GEOLOGICAL SURVEY CIRCULAR 231

EXPLORATORY DRILLING PROGRAM OF 

THE U. S. GEOLOGICAL SURVEY 

FOR EVIDENCES OF ZINC-LEAD 

MINERALIZATION IN IOWA 

AND WISCONSIN, 1950-51
UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

GEOLOGICAL SURVEY CIRCULAR 231

EXPLORATORY DRILLING PROGRAM OF THE U. S. GEOLOGICAL SURVEY

FOR EVIDENCES OF ZINC-LEAD MINERALIZATION

IN IOWA AND WISCONSIN, 1950-51

By Alien F. Agnew, Arthur E. Flint, and John W. Allingham

Prepared in cooperation with the 

Wisconsin Geological and Natural History Survey

Washington, D. C., 1963

Free on application to the Geological Survey, Washington 25, D. C.
EXPLORATORY DRILLING PROGRAM OF THE U. S. GEOLOGICAL SURVEY

FOR EVIDENCES OF ZINC-LEAD MINERALIZATION

IN IOWA AND WISCONSIN, 195051

By Alien F. Agnew, Arthur E. Flint, and John W. Allingham

CONTENTS

Page

Abstract..................................... 1

Introduction.................................. 2

Purpose and scope of exploration.......... 2

History and mineral production of district.. 2

Previous geologic work .................. 2

Acknowledgments........................ 2

General geology of the district................. 4

The Tete des Morts area, Iowa ................ 4

Results of geologic mapping and

exploratory drilling .................... 5

Stratigraphy ........;.............. 5

Structure.......................... 5

Evidence of mineralization .......... 7

Recommendations ....................... 7

Page

The Highland area, .Wisconsin................. 7

Stratigraphy .......,..._............... 9

Upper Cambrian.................... 9

Lower Ordovician ................. 9

Middle Ordovician ................. 9

Results-of geologic mapping............... 9

Evidences of mineralization......... 9

Structure.......................... 10

Results of exploratory drilling............ 10

Recommendations....................... 10

Literature cited.............................. 11

Generalized logs of drill-hole explorations...... 12

Tete des Morts area..................... 12

Highland area........................... 21

ILLUSTRATIONS

Page

Plate 1. Map of the Tete des Morts area showing location of holes drilled by the

U. S. Geological Survey.............................................................. In pocket

Cross sections of holes drilled by the U. S. Geological Survey in the Tete des Morts area..... In pocket

Map of Highland area showing location of holes drilled by the U. S. Geological Survey........ In pocket

Cross sections of holes drilled by the U. S. Geological Survey in the Highland area .......... In pocket

Index map showing location of the Wisconsin-Illinois-Iowa zinc-lead mineralized district .......... 3

Map showing location of the Tete des Morts and Highland areas and the

Black Jack-Bautsch trend ................................................................. 3

Stratigraphic column of the Tete des Morts area................................................ 6

Stratigraphic column of the .Highland area..................................................... 8

2.

3.

4. 

Figure 1.

2.

3.

4.

ABSTRACT

The Upper Mississippi Valley zinc-lead district 

covers 2, 500 square miles of Wisconsin, Illinois, and 

Iowa. It is one of the oldest mining districts in the 

United States, as lead mining by settlers began in 

1788. Zinc has been mined since 1859, and the 

present production is more than ten times that of lead.

Rocks exposed in the district range from Early 

Ordovician to Middle Silurian in age, and, except for 

the St. Peter sandstone and the Maquoketa shale, 

consist mainly of dolomite. Structural compression 

has resulted in gentle folds and faults; principal trends 

are northwestward, northeastward, and eastward.

Galena (lead sulfide) has been mined principally 

from vertical joints in the upper, noncherty part of 

the Galena dolomite. On the other hand, sphalerite

(zinc sulfide) and a minor amount of smithsonite 

(zinc carbonate) are found as veins, breccia ore, and 

disseminations in the lower, cherty part of the Galena 

dolomite, in strata of the Decorah formation, and in 

the upper beds of the Platteville formation; these 

"lower-run" ore bodies are in inclined reverse faults 

(pitches) and associated bedding-plane faults (flats) 

that are localized along synclinal trends. Lead and 

zinc minerals are found in beds of the Prairie 

du Chien group where they are exposed along the 

northern edge of the district.

