as well as lead, in the region indicated, and in other districts the same metals can be traced, but not in paying quantities. In other sections of the country, the production of lead is a necessary part of the process of mining for the precious metals, and, for that reason, pure lead mining is comparatively at a discount for a time ; but, whenever the best product of lead is demanded, the mines in our State and in Illinois will not fail to be largely called upon. Our Island of Wisconsin, growing from its Archaean core by concentric additions, is already much larger than the area of the State within which it took its rise, and still the aggregation continues.

Cincinnati or Hudson River shale followed the deposition of Galena limestone, a thickness of 200 feet having resulted ; but the clayey bed has not become hardened to such an extent as to resist weathering wherever an exposure has occurred, and, in consequence, that layer is, in many localities, conspicuous by its absence. Some parts of the sediment have hardened well, becoming shale or limestone, according to the preponderance of the elements deposited. Many of the vertical cliffs of Green Bay are beautifully colored shales of this foundation, their hues being almost as varied, though less brilliant than those of the rainbow. The eastern side of the Green Bay - Rock River Valley - shoAvs how easily and completely this formation can be eroded, the less yielding Niagara limestone, which overlies the shale, being left as a kind of pent-house roof over the rapidly receding bed beneath. This phenomenon has procured for the principal feature in the cliff the name of the Ledge. The mounds in Southwestern Wisconsin owe their prominence to the rapid erosion of the shale, by which, at one time, they were surrounded. Corals and other fossils are numerous in this composite formation, and a little intelligent attention to the conditions of life under which they were deposited might have saved much time, labor and capital, uselessly expended in the search for coal. This formation, which marks the close of the Lower Silurian age, underlies the mounds in the lead region, forming only a narrow belt on the eastern margin of the valley above mentioned. Other conditions of life were now to write their history on the rocks.

Clinton iron ore, sometimes known as "seed ore," elsewhere known as "shot ore," is found deposited on the beds of shale at detached spots, probably at points that were once protected basins. It is a peculiar lenticular deposit, which might well give rise to all the variations of nomenclature which invite our attention. In this State, the prominence of this mineral aggregation at one point has led to its being denominated "Iron Ridge ore." The beds are quarried as easily as limestone, the soft ore being arranged in horizontal layers, which, at the point just indicated, have a thickness of twenty-five feet. Like deposits, in much smaller quantities, are found at Depere, and at Hartford and at Depere smelting works are in operation, besides which, this ore is shipped to markets more and less remote, to be sold for reduction. The greatest era of limestone formation in the history of our island followed this deposit of iron ore, and we may well devote some attention to the vast aggregate of about eight hundred feet, which was deposited in the beds of Niagara limestone. The old processes were repeated in all essentials, but the operation was long continued, and the conditions were favorable to marine life in that shallow sea, dotted with large islands, having a temperature almost, if not entirely, tropical. The Rocky Mountains and the Alleghanies protected this plateau from the intrusion of cold currents, if there were any such, which might have been fatal, prematurely, to the tiny artificers which were giving their lives and substance to build up this continent, as other and greater beings have since given their lives and substance - a more intelligent and volitional sacrifice - to build up and maintain its inestimable liberties. Reefs, not unlike the coral formations that prevail in the Pacific Ocean, appeared toward the close of this era of deposition, and there is no reason to doubt that the same agencies that are now at work in the Polynesian group, converting islands into continents, were then employed in the more than fairy transformation to which we are beholden for a home on this favored spot of earth - the haven for the afflicted peoples of all lands - which, ere this century comes to an end, will probably carry a Caucasian population of 300,000,000 souls.

Among the animal life of the time, we find unquestionable records of corals ; mollusks, that have been called the oyster of those seas ; stone lilies, or crinoids, having the appearance of a plant converted into stone, and still animal ; trilobites, in great number and never-ending variety ; and gigantic cephalopods, which seem to have been monarchs in that domain. The reef rocks were very irregular, and near them were extensive beds of sandstone, largely calcareous, beyond which is found a pure, compact dolomite, formed from a deposition of fine calcareous mud. The Niagara limestone lies in a broad belt, adjacent to Lake Michigan. It is all more or less magnesian, contains much pure dolomite, but is varied in composition, some beds being coarse and heavy, other layers being even-bedded and close-grained, while yet others are impure, cherty and irregular. There is a thin-bedded, slaty limestone on Mud Creek, near Milwaukee, which is commonly, and perhaps rightly, attributed to this formation ; but the fossils found therein are few and equivocal, as, indeed, are all the evidences that might be expected to determine its period of deposit. A similar formation, somewhat more rich in fossils, is found near Waubeka, in Ozaukee County, and the greater weight of evidence thus procured favors the era of the great limestone deposit; but the area covered is small, and the two beds are of little practical value. The Silurian age in Wisconsin was now ended. The island was large, almost continental in proportions. Sandstone, limestone and shale contributed each their concentric belt, and the sea retired, save when, at rare intervals, it was stirred to its depths with a vain desire to reassert its old dominion.

