USA > Iowa > Scott County > History of Scott County, Iowa > Part 7
Note: The text from this book was generated using artificial intelligence so there may be some errors. The full pages can be found on Archive.org (link on the Part 1 page).
Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 7 | Part 8 | Part 9 | Part 10 | Part 11 | Part 12 | Part 13 | Part 14 | Part 15 | Part 16 | Part 17 | Part 18 | Part 19 | Part 20 | Part 21 | Part 22 | Part 23 | Part 24 | Part 25 | Part 26 | Part 27 | Part 28 | Part 29 | Part 30 | Part 31 | Part 32 | Part 33 | Part 34 | Part 35 | Part 36 | Part 37 | Part 38 | Part 39 | Part 40 | Part 41 | Part 42 | Part 43 | Part 44 | Part 45 | Part 46 | Part 47 | Part 48 | Part 49 | Part 50 | Part 51 | Part 52 | Part 53 | Part 54 | Part 55 | Part 56 | Part 57 | Part 58 | Part 59 | Part 60 | Part 61 | Part 62 | Part 63 | Part 64 | Part 65 | Part 66 | Part 67 | Part 68 | Part 69 | Part 70 | Part 71 | Part 72 | Part 73 | Part 74 | Part 75 | Part 76 | Part 77 | Part 78 | Part 79 | Part 80 | Part 81 | Part 82 | Part 83 | Part 84 | Part 85 | Part 86 | Part 87 | Part 88 | Part 89 | Part 90 | Part 91 | Part 92 | Part 93 | Part 94 | Part 95 | Part 96 | Part 97 | Part 98 | Part 99 | Part 100 | Part 101 | Part 102 | Part 103 | Part 104 | Part 105 | Part 106 | Part 107 | Part 108 | Part 109 | Part 110 | Part 111 | Part 112 | Part 113 | Part 114 | Part 115 | Part 116 | Part 117 | Part 118 | Part 119 | Part 120
72
HISTORY OF IOWA.
caseades. For the first 25 miles above its mouth, the valley is very broad, with a broad, flat flood plain, with gentle slopes, occasionally showing indistinctly defined terraces. These terraces and valley bottoms constitute some of the finest agricultural land of the region. On the Iowa side of the valley the upland presents abrupt bluffs, steep as the materials of which they are composed will stand, and from 100 to nearly 200 feet high above the stream. At rare inter- vals, about 15 miles from its month, the cretaceous strata are ex -. posed in the face of the bluff's of the Iowa side. No other strata are exposed along that part of the valley which borders our State, with the single exception of Sioux quartzite at its extreme north- western corner. Some good mill-sites may be secured along that portion of this river which borders Lyon County, but below this the fall will probably be found insufficient and the locations for dams insecure.
Missouri River .- This is one of the muddiest streams on the globe, and its waters are known to be very turbid far toward its source. The chief peculiarity of this river is its broad flood plains, and its adjacent bluff deposits. Mueh the greater part of the flood plain of this river is upon the Iowa side, and continues from the south boundary line of the State to Sioux City, a distance of more than 100 miles in length, varying from three to five miles in width. This alluvial plain is estimated to contain more than half a million of aeres of land within the State, upward of 400,000 of which are now tillable.
The rivers of the eastern system of drainage have quite a differ- ent character from those of the western system. They are larger, longer, and have their valleys modified to a mneli greater extent by the underlying strata. For the latter reason, water-power is much more abundant upon them than upon the streams of the western system.
