Chapter XXXV: Introduction: OF THE PALÆONTOLOGICAL ROCKS.--After passing some fifty (1)

miles below this locality there are evidences that the river, in its progress south, has now reached the vicinity of the great carboniferous and metalliferous formations, which, for so great a length, and in so striking a manner, characterize both banks of the Mississippi below St. Anthony's Falls. About nine or ten miles before reaching these Falls, this change of geological character is developed; and on reaching the Falls the river is found to be precipitated, at one leap, over strata of white sandstone, overlaid by the metalliferous limestone. The channel is divided by an island, and drops in single sheets, about sixteen to eighteen feet, exclusive of the swift water above the brink, or of the rapids for several hundred yards below. This sandstone is composed of grains of pure and nearly limpid quartz, held together by the cohesion of aggregation. If my observations were well taken it embraces, sparingly, orbicular masses of hornblende. It is horizontal, and constitutes, in some places, walls of stratification, which are remarkable for their whiteness and purity. This sandstone is overlaid by the cliff limestone, the same in character, which assumes at some points a silicious, and at others, a magnesian character. It is manifestly the same great metalliferous rock which accompanies the lead ore of Missouri and mines of Peosta or Dubuque. There rests upon it the elder drift stratum of boulders, pebble, and loam, which marks the entire valley. This latter embraces boulders of quartz and hornblende rock, along with limestones and sandstones. It is overlaid by about eighteen inches of black alluvial carbonaceous mould.

From St. Anthony's Falls the river is perpetually walled on either side with those high and picturesque cliffs which give it so imposing and varied an appearance, and its current flows on with a majesty which seems to the imagination to make it rejoice in its might, confident of a power which will enable it to reach and carry its name to the ocean in its unchanged integrity.

ST. PETER'S RIVER AND VALLEY.--The importance, fertility, and value of this tributary have particularly impressed every member of the party. Its position as the central point of the Sioux power, and its border position to the Chippewas, the representative tribe of the great Algonquin family, render it now a place of note, which fully justifies the policy of the department in establishing a military post at the confluence of the river; and the importance cannot soon pass away, in the progress of the settlement of the Mississippi Valley.[229] It is the great route of communication with the valley of the Red River of the North, and the agricultural and trading settlements of Lord Selkirk in that fertile valley, and its complete exploration by a public officer is desirable, if not demanded.[230]

[229] Thirty years has made it the centre of the new territory of
Minnesota, which has now entered on the career of nations.

[230] This object was accomplished by an expedition by Major L. Long,
in 1823.

Of its geological character but little is known, and that connects it with both the great formations which have been noticed as succeeding each other at the great Peace Rock. That the granitical formation reaches it at a high point is probable, from the large reported boulders. The Indians bring from the blue earth fork of it, one of their most esteemed green and blue argillaceous pigments, of which the coloring matter appears to be carbonate of copper. They also bring from the Coteau des Prairie, probably Carver's "shining mountains," specimens of that fine and beautiful red pipe stone, which has so long been known to be used by them for that purpose. This mineral is fissile, and moderately hard, which renders it fit for their peculiar ripe sculptures. I found small masses of native copper in the drift stratum at the mouth of this stream, on the top of the cliffs on the Mississippi, opposite the mouth of the St. Peter's.

CRYSTALLINE SAND ROCK.--This stratum reveals the same crystalline structure which is so remarkable in the sandstone caves, near the Potosi road, in the county of St. Genevieve, Missouri; and the sand obtained from it, like that mineral, would probably fuse, with alkali, in a moderate heat, and constitute an excellent material for the manufacture of glass. It is also, like the Missouri sandstone, cavernous. In both situations, these caves appear to be due to water escaping through fissures of the rock, where its cohesion is feeble, carrying it away grain by grain.

In stopping at one of these caves, about twelve miles below St. Peter's, we found this cause of structure verified by a lively spring and pond of limpid water flowing out of it.

VALLEY OF THE ST. CROIX.--This river originates in an elevated range of the elder sand and pebble drift, which lies on the summit between the Mississippi system of formations, and the Lake Superior basin. It communicates with the Brulé, which is "Goddard's River" of Carver, and with the Mauvaise or Bad River of that basin. Specimens of native copper have been found on Snake River, one of its tributaries.[231]

[231] This river was explored by me in 1831 and 1832, in two separate
expeditions in the public service, accounts of which have been
published in 1831 and 1832, of which abstracts are given in the
preceding pages.

GEOLOGICAL MONUMENTS.--In descending the river for the distance of about one hundred miles below St. Anthony's Falls, my attention was arrested, on visiting the high grounds, by a species of natural monuments, which appear as if made by human hands seen at a distance, but appear to be the results of the degradation and wasting away, on the Huttonian theory, of all but these, probably harder, portions of the strata.

LAKE PEPIN.--This sheet commends itself to notice by its extent and picturesque features. It is an expansion of the river, about twenty-four miles long, and two or three wide. Both its borders and bed reveal the drift stratum, and the observer recognizes here, boulders of the peculiar stratification which has, in ancient periods, characterized the high plateaux about the sources of the river. Such are its hornblendic, sienite, quartz, trap, and amygdaloid pebbles, and that variety of the quartz family which assumes the form of the agate and other kindred species. Moved as these materials are annually, lower and lower, by the impetus of the stream, other supplies, it may be inferred, are still furnished by the shifting sand and gravel bars from above. The mass must submit to considerable abrasion by this change, and the diminished size of the drifted masses become a sort of measure of the distance at which they are found from their parent beds.

CHIPPEWA RIVER.--This stream is the first to bring in a vast mass of moving sand. Its volume of water is large, which it gathers from the high diluvial plains that spread southwest of the Porcupine Mountains, and about the sources of the Wisconsin, the Montreal, and the St. Croix Rivers, with which it originates.

TROMPELDO (_Le Montaine des Tromps d'Eaux_).--This island mountain stands as if to dispute the passage of the Mississippi, whose channel it divides into two portions. Distinct from its height, which appears to correspond with the contiguous cliffs, and in the large amount of fresh debris at its base, it presents nothing peculiar in its geology.