The Devonian age marked one of those oscillations when there was an invasion of the eastern margin of the island by the sea, and the Hamilton cement rock was the chief result of that advance, its hydraulic properties being due to a happy admixture of magnesian limestone with silicious and aluminous materials. There was now a new dawn of life, the vertebrate animals appeared by their lowest type, the fish, but even that was a great ascension in the scale of being from protozoans, radiates, mollusks and articulates. The early types of life did not disappear but the process which Darwin has named " the survival of the fittest " was affording its advantages to the better forms of the lower orders. We cannot estimate the extent to which erosion operated on the deposit, but beyond doubt it was considerable. An area, not large, on the lake shore, north of Milwaukee, with a landward stretch of about six miles, marks the size of the bed which has been found, and the cement rock which is highest in repute is found on Milwaukee River, near the city. Thus endeth the record of the ocean on our island, although there may have been subsequent visits, too brief for Neptune to leave his monograph.

The imagination of the reader may conjure up the progressive changes of our island from the crystalline heart as leaf after leaf was added to the structure by the myriads of lives that built themselves into the simple yet wonderful development, until the insular state was lost, and many islands had become a mighty continent, inviting other and better forms of life than those that we have seen in the limestone and other deposits ; but, while the several belts are being called to their position, we must not lose sight of that unceasing erosion which bears so large a part in the phenomena of deposit. The continent was lifted to its place, and aerial denudation began, or rather continued, the work long since initiated, of bringing the softer formations from their several altitudes to clothe the valleys with a mantle soon to become vernal under some law of progression which it is not permitted to us to comprehend. The Carboniferous age, marked elsewhere by carboniferous phenomena, the Mesozoic era and the earlier Tertiary period is beyond the point indicated a blank in Wisconsin. The time for the deposition of vegetal matter, which has given us rich coal measures elsewhere, was not so improved in Wisconsin.

The Glacial period has not left its record in all parts of Wisconsin, but the story is widely told by the drift and by many other signs just as certain. The country was invaded by masse's of ice in broad sheets that acted like a mighty planing instrument upon the surface, over which it glided with a slow motion, which even to this day is a puzzle to the scientist. Men eminent as Tyndall and Forbes have bent their mighty intellects to solve the mystery in the Alps, where the glacier is perpetually advancing, by night as well as by day, in winter as surely though more slowly than in summer, and still we cannot determine certainly how the frozen, semi-elastic mass moves in its course, accommodating itself to all the sinuosities in the channel, varying its momentum in different parts of the stream, with a regularity that admits of accurate forecast, and still progressing even on great declivities with a speed hardly exceeding twenty inches in twenty-four hours.

Our ice-stream came down from the north, having but small declivities to favor its progression, sometimes even forcing its way over heights that might have been supposed effectual barriers, bringing in its lower surface, and sometimes - perhaps though rarely - on its upper face also, masses of rock and gravel to us from their normal resting-places as the inexorable force moved on, and ultimately scattered or deposited en masse miles away from the points of departure. The polished and grooved strata upon which the ice-plane has plowed its strice may be found by careful search in all parts of the globe that have been subjected to glaciation, and, consulting such marks, we find that one prodigious tongue of ice scooped its way through the bed of Lake Michigan, a smaller tongue meauAvhile traversing the valley of Green Bay and Rock River, and through what is now the region of Lake Superior another mass of ice moved to the southwest upon Minnesota. These channels, affording outlets for the ice, appear to have diverted the invading force from the southAvestern portion of Wisconsin, where a considerable region is found quite free from niorainic drift and from the strife that attend the movements of glaciers.

