Fillmore County, Minnesota - Chapter with an unread heading (no. 32 of those read), 1882 (part 2 of 2)

At Foreston, one mile south of the State line, the Galena appears in the lower river bluffs, and is in very rough and heavv beds. It presents numberless cavities of all shapes, as large as a thimble, and larger, and often iron-stained. It here has a noticeable dip to the south. While it is fossiliferous, it is so coarsely and so complet?ly crystalline that the fossils are either entirely absorbed or remain as indistinct impressions or im- perfect casts. It contains white calcite in some large masses. The river itself at Foreston is probably on the Trenton, the water-power there improved being due to a change from the firm Galena layers to a softer shale, indicating the upper portion of the Trenton. On the State line, due north from Foreston, a limestone appears in the road, of a coarsely crystalline grain, with calcite and Cfivities, entirely like the Galena. It is observable in a number of the hill tops, and extends half a mile at least, north of the State line. At a point about a mile north of the State line, north from Foreston, and a fourth of a mile east, the upper Trenton appears on the northeast side of a ravine, while the Galena appears on the southwest side, the road running between the two. The rock has ' a perceptible dip toward the south. The Galena occupies the high river-bluffs from that point nearly to Granger, on the north side of the river, when it passes to the south and the Trenton takes its place, both having a dip toward the south. At a point two miles west of Granger the Galena is 15 or 20 feet thick in the top of the river bluffs, the Trenton underlying. Tliese thick beds give a 8(|uarenes8 and prominence to the io^A of the bluffs, presenting a perpendicular rock- wall toward the river. Large masses of this rock fall from the bluffs and weather into the usual rough forms. Though this exposure embraces rock that is a little softer than the Galena at Foreston, yet in color, crystallization, and all general characters it is the same.

The Maquoketa Shales. - This is the name given to the Ciiiclimati Group of shales and limestones, as they appear in Iowa, by Dr. C. M. Wliite, of the Iowa survey of 1870. Without questioning the correctness of his conclusion that where these shales appear in Iowa they embrace a distinct portion, only, of that series known as the Cincinnati Group, his designation is provisionally adopted in our nomenclature. While it is certain that this formation enters the State from Iowa, being seen two miles south of the State line, at Lime Springs, it is still true that not a single observation has yet been made of it within the limits of the state of Minnesota. Being made up of soft materials, its outcrops are to be sought in the low levels, along the bottoms of ravines. As its area i)i Fillmore c6unty is covered by the northern drift, it will probably be a long time before any well authenticated localities of its existence are known.

The Niaqaba Limestone. - This formation has been identified in Fillmore county, at but one point. It is much more enduring than the shales underlying it, but it enters on a drift- covered area, with small valleys of drainage only, some distance south of the State line. The nearest important point of its known outcrop is at Lime Springs, in Iowa. It differs from the Galena limestone in being much lighter colored, especially when broken or powdered. It is strongly crystalline, and often porous, but it is also, in some parts, a very firm and enduring limestone. It also has a very different and much more abundant fossil fauna. It is separated from the Maquoketa shales, at Lime Springs, by a limestone breccia of about 18 inches. Its color, in its heavier and close-textured portions, is somewhat grayish, or leaden, and it is interbedded with hard shale, which turns nearly white on exposure. This shale, in broken pieces, makes up the larger part of the breccia mentioned, and falls down the bluff in that condition, where it is lost in the weather, the framework of the cement only remaining, making a curious open network or mesh, the partitions and threads enclosing angular apartments. The great bed of shale, which causes the water power here, may have a thickness of 75 or 80 feet exposed, at the quarry of Mr. John Smith, though near the mill it is reduced to ten or fifteen feet. Throughout the most of that interval, a heavy debris covers it from sight, tbe overlying Niagara only being visible along the top of tbe blufl*. The Niagara has a dip of five or six degre a to the southwest, and passes below the lower Devonian {Oornifcrous*) which is exposed and quarried at Lime Springs station, about a mile further south. The thickness of the Niagara included in that interval may be 100 or 150 feet. This underlying bed of shale gives rise to springs of limy water that enter the river along the bluff, and gave origin to the name of the village.

In the southeast quarter of section thirty-three, York, about forty rods north of the State line, is a very small exposure of the Niagara, in the bottom of a ravine, with the Devonian in the enclosing hillsides. A slight opening has been made in thes'3 beds, which are very porous and light colored, and about three inches in thickness. Although no fossils were found here to identify the formation, the presence of a very different rock, well known as the Devonian, in the hills and ridges sr.rrounding it, as well as the strong resemblance

The Devonian Limestones. - In the report for 1874, the Devonian limestones were described as occurring at Le Roy, in Mower county. It was then supposed that those limestones extended but a short distance east of Le Roy. They have been found during tbe past summer to extend considerably further east, and to embrace an area in Fillmore county fully ten miles wide on the southem border. Along the westvrn boundary of Fillmore county the width of this Devonian belt is not certainly known, but it has about the same width as on the southern. Hence the eastern boundary line of the Devonian in Mower county should run from about section thirteen, Bennington, northwestwardly to about section seven, in Pleasant Valley. The Silurian area, as laid off on tbe map of that county, should probably embrace the Niagara, the Maquoketa, and the Galena, overlain, in the northeast (Racine), by the Cretaceous.