PAINTED ROCK.--This vicinity is chiefly noted for its large and fine specimens of fresh-water shells.

WISCONSIN.--Like the Chippewa, this stream brings down in its floods, vast quantities of loose sand, which tend to the formation of bars and temporary islands. It originates in the same elevated plains, and bespeaks a considerable area at its sources, which must be arid. It is a region, however, in which lakes and rice lands abound, and it may, in this respect, be geologically of the same formation as the higher plateaux of the Mississippi, above the Sandy Lake summit. Its sides produce many species to enrich our fresh-water Conchology.

LEAD MINES OF PEOSTA AND DUBUQUE.--In my researches into the mineral geography of Missouri, in 1818 and 1819, I had explored a district of country between the rivers Merrimak and St. Francis, and on the Ozarks, which revealed many traits which it has in common with the Upper Mississippi. There, as here, the mineral deposits appear to be, in many cases, in a red marly clay, whether the clay is overlaid by the calcareous rock or not. There, as here, also, the limestone and sandstone strata are perfectly horizontal. The leads of ore appear, in this section, to be followed with more certainty, agreeable to the points of the compass; but this may happen, to some extent, because the practice of mining on individual account, with windlass and buckets, in the Missouri district, has led common observers to be more indifferent to exact scientific methods. To say that the digging, at these mines, is equally, or more productive, is perhaps just. Capital and labor have been rewarded in both sections of the country, in proportion as they have been perseveringly and judiciously expended.

I found much of the ore, which is a sulphuret, at Dubuque's Mines, lying in east and west leads. These leads were generally pursued in caves, or, more properly, fissures in the rock. In one of the excavations which I visited, the digging was continued horizontally under the first stratum of rock, after an excavation had been made perpendicularly, through the top soil and calcareous rock, perhaps thirty feet. The ore is a broad-grained cubical galena, easily reduced, and bids fair very greatly to enhance the value and resources of this section of the West.

Similar mines exist at Mississinawa, and the River Au Fevé,[232] both on the eastern or left bank of the Mississippi. And a system of leasing or management, such as I have suggested for the Missouri mines, appears equally desirable.

[232] GALENA has subsequently been made the capital of these mines.

QUARTZ GEODES.--The amount of silex in the cliff limestone is such, in some conditions of it, as to justify the term silico-calcareous. This condition of the rock at the passage of the Mississippi through the Rock River and Des Moines Rapids, is such as to produce a very striking locality of highly crystalline quartz geodes, which accumulates in the bed of the stream. Many of these geodes are from a foot to twenty-two inches in diameter, and on breaking them they exhibit resplendent crystals of limpid quartz. Sometimes these are amethystine; in other cases they present surfaces of chalcedony or cacholong. The latter minerals, if obtained from the rock, and before unduly hardening by exposure, would probably furnish a suitable basis for lapidaries.

INTERMEDIATE COUNTRY IN THE DIRECTION TO GREEN BAY.--There is a line which separates, on the north, the granitical and trap region from the metal-bearing limestone, and its supporting sandstone. This formation of the elder series of rocks, having been traced to the south shore of Lake Superior, and having been seen to constitute the supporting bed of the alluviums and diluviums of the Upper Mississippi, above the Peace Rock, it may subserve the purpose of inquiry to trace this line of junction by its probable and observed boundaries.

The line may be commenced where it crosses the Mississippi, at the Peace Rock, and extended to the St. Croix, the falls of which are on the trap-rock, to the sources of the Chippewa at Lac du Flambeau, and the Wisconsin near Plover Portage. The source of Fox River runs amid uprising masses of sienite, and this formation appears to pass thence northeasterly, across the Upper Menominee, to the district of the Totosh and Cradle-Top Mountains, west of Chocolate River, on the shores of Lake Superior.

I observed the crystalline sandstone and its overlying cliff limestone, along the valley of the Wisconsin, where ancient excavations for lead ore have been made. There is an entire preservation of its characters, and no reason occurs why its mineralogical contents should not prove, in some positions, as valuable as they have been found in Missouri, or in the Dubuque district west of the Mississippi.

On reaching the Wisconsin Portage, the limestone is found to have been swept by diluvial action, from its supporting sand rock. Such is its position not far north of the highest of the four lakes, and again at Lake Puckway, in descending the Fox River; consequently, there are no lead discoveries in this region. On coming to the calcareous rock, which is developed along the channel of the river, below Winnebago Lake, it appears rather to belong to the lake system of deposits. Its superior stratum lies in patches, or limited districts, which appear to have been left by drift action. Petrefactions are found in these districts, and the character of the rock is dark, compact, or shelly. The lower series of deposits, such as they appear at the Kakala Rapids, at Washington Harbor, in the entrance to Green Bay, and in the cliffs north of Sturgeon Bay and Portage, are manifestly of the same age and general character as the inferior stratum of Michilimackinac and the Manatouline chain.

BASIN OF LAKE MICHIGAN.--This basin, stretching from the north to the south nearly four hundred miles, lies deeply in the series of formation of limestones, sandstone, and schists, to which we apply the term of the Michilimackinac system. Its north and west shores are skirted from Green Bay to a point north of the Sheboygan, with the calcareous stratum. At this point, the ancient drift, the lacustrine clay of Milwaukie and the prairie diluvium of Chicago, constitute a succession, of which the surface is a slightly waving line of the most fertile soils.

Among the pebbles cast ashore at the southern head of this lake I observed slaty coal. It seems, indeed, the only one of the lakes which reaches south into the coal basin of Illinois. If the level at which coal is found on the Illinois were followed through, it would issue in the basin of the lake below low-water mark. Digging for this mineral on the Chicago summit, promises indeed not to be unsupported by sound hypothesis.