Des Moines River .- This river has its source in Minnesota, but it enters Iowa before it has attained any size, and flows alnost centrally through it from northwest to southeast, emptying into the Mississippi at the extreme southeastern corner of the State. It drains a greater area than any river within the State. The upper portion of it is divided into two branches, known as the cast and the west forks. These unite in Humboldt County. The valleys of these branches above their confluence are drift valleys, except a few small exposures of subearboniferous limestone about five miles above their confluence. These exposures produce several
73
HISTORY OF IOWA.
small mill-sites. 3 The valleys vary from a few hundred yards to half a mile in width, and are the finest agricultural lands. In the northern part of Webster County the character of the main valley is modified by the presence of ledges and low cliffs of the sub-ear- boniferous limestone and gypsum. From a point a little below Fort Dodge to near Amsterdam, in Marion County. the river runs all the way through and upon the lower coal-measure strata. Along this part of the course the flood-plain varies from an eighth to a mile or more in width. From Amsterdam to Ottumwa the subear- boniferous limestone appears at intervals in the valley sides. Near Ottumwa the subcarboniferous rocks pass beneath the river again, bringing down the coal measure strata into its bed; they rise again from it in the extreme northwestern part of Van Buren County, and subcarboniferous strata resume and keep their place along the valley to the north of the river. From Fort Dodge to the northern part of Lee County the strata of the lower coal measures are pres- ent in the valley. Its flood-plain is frequently sandy from the debris of the sandstone and sandy shales of the coal measures pro- duced by their removal in the process of the formation of the val- ley. The principal tributaries of the Des Moines are upon the western side. These are the Raccoon, and the three rivers, viz .: South, Middle and North Rivers. The three latter have their sources in the region occupied by the upper coal measure lime- stone formation, flow eastward over the middle coal measures, and enter the valley of the Des Moines upon the lower coal measures. These streams, especially South and Middle Rivers, are frequently bordered by high, rocky cliffs. Raccoon River has its source upon the heavy surface deposits of the middle region of Western Iowa, and along the greater part of its course it has excavated its valley out of those deposits and the middle coal-measures alone. The valley of the Des Moines and its branches are destined to become the seat of extensive manufactures, in consequence of the numer- ous mill-sites of immense power, and the fact that the main valley traverses the entire length of the Iowa coal fields.
Skunk River .- This has its sonree in Hamilton County, and runs almost its entire course upon the border of the onterop of the lower coal measures, or, more properly speaking, upon the snb- carboniferous limestone, just where it begins to pass beneath the coal measures by its southerly and westerly dip. Its general course is southeast. From the western part of Henry County, up as far
74
HISTORY OF IOWA.
as Story County the broad, flat flood-plain is covered with a rich, deep clay soil, which, in time of long continued rains and over- flows of the river, has made the valley of Skunk River a terror to travelers from the earliest settlement of the country. There are some excellent mill-sites on the lower half of this river, but they are not so numerous or valuable as on other rivers of the eastern system.
Iowa River .-- This river rises in Hancock County, in the midst of a broad, slightly undulating drift region. The first rock ex- posure is that of subcarboniferous limestone, in the southwestern corner of Franklin County. It enters the region of the Devonian strata near the southwestern corner of Benton County, and in this it continues to its confluenee with the Cedar in Louisa County. Below the junction with the Cedar, and for some miles above that point, its valley is broad, and especially on the northern side, with a well-marked flood-plain. Its borders gradually blend with the uplands as they slope away in the distance from the river. The Iowa furnishes numerous and valuable mill-sites.
Cedar River .- This stream is usually understood to be a branch of the Iowa, but it ought, really, to be regarded as the main stream. It rises by numerous branches in the northern part of the State, and flows the entire length of the State, through the region occupied by the Devonian strata and along the trend ocenpied by that formation. The valley of this river, in the upper part of its course, is narrow, and the sides slope so gently as to scarcely show where the lowlands end and the uplands begin. Below the con- fluence with the Shell Rock, the flood-plain is more distinctly marked, and the valley broad and shallow. The valley of the Cedar is one of the finest regions in the State, and both the main stream and its branches afford abundant and reliable mill-sites.
Wapsipinnicon River .-- This river has its source near the source of the Cedar, and runs parallel and near it almost its entire course, the upper half upon the same formation -- the Devonian. In the northeastern part of Linn County it enters the region of the Niagara limestone, upon which it continues to the Mississippi. It is 100 miles long, and yet the area of its drainage is only from 12 to 20 miles in width. Hence, its numerons mill-sites are unusually secure.