I into at least two parts, the upper portion, which contains more shale, being the probable equivalent of the Hamilton, and the lower, which greatly resembles the Lower Oomiferous, of the Ohio Geological Reports. The distinctively Onondaga features of the Ohio Oomiferous are the only ones seen in Fillmore county. The color of this limestone is like* that of the Galena, but its even and non-vesicular texture is enough to dis-

I tinguish it from that at a glance. The bedding is also less thick, being, when in exposure, usually less than eight inches, though when quarried it is in heavy beds. It is a yellowish, magnesian limestone, sometimes with a finely siliceous composition, and is suitable for most purposes in com-

' mon masonry. It is tolerably free from calcite lumps, but has some chert nodules. It has a few fossil brachiopods, as Atryda^ and an incnisting bryozoon like Fenestella,

At Lime Springs station is a quarry in the Lower Devonian, exposing about ten feet. At Hopkins* quarry, situated two miles west and a little south of Lime Springs, about twelve feet, in heavy layers, can be seen, without fossils, but holding some tiint. Dip southeast. At Chester sim- of a mile south of the State lioe. It is here in heavy beds, of a soft, imifonn, granular texture and yellowish color, useful for a cut stone.

Southeast quarter of section twenty, Beaver. This rock is again seen here, exposed along the banks of Slough Creek; owner's name unknown. It here shows a brachiopod resembling Orthh, and. a radiating FciiesteUa. It is in the midst of an uninhabited prarie, and only weathered pieces can he found.

Southeast quarter of section eighteen, Beaver. About fourteen years ago a cellar, dug for a farmer's residence, furnished stone of the same kind in sufficient quantity to construct his house, now owned by Mr. James Smith. Similar rock again appears in the road in the northwest quarter of section twenty, Beaver, but is somewhat more vesicular.

Widow Skarie has a small quarry in a yellowish* fine-grained rock, almost non-fossiliferous, and probably of the Lower Devonian, on the southeast quarter of section twenty -eight, Bloomfield. Outwardly this inuch resembles the Cretaceous sandstone, as exposed at Austin, in Mower county, but it has a doubtful brachiopod that appears like Atrypa. Its weathered color, its homogeneity and fineness of grain, its irregularly rounded cavities, containing loose, ochreous dirt, combine to make it Cretaceous. It is with some doubt classed as Lower Devonian.

This limestone is found in loose pieces, and often in surface exposures, on the tops of knolls, near the State line, sections thirty- three and thirty -four, Yo]*k, the porous, white Niagara appearitig in the ravines.

The Crbtaceous. - No attempt is made to map out the Cretaceous area in Fillmore county, inasmuch as it is all embraced in the drift- covered portion, and but one or two localities of its existence are known. It probably extends no further east, however, at any point, than the east side of the first tier of towns along the western border of the county. Its area is most reliably indicated by the surface features, in the absence of actual outcrops. Guided by this only it is supposed to occupy the fiat and prairie portion of Sumner Township, stretching southward through Spring Valley and Bloomfield and covering the most of Beaver, and perhaps portions of York. Judging from the prevalence of Cretaceous features in the drift-clay exposed in the railroad cut at Lime Springs, it has played an important part in originating the materials of the heavy drift covering that spreads over not only the western portion of Fillmore comity, but all the counties of the State further west.

The lower portion of the Cretaceous, which is that represented in Minnesota, consists of sandstones and lignitiferous clays or shales - the sandstones lying at the b^se of the formation and being the same that Dr. White has denominated in Iowa the "Nishnabotany Sandstone." Above this sandstone, which is often white and incoherent, with a thickness of about one hundred feet, so far as observed, is a clayey member of the Cretaceous which has been identified by Mr. F. B. Meek as the Fort Benton Group, of Messrs. Meek and Hayden. This is well exposed in the region of the Upper Minnesota Valley, and contains some impure lignite, and is found in small pieces disseminated with its fossils, through the drift-clay cut at Lime Springs, a couple of miles south of Fillmore county, in Iowa. The Niobrara, or chalky member of the Cretaceous, may also exist in the extreme western portion of the State.