After passing Chicago, of which a sketch is added, the sands which begin to accumulate at the Konamik, the River du Chemin, and the St. Joseph's River,[233] appear in still more prominent ridges, skirting the eastern coasts to and beyond Grand River. These sands, which are the accumulations of winds, are cast on the arable land, much in the manner that has been noticed at the Grand Sable on Lake Superior, and reach the character of striking dunes at the coast denominated the Sleeping Bear. The winds which periodically set from the western shore, produce continual abrasions of its softer materials, and are the sole cause of these intrusive sand-hills. Pent up behind them, the water is a cause of malaria to local districts of country, and many of the small rivers upon this side are periodically choked with sand. The sketch transmitted of this bleak dune-coast (omitted here), as it is seen at the mouth of Maskigon Lake, will convey a false idea of the value of this coast, even half a mile from the spot where the surf beats. It is designed to show the air of aridity which the mere coast line presents. The stratification regains its ordinary level and appearance before reaching the Plate or Omicomico River, and the peninsula of the Grand Traverse Bay, and the settlements of the Ottawa Indians on Little Traverse Bay, afford tracts of fertile lands. Point Wagonshonce consists of a stratum of limestone of little elevation, which constitutes the southeast cape of the strait. Here a lighthouse is needed to direct the mariner.

[233] The subjoined petrifaction of a leaf, apparently a species of
betula, was obtained on this river. See _ante_, p. 206.

LAKE HURON.--Notices of this sheet of water have been given in our outward voyage. It appears rather as the junction of separate lakes which have had their basins fretted into one another, than as one original lake. Michigan is connected with it through the Straits of Michilimackinac. The Georgian Bay, north of the Manatouline chain, seems quite distinct. The Saganaw Bay is an element of another kind. The Manitouline chain separates the calcareous and granitic region, and its numerous trap and basaltic islands towards the north shore, of which there are many thousands, denote that it has been the scene of geological disturbance of an extraordinary kind.

ULTERIOR CONCLUSIONS.--In taking these several views of the geological structure of the Northwest--of the Lake Superior basin, and of the valleys of the St. Louis River--the region about the Upper Mississippi, its striking change at the Falls of St. Anthony--and the valleys of the Wisconsin and Fox Rivers, and the basins of Lakes Michigan and Huron, I am aware of the temerity of my task. Allowance must, however, be made for the rapidity of my transit over regions where the question was often the safety and personal subsistence of the party. A very large and diversified area was passed over in a short time. At no place was it possible to make elaborate observations. A thousand inconveniences were felt, but they were felt as the pressure of so many small causes impeding the execution of a great enterprise. A sketch has been made, which, it is hoped, will reveal something of the physical history and lineaments of the country. These glimpses at wild scenes, heretofore hid from the curious eye of man, have been made, at all points, with the utmost avidity. I have courted every opportunity to accumulate facts, and I owe much to the distinguished civilian who has led the party so successfully through scenes of toil and danger, not always unexpected, but always met in a calm, bold, and proper spirit, which has served to inspire confidence in all; to him, and to each one of my associates, I owe much on the score of comity and personal amenity and forbearance; and I have been made to feel, in the remotest solitudes, how easy it is to execute a duty when all conspire to facilitate it.

The views herein expressed are generalized in two geological maps (hereto prefixed), which, it is believed, will help to fix the facts in the mind. They exhibit the facts noticed, in connection with the theory established by them, and by all my observations, of the construction of this part of the continent.

The mineralogy of the regions visited is condensed in the following summary, drawn from my notes, which, it is believed, constitutes an appropriate conclusion to this report.

With the exception of one species, namely, the ores of copper, the region has not proved as attractive in this department as I found the metalliferous surface of Missouri. There are but few traces of mining, and those of an exceedingly ancient character, in the copper region of Lake Superior. The excavations in search of lead ore on the Upper Mississippi do not date back many years, but the indications are such as to show that few countries, even Missouri, exceed them in promises of mineral wealth.

I have employed the lapse of time between the termination of the exploration and the present moment, to extend my mineralogical observations to some parts of the Mississippi Valley which were not included in the line of the expedition, but which were visited in the following year, in the service of the Government, namely, the Miami of the Lakes, and Wabash Valleys, the Cave in Rock Region in Lower Illinois, and the Valley of the River Illinois. The whole is concentrated in the following notices:--

_Tabular View of Minerals observed in the Northwest._

I. ORES.

_Genera._ _Species._ _Subspecies._ _Varieties._
{ Copper { Native copper. { Fibrous.
{ { Green carbonate of copper { Compact.
{ Lead Sulphuret of lead Common.
{ Zinc Sulphuret of zinc Blende.
{ { { Common.
{ { { Radiated.
METALLIC { { Sulphuret of iron { Spheroidal.
MINERALS { { { Cellular.
{ { { Hepatic.
{ Iron { Magnetic oxide of iron Iron sand.
{ { Specular oxide of iron. Micaceous.
{ { { Ochrey.
{ { Red oxide of iron { Scaly.
{ { { Compact.
{ { Brown oxide of iron Ochrey.
{ Silver.

II. EARTHS AND STONES.

_Genus._ _Species._ _Varieties._

{ { { Milky.
{ { { Radiated.
{ { { Tabular.
{ { Common { Greasy.
{ { quartz { Granular.
{ { { Arenaceous.
{ { { Pseudomorphous.
{ { { Amethystine.
{ { Amethyst
{ {
{ { Ferruginous {
{ { quartz { Yellow.
{ { { Red.
{ Quartz { Prase
{ { { Common.
{ { { Cacholong.
{ { Chalcedony { Carnelian.
{ { { Sardonyx.
{ { { Agate.
{ { Hornstone
{ { { Common.
{ { Jasper { Striped.
{ { { Red.
{ { Heliotrope
SILICIOUS { { OPAL COMMON.
MINERALS {
{ Silicious { Common.
{ slate { Basanite.
{
{ Petrosilex
{ { Common.
{ Mica { Gold yellow.
{
{ { Common.
{ Schorl { Indicolite.
{
{ Feldspar Common.
{ Prehnite Radiated.
{
{ Hornblende { Common.
{ { Actynolite.
{
{ Woodstone { Mineralized wood.
{ { Agatized wood.