When a time of greater warmth asserted its power, the extremities of the glaciers were melted, sometimes more rapidly than the mass moved forward, and thus the drift remained wherever the process of liquefaction dropped it, unless some later march of the ice stream, under the favorincT winds of winter, once more pushed its vanguard to the point from which it had been driven,°heaping up the drift that had been scattered through its channel in a great moraine at its terminus. The retreats and advances of this stream of ice have, in many parts of this continent, quite changed its normal aspect, and nowhere can we find more striking manifestations of the power that was thus exerted than in Wisconsin. The remarkable chain of hills known as the Kettle Range is entirely a drift formation, and the curious winding line thus presented to eyes in search of novel scenery suggests a battlement defending the furthest line marked by the glacier. At a secondary stage of advancement, when tlie temperature permanently changed and the frozen mass must needs return to its former condition of fluidity, there was a torrent in some regions, and there were lakes in others according to the configuration of the surface, and a depression of the land toward the north ascribed to this era is considered as one of the determining causes of the former extension of the great lakes where the ice-plow had found grooves best suited to its operations. The red clay that borders Lakes Michigan and Superior, and that may be found as far up as Fond du Lac, in the Green Bay Valley, marks a time when these waters covered a much wider area than they now fill, but whether tlie diminution still continues this deponent saith not. The wealth of lakes and tiny lakelets, for which Wisconsin is famous, is probably due to the waters of the glaciers filling the strange undulations which the morainic drift had caused, sometimes damming a narrow valley, as at Devil's Lake, at others presenting only shallow depressions.

The Kettle Range has been made the subject of a special disquisition by Prof Chamberlin, the brochure being published in Paris during his attendance at the Geological Convention in that city in 1878, which the Exposition Universelle was the great event in the scientific as well as in the fashionable world. The conclusions reached by the chief geologist embody the main facts known as to the Kettle moraine so completely and, withal, so skillfully woven into his narrative, that we feel bound to summarize that production. The moraine known as the Potash Kettle Range, since abbreviated in name, resembles the Kames, Eskers, Asar and Raer, of Scotland, Ireland, Sweden and Norway, respectively, and is also similar in formation to more recent deposits in Switzerland. It is an extensive belt of drift hills and ridges, peculiar and distinctive, traversing the quaternary deposits, and disposed in vast loops about the great lakes, challenging the attention of mankind to the mode of their deposit. The belt is certainly not less, and is presumably much more, than two thousand miles in length, with a breadth varying from one mile to thirty miles in different parts of its extent. Seldom more than three hundred feet in height, it occasionally may be found exceeding four hundred feet above its base, but is generally much less ; so that it is the continuity of the formation, rather than any other feature, as a rule, that commands attention ; still, there"' are points where the range is conspicuous for its abruptness and irregularity.

Dr. Lapham, in his ''Antiquities of Wisconsin," briefly described the belt as seen by him in the eastern part of the State, prior to 1855, calling attention to the peculiar depressions which first suggested the name of the Potash Kettle, as descriptive ; and attributed the feature in question to" the solvent, erosive action of under-drainage, forming " sinks." Col. Whittlesey, several years later, published through the same medium, the Smithsonian Institution, his observations on "Moraine Cavities" in Wisconsin, Ohio and Minnesota, attributing their presence to the building-in of ice-masses with the debris when the range was formed, the ice naturally leaving a depression when subsequently thawed. There were other suggestions not material to this issue in the same paper, which need not be further noticed. Dr. Andrews described the Kettle Range, in Eastern Wisconsin, with which he associated contiguous gravel deposits, claiming for the formation a length of two hundred miles, and a breadth of twenty miles, terminating in the bowlder clay of Illinois, but he ascribed its formation to a vast and violent current of water sweeping down from the north. Other and minor observations and speculations on this interesting subject left the matter practically at the point indicated until 1873, when the (geological survey, since completed, was commenced by order of the Legislature of Wisconsin. The gentlemen surveying in Ohio under circumstances similar to our own, gave attention to the rancre in that State, but they were much divided in opinion as to its origin, some inclining to the vie^w that it was a moraine, while others favored ideas of grounding ice and the escaping waters of the great lake passing over the watershed where the range is located.