So far as Fillmoje county is concerned the presence of the Cretaceous is known more by certain indirect or secondary evidences, than by the actual discovery of ite beds in situ. In the extreme northeastern corner of Mower county it was struck by a farmer io digging a well. It there has the form of the fine-grained sandstone seen at Austin. The surface features that prevail at that point pass into the nortwestem corner of Fillmore county, and cover the most of Sumner Township. Southward, at Spring Valley, a similar stone appears in the north side of the creek, where it has been opened for building purposes by Messrs. James Wilder and Henry Thayer. It is here a fine-grained, argillaceous sandstone that cracks and crumbles on freezing. It has been given up as worthless for a building material. Near the same place, on David Higby's farm, in the southwest quarter of section thirty -two, is a very fine and tough clay, of a generally bluish color, almost entirely free from grit, which is spread out over a wide area lying but a few feet below the surface. The overlying soil, which is annually plowed, is a black loam, (rather clayey) varying below to a yellow, clayey loam. This clay was discovered several years ago, but nothing has been done that will demonstrate or indicate its real origin, though it is evidently not a part of the drift. It iias the appearance of being suitable for pottery or for brick, but would require some sand. A soapy, variegated clay also occurs at J. W. Smith's brick yard, two miles northwest of Spring Valley, though a drift clay, with some gravel, is used in the manufacture of brick. A similar clay is met in abundance at Spring Valley village, but it is mingled with limestone fragments and drift materials.

Besides these clayey deposits, which are believed to have resulted from the degradation, or more or less perfect preservation, of the lower Cretaceous clays, there are a number of white sand deposits in the same portion of the county, which probably are referable to the incoherent layers of the Nishnabotany sandstone. One of these occurs north of Mr. J. W. Smith's brick yard, on section seventeen. Spring Valley. Another is situated on C. C. Temple's laud, southeast quarter of section eight, Bloomfield, where it is twenty feet thick at least, having been tested to that depth, the lx)ttom never having been readied. It here occurs in an open prairie country, and is known to spread out over many acres, lying but two or three feet below the surface. It lies on the Galena, of course unconformably. It is not a purely white sand, like the St. Peter, but yellowish white. It is sometimes very five, but varies to coarse. Another deposit of this sand is on Mr. Andrew McNee's land in the northwest quarter of section twenty -two, Bloomfield, and still another on J. M.' Rexford's, in the northeast quarter of section thirty-six, where it has been opened, as at the other points named, and used for mortar. These are situated in an undulating tract, with some shrubs and trees. These sand beds are not regarded as belonging to the Cretaceous rock in situ, but as being copious local products, under drift agencies, of the Cretaceous. Sometimes they embrace lumps of clay, of a greenish color, like the Fort Benton, and sometimes they show oblique stratification. They are entirely uncemented, so as to be shoveled directly into the wagon. Another singular deposit, in the same manner referable to the immediate presence of the Cretaceous, occurs on the southwest quarter of section fifteen, Bloomfield, land of Peter Peterson. Here a series of knolls, which embrace, indeed, that in which is Mr. Andrew Mc- Nee's white sand pit, and are covered with aspen and hazel brush, are found, many of them, to be comp )sed of a beautiful, coarse gravel, the greater part being white, often limpid, quartz, the size of the pebbles varying from that of a pea to that of a hazlenut. On these knolls are a few northern drift boulders, and no doubt the gravel was also placed in the position it now occupies by the drift forces. This gravel, so remarkably homogeneous, like the white sand deposits mentioned, can only he referred to the immediate proximity of the lower Cretaceous. It could not have been far transported without being mixed with other rock I material. It distinctly points to the existence of I a coarse gravel or conglomerate in the lower Cretaceous, which has not yet been discovered. It indicates also the littoral nature of the Cretaceous beds from which it was derived. ] There is still another indirect eridence of the - existence of the Cretaceous in the western portion of Fillmore county. There are heavy deposits of limonite iron ore, bearing some unascertained rela- I tiou to the Cretaceous, or to the drift found in the I southwestern part of the county. In the Second I Annual Report of the Survey, mention was made I of the occurrence at a number of places in the Min- I nesota valley, and in that of the Blue Earth, of a coating of iron ore on the Lower Silurian rocks, where they are unconformably overlain by the Cretaceous. Dr. Shunard says of this: {Owen's Gcolagirnl Surcey of Wineomitiy Iowa, and Minite- 8ota, page 487.) **The nodules of iron ore have mostly a concentric structure, and appear to be of good quality. The superficial indications render it probable that this bed of iron ore may be both extensive and easily accessible." In Fillmore I county a discovery was made by Mr. C. C. Temple, in digging a well near his sand pit, already described, and referred to the Cretaceous as* its probable source, which throws some light on the I manner of occurrence of the limonite referred to. ' He testifies that this bed of iron ore is at least fhir(f/-8tx feet in thickness. In his well, which is six feet circular at the top, he dug down about ' eighteen feet, when he reached roek, fragments thrown out revealing the Galena limestone. He I describes the* rock as occupying but about onehalf of the diameter of the shaft he was digging, which afforded great quantities of soft limonite, or ochre. He drilled into the iron-ore a depth of thirty -six feet. A number of wells in, the vicinity of Etna, a few miles further southeast, also struck a similar iron ore. On section thirty-six, Bloomfield, a great many loose pieces of porous limonite ( arc found in the fields, having been plowed up in the soil. The county surveyor, Mr. J. Gregor, also fouDd it impossible to lay out the quarter sections of that section in the usual manner, by the use of the magnetic needle, though the original United States surveyors record no unusual disturbance of the magnetic needle. Limonite iron ore is regarded usually as non-magnetic. In large quantities, near the surface, it seems to influence the magnetic currents. What relation this ore bears to the Cretaceous is no.t known, except that it has been found to overlie the Silurian rocks, or to cover their surfaces with a scale where the Cretaceous overlies them unconformably. Further and more minute observations in ether places may reveal its real source and its value. The reader is referred to the Second Annual Report for an account of the Cretaceous over the L(twer Stluman,&t Mankato, in the valley of the Minnesota.