{ { Calcareous {
{ { spar { Crystallized.
{ { { Lamellar.
{ { Granular
{ { limestone
{ {
{ { Compact { Common.
{ { limestone { Earthy.
{ {
{ { Agaric {
{ { mineral { Common.
{ Carbonate { { Fossil farina.
{ of lime {
{ { { Oolite.
{ { Concreted {
{ { carbonate { Calcareous { Stalactite.
{ { of lime { sinter { Stalagmite.
{ { {
{ { { Calcareous tufa.
CALCAREOUS { { Pseudomorphous carbonate
MINERALS { { of lime.
{ { Marl Ludus helmontii.
{ { Fibrous.
{ Sulphate { Granular.
{ of lime Gypsum { Granularly foliated.
{ { Earthy.
{ Fluate of
{ lime Fluorspar

_Genus._ _Varieties._
{ { Argillite.
{ Argillaceous slate { Bituminous shale.
{
{ Chlorite Chlorite slate.
{ Stautoride.
ALUMINOUS MINERALS { { Potters' clay.
{ { Pipe clay.
{ { Variegated clay.
{ Clay { Blue sulphated clay.
{ { Green sulphated clay.
{ Opwagunite.

{ Serpentine Common serpentine
MAGNESIAN MINERALS { Steatite Steatite.
{ Asbestus Com. asbestus.

BARYTIC MINERALS Sulphate of barytes Lamellar.
STRONTIAN Sulphate of strontian Foliated.

III. COMBUSTIBLES.

{ { Petroleum.
{ Bitumen { Maltha.
BITUMINOUS MINERALS { { Asphaltum.
{
{ Graphite Granular graphite.
{ Coal Slate coal.

IV. SALTS.

{ { Native salt.
Soda { Muriate of soda ..... { Salt springs.
{
{ Alkaline sulphate of Alum.
{ alumina

a. _Metallic Minerals._

1. COPPER.

This metal is frequently found, in detached masses, in the diluvial soil along the southern shore of Lake Superior, and in the high and barren tract included between Lakes Huron, Michigan, and Superior, and the Mississippi River, as general boundaries. Thus, it has been found upon the sources of the Menomonie, Wisconsin, Chippewa, St. Croix, and Ontonagon Rivers, but most constantly, and in the greatest quantity, upon the latter. There are many localities known only to the aborigines, who appear to set some value upon it, and have been in the habit of employing the most malleable pieces in several ways from the earliest times. It occurs mostly in detached masses, resting upon, or imbedded in, diluvial soil. These masses, which vary in size, are sometimes connected with isolated fragments of rock. Such is the geognostic position of the great mass of native copper upon the banks of the Ontonagon, which has been variously estimated to weigh from two to five tons. This extraordinary mass is situated at the base of a diluvial precipice composed of reddish loam and mixed boulders and pebbles of granite, greenstone, quartz, and sandstone and diallage rocks. The nearest strata, in situ, are red sandstone, grauwacke, and greenstone trap. A company of miners was formerly employed in searching for copper mines upon the banks of this river. They dug down about forty feet into the diluvial soil, at a spot where a green-colored water issued from the hill. In sinking this pit, several masses of native copper were found, and they discovered, as their report indicates, the same metal "imbedded in stone." But the enterprise was abandoned, in consequence of the falling in of the pit.

At Keweena Point, on Lake Superior, I found native copper along the shore of the lake, constituting small masses in pebbles, and, in one instance, in a mass of several pounds' weight, which was found in the Ontonagon Valley. I also observed the green carbonate of copper, in several places, in the detritus. The strata of this point appear to be charged with this mineral, particularly in its native forms. Hardly a mass of the loose rock is without some trace of the metal, or its oxides or salts. It would be difficult, on any known principles, to resist the testimony which is offered, by every observer, to favor the idea that extensive and very valuable mines exist. The whole lake shore, from this peninsula to the Montreal River, is replete with these evidences.

There are indications that this mineral pervades the rocks and soils, in a radius of one hundred and fifty miles or more, south and west of this central point. It has been discovered at the sources of the Menominee, Chippewa, Montreal, and St. Croix, and even at more distant points.

At St. Peter's, in digging down for the purpose of quarrying the rock, about eighteen inches depth of dark alluvium was passed; then a deposit of diluvial soil, with large fragments of limestone, greenstone, quartz rock, &c., about six feet; and, lastly, one foot of small pebbles, &c., constituting the copper diluvium. No large mass was found; nor any veins in the rock.

2. LEAD.

The only ore of lead known to exist within the limits to which these remarks are confined, is the sulphuret. In the year 1780, Peosta, a woman of the Misquakee, or Fox tribe of Indians, discovered a lead mine upon the west banks of the Mississippi, at the computed distance of twenty-five leagues below Prairie du Chien, which the Indians, in 1788, gave Julian Dubuque a right to work. This permission was partially confirmed by the Baron de Carondelet, Governor of Louisiana, in 1796. No patent was, however, issued; but Dubuque continued to prosecute the mining business to the period of his death, which happened in 1810, when the mines were again claimed by the original proprietors.

The ore is the common sulphuret of lead, or galena, which Dubuque stated to have yielded him seventy-five per cent. in smelting in the large way. He usually made from 20,000 to 40,000 pounds per annum.

I made a cursory visit to these mines, and found them worked by the Fox Indians, but in a very imperfect manner. They cover a considerable area, commencing at the mouth of the Makokketa River, sixty miles below Prairie du Chien. Traces of the ore are found, also, on the east bank of the Mississippi at several points. It occurs disseminated in a reddish loam, resting upon limestone rock, and is sometimes seen in small veins pervading the rock; but it has been chiefly explored in diluvial soil. It generally occurs in beds having little width, and runs in a direct course towards the cardinal points. They are sometimes traced into a crevice of the rock. At this stage of the pursuit, most of the diggings have been abandoned. Little spar or crystalline matrix is found in connection with the ore. It is generally enveloped by a reddish, compact earth, or marly clay. Occasionally, masses of calcareous spar occur; less frequently, sulphate of barytes, green iron earth, and ochrey brown oxide of iron. I did not observe any masses of radiated quartz, which form so conspicuous a trait in the surface of the metalliferous diluvion of the mining district of Missouri.