Dr. Lapham, chief of the geological corps in this State in 1873, returning to the question with interest unabated, and with much better facilities for investigation, assigned the Kettle Range as a subject for study to Prof. Chamberlin, suggesting that the ridge might have marked an ancient shore line. The line of investigation pursued by Mr. Chamberlin, now Chief Geologist, soon convinced him that the shore-line theory was as untenable as the Andrews idea of violent currents of water from the north. The investigation was not entirely confined to this State, although, of course, this was the main field of observation. Forked tongues of ice had left their limits so clearly marked by drift deposits, about twenty miles north of the State line, that our friend was placed at once on the track, which he has since pursued and verified. In the year 1875, at the session of the Wisconsin Academy of Science, Arts and Letters, the main results arrived at in this inquiry were presented with maps and drawings, showing the determination of general drift movements, and that the range is a moraine formed by glaciers occupying the troughs of Lake Michigan and Green Bay, skirted on the west by a like deposit. The suggestion then thrown out has been verified by Prof Irving, together with later conjectures as to the extension in Northern Wisconsin. The conclusions reached in this way threw light upon two questions : determining hoAv the range had been deposited, and, also, Avhy a certain large area in this State, and in Minnesota, Iowa and Illinois, is driftless. Profs. Winchell, Irving and Chamberlin are agreed that the area in question is driftless, because the ice streams were deflected by the easier exit offered through the valleys of the great lakes and through Green Bay. The several eminent authorities quoted, arrived at the same conclusion on the facts observed, without previous concert, prior to publication ; consequently, we may well consider the solution as a demonstration.

Outwardly, the formation presents an irregular, intricate series of hills and ridges, rapidly but often gracefully undulating, having well-rounded domes, conical peaks, winding ridges, sometimes geniculated, short, sharp spurs, mounds, knolls and hummocks in a variety of combinations, and corresponding with depressions just as remarkable, or even still more striking. These depressions have given their name to the range ; many are circular in outline, hence the title " potash kettles ;" but the major part are not nearly so symmetrical. Some of the cavities resemble a bell inverted ; others are shallow saucers ; and others are rudely trough-like, oblong, oval, elliptical, or even winding ; but to describe their various configurations would demand a volume. Their depths vary from mere indentations to sixty feet, or even more in the symmetrical forms, while the irregular sinks show a depth often exceeding one hundred feet. Occasionally the sides of the kettles are about as steep as the material will lie, an angle of from thirty to thirty-five degrees with the horizon, but usually the slope is much less declivitous. The kettles seldom exceed five hundred feet in diameter, but it is not easy to define their limits. Numerous small lakes dot the course of the range, having neither inlet nor outlet, and suggesting the process by which, under favoring circumstances as to drainage, the depressions may have been formed. In the base of some kettles there are yet ponds of water, arrested in their escape, and waiting the slow process of evaporation ; and some of the lakes range from two to three miles in diameter, the increase proceeding by degrees hardly perceptible. Many of the hills in what is called the "Knobby Drift," resemble inverted kettles; and trough-like, winding hollows are offset by sharp serpentine ridges, giving to this range a distinctive character, notwithstanding its lack of altitude; but the features indicated are subordinate to the characteristics of the main range, being most abundant on its more abrupt face, though to be found on every side, and in all varieties of situation, sometimes even on areas level by comparison, adjacent to the main range, and again in the valleys, the ridges being free; or on the ridges, the valleys showing no trace of like action; or distributed indifferently over each.