The Drift. - The drift presents some interesting features in Fillmore county. Tlie western limit of that well-known tract denominated 7^ he I>riflle4ss Area^ by Prof. J. D. Whitney, crosses this county. This boundary is not well defined. There is a very conspicuous absence of the bluish clay, and the northern boulders that distinguish the true northern drift sheet of coimties further west and north, tliroughout the eastern two-thirds of the county: the boundary line running approximately, from the southeast comer of Bristol township to the northeast comer of Jordan. West of that line, which >s modified, in its course, by valleys and uplands, is a belt of five or six mik s in width, which is characterized by an overlapping of the loess loam on the thinning out edge of the drift sheet. This belt is characterized further by peculiar local modifications of the materials of the drift, due to the underlying rock, as mentioned under the head of Gretaceoim, West of this belt the true drift becomes prevalent, consisting of clay, with many boulders.

That tract which is regarded as driftless is, so far as Fillmore county is concerned, not without some evidences of having been subjected, at some time, to a force similar to that which is supposed to have deposited the great drift-sheet of the northwest. There are isolated patches of gravel, with small stones, sometimes cemented into a crag, which have been noted in Fillmore county, scattered sparingly over the eastern part of the county, as the following field minutes will show :

Drift occurs in the form af gravel and boulders, some of them a foot in diameter, in the southwest quartt r of section four, Fountain, on the east bank of Sugar Creek, in the road; seen in going east from the quarry of Enoch Winslow. At Fountain village there is said to be no drift between the loess loam and the rock.

At Spring Valley the drift is so prevalent that the surface of the country is smooth, and has a lighter colored soil, with much more clay. There are but few stcmes or gravelly patches. The loess loam is hardly noticeable. One large boulder lies at the street corner, half a mile south of the corporate limits.

Between Baldwin's mill, section twenty-one, Forestville, and the State line, due south, the country is one of drift prairie, nearly the whole distance, with stones and boulders, some of the latter pretty large.

At Etna, section thirty-six, Bloomfield, among a variety of stones pertaining to the drift, may be seen an occasional one that is ylaciated.

At Granger there is a light drift, and also where the road turns north to Preston, in the northeast quarter of section thirty-six, Bristol; but it beff ' C comes lighter still, or entirely invisible, in traveling to Preston. In its place a heavy, rich loam, rather clayey, covers the country, and smooths it off almost as eflfectually as if drift-covered. A well, being dug about five miles south of Preston, on the high Trenton area, passes through this loam eighteen feet before striking the rock.

About four miles southeast of Preston a large green, dioritic boulder may be seen lying in the loess loam, in the road, and a red quartzose peb- 'ble. The pebbles that appear in gullies by the roadside, in the loam area, are generally of chert, from the rock of the locality. It cannot be ascertained whether this dioritic boulder lies on other drift deposits, but it is surrounded laterally only by the loam.

At Elliota is a thin drift, in the form of pebbles, the largest being three or four inches in diameter. Thence northeastward to Newburg nothing but the yellow loam is observable. Between Newburg and Riceford, situated on the western edge of Houston county, no northern drift is visible; but at Riceford, which lies in a deep and narrow gorge, a few drift pebbles occur in the street.

About the center of section twenty-nine, Holt, is a deposit of drift gravel. It may be seen in descending the hill northward, just before the road forks to Whalan and Lanesboro. It is considerably cemented by lime, forming a crag, large lumps of which, some eighteen or twenty inches thick, have been used for embankment on the lower side of the road. In some parts it is quite fine, and useful for mortar, for which it has been hauled away, It is at least ten feet thick.

Section nineteen. Pilot Mound. In the road going to the river from the south are a lot of boulders and other drift. The same can be Been on the north side, going up from the ford. The deposit seems to be five or six feet thick, gradually mingling with, and finally becoming replaced by the loess loam.

Drift pebbles and clay occur at the crossing of Watson's Creek, on the direct road between Fountain and Preston, and on the terrace of the Shakopee limestone, a quarter of a mile south of the oreek.

An occasional boulder is seen in the river valley at Gainer's Mill, section thirty-one, Jordan, but the most of ths surface covering on the rock, in the high prairie region, seems to be of loess loam.

East of Highland Post-office, in Holt township, section thirty -six, is a conspicuous deposit of drift, exposed in the road, in the form of a stony gravel. It lies on the brow of the Shakopee terrace.