Sufficient attention does not appear to have been bestowed, by mineralogists, upon the metalliferous soil of the Mississippi Valley. It is certainly very remarkable that such vast deposits of lead ore, accompanied by veins of sulphate of barytes, calc spar, and other crystallized bodies, should be found in alluvial beds; and it would be very interesting to ascertain whether any analogous formations exist in Europe, or in any other part of the earth's surface. It is one of the most striking features of this deposit, that the ore, spars, &c., do not appear as the debris of older formations, and have no marks of having been worn or abraded, like those extraneous masses of rock which are very common in the alluvial soil of our continent. The lead ore and accompanying minerals appear to have been crystallized in the situations where they are now found. We should, perhaps, except from this remark the species of lead called _gravel ore_ by the miners, which is in rounded lumps, and is never accompanied by spars.

Sulphuret of lead is also found near the spot where the small River Sissinaway enters the Mississippi, and two leagues south of it, upon the banks of the River Aux Fevre, at both of which places considerable quantities have been raised, and continue to be raised, for the purposes of smelting, by the Fox and Sac tribes of Indians. At these places, it is most frequently connected with a gangue of heavy spar and calcareous spar, with pyrites of iron. I procured from a trader, at Dubuque, several masses of galena crystallized in cubes and octahedrons.

In descending the Upper Mississippi, a specimen of galena was exhibited to me, by a Sioux Indian, at the village of the Red Wing, six miles above Lake Pepin, said to have been procured in that vicinity. Galena is also reported to have been discovered in several places on the south side of the Wisconsin River, and these localities may be entitled to future notice, as furnishing important hints.

3. ZINC.

The sulphuret of zinc (black blende) is found disseminated in limestone rock along the banks of Fox River, between the post of Green Bay and Winnebago Lake. Although frequently seen in small masses, no body of it is known to exist. I also found blende, in small, orbicular masses of calcareous marl, along the east shore of Lake Michigan, between the Rivers St. Joseph and Kikalemazo.

4. IRON.

This mineral is distributed, in several of its forms, throughout the region visited, although but little attention has yet been directed to its exploration. In the basin of Lake Superior it exists, in valuable masses, in the form of a magnetic oxide, on the coasts of the lake between Gitchi Sebing (Great River), called by the French Chocolate River, and Granite Point. Specimens from Dead River (Riviere du Morts) and Carp River, the Namabin of the Indians, in this district, denote the latter to be the chief locality. It is the iron glance, and occurs in mountain masses.

_Sulphuret of Iron._--This variety is found, in limited quantities, in a state of crystallization, in clay beds, on the west shore of Lake Michigan, between Milwaukie and Chicago. It is frequently in the form of a cube or an octahedron. Some of the crystals are in lumps of several pounds' weight, with a metallic lustre. Often the masses, on being broken, are found radiated, sometimes cellular, and occasionally irised.

_Iron Sand._--The breaking-up and prostration of the sandstone and other sedimentary formations, along the shores of lakes Michigan, Huron, and Superior, liberates this ore in considerable quantities. It arranges itself, on the principle of its specific gravities, in separate strata along the sandy shores, where it invariably occupies the lowest position at and below the water's edge. The shores of Fond du Lac, on Lake Superior, may be particularly mentioned as an abundant locality.

_Micaceous Oxide of Iron._--In detached mass, among the debris of the River St. Louis and of Fond du Lac. It exists in veins in the clay slate which characterizes the banks of this river.

_Ochrey Red Oxide of Iron._ (Red ochre)--Is produced near a spot called the Big Stone, on the head of the River St. Peter's. It is said to occur in a loose form, in a stratum of several inches thick, lying below the soil of a level dry prairie or plain. The Sioux Indians, who employ it as a paint, make this statement. The color of a portion given to me by them is of a bright red; and a considerable proportion of the mass is in a state of minute division. Particles of quartz are occasionally mixed with it. This ore of iron is also represented to be found in the prairies north of Gros Point, along the west shore of Lake Michigan, between Milwaukie and Chicago.

Ochrey red oxide of iron occurs on the shores of Big Stone Lake, at the source of the St. Peter's River. A large spring rises from a level, dry plain, a few feet beyond which the mineral occurs. The Indians, who employ it as a pigment, take it up with their knives. The stratum is about eight inches thick, but just below the surface it is mixed with common earth. The spring of water is pure and unadulterated.

5. SILVER.

The belief in the existence of silver ore in the region of the lakes, and particularly on Lake Superior, seems to have early prevailed. So much confidence was placed in the reports of its existence, that Henry tells when a company was formed in England for exploring the copper mines of Lake Superior (A. D. 1771), they were impelled to the search more from an expectation of the silver, which it was hoped would be found in connection with it, than from the copper.[234]

[234] This metal has subsequently (namely, in 1844) been found to
constitute a percentage in the native copper of the Eagle River mines
of Lake Superior. Traces of it were found in a mass of native copper
found on the shores of Keweena Lake, by Mr. Moliday, in 1826. A mass
of pure silver was discovered in a boulder in the drift of Lake
Huron, west of White Rock, in 1824. These discoveries induce the
belief that this element will be found to be extensively present in
the eventual metallurgic operations of the Lake Superior basin.

b. _Silicious Minerals._

1. QUARTZ.

This interesting species being distributed in its numerous varieties throughout the region visited, I shall confine my notices to a few localities.

Subs. 1.--_Common Quartz._

Occurs in the form of large water-worn masses along the shores of Lakes Huron, Michigan, and Superior. Also, in veins in the granite of Lake Superior, and in the argillite of St. Louis River. These localities all consist of the opaque varieties, with a slight degree of translucence in some places. It exists in mass at Huron Bay, Lake Superior, and in fragments of red jasper on Sugar Island, St. Mary's River.