Turkey River .- This river and the Upper Iowa are, in many respects, unlike other Iowa rivers. The difference is due to the great depth to which they have eroded their valleys and the
.
75
HISTORY OF IOWA.
different character of the material through which they have worked. Turkey River rises in Howard County, and in Winneshiek County, a few miles from its source, its valley has attained a depth of more than 200 feet, and in Fayette and Clayton Counties its depth is increased to three and four hundred feet. The summit of the uplands, bordering nearly the whole length of the valley, is capped by the Maquoketa shales. These shales are underlaid by the Galena limestone, between two and three hundred feet thick. The valley has been eroded through these, and runs upon the Trenton limestone. Thus all the formations along and within this valley are Lower Silurian. The valley is usually narrow, and without a well-marked flood-plain. Water-power is abundant, but in most places inaccessible.
Upper Iowa River .- This river rises in Minnesota, just beyond the northern boundary line, and enters our State in Howard County before it has attained any considerable size. Its course is nearly eastward until it reaches the Mississippi. It rises in the region of the Devonian rocks, and flows across the ontcrops, respectively, of the Niagara, Galena and Trenton limestone, the lower magnesian limestone and Potsdam sandstone, into and through all of which, except the last, it has cut its valley, which is the deepest of any in Iowa. The valley sides are almost everywhere high and steep, and cliffs of lower magnesian and Trenton limestone give them a wild and rugged aspect. In the lower part of the valley the flood plain reaches a width sufficient for the location of small farms, but usu- ally it is too narrow for such purposes. On the higher surface, however, as soon as you leave the valley you come immediately upon a cultivated country. This stream has the greatest slope per mile of any in Iowa, and consequently it furnishes immense water- power. In some places where creeks come into it, the valley widens and affords good locations for farms. The town of Decorah, in Winneshiek County, is located in one of these spots, which makes it a lovely location; and the power of the river and the small spring streams around it offer fine facilities for manufacturing. This river and its tributaries are the only tront streams in Iowa.
Mississippi River .- This river may be described in general terms, as a broad canal cut out of the general level of the country through which the river flows. It is bordered by abrupt hills or bluffs. The bottom of the valley ranges from one to eight miles in width. The whole space between the bluff's is occupied by the river and its bottom, or flood plain only, if we except the occa-
76
HISTORY OF IOWA.
sional terraces or remains of ancient flood plains, which are not now reached by the highest floods of the river. The river itself is from half a mile to nearly a mile in width. There are but four points along the whole length of the State where the bluffs approach the stream on both sides. The Lower Silurian formations compose the bluff's in the northern part of the State, but they gradually dis- appear by a southerly dip, and the bluffs are continued successively by the Upper Silurian, Devonian and Subearboniferons rocks, which are reached near the southeastern corner of the State.
Considered in their relation to the present general surface of the State, the relative ages of the river valley of Iowa date baek only to the close of the glacial epoch; but that the Mississippi and all the rivers of Northeastern Iowa, if no others, had at least a large part of the rocky portions of their valleys eroded by pre-glacial, or perhaps even by palæozoie rivers, can searcely be doubted.
GEOLOGY.
Geologists divide the soil of Iowa into three general divisions, which not only possess different physical characters, but also dif- fer in the mode of their origin. These are drift, bluff and alluvial and belong respectively to the deposits bearing the same names The drift occupies a much larger part of the surface of the State than both the others. The bluff has the next greatest area of sur- face, and the alluvial least.
All soil is disintegrated rock. The drift deposit of Iowa was derived to a considerable extent from the rocks of Minnesota; but the greater part of Iowa drift was derived from its own rocks, much of which has been transported but a short distance.
In Northern and Northwestern Iowa the drift contains more sand and gravel than elsewhere. In Southern Iowa the soil is frequently stiff and elayey.
The bluff soil is found only in the western part of the State, and adjacent to Missouri River. Although it contains less than one per cent. of clay in its composition, it is in no respect inferior to the best drift soil .