It is noticeable that in nearly every instance where drift pebbles occur in the region known as driftless, they lie on or very near an outcrop of firm rock. They frequent the brows of the terrace formed by the Shakopee limestone. The above named localities are nearly all embraced within the boundaries of the driftless tract, as already defined in Fillmore county. These patches of northern drift present the appearance of greater age than the drift of the western portion of the county, and are believed to belong to a glacial epoch that preceded the epoch that produced the great drift sheet of the northwest. An "interglacial epoch" separated them. It was probably during that interglacial epoch that grew the peat and coniferous vegetation that has been found in considerable abundance embraced within the great drift sheet, (or at leabt below fifty feet of drift materials) round its outer margin, as mentioned already in a report on Mower county, and as further demonstrated in Fillmore county. It is this older drift that is covered deeply by the loess loam, and tl /« within the loam-rocered portion of the count thru trm river terrac^^ of allmial cfmiposition^ are found.

Ancient Peat and Vegetation in the Drift Deposits. - O ving to the great geological interest cennected wilh the discovery made last year of a peaty bed within the drift deposits of Mower county, a careful search was made in the survey of Fillmore county for further information concerning its o: igin and exact relations. There were found to be quite a number of plaoes in the westem portion of the county where farmers, in digging wells, had struck this bed of vegetation. No opportunity has been afforded to make a personal inspection ot this bed, and owing to the indetiniteness of the information derivable from the farmers themselves, and its contrarity, it is thought best to give only the statements of Mr. Calvin E.

Huntley, of Spring Valley, a professional welldriller. Throughout the whole of the county there is much difficulty in obtaining ready water for farm and domestic use, and a great many wells are drilled deeply into the rock. This is owing to the canoned character of the rock surface, both within the drift area and the loam-covered portion. These canons serve as subterranean drains, though they are generally filled with drift in the western part of the county. Mr. Himtley furnishes the following facts concerning this bed of vegetation. Some of these localities are within the limits of Mower county :

Northwest quarter of section six, Beaver. Land of Andrew Oleson (Early. It was found here at the depth of tairty feet, situated on a ridge in prairie country. It was two or three feet thick, and had a blue clay both above and below it, then struck a lime rock.

Northeast quarter of section twelve, Le Roy, Mower county. Land of D. B. Bosworth. Tbis was also on a high ridge, with blue clay above and below it, and lay at the depth of about twentyfive feet below the surface. It had a depth of seven feet, and contained -decayed stuff, like pressed hay."

Northeast quarter of section one, Le Roy, Mower county. Land of Ole Knutson (Stolely): found at the depth of thirty feet: five feet thick, blue clay above and two feet of black clay below; then lime rock.

Section thirty, Bennington, Mower county, on land of Cents Everson. This is situated on a fiat, and was found from thirty to thirty-two feet below the surface. It was three feet thick, ond lay l^elow blue clay. Below it was gravel to the thickness of eight feet, when the well struck lime rock.

Southeast quarter of section nine, Bennington, Mower county ; land of John Mehan. It here had blue clay both above and below it, and a thickness of two feet. It lay at the depth of twenty feet. The underlaying blue clay was gravelly.

It was met in the same town on Robert Cooper's land, at the depth of twenty -five or thirty feet. It was here on a very high ridge. It was in a blue clay, with gravel both above and below. It was here three or four feet thick. This well was abandoned on account of quicksand.

On the slope, northeast from Mr. Cooper s, it was reported to have been met with at the depth of six or seven feet from the surface, on the land of Mr. Bass.

Section two, Sumner. Land of Wm. Bailey; met a deposit which was embraced between layers of what was then supposed to be lime rock. This deposit was two feet thick, and consisted entirely of wood. Rock was struck at the depth of eight feet. This wood was thirty-five feet below tlie surface. The owner called the rock "grindstone rock." (This was probably the Austin sandstone, of the Cretaceous, and the wood a lignite belonging to the same age.

North part of section twenty- eight, Spring Valley; land of A. B. Hutchinson. An irony deposit, having an unknown thickness, was struck at the depth of thirty-five feet.

This was also met in the central part of Racine, on the farm of D. Reed, at the depth of twentyfive or twenty-six feet, having a thickness of two or three feet. It came up in chunks which glistened, and looked like iron ore.

Under the head of Grclaceons the reader will find further statements concerning this iron ore. Two miles west of Spring Valley, on the land of O. H. Rose, Mr. Leonard made an observation on a deposit of surface crag. This he found abundantly cemented with iron, lying on a sloping surface, covering twenty-five or thirty square rods, rendering the land unfit for cultivation, in the vicinity of no rock blufT, and on a prairie c<>untry. Iron ore was thrown out of a well in the southwest quarter of section twenty-four, Bloomfield. It was said to have come out in chunks, and to be as heavy as iron. It lises to the surface, and the plow cannot be passed through it. This is owned by Geo. H. Smith. Again, on H. T. Odell's land, section thirty- six, Bloomfield, it is found in scattered lumps variously mingled with the soil, and with other stone. These surface pieces are impure, and often hold cemented gravel and pebbles. They are also loose and porous, and pass into ocher. Similar pieces occur on section one. Beaver, land of O. A. Boynton.