1. _Radiated Quartz._--In detached masses on the Grange, and also at the rapids of the River Desmoines, on the Upper Mississippi. At the Grange, the crystals, which are usually minute, sometimes possess a cinnamon color, or pass into a variety of crystallized ferruginous quartz.

2. _Tabular Quartz._--In small, flattened masses along the shores of Lake Pepin. These masses are transparent, or only translucent. Their color is generally white, but sometimes yellow. They appear to be closely allied to chalcedony.

3. _Greasy Quartz._--In detached masses along the shores of Lake Superior.

4. _Granular Quartz._--At the Falls of Puckaiguma, on the Upper Mississippi, in large, compact beds rising through the soil. Also, in some conditions of the cliffs commencing at the Falls of St. Anthony, Carrer's Cave, &c.

5. _Arenaceous Quartz._--This is sometimes the condition of fine, even-grained, translucent sand rock of the preceding localities. Valuable as an ingredient of glass.

6. _Pseudomorphous Quartz._--On the shores of Lake Pepin, occasionally. These masses appear to have taken their crystalline _impress_ from rhomboidal crystals of carbonate of lime.

7. _Amethystine Quartz._--In the trap-rock of Lake Superior.

Subs. 2.--_Amethyst._

This mineral occurs most frequently in the condition of amethystine quartz, in hexahedral prisms, lining the interior of geodes, in the bed of the River Desmoines, and on the Rock Rapids, in the channel of the Mississippi. The crystals which I have examined are generally limpid, with a high lustre, and of a pale violet color. Sometimes the tinge of color approaches to a full red, or is only apparent in the summit of the crystal. These geodes are sometimes eight or ten inches in diameter, with a rough and dark-colored exterior, often so nearly spherical as to resemble cannon _balls_. Some of the finest specimens I have observed from this locality are preserved in the museum of Gov. Clarke, at St. Louis, Missouri.

Subs. 3.--_Ferruginous Quartz._

In amorphous masses, of a deep-red, brown, or yellowish-red color, along the southern shore of Lake Superior. Likewise, crystallized, in very minute hexagonal prisms, terminated by six-sided pyramids, of a reddish color, on the summit and declivities of the Grange de Terre.

Subs. 4.--_Prase._

In the drift of Lake Superior. Its color is a light green and not fully translucent. It possesses a hardness and a lustre intermediate between waxy and resinous.

Subs. 5.--_Chalcedony._

1. _Common Chalcedony._--In globular or reniform masses imbedded in trap-rock, on the Peninsula of Keweena, Lake Superior. It is found sometimes in association with other quartz minerals. Its color is white or gray, sometimes veined or spotted with red. Also, constituting the interior lining of geodes at the rapids of Rock Island and the River Desmoines. These geodes, on breaking, often present a mammillary surface. In the form of translucent fragments, with a highly conchoidal fracture, among the debris of the shores of Lake Pepin. These fragments possess an extremely delicate texture, color, and lustre.

2. _Cacholong._--Some loose fragments of this mineral exist along the west shore of Lake Michigan, between Green Bay and Chicago. These fragments possess small cavities studded over with very minute and perfect crystals of quartz.

3. _Carnelian._--This mineral occurs in fragments in the debris of Lake Superior; also, in the amygdaloid; also, around the shores of the Upper Mississippi. Its color is various shades of red, or yellowish red, sometimes spotted or clouded, fully translucent, and occasionally presenting a considerable richness and beauty. Most commonly, the fragments are too small to be applied to the purposes of jewelry. Sometimes it is seen in very regular spheroidal masses, which contain a nucleus of radiated quartz. Some of the specimens would be considered as sardonyx.

4. _Agate._--Is found with the preceding. It is more frequently found in larger masses, in the rock, which are sometimes spheroidal, reniform, or globular. These agates are chiefly arranged in concentric layers, which are white, red, yellow, &c., according to the colors of the different varieties of chalcedonies, carnelians, &c., of which they are composed. A close inspection would also separate them into several varieties--as onyx, agate, dotted agate, &c.

Subs. 6.--_Hornstone._

In nodular or angular masses, imbedded in the secondary limestone of the west shores of Green Bay; and in the beds of argillaceous white clay strata of Cape Girardeau, of Missouri. Also, on the hills of White River, Arkansas.

Subs. 7.--_Jasper._

1. _Common Jasper._--In detached fragments, yellow, in the drift of Lake Superior.

2. _Striped Jasper._--With the preceding. Most commonly, these specimens consist of alternate bands of red and black, or brown.

3. _Red Jasper._--In quartz rock, Sugar Island, River St. Mary's, Michigan. Masses of this mineral have been met in situ.

Subs. 8.--_Heliotrope._

A fine specimen of this mineral, now before me, was procured at the mouth of the Columbia River, Oregon. It is in the form of an Indian dart. Its color is a deep uniform green, variegated with small spots of red; those parts which are green being fully translucent, the others less so, or nearly opaque. This beautiful mineral is represented to have been in common use by the Indian tribes of the Northwest Coast, for pointing their arrows, previous to the introduction of iron among them. It differs chiefly from the dotted jaspers of Lake Michigan, in its translucence and green color.

Subs. 9.--_Opal._

Common opal occurs as a constituent of agate, along with chalcedony rarely, in the drift on the south shore of Lake Superior.

2. SILICIOUS SLATE.

1. _Common._--In subordinate beds, in the argillite of the River St. Louis, northwest of Lake Superior.

2. _Basanite_ (_Touchstone_).--In detached fragments in the drift on Lake Superior, and along the banks of the Upper Mississippi generally.