The range is composite, being made up of rudely parallel ridges, that unite at some points, interlock at others, and appear to have advanced and retreated in the mazes of their morainic dance, until suddenly stricken with fixity in their most eccentric combinations. The ridge within the ridge is sometimes clearly traceable between component ridges, and the depressions resultant from such divergences, are. often the areas filled by the larger lakes on the range. Some ridges cross the trend of the main range, and transverse spurs may be called common. The component ridges are frequently broken and irregular in height and breadth as in all else, just as we might have predicted would be the case, could we have seen the terminal moraines of certain Alpine glaciers understandingly, and then have been called upon to forecast the operation of similar forces, on a scale immensely greater, in this country, with variations for the widely differing contour. Most of the Swiss glaciers of our time terminate in narrow valleys with steep, sloping sides, hence their debris takes the form of lateral ridges, like a torrent-washed valley deposit. Some of them, in their recently advanced state, are found in more open valleys, with a gentle inclination, and, in such cases, terminal moraines have been formed from the ground moraines of the glacier, differing only from our Quaternary formations, in the presence of medial and lateral morainic matter, which, in the very nature of things, cannot be found in our more open country. The Rhone glacier has left three ridges, which, except that they are diminutive, might be studied as models of the topographical eccentricities which we have endeavored to describe. The two outer ridges are now covered with grass and shrubs, but the inner and later ridge is still bare, graduating into the ground moraine of the retreating glacier, which by some new advance may yet heap all their scattered material to magnify the last ridge of the trio, or to establish a quartette. The glaciers of the Grindelwald have left similar moraines in part, presenting a perfect analogy with our range; such as may also be found near the Glacier du Bois, the Argentine, and the Findelen ; though less strikingly in the case last named. Terminal moraines alone must be relied on for analogies with our ranges. The formations have been pretty thoroughly interrogated as to their materials, as well as for their arrangement, to assist in determining their origin. The Kettle Range, in its typical development, consists mainly of clay, sand, gravel and bowlders, gravel being most conspicuously exposed. The belt at many points exhibits two formations, perfectly distinguishable ; that which is uppermost, but not constituting the heights of the range, being sand or gravel, which covers the lower stratum like a sheet, over large and diverse areas, and, in many cases, suggests a much greater quantity in the superficial coating than is actually present. The coating of gravel tends to level and mask the irregularities of the main formation, but the aspects presented by the mass are still billowy and undulatory, a margin often being found on the flank of a ridge stretching away into a sand-flat, or gravel plain. Gravel is a large constituent in the Kettle Range, and wherever the forms are most symmetrical, the presence of gravel in increasing proportions may be assumed. Some minor knolls and hills are almost entirely composed of sand and gravel, including bowlders occasionally. The core of the range is, however, a confused commingling of clay, sand, gravel and boAvlclers, the latter sometimes many feet in diameter, and grading down to the very finest rock flour; sometimes without an angle abraded, and again thorouglily rounded by the rolling and planing process they have undergone. The cobble-stones are found splierically rounded, unlike beach gravel, which has been subjected to a sliding motion, and is thereby flattened.

There is no stratification in the heart of the range, but immediately thereupon stratification commences, partly simultaneous with the first deposition, and the rest by subsequent modification. The local overlying beds are stratified, but often inclined, rather than horizontal, and frequently discordant, undulatory or irregular, but the main point of the glacier theory is to establish non-stratification at the heart. The source whence the material was obtained to form the range in this State, cannot be doubted. Coarse rock is present in large quantities, so that identification is easy, and the distances that have bceu traversed can be estimated with measurable certainty, from the marks of abrasion. Man}' derails establish the main proposition, but a single case must be relied on iuv iilu:,tration, jircmj.^l.ig merely that the instance cited is in perfect accord with the mass from which it is selected. The rock formations below the range, in many of its windings, offers material aid in determining the limits of the superimposed mass. The Green Bay loop of the range, itself raorainic, surrounds on all sides except the north, several scattered masses or knobs of granite, porphyry and quartzite, which protrude through the limestone and sandstone that prevail in that region, and the significance of these knobs will not fail to be perceived by the reader. The adjacent formations gave their several contributions to the range, but only to a limited section, invariably in the line of glacial striation. Take any segment of the range, and you find a noteworthy quota derived from adjacent rocks in the line of striation ; and generally a less proportion from the successive formations backward for three hundred miles or more, alono; the line of glacial movement. The agency that produced the range, gathered material along its line of march for at least three hundred miles, freezing to the recruited matter of all kinds, but finding its great accumulations near the terminal moraine. The range changes its components in dift'erent parts of its course, in obedience to the law indicated, showing physical and lithological characteristics exactly corresponding with the formations less and more distant whence they were thus derived. The moraines of Switzerland exhibit parallel facts. The margins of the great moraine on the flanks of the Juras, are in a great degree bowlder-clay from the limestone in that vicinity, the proportion derived from the more distant Alps being small by comparison. The more recently formed moraines derived from the Bois, A^ierch, Rhone, Aar, and other such glaciers, which pass over granite, are composed mainly of sand, gravel and bowlders, with little clay ; while the glaciers of the Zermatt region, which traverse schistose rocks, and those of the Griiidelwald, that move over limestone in all their later course, are rich in clay. The Professor found some moraines that were almost exact reproductions of the phenomena observable in the Kettle Range, unstratified, commingled debris in the main ; but stratified and assorted material was also found ; as for instance, in the inner moraine of the Upper Grindelwdld glacier there was much tine assorted gravel and coarse sand heaped together in curious peaks and ridges strangely placed on the sides and sumrait of the moraine.