Wood was taken from two wells in Jordan township, sections twenty-nine and thirty, on land of M. Bobbins and Geo. Hare. This is also on a high prairie. In Mr. Hare's well was said to have been a tree.

The Loess Loam. - The greater portion of the county is covered with this loam. It contains no gravel or boulders, or with very rare exceptions, but consists almost entirely^ of fine siliceous material which becomes, in some places, quite clayey, making a very slippery mud when wet. This, in outward appearance, is of a light, yellow or rusty color, and differs in that respect from the loam seen on the drift-covered portion of the county, ' which is frequently black, or brown, varying to an ash color when mingled with a considerable per cent, of clay from the drift, and also contains gravel. The loess loam is very homogeneous over wide tracts, while that in the drift area is subject to local and sudden variations. The loess loam is indistinctly stratified, especially in the valleys, but the usual ap|)earance is that of non-stratiUcation. This stratified arrangement is rendered the less evident from the great similarity of the materials from the top to the bottom. It does not consist, apparently, in any change from coarse to fine in the sedimentation, but in a lamination of the homogeneous clayey loam, and is easily obliterated by exposure, or by trickling water. This condition was noted particularly at Preston, and indicates that it was deposited in still, or gently moving water. Where this loam lies over the old northern drift, it passes through a gravelly stage, the materials of the loam mingling with the coarser portions of the drift, and becoming finally replaced by the drift. The drift patches covered by this loam, pertaining to the eastern and central portions of the county, and believed to belong to an earlier drift epoch, are, so far as seen, made up of gravel and sand, with small stones. No drift day^ like that which covers the western part of the county, has been seen overlain by the loess loam, except that which pertains to the general drift sheet of the Northwest, and which occupies a narrow belt of five or six miles wide, where the loam overlaps the later drift. It would be reasonable, however, to expect that some such clay would be found. The pebbles that are thus mixed with the lower portion of the loam are smooth and waterwoni, not covered with a coating of decayed material of the same nature as the pebbles themselves, as they would be expected to be if the loam were derived from the decay, in situ, of the materials of the drift. The thickness of the loess loam sometimes reaches twenty feet in the open upland, and, under favorable circumstances, where it might have accumulated laterally, as well as j erpendicularly, it is much more. It is thickest in the eastern part of the county.

Alluvial Terraces. - At Preston, besides the flood plain, the river has a high terrace- plain. The Stanwix House stands on it. It consists of loam undistinguishable from the loess loam that covers that portion of the county. The same may be seen at Lanesboro, and at Whalan, but it is not conspicuous. At Rushford fragmentary remains of this high terrace are seen in the valleys of the tributary streams. Along the main valley they are not well preserved. There are two terrace levels, besides tbe flood plain. The highest terrace plain is from seventy to eiglity feet above the second, and about 130 feet above the river. The lower terrace, on which Rushford stands, is about forty feet above the river, and is probably never reached by the river in eveh the highest water. Within this lower terrace-plain, which spreads out laterally and forms the most of the alluvial land between the rock-blutfs, is the river channel, and a still lower flood-plain about twenty feet above the river at low stage. A similar high terrace is seen along the Mississippi River at Winona, in Winona county, rising about ninety-five feet above the river, while the flat, on which the city of Winona stands, is about twenty -five feet above the river at the boat landing, in low stage of water. At Rushford and Winona the high terrace consists of a material different from the loam that overspreads the country, being made up of stratified sand. This terraced condition of the valleys of Root River, and of the Mississippi, is confined, so far as observed, to the loam -covered area, which nearly coincides with the "driftless area," as defined and described by Prof. Whitney.

Material Resources - Fuel. - In addition to the products of the soil which will always be her chief source of material wealth, Fillmore county cannot expect any important mineral discoveries to augment her material prosperity* She has a good supply of forest for purposes of common fuel, and will not suffer from the absence of coal, as some of the counties further west have suffered. She will have to depend on her native forest trees, or on those that are being propagated successfully, for the most of her home fuel supply. There is as marked an absence of peat in this county as there is in Mower, but a single locality being noted. That occurs on the southeast quarter of section twenty-six, Spring Valley, land of Jolm Kleckler and David Broxlem, and is said to be about four feet thick, covering four or five acres. There is no doubt but other, isolated, small areas, of a turf -peat, also exist in the county, but the circumstances which promoted the production of so large a surface of peat in Freeborn county, are certainly wanting in Fill- more county. The frequency of lakes and swamps, and abundance of peat, coinciding as they do in Freeborn county, taken with the absence of both in Mower and Fillmore, point to the existence of a common cause for these surface features.