The alluvial soil is that of the flood-plains of the river valleys, or bottom lands. That which is periodically flooded by the rivers is of little valne for agricultural purposes; but a large part of it is entirely above the reach of the highest flood, and is very productive.
77
HISTORY OF IOWA.
The stratified roeks of Iowa range from the Azoie to the Meso- zoic, inelusive; but the greater portion of the surface of the State is oceupied by those of the Palæozoie age. The table below will show each of these formations in their order:
SYSTEMS. AGES.
GROUPS. PERIODS.
FORMATIONS. EPOCHS.
THICKNESS IN FEET.
Cretaceous .. . .
Lower Cretaceous .. .
Woodbury Sandstone and Shales.
130
Nishnabotany Sandstone.
100
Upper Coal Measures.
200
Coal Measures.
Middle Coal Measures.
200
Lower Coal Measures.
200
Carboniferous. . .
St Louis Limestone ..
75
Subcarboniferous
Burlington Limestone.
196
Devonian ..
Hamilton
Hamilton Limestone and Shales,
200
Upper Silurian.
Niagara.
.Niagara Limestone.
350
Cincinnati
. Maquoketa Shales
80
Trenton.
Trenton Limestone.
200
Lower Silurian.
St. Peter's Sandstone
80
Primordial.
Lower Magnesian Limestone .. .
250
Potsdam Sandstone.
300
Azoie ..
. Huronian.
Sioux Quartzite.
50
AZOIC SYSTEM.
The Sioux quartzite is found exposed in natural ledges only upon a few aeres in the extreme northwest corner of the State, upon the banks of the Big Sioux River. for which reason the specific name of Sioux quartzite has been given them. It is an intensely hard rock, breaks in splintery fracture, and of a color varying, in different localities, from a light to deep red. The process of metamorphism has been so complete throughont the whole forma- tion that the rock is almost everywhere of uniform texture. The dip is four or five degrees to the northward, and the trend of the outerop is eastward and westward.
LOWER SILURIAN SYSTEM.
Primordial Group .- The Potsdam sandstone formation is ex- posed only in a small portion of the northeastern part of the State. It is only to be seen in the bases of the bluffs and steep valley sides which border the river there. It is nearly valueless for economie purposes. No fossils have been discovered in this formation in Iowa.
Post Tertiary.
. Drift. .
10 to 200
Inoceramous Bed.
50
Keokuk Limestone ...
90
[ Kinderhook Beds ..
175
( Galena Limestone ..
250
78
HISTORY OF IOWA.
Lower Magnesian Limestone .- This formation has but little greater geographical extent in Iowa than the Potsdam sandstone. It lacks a uniformity of texture and stratification, owing to which it is not generally valuable for building purposes. The only fos- sils found in this formation in the State are a few traces of eri- noids, near McGregor.
The St. Peter's Sandstone formation is remarkably uniform in thickness throughout its known geographical extent, and it occu- pies a large portion of the northern half of Allamakce County, im- mediately beneath the drift.
Trenton Group .- With the exception of the Trenton limestone, all the limestones of both Upper and Lower Silurian age in Iowa are magnesian limestones-nearly pure dolomites. This formation occupies large portions of Winneshiek and Allamakec Counties, and a small part of Clayton. The greater part of it is useless for economie purposes; but there are some compact, even layers that furnish fine material for window eaps and sills. Fossils are so abundant in this formation that in some places the roek is made up of a mass of shells, corals and fragments of trilobites, cemented by calcarcous material into a solid rock. Some of these fossils are new to science and peculiar to Iowa.
The Galena limestone is the upper formation of the Trenton Group. It is 150 miles long and seldom exceeds 12 miles in width. It exhibits its greatest development in Dubuque County. It is nearly a pure dolomite with a slight admixture of silicious matter; good blocks for dressing are sometimes found near the top of the bed, although it is usually unfit for such a purpose. This formation is the source of the lead ore of the Dubuque lead inines. The lead region proper is confined to an area of about 15 miles square in the vicinity of Dubuque. The ore occurs in vertical fissures, which traverse the rock at regular intervals from east to west; some is found in those which have a north and south direc- tion. This ore is mostly that known as Galena, or sulphuret of lead, very small quantities only of the carbonate being found with it.