To prove the relation of the range to the movements of the drift is, of course, vital to our purpose - to show that the ridge was located by glacial action. The grooving of the rock surface is one method of determining the course of the ice current ; the direction from whence the materials must have been convoyed, the abrasions of rock prominences, the trend of elongated domes of polished rock, and the arrangement of the depo^it^ topographically - are all means that mav assist us in the demonstration, and they concur in placing beyond question the work of the glacier in the Kettle Range wherever opportunities have been found to test them exhaustively. The erratics from the protruding knobs of arch?ean rocks, which have been alluded to, were traced along their line of travel, as marked by striations, to the glacier-plowed parent rock, from which lines of erratics have been deposited along the ice march as they fell. Observations in Eastern Wisconsin have determined that, betwee i Lake Michigan and the Kettle Range adjacent, the direction was obliquely up the slope southwestward toward the range. Between the Green Bay Valley and the range, after surmounting the cliff that borders the valley, the direction was obliquely down the slope southeastward. In the Green Bay trough, the glacier moved up the valley to its water-shed, and then descended Rock River Valley. Between Green Bay Valley and the range on the west, the course was up the slope southwesterly or westerly, as the position was more or less favorable. These movements have been carefully ascertained after collecting an immense mass of data, and they exhibit a marked divergence fVom the main channel toward the margin of the striated area, of which the Kettle Range is the ultima thulc Beyond our own State, a great deal of valuable matter tending in this direction has been accumulated, showing that the main channels of the ice streams were the troughs of Lake Superior, Lake Michigan, and of the two lakes, Erie and Ontario, besides which there were lesser glaciers, cUt still great ones, pjaning and plowing their several courses along the basins of the bays of Saginaw, Green and Keweenaw. The wasting and disappearance of each glacier on every margin and its advance, grinding under its ponderous weight the less elastic materials which it held imprisoned, will, when properly considered, fully account for the striations which mark its course, and for their divergence from the main channel ; but for some time the plowed lines now so easily explained by the aid of science were sore stumbling-blocks to the inquiring minds which have solved the problem. The topography of the range may be best described by an imaginary journey along its course. Starting from the northern extreme of the range in Wisconsin, midway between the southern point of Green Bay and Lake Michigan, we mount an eastward-sloping rocky incline, the base of the range being only about two hundred feet above the level of Lake Michigan. Our course lies southwest, up the rocky slope to its crest. Twenty miles north of the Illinois line, there is a division, one portion stretching toward the south, while the other curves westward, crossing Rock River Valley, descending therein at least three hundred feet lower than the rocky crest w'jiich the glacier just as certainly traversed. Curving now gradually to the north after passing Rock River, the range crosses the water-shed between the rivers Rock and Wisconsin, and the great bend of the latter, sweeping directly over quartzite ranges with a vertical undulation of more than seven hundred feet, then ascending the water-shed between the Mississippi and the St. Lawrence drainage areas, estimated at from seven hundred to eight hundred feet above Lake Michigan. Crossing the head-waters of Wisconsin River within about fifty miles from the State's northern boundary, we descend obliquely the east slope of the Chippewa Valley, and, having crossed that part of our course, curve rapidly to the north and along its western margin to the water-shed of Lake Superior. Returning along this line to complete our tour of investigation, we find the range branching near the northern limit of Barron County. We travel with the western line southwestward to Lake St. Croix, on the boundary of Wisconsin, and move onward into Minnesota. Taking the State Geologist of Minnesota for our guide in that region, we find an extensive deposit of drift-hills on the water-shed between the Mississippi and Minnesota Rivers, and a line of similar accumulations, less definite and continuous, stretching southward from the neighborhood of St. Paul into Iowa; between which we are somewhat at a loss to imagine which is the true moraine, or whether each may fairly lay claim to that distinction. Probably the line re-curves north of the center of Iowa, so we continue our journey northwesterly until we strike the Coteau de Prairie of Dakota, where, uncertain as to the possible limits of the tour, we reluctantly abandon the gigantic monograph of the glacier, still to be followed by inquirers and questioned as to the time and conditions under which the ice-king defined his bounds and set up this rampart to mark the decline of his empire. Returning now to the bifurcation in Southeast Wisconsin, we follow the range as it strikes south into Illinois after an interesting flexure near our State line; but the range loses its more pronounced features in the Sucker State, broadening its base and lowering its crest, until, as it rounds Lake Michigan, it is well nigh lost. East of the Lake, trending northward in Michigan, the range resumes its old-time characteristics and is aggressive enough to develop two belts, one bearing northerly between the Great Lake and the Saginaw Valley, and the other northeasterly between that valley and the basin of the Erie. The first-named belt is hypothetical rather than actual, though not altogether hypothetical, and beyond the points already indicated there is abundant room for speculation, but little clearly defined knowledge. There is a line of drift-hills in Ohio with a surface analogous to our moraines, occupying the Tvater-shed between Lake Erie and the Ohio River, stretching across that State and extending westward into Indiana, probably very near to, if not actually joining, the belt already described. Ohio and Indiana geologists claim that parts of those States have sustained a degree of erosion altogether exceptional in the Maumee- Wabash Valley, and it might hardly be expected that the moraine would come out of such an ordeal in any other than a fragmentary condition ; so we may have to content ourselves with a partly speculative range in the regions named, but some remains will certainly be found when adequate and critical search shall be made to connect the Ohio belt with the western range. A similar formation is described in New York reports as extending along the southern part of Long Island, and the same range is traced across New Jersey by Prof. Cook, who is satisfied that it is a terminal moraine.