Since 1942 the U. S. Geological Survey has 

been studying the geology of the zinc-lead district 

and has been mapping the structure, stratigraphy, 

and the occurrences of ore bodies. The program 

here described was centered in two areas at the 

margin of the district. Twenty-five holes that 

totalled 7,466 feet were drilled in 1950-51. In the
Tete des Morts area, Iowa, the drilling showed 

lithology, structure, and evidences of mineralization 

that are favorable indications of the possible existence 

of pitch-type lower-run ore bodies; it showed a lateral 

extension of the potentially productive part of the 

district. In the Highland area, Wisconsin, lithology 

and evidences of mineralization found in strata of the 

Prairie du Chien group indicate that this unit might 

warrant further investigation as a potential source of 

ore at a lower stratigraphic position than that now 

being prospected in the main part of the zinc-lead 

district, farther south. Drilling in beds of the Prairie 

du Chien showed a vertical extension of the potentially 

productive part of the district.

INTRODUCTION 

Purpose and scope of exploration

The exploratory drilling program of the U. S. 

Geological Survey in Iowa and Wisconsin in 1950 and 

1951 was part of a continuing comprehensive geologic 

investigation of the zinc-lead district (figs. 1 and 2) 

that began in 1942. The principal purpose of the 

drilling was to provide geologic data related to the 

over-all objective of extending laterally, (geographically) 

and vertically (stratigraphically) the favorable indications of and known potentialities for zinc and lead ore 

(Agnew and Heyl, 1947, p. 228.)

The southern limit of current activity in the 

Wisconsin-Illinois-Iowa mining district is the Black 

Jack-Bautsch fold, an ore trend (fig. 2) a few miles 

south of Galena, 111. Because the currently mined ore 

bodies are large and rich and were discovered during 

recent years as a result of new geological ideas regarding the occurrence of ore, it was proposed to 

explore an area in Iowa, just to the west of the Black 

Jack-Bautsch mines. Answers to several geologic 

questions were sought:

1. Is the lighology of the Tete des Morts area 

similar to that in the Black Jack-Bautsch 

trend 5 miles to the east?

2. Are structural features (Willman and 

Reynolds, 1947, pp. 14-15) similar?

3. Are products of mineralization similar?

Thus, the exploration in the Tete des Morts area was 

primarily an attempt to indicate a geographic, or 

lateral extension of the main ore-bearing zone of the 

zinc-lead district.

Lead and zinc minerals in the Lower Ordovician 

Prairie du Chien group have been found in several 

localities, particularly in the northern part of the 

mining district (Heyl, Lyons, and Agnew, 1951 ). In 

the Highland area, surface indications of lead mineralization in the Prairie du Chien group are particularly 

abundant, and a deep shaft had been sunk in this area 

to mine lead ore. Furthermore, lead was in short 

supply when the Geological Survey program was being 

planned. The drilling in the Highland area, therefore, 

was an attempt to obtain information regarding the 

(1) stratigraphic occurrence, (2) structural relations, 

and (3) mineralogic relations of lead in the Prairie 

du Chien group. It was an attempt to extend vertically 

the zinc-lead district the search for a stratigraphically lower-producing zone.

Preliminary geologic studies in the Tete des 

Morts and Highland areas were made in the summer 

of 1950 in order to choose the most promising localities for drilling. Five properties were selected, 

and 25 holes were drilled by cable-tool rigs between 

September 10, 1950, and May 25, 1951; the holes 

aggregated 7,466 feet of drilling.

History and mineral production of district

The zinc-lead district in Wisconsin, Illinois, 

and Iowa is one of the oldest mining areas in the 

United States. The lead mines in the Dubuque area 

were among the earliest worked by white men, beginning in 1788 with Dubuque's Concession. The annual 

production of lead increased rapidly in the late 1820's 

and reached a maximum of about 27,000 tons of lead 

metal in the middle 1840 's, when the district contributed 85 to 90 percent of the lead produced in the 

United States. Lead mining in this district declined 

gradually until 1878, when the annual output was less 

than 5,000 tons.

Zinc production did not begin until 1859, as 

before that time no market existed. In 1859 zinc 

carbonate and in 1867 zinc sulfide were first mined, 

and by 1873 zinc sulfide had replaced' zinc carbonate 

as the district's major ore. By 1872 zinc production 

was about twice that of lead. The zinc-lead ratio 

increased only slightly until World War I when it 

suddenly became about 20 to 1 in 1917, and the peak 

of .zinc output from this district was more than 

64,000 tons of zinc metal. By 1930 most of the large 

mining companies had left the district, and for the 

next 10 years zinc-lead production was generally low 

until the demands of World War II rejuvenated zinclead activity in 1941. Several large mining companies 

entered the district after 1944, and a large program 

of exploration and mining is now under way. Mines 

in the district produced about 1, 120,000 tons of zinc 

metal from 1859 to 1947 and about 815,000 tons of 

lead metal from 1800 to 1947.