Iron. - Throughout the western portion of the county there is a great deal of surface iron, manifesting itself generally in the form of a cement in gravel, forming a dark -colored crag. There is also much evidence of the existence of a heavy continuous layer or deposit of limonite iron ore a few feet below the surface, in Bloomfield and Beaver townships. The details of these localities, and of the evidence of iroti, so far as ascertainable, have been given under the heads of Cretaceom and Drift, Should this bed prove to be extensive, its actual value for commercial purposes may vary greatly from its intrinsic value. It consists of a loose-textured hydrated peroxyd, with ochery impurities, and bears a close resemblance to some bog-ore deposits; but its occurrence on high land, instead of in swamps, necessitates some other explanation for its existence than that ascribed to the occurrence of most bog-ore deposits. It may have originated during that swampy condition of Southern Minnesota when the peat grew that is embraced in the drift deposits, as already detailed. It is not probable that it will ever be found valuable for the manufacture of iron. Before the opening up of the vast, and richer, iron ore beds of Michigan and Missouri, the bog-ores were Considerably used in the production of iron, on a small scale, in several of the western States, but the small furnaces that smelted them have all ceased operations many years ago. Anotlier obstacle to the utilization of this deposit in Fillmore county, will be the lack of fuel in convenient and sufficient quantities.

Lead. - While the Galena limestone, which is eminently lead-bearing at Dubuque and Galena, passes, in its northwest-em trend, across the southwestern portion of Fillmore county, it has not been discovered to afford the same amount of lead as in Iowa and Illinois. Indeed, at points more remote from the Mississippi River, in Iowa, no remarkable deposits of lead have been obtained from it. There is not a total absence of lead from its layers, since a few localities are known to have afforded it in limited quantities. The same is true of the lower Trenton; which seems to indicate that the presence of lead in the limestones of this region does not de]^)end cn the kind or age of the formation, but rather on some later,. superimposed conditions that prevailed over the region, subjecting various formations to the same influences.

Quicklime. - All the limestones of the county are suitable for quicklime, but by far the greater quantity is made from the upper Trenton. In the townships of Sumner and Spring Valley, all the circumstances necessary for the cheap and rapid production of quicklime of the best quality coexist, viz: a suitable limestone, abundant exposure, and plenty of fuel. The Trenton there forms some of its characteristic outcrops, constituting the bluffs of the streams continuously for many miles, and rising a hundred or a hundred and fifty feet above the valleys. The kilns are built at the foot of the bluff, and the stone is cheaply obtained, without much cost of transportation. Wood is also abundant at present, much of that portion of the county being covered by a heavy forest growth.

no noteworthy difference in th? quality either of the rock or of the lime produced. According to the testimony of several, however, there are certain layers, near the bottom of the formation, which are not suitable for quicklime. Some layers also are arenaceous, and have to be avoided, but the great mass of the rock is exceedingly well adapted to making quicklime.

The kilns us 3d are, for the most part, of the rudest construction, presenting no improvement over the ancient and well-known "pot-kiln." They have to be emptied and refilled for every burning. Mr. L. G. Odell has the only draw-kiln seen in the county. The lime itself is generally nearly white after being burnt, but in some places it has an ashen white color, though on slacking it is always white. It slacks with rapidity, evolving considerable heat. It requires from sixty to seventy -two hours to burn a kiln, depending on the size of the kiln, and somewhat on its shape, and consuming about ten cords of dry mixed wood. When freshly and thoroughly burnt, one bushel by measure weighs about 75 pounds, but if not well burnt, it will exceed 80 pounds.

The Shakopee is not used for making lime in Fillmore county, though it is extensively burned in the lower Minnesota valley, at Maukato and at Shakopee. The St. Lawrence limestone is somewhat employed for this purpose, and affords a lime that is nearly white, and is said to weigh 80 pounds per bushel of measure. Mr. Sherman's kiln holds about 300 bushels, and requires 10 to 11 cords of wood for thorough calcination, burning about 48 hours. But little is shipped from here. The lime is about white, and slacks perfectly white.

Brick. - There is no lack of materials for making common red brick. In some places the surface of the drift clay is used, containing some fine gravel, and at others the loess-loam. Brickmaking machinery was met with in the survey of the county at the following points:

Gold, Copper. - In small quantities gold has been washed, by rude methods, from the drift at several points in the county. It was found on Luke Hague's land, in gravel, in the northeast quarter of section twenty-six. Spring Valley, and at Yearian*s saw-mill, in section thirty-one, Jordan. There are accounts also of fragments of native copper having been found in the drift. It is hardly necessary to say that these discoveries do not indicate any valuable deposit of the kind in the rocks of the localities where they may be found, They pertain to the drift, and have been transported hundreds of miles along with the other foreign substances in which they occur, from the northern part of the State. Such discoveries have sometimes awakened an interest that has culminated in stock companies formed for mining, and in the wasting of thousands of dollars. Similar small quantities of gold can be got by a minute washing of the drift at almost any place where the drift sheet is attenuated, or where the older glacial drift has been denuded, leaving the gold, which is indestructible, either by the lapse of time or by the chemistry of the elements, on the rook surface underlying. Almost every geological report in the country makes mention of them, extending at leadt through Ohio, Illinois, Indiana, Wisconsin, and Iowa.