Sufficient investigation may yet establish the oneness of our morainic belt, and prove a yet vaster extension, but history records only what is known.

We come now to consider the mineral resources of the State - metallic ores from which metals are extracted, and non-metallic minerals which are applied in numerous ways, with but slight preliminary treatment, in the mechanic and economic arts, to increase the comfort of mankind. Wisconsin possesses, in large degree, the ores of lead, zinc, iron and copper, and in degrees almost infiaitesimal, even the more precious metals. The non-metallic substances principally found are building stone, brick clay, cement rock, kaolin, glass sand, peat and limestone for lime and flux. Lead and zinc are found in the same region, under like conditions and often together. Lead has long been the most important metalliferous product of the State, but the demand for our lead is not so great as formerly, and the labor employed suffers a corresponding reduction. Lead and zinc ores have been discovered in limited quantities in the archiean rocks in the northern part of this State, which we have described elsewhere as the core about which the concentric bands of other formations aggregated in transforming the Island of Wisconsin into part of this continent. The economic value of the deposits named is wisely doubted. The chief supply of those metals in this State comes from that section of the southwest west of Su^ar River and south of the valley of the Wisconsin River, from the head-waters of the first-named stream westward. That is the lead region, and, with small additions of territory included in Iowa and Illinois, the lead regions of the Upper Mississippi can be accurately delineated.

France became impressed with the belief that the valley of the Mississippi was rich in metals, during the seventeenth century, and in the next century the fearful climax of speculation known as the " Mississippi Bubble " was largely due to the assum.ption that the valley was auriferous. Nicholas Pcrrot is said to have discovered lead here about the year 1G92, but the supposed discoverer does not mention the fact in the only work of his pen that has been preserved. Le Sueur, famous for his voyage up the Mississippi in the first year of the eighteenth century, found lead on the banks of that river near what is now the southern limit of our State. Capt. Carver found lead in the Blue Mounds in 17G6, the Indians being unaAvare of its value as an ore, although conversant with its appearance. The first raining for lead in this country with which we are conversant was undertaken in 1788 by Julicn Dubuque, who continued his operations near the site of the city named for him until 1810, the time of his death. For twelve years from that time, lead raining was a lost art among the American people, but after 1821 that industry was resumed with great profit, and has been prosecuted ever since, attaining its maximum of production between the two years 1845 and 1847, until the silver-lead -nines of Utah rose into prominence, with other such mines in the Rocky Mountains. The lead mines of the Mississippi Valley eclipsed all the other mines in the United States in the production of lead, and the production of that metal is still large in the region with which we are most concerned. Wisconsin gives but one form of lead ore in quantity, sulphide of lead or galena, which, when free from foreign admixtures, shows over 86 per cent of pure lead mixed mechanically with sulphur. Ordinarily, galena contains silver, but the ore in Wisconsin has only the slightest trace of the more precious metal.