Previous geologic work

The mining district was studied intermittently 

but rather thoroughly by government survey parties 

from 1836 until about 1916. From 1916 to the late 

1920's the geologic investigations were carried out 

by company geologists. During the 1930's research 

by faculty and students of universities nearby kept 

geologic interest alive; however, except for the work 

of Behre (1939), these studies were directed toward 

specific phases of geology rather than general investigations of the entire district.

Numerous publications resulted from the 

previous geologic work, but an adequate resume or 

bibliography is not within the scope of this brief report.

Acknowledgments

The Wisconsin Geological and Natural History 

Survey supplied part of the funds for the supervision 

of the drilling program.

C. W. Tandy, Jr., aided by surveying during 

the preliminary geologic investigations of the 

two areas.
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Figure 1. Index map showing the location of the Wisconsin-Illinois-Iowa zinc-lead mineralized district.

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Figure 2. Map showing the location of the Tete des Morts and ffighland areas and the Black Jack-Bautsch trend.

3
GENERAL GEOLOGY OF THE DISTRICT

Much of the bedrock in the Wisconsin-IlMnoislowa zinc-lead district is covered with a mantle of 

Pleistocene and Recent loess as much as 35 feet thick.

The sedimentary rocks exposed in the 

district range from Early Ordovician to Middle 

Silurian in age. A generalized summary of the 

rocks, compiled from outcrop and drill-hole 

data, is as follows:

Silurian system. 

Kankakee limestone of Savage (1916) 

Edgewood limestone 

Ordovician system.

Maquoketa shale 

Prairie du Chien group 

Cambrian system.

TYwo o"Ko r>Vi fin TirScfh OTI&

Dominant lithology

j Dolomite, chert ----- 

Shale, dolomite 

Dolomite, chert ----- 

Limestone, dolomite, 

chert. 

Limestone, dolomite, 

shale. 

Sandstone 

Dolomite, chert, 

shale, sandstone.

Dolomite, sandstone, 

siltstone. 

Sandstone, shale, 

siltstone. 

Sandstone, shale, 

siltstone.

Average thickness 

(feet)

150-1-

105-200 

220-230 

35-^5

55-75 

\ 280-320

120-150 

110-140 

800-1000

The zinc-lead district lies on the south side of 

the Wisconsin pre-Cambrian high (Thwaites,and 

Howell, 1935); it is just west of the structural extension southward toward the LaSalle anticline in 

Illinois (Thwaites, Howell, and Jones, 1935). The 

strata of the district have been gently flexed and 

broken. Although the folds are of small amplitude 

and are generally local, general axial trends can be 

traced for several miles. These trends are northeastward and northwestward; eastward folds of similar 

continuity are less common. Faults are of relatively 

small magnitude and are of three general types 

reverse, normal, and tear. Dip-slip displacement 

on the reverse faults is less than 6 feet, but strikeslip displacement on the tear faults is known to be at 

least 35 feet and may be as much as 200 feet or more.

Solution effects that accompanied the zinc-lead 

mineralization accentuated the tectonic structural 

features and altered the lithologic features of the rocks.

Deposits of zinc-lead are found mainly in the 

lower part of the Galena dolomite ("drab" of local 

usage), the Decorah formation ("gray, " "blue, " "oil 

rock," and "clay bed" of local usage), and the upper 

part of the Platteville formation ("glass rock" and 

"Trenton" of local usage). Lead was recovered from 

vertical joint crevices in the upper, noncherty part 

of the Galena dolomite. The galena in these "upperrun" deposits occurred as isolated crystals (dice lead) 

or clusters (cog lead) in a matrix of dolomite sand, 

as veins (sheets) less than an inch thick, and as pods 

several feet wide. Podlike forms of ore were present 

in "openings" (Whitney, 1858, p. 438) at favorable 

stratigraphic horizons. At one or more of these 

horizons, similar podlike enlargements occurred at 

intervals along a crevice. At intersections of

crevices, "chimneys" or pipes of galena were sometimes found. Individual crevices were mined for 

lengths as much as 1, 700 feet.