Cincinnati Group .- The surface occupied by the Maquoketa shales is more than 100 miles in length, but is singularly long and narrow, seldom reaching more than a mile or two in width. The most northern exposure yet recognized is in the western part of Winneshiek County, while the most southerly is in Jackson Connty, in the bluff's of the Mississippi. The formation is largely composed of bluish and brownish shales, sometimes slightly are-
.
79
HISTORY OF IOWA.
naceons, sometimes calcareous, which weather into a tenacions clay upon the surface, and the soil derived from it is usually stiff and clayey. Several species of fossils which characterize the Cincin- nati Group are found in the Maquoketa shales, but they contain a larger number than have been found any where else in these shales in Iowa, and their distinct faunal characteristics seem to warrant the separation of the Maquoketa shales as a distinct for- mation from any others of the group.
UPPER SILURIAN SYSTEM.
Niagara Group .- The area occupied by the Niagara limestone is 40 and 50 miles in width and nearly 160 miles long from north to sonth. This formation is entirely a magnesian limestone, with a considerable portion of silicions matter, in some places, in the form of chert or coarse flint. A large part of it probably affords the best and greatest amount of quarry rock in the State. The quarries at Anamosa, Le Claire and Farley are all opened in this formation.
DEVONIAN SYSTEM.
Hamilton Group .- The area of surface occupied by the Hamil- ton limestone and shales, is as great as those by all the formations of both Upper and Lower Silurian age in the State. Its lengthi is nearly 200 miles, and width from 40 to 50. It trends in a north- westerly and southeasterly direction. A large part of the material of this is quite worthless, yet other portions are valuable for economie purposes; and, having a large geographical extent in the State, is a very important formation. Its value for the production of hydraulic lime has been demonstrated at Waverly, Bremer County. The heavier and more uniform magnesian beds furnish material for bridge piers and other material requiring strength and durability. All the Devonian strata of Iowa evidently belong to a single epoch. The most conspicuous and characteristic fossils of this formation are brachiopods, corals and mollusks. The coral Acervularia Davidsoni occurs near Iowa City, and is known as "Iowa City marble " and " bird's-eye marble."
CARBONIFEROUS SYSTEM.
Of the three groups of formations that constitute the carbonifer- ous, viz., the subcarboniferous, coal measures and Permian, only the first two are found in Iowa.
80
HISTORY OF IOWA.
Subcarboniferous Group .- This group occupies a very large area of surface. Its eastern border passes from the northeastern part of Winnebago County, with considerable directness in a southeasterly direction to the northern part of Washington County. It then makes a broad and direet bend nearly eastward, striking the Mississippi at Muscatine. The southern and western bound- aries are to a considerable extent the same as that which separates it from the real field. From the southern part of Pocahontas County it passes southeast to Fort Dodge, thence to Webster City, thence to a point three or four miles northeast of Eldora, in Har- din County, thence sonthward to the middle of the north line of Jasper County, thence southeastward to Sigourney, in Keokuk County, thence to the northeastern corner of Jefferson County, thence sweeping a few miles eastward to the southeast corner of Van Buren County. Its are is about 250 miles long and from 20 to 50 miles wide.
The Kinderhook Beds. - The most southerly exposure of these beds is in Des Moines County, near the mouth of Skunk River. The most northerly now known is in the eastern part of Pocahontas County, more than 200 miles distant. The principal exposures of this formation are along the bluffs which border the Mississippi and Skunk Rivers, where they form the eastern and northern boundary of Des Moines County; along English River, in Wash- ington County; along the Iowa River in Tama, Marshall, Hamlin, and Franklin Counties, and along the Des Moines River in Hum- boldt County. This formation has considerable economic value, particularly in the northern portion of the region it occupies. In Pocahontas and Humboldt Counties it is invaluable, as no other stone except a few boulders are found here. At Iowa Falls the lower division is very good for building purposes. In Marshall County all the limestone to beobtained comes from this formation, and the quarries near Le Grand are very valuable. At this point some of the layers are finely veined with peroxide of iron, and are wrought into both useful and ornamental objects. In Tama County the oolitie member is well exposed, where it is mannfact- nred into lime. Upon exposure to atmosphere and frost it crum- bles to pieces; consequently it is not valuable for building purposes.