3. PETROSILEX.

In large isolated masses in the bed of the Illinois River, on the shallow rapids between the junction of the Fox and Vermilion Rivers. It is mostly arranged in stripes or circles of white, gray, yellow, &c., resembling certain jaspers, or approaching sometimes to hornstone. The bed of the Illinois River, at this place, is a species of gray sandstone. Also, in detached fragments, on the south shore of Lake Superior, intimately mixed with prehnite. In regard to the latter, Professor Dewey, of Williamstown College, writes me: "I have received from Dr. Torrey, a curious mixture of petrosilex and prehnite, in imperfect radiating crystals, which was sent him by you and collected at the West. He did not tell me the name, but examination showed what it was. The association is singularly curious." The locality of this mineral is Keweena Point, Lake Superior.

4. MICA.

Occurs rarely in the granite of Lake Superior. It is found in place on the Huron Islands. Also, in minute folia, in the alluvial soil of the Upper Mississippi. A beautiful aggregate, consisting of plates of gold-yellow mica, connected with very black and shining crystals of schorl, has been dug up from the alluvial soil of the Island of Michilimackinac.

5. SCHORL.

1. _Common Schorl._--In crystals, in boulders of granite, at Green Bay.

2. _Tourmaline._--With the preceding.

6. FELDSPAR.

As an ingredient in the granite of Huron Islands, Lake Superior. Also, in detached masses of granite along the west shores of Lake Michigan. Also, in the form of prismatic crystals of a light-green color, in the rolled masses of hornblende, porphyry, greenstone, and epidotic boulders of Lakes Huron, Michigan, and Superior.

7. PREHNITE.

This mineral occurs at Keweena Point, on Lake Superior. It is found in connection with isolated blocks of amygdaloid, of primitive greenstone, and of petrosilex. Sometimes native copper, and carbonate of copper, are also present in the same specimen. In some instances, a partial decomposition has taken place, converting its green color into greenish-white, or perfect white, and rendering it so soft as to be cut with a knife. Sometimes the grains or masses of native copper are interspersed among the prehnite, and slender threads of this metal occasionally pass through the aggregated mass of greenstone, prehnite, &c., so that, on breaking it, the fragments are still held together by these metallic fibres.

8. HORNBLENDE.

1. _Common Hornblende._--Occurs as a constituent of the hornblende rocks near Point Chegoimegon, Lake Superior. Also, at the Peace Rock, on the Upper Mississippi, and in certain granite aggregates, and rolled masses of porphyries, &c., around the shores of Lakes Huron, Michigan, and Superior.

2. _Actynolite._--In slender, translucent, greenish crystals, pervading rolled masses of serpentine, on the west shores of Lake Michigan.

9. WOODSTONE.

1. _Mineralized Wood._--In bed of the River Des Plaines, Illinois.

2. _Agatized Wood._--This variety of fossil wood is found along the alluvial shores of the Mississippi and of the Missouri.

c. _Calcareous Minerals._

1. CARBONATE OF LIME.

Of a substance so universally distributed throughout the western country, it will not be necessary to give many localities, and these will be principally confined to its crystalline forms.

Subs. 1.--_Calcareous Spar._

_Crystallized Calcareous Spar._--This mineral occurs, in minute rhomboidal crystals, in the calcareous rock of the Island of Michilimackinac. Sometimes these crystals fill cavities or seams of the rock, or are studded over the angular surfaces of masses of vesicular limestone of that island. I also found this mineral at Dubuque's mines, and in small crystals in the metalliferous limestone bordering the Fox River, between the post of Green Bay and Winnebago Lake, where it is associated with iron pyrites and blende.

Subs. 2.--_Compact Limestone._

In proceeding northwest of Detroit, this mineral is first observed, in situ, on an island in Lake Huron. It is afterwards found to be the prevailing rock along the south and southwest shores of Lake Huron. In many places, it incloses fossil remains. Sometimes it is _earthy_, as at Bay De Noquet, a part of Green Bay, on Lake Michigan, where it contains very perfect remains of the terrebratula. (Parkinson.) In other places, no remains whatever are visible, and the structure is firm and compact; or even passes, by a further graduation, into transition-granular, of which, it is believed, the west shores of Lake Michigan afford an instance. It is most commonly based upon sandstone, which also contains, in many places, the fossil organized remains of various species of crustaceous animals, and of vegetables, sometimes, coal, &c.

Subs. 3.--_Agaric Mineral._

This mineral substance occurs in crevices and cavities in the calcareous rock of the Island of Michilimackinac, Michigan.

Subs. 4.--_Concrete Carbonate of Lime._

1. _Calcareous Sinter._--In the form of _stalactites_ and _stalagmites_, in a cave situated near Prairie du Chien, on the Upper Mississippi.

2. _Calcareous Tufa._--A remarkable formation of tufa is seen on the east banks of the Wabash River, near Wynemac's Village, about ten miles above the junction of the Tippecanoe. It extends for several miles, and is deposited to the thickness of thirty or forty feet above the water, forming cliffs which are covered with alluvial soil and sustain a growth of forest trees. The precise points of its commencement and disappearance were not observed. The structure is cellular or vesicular, and resembles, in some places, a coarse dried mortar. It is very light, and possesses a white color in inferior situations, but the surface is somewhat colored by fallen leaves and other decaying vegetation. It imbeds fluvatile shells and some vegetable remains, the species of which have not been ascertained. The opposite, or west side of the river consists of a kind of puddingstone, or caschalo, made up of pebbles of quartz, &c., cemented by carbonate of lime, of a yellow color and translucent. This beautiful aggregate is overlayed by a stratum, of fifteen or twenty feet in thickness, of diluvial soil. These localities fall within the limits of the State of Indiana; but on territories still occupied, if not owned, by the aborigines.

3. _Pseudomorphous Carbonate of Lime._--This form of carbonate of lime occurs in Pope County, Illinois, a district celebrated for its fluorspar, lead, crystallized quartz, &c., and bearing the unequivocal marks of a secondary formation. Scattered in large masses over the soil, we observe compact limestone, with very perfect cubical, octahedral, or other regular cavities, which have manifestly originated from crystals of fluorspar. The most common _impress_ of this kind appears to have resulted from two cubes variously joined--a form of appearance very common to the Illinois fluates. Some of these cubical cavities exceed three inches square; but in no case is any remaining portion of the spar in these cavities, or anywise connected with the fragments of limestone thus impressed, although, at the same time, the spar is very abundant in the alluvial soil where these curious limestones are found.