Building Stonb. - With this necessary article Fillmore county is well supplied, and it has been put to an extensive use. There are hundreds of openings made to supply a local demand, besides a great many more extensive quarries, which are known for a good many miles round. A great deal of stone for building is shipped to counties west, which are drift covered, and without accessible building stone. Probably three-fourths of the building -stone used in the county is derived from, the Trenton, the other fourth being made up of the Galena and the St. Lawrence. The Lower Trenton is most frequently employed. This is largely owing to the prominent manner of its outcrops, as shown under the head of Drainage and Surface- Features, The Upper-Trenton has been used in the construction of several schoolhouses and private residences. At Spring Valley the Galena is principally used. At Lanesboro,

Probably the best known quarry in the county is that of Mr. Joseph Taylor, near Fountain. It is situated near the railroad, from which a side track allows the loading of cars. It is in the Lower Trenton, and supplies the **blue limestone^' that is so largely shipped by the Southern Minnesota Railroad to points on its line in Mower, Freeborn, and Faribault counties. The beds are usually less than, six inches in thickness, and they are easily broken to any desired size. It is a hard stone, not easily cut, but can be dressed if necessary. It is not injured by disseminated shale, as much of the Lower Trenton is, and hence makes a very durable material. At Fountain are several buildings constructed of this stone.

Besides the quarries in the Trenton that have been mentioned in giving the scientific geology of that formation, a number were visited at which no new facts of interest were noted. Such were Ole Oleson's, in the northeast quarter of section thirty -six. Harmony ; Wm. Wilbright's and Martin Quinn^s, section fifteen, Forestville; George Drury's, section three, Bristol; Garret Mensing's, in the southwest quarter of section twenty-seven, Forestville. It would be impossible, and unnecessary, to mention all the places wheVe this limestone has been wrought. In traveling over the county a number of stone houses for residence were seen, belonging to farmers. Such are O. Hara's, in the southwest quarter of section eighteen, Amherst, from the Trenton ; Mr. George Park's section thirty -seven, Bloomfield, from the Galena of Mr. S. S. Belding*8 quarry. The stone mill at Preston is of the Trenton. Of the quarries in the Galena at Spring Valley, those of Mr. Shumaker and of Mr. Allen are the most important. The former furnishes a beautiful fine-grained cut-stone for trinunings, as well as stone for common walls. The latter supplies a darker-colored, and coarser stone, which has been considerably used.

From the St. Lawrence limestone a very fine building stone is obtained. It is a fortunate circumstance that very much of this formation is in regular, and often in heavy layers. These are also not so firm as to resist the usual means for quarrying. When the beds are broken the blocks are found to possess often a finely vesicular texture.

Their color is a very light yellow, or buflf, resembling that of the well-known "Milwaukee brick." The principal buildings at Lanesboro, including the Lanesboro Hotel, the flouring mill of Thompson & Williams, the Presbyterian and Catholic churches, the public schoolhouse, and a number of stores, are of the St. Lawrence, quarried at Lanesboro, . and from land owned by the Lanesboro Company. At Whalan are excellent opportunities for obtaining this stone in its best condition. It has been somewhat wrought on Whalan's bluff. Quarries in the same are owned at Rushford by William Crampton, Joseph Otis, and Hiram Walker. Mr. Crampton's quarry furnished the stone put into Boyum's store, and also that of A. K. Hanson's. Mr. E. Larson's was built from Mr. Otis' quarry, and that of Kierland & Son from Mr. Walker's. At Amherst Post-office the Jordan is quarried some for foundations, and the Shakopee at Chatfield.

Sand fok Mortar and Concrete. - Wherever the St. Peter sandstone is accessible it is employed for making mortar. It is equally good for hardfinish, being when taken from some depth, purely white and of very uniform fineness. There are, however, some portions of the county where it is much more difficult to obtain a sand suitable for conmion mortar. In the western part of the county a white sand, or one nearly white, is obtained from deposits referable to the Lower Cretaceous. These have been mentioned under the head of Cretaceous. They are found on the land of 0. C. Temple, in the southeast quarter of section eight, Bloomfield, on section seventeen, Spring Valley, on Andrew McNee's land, in the northwest quarter of section twenty-two, Bloomfield, and on J. M. Rexford's, in the northeast quarter of section thirty -six. Besides these sources for mortar-sand, the Jordan sandstone, which is often as incoherent as the St. Peter, can be used to advantage, though it is rather more apt to be cemente<l by iron. There can be no question but the compact and impervious nature of the green shales of the lower Trenton have preserved the incoherency of the St. Peter, by preventing the downward percolation of ferriferous and calcarous waters, which certainly would have left their impurities in the form of cement among its beautiful white grains.

these substances in the form of a concrete. Several such are found at Fillmore, also in Jordan, and at Bushford; but this method is not general. The material is cast in the form of large brick, having the color of common brown mortar, and these blocks are laid up much like common brick walls. Patent presses are used to make the concrete blocks.