The remains of fishes are the only fossils yet discovered in this formation that can be referred to the sub-kingdom Vertebrata; and so far as yet recognized, they all belong to the order Selach- ians. Of Articulates, only two species have been recognized,
81
HISTORY OF IOWA.
both of which belong to the genus Phillipsia. The sub-kingdom Mollusca is also largely represented. The Radiata are repre- sented by a few crinoids, usually found in a very imperfect condi- tion. The sub-kingdom is also represented by corals. The prom- inent feature in the life of this epoch was mollusean. It overshad- owed all other branches of the animal kingdom. The prevailing elasses are: Lamellibranchiates, in the more arenaceons portions; and Brachiopods in the more calcareous portions. No remains of vegetation have been detected in any of the strata of this formation.
The Burlington limestone formation consists of two distinct eal- careous divisions, separated by a series of silicious beds; both divi- sions are crinoidal. The Burlington limestone is carried down by the southerly dip of the Iowa rocks, so that it is seen for the last time in this State in the valley of Skunk River, near the southern boundary of Des Moines County; it has been recognized in the northern part of Washington County, which is the most northerly point that it has been found; but it probably exists as far north as Marshall County. Much valuable material is afforded by this formation for economie purposes. The upper division fur- nishes excellent common quarry rock. Geologists are attracted by the great abundance and variety of its fossils-crinoids-now known to be more than 300.
The only remains of vertebrates discovered in this formation are those of fishes, and consist of teeth and spines. Bones of bony fishes are found in these rocks, and on Buffington Creek, Lonisa County, is an exposure so fully charged with these remains that it might with propriety be called bone breccia. Remains of Artien- lates are rare in this formation; so far as yet discovered, they are confined to two species of trilobites of the genus Phillipsia. Fos- sil shells are very common.
The two lowest classes of the sub-kingdom Radiata are represented in the genera Zaphrentis, Amplexus and Syringapora, while the highest elass, Echinoderms, are found in most extraordinary pro- fusion.
The Keokuk limestone formation is to be seen only in four counties: Lee, Van Buren, Henry and Des Moines. In some localities the upper silicious portion is known as the Geode bed; it is not recognizable in the northern portion of the formation, nor in connection with it where it is exposed, abont 80 miles below Keokuk. The geodes of the Geode bed are more or less masses of silex, usually hollow and lined with crystals of quartz; the outer
5
82
HISTORY OF IOWA.
ernst is rough and unsightly, but the crystals which stud the in- terior are often very beautiful; they vary in size from the size of a walnut to a foot in diameter.
This formation is of great economic value. Large quantities of its stone have been used in the finest structures in the State, among which are the postoffices at Dubuque and Des Moines. The prin- cipal quarries are along the banks of the Mississippi, from Keokuk to Nauvoo. The only vertebrate fossils in the formation are fishes, all belonging to the order Selachians, some of which indi- cate that their owners reaclied a length of 25 or 30 feet. Of the Articulates, only two species of the genns Phillipsia have been found in this formation. Of the Mollusks no Cephalopods have yet been recognized in this formation in Iowa. Gasteropods are rare; Brachiopods and Polyzoans are quite abundant. Of Radi- ates, corals of genera Zaphrentis, Amplexus and Anlopora are found, but crinoids are most abundant. Of the low forms of ani- mal lite, the protozoans, a small fossil related to the sponges, is found in this formation in small numbers.
Need help finding more records? Try our genealogical records directory which has more than 1 million sources to help you more easily locate the available records.