2. SULPHATE OF LIME.

Subs. _Gypsum._

1. _Fibrous Gypsum._--In the alluvial soil of the St. Martin's Islands, Lake Huron. The fibres are sometimes five or six inches in length, of a white color and delicate crystalline lustre. Sometimes these fibrous masses are partially colored yellow or brown, apparently from the clay, or mixed alluvion, in which they are imbedded.

2. _Granular Gypsum._ } 3. _Granularly-Foliated Gypsum._ } With the preceding. 4. _Earthy Gypsum._ }

3. FLUATE OF LIME.

_Fluor-Spar._--On the United States Mineral Reserve, Pope County, Illinois. This locality is abundant, and the mineral readily and constantly to be obtained. I first obtained specimens in June, 1818, and afterwards visited it in July, 1821. It is disseminated in loose masses throughout the soil, and in veins in the calcareous rocks. The spot most noted and resorted to, and where the original discovery was made, is four miles west of Barker's Ferry, at Cave-in-Rock, on the banks of the Ohio, and about twenty-six miles, by the course of the river, below Shawneetown. It is situated in the midst of a hilly, broken region, called _the Knobs_, a tract of highlands intervening between the banks of the Ohio and the Saline. The distance of this range from north to south, or parallel with the course of the Ohio, cannot be stated. It probably extends from near the banks of the Wabash River to the Little Chain of Rocks. Its breadth--from Barker's Ferry, west, to Ensminger's, at the Saline, is about twenty miles. It thus separates, by a rocky border, the prairies of the Illinois from the current of the Ohio River. These knobs, wherever observed, bear the indubitable marks of secondary formation, and may be stated to consist, essentially, of compact limestone resting on sandstone. The sandstone is sometimes so much colored by iron, and by globular or irregular masses of iron stone, as to give that rock a very singular aspect. This may be particularly instanced in the mural front of the Battery rocks on the banks of the Ohio. Every part of this formation has more or less the appearance of a mineral country; and it is already known as the locality of ores of lead, iron, and zinc, of crystallized quartz, of opal, heavy spar, crystallized pyrites, and of very perfect fossil madrepores. In one place (near the head of Hurricane Island) this spar forms a very large and compact vein, dipping under the bed of the Ohio. Where the rock has been explored, it is found in connection with sulphuret of lead, but it has been mostly procured, because most easy of access, in the alluvial soil. I went out about half a mile west of the Ohio, where a new locality has been opened, and, in removing about five or six solid feet of earth, procured as many specimens as filled a box of fourteen inches square. None of these were more than two feet below the surface. One of these specimens is an irregular octahedral crystal, eight inches in diameter. The color of these masses is various shades of blue, violet, or red, sometimes perfectly white or yellow; and the form most commonly assumed is a cube, sometimes truncated at two or more angles, or variously clustered. The external lustre of the crystals, raised from alluvial soil, is feeble, but quite brilliant when taken from veins and cavities in the rock. These spars from the alluvion do not appear to exist as rock debris, or fragments worn off from other formations, but as original deposits. There are no marks of attrition. They appear as much in place as the limestone rocks below. It should also be recollected that this mineral tract is terminated by one of the greatest and most valuable salt formations in the western country--that of the Illinois Saline.

_Septaria: Ludus Helmontii._--This variety of calcareous marl is found, in orbicular or flattened masses, along the eastern shores of Lake Michigan, between the rivers St. Joseph's and Kalemazo. Its original situation appears to be the beds of marly clay which form the banks of Lake Michigan at these places, from which these masses have been disengaged by the waves, and left promiscuously among the washed and eroded debris of the shore. These masses are penetrated by numerous seams and lines of calcareous spar, sometimes radiating star-like, or intersecting each other irregularly. Occasionally, these seams are filled with sulphuret of zinc, and in these cases the spar, if any be present, is rose-colored.

d. _Aluminous Minerals._

1. ARGILLACEOUS SLATE.

1. _Argillite_, or _Common Argillaceous Slate_.--Along the banks of the River St. Louis, at the Grand Portage, &c. It occurs in a vertical position, embracing veins, or subordinate beds, of grauwakke, milky quartz, chlorite slate, and silicious slate, &c. It is bounded on one side by red sandstone, and on the other by an extensive tract of diluvial soil.

2. _Bituminous Shale._--In detached masses, along the shores of Lake Huron, between Fort Gratiot and Thunder Bay. It contains amorphous masses of iron pyrites, of a yellow color and metallic brilliancy, which soon tarnishes on exposure to the air.

2. CHLORITE.

_Chlorite Slate._--In subordinate strata in the argillite of the River St. Louis.

3. STAUROTIDE.

In garnet-colored crystals, in detached blocks of mica-slate, in the drift of Lake Huron. These crystals consist of two intersecting six-sided prisms, truncated at both ends, forming the cross. They are nearly opaque, or feebly translucent on the fractured edge.

4. CLAY.

1. _Plastic Clay._--Very extensive beds of this clay are seen along the west shore of Lake Michigan, between Sturgeon Bay Portage and Chicago. Its color is generally a light blue, verging sometimes into deep blue or grayish-white. It is plastic in water, adheres strongly to the tongue, takes a polish from the nail, and emits an argillaceous odor when moistened or breathed upon. These beds of clay frequently contain iron pyrites, both in the crystallized and amorphous state.

2. _Pipe Clay._--In the flats of the St. Clair and Lake George, Michigan. A bed of clay, apparently answering to this description, exists at White River, Lake Michigan. Its color is a grayish-white, verging to blue. It is very unctuous and adhesive when first raised, but acquires more or less of a meagre feel as it parts with its moisture, drying in firm and compact masses.