There are two varieties of zinc ores produced in our mines - sphalerite, sometimes mavmatite, and smithsonite - the first a sulphide containing about 10 per cent of iron, known to the miners as "blackjack;" the pure sulphide of zinc contains about 67 per cent of the metal. Smithsonite, popularly known as "dry bone," is an iron-bearing carbonate, which is produced abundantly. Both the ores, lead and zinc, in the several varieties named, and some others, are limited practically to the beds of Galena and Trenton limestone, which have already been described in their order, underlaid by almost horizontal strata, deposited upon the archa?an rocks the crystalline mctamorphic sedimentary upheaval, to which we are under so many obligations. The order of their coming has been already given, and the facts of their partial erosion ; but the strata attain a depth in all of nearly two thousand feet in the lead region. Galena bull" and blue limestones are, in all, about three hundred and seventy-five feet thick, the upper and lower strata of the deposits being, in a metallic sense, barren. The blue and buff layers are the main depositaries of zinc, and lead is the chief product of the Galena limestone; but the layers all produce both metals in greater and less proportion. The deposits of ore are found in crevices sometimes vertical and sometimes lateral, the simplest and commonest form being a crack in the rock, probably a few inches "vvide, having a flat extension beneath, worn by the water as it percolated through the stratum, leaving the chemical residue to be found by enterprising men. Some of these extensions are several hundred feet in length and breadth, vast chambers forty feet in height, lessening to nothing on every side, and brilliant with incrustations that might enrich a palace. The imagination of the reader may riot at will in conjuring up the wondrous forms of beauty assumed by these subterranean cavities, without danger that his most extravagant creation will surpass the reality in favored instances ; but many of the chambers contain masses of loose rock disintegrated, but not carried away, containing large quantities of Galena ; and the ore in numberless instances is found in cubes and stalactites, crystalline embodiments of the wealth that rewards patient labor. The limestone has been creviced in two directions, rudely indicating the points of the compass, the lines treading east and west being the most productive of metal. Vertical crevices are seldom found in the lower stratum or buff limestone ; hence the ores of zinc are not found in the vertical openings to any extent. Sometimes many of the chambers or "flat openings," sheets, or crevices, are worked together with manifest advantage to the miners. Occasionally the flat openings contain little or no galena, but are well supplied with "black jack " and " dry bone " ores and cleavable calcite, as well as marcasite or sulphide of iron on roof and floor, the area between being clear. Vertical crevices characterize the galena proper, as a rule, and the flat openings are looked for generally in the blue and buff limestones, so that zinc is principally obtained in such chambers.

Until the yqar 18G0, the zinc ores, being more refractory than galena, were not considered capable of being worked with profit, the clay and fuel for smelting having to be brought from great distances, so that freights were enormous; but about the time named the plan of sending ore to La Salle, 111., was initiated, and has since been prosecuted with much advantage, as it is cheaper to send the ore for reduction to the fuel and clay than to bring the other substances to the mining district in sufficient quantity for the work. The innumerable purposes to which zinc is increasingly applied in daily life render it certain that the large deposits of the ore obtainable in this State will long continue to be a source of wealtn. The geological survey of the State has been of immense advantage in determining the localities in which the deposits of galena and buff and blue limestone have been more or less extensively eroded by atmospheric influences, and the economic value of such inquiries will be found in the saving of money and labor from being invested, where, even though the ores may be discovered, they do not exist in sufficient quantities to justify large outlay for permanent works. The practical miner knows the worth of accurate scientific investigation.

Iron is not yet one of the great products of Wisconsin, but those who have read the former pages of this chapter cannot tail to know that there are great possibilities in the future in this respect. Many blast furnaces are now employed in the eastern section of the State, reducing ores brought from Michigan, but there are other furnaces dealing with ores from our own mines, and their number and profits will very largely increase. Our best iron fields are, beyond doubt, in the north, where the country is heavily wooded, and where much patient exploration and many tentative experiments should prepare the way for large investments, such as will afford remunerative employment to skilled miners and workmen for centuries in developing this branch of our great mineral resources. In describing the several ores from which iron is obtained, we shall try to avoid technical phraseology except in those instances in which the technique has become a popular possession. Red hematite ores contain iron in an earthy condition, as anhijdrous sesquioxide, without luster, although when pure fully 70 per cent of metallic iron is present. The mined ore is seldom pure, and the mechanical combination of foreign substances reduces its value generally to about 50 per cent, or even less. Clinton iron ore is our most important find in this State of red hematite, at present being exploited, the name being derived from the locality in Oneida County, N". Y., where it was first obtained. Its rocks are limestones and shales in the Silurian formation, and its characteristics are marked so unvaryingly that any person once familiar with the ore cannot fail to recognize its presence in new positions. This