In the lower, cherty part of the Galena dolomite, 

in beds.of the Decorah formation, and in the upper 

part of the Platteville formation zinc and some lead 

ore deposits were mined from reverse faults (pitches) 

and associated bedding-plane faults (flats) in the 

limbs of synclines. In one of these "lower-run" ore 

bodies the minerals replaced the rock and filled vugs, 

constituting a "brangle" (solution-breccia zones of 

dolomite blocks cemented by sphalerite and marcasitepyrite) type of ore in the "core ground," which lies 

on the footwall side of and extends to within a few. 

feet of the pitch. The ore bodies were as much as 

30 feet or more high (in the Black Jack mine more 

than 120 feet), 100 feet or more wide, and 3, 500 feet 

or more long, although the average length was perhaps 

1,000 feet.

The Prairie du chien group constitutes a lower, 

potentially ore -bearing zone, as in a few places in the 

northern part of the district galena has been 

mined from dolomite beds in the upper part of the unit.

THE TETE DES MORTS AREA, IOWA

The Tete des Morts area is in southeasternDubuque 

County and northeastern Jackson County, Iowa (fig. 2). 

The area in which drilling was done is about 1 .square 

mile and is bounded on the northeast by the Mississippi 

River. Relief is about 160 feet, and the upland is under 

cultivation.

Lead ore was mined in this area by the Indians, 

and its occurrence was briefly described by Owens (1840),
who stated that by 1839 at least 15,000 pounds of lead 

ore had been raised from H. H. Gher's diggings 

(pi. 1). The Tete des Morts diggings, however, have 

never been very productive and have long since been 

abandoned. Lead ore has been mined in recent years 

from shafts on Kohlenberg's land and from shafts a 

mile and a half southeast of Gordon's Ferry. Zinc 

minerals were reported in one of the shafts on the 

Kohlenberg farm.

Before the drilling, exploration, which will be 

described, a reconnaissance survey of the structural 

geology was made by Agnew and Flint along the 

Mississippi River bluff and back from the River, up 

the tributary valleys. Two synclines were found, one 

northeastward and the other northwestward in trend 

(pi. 1). Steep dips, a shattered zone in the rocks, and 

iron minerals indicative of a pitch zone were seen at 

the southeast end of the meander intheTetedesMorts 

River in sec. 3. Joint strikes were mapped, and the 

pattern showed general northwestward, northeastward, 

and eastward trends.

The lowest beds exposed in the Tete des Morts 

area are a few feet of cherty dolomite at the top of 

the lower, or cherty unit of the Galena dolomite. The 

upper, or noncherty beds of the Galena are seen along 

the bluffs of the Mississippi and Tete des Morts Rivers 

and provided most of the data fox1 mapping the geologic 

structure. The lower beds of the Maquoketa shale are 

exposed in the upper reaches of a few small ravines.

Shafts and smaller pits, remnants of lead 

diggings that are as much as 100 years old, were also 

located by reconnaissance geologic mapping. The 

lithology of material on the dump indicated that the 

productive zone was stratigraphically above the top of 

the cherty unit of the Galena dolomite. Iron minerals 

in the exposure of the pitch zone along the Tete des 

Morts River ranged in stratigraphic position from a 

few feet below the top of the cherty beds upward for 

about 75 feet.

Between September 10, 1950, and February 15, 

1951, two properties in Iowa were drilled; the drilling 

totaled 13 holes and 4,036 feet. Cuttings were sacked 

for every 5 feet of drilling and were examined with a 

binocular microscope. (Summary logs are included 

on pp. 11-36.)

Results of geologic mapping and 

exploratory drilling

Stratigraphy. The St. Peter sandstone was 

penetrated in only one hole, Schenk 1, which cut 

through 18 feet of a quartz sandstone (fig. 3). A pyritecemented streak was found in the upper part of the 

unit; however, such streaks are common in the 

St. Peter in the upper Mississippi Valley district and 

have no known significance concerning the proximity 

of ore bodies.

The Platteville formation is 64 feet thick in 

Schenk hole 1,. the only hole penetrating the base of 

this formation. In this hole the lower part of the 

Platteville formation consists of light-brown dolomite 

(Pecatonica dolomite member), overlying thin green 

shale (Glenwood shale member). The McGregor

limestone member is a gray limestone in Schenk 

holes 1 to 3, which penetrated its entire thickness. 

The uppermost member of the Platteville, the 

Quimbys Mill member or "glass rock " of local usage, 

is limestone except in Kohlenberg hole 2, where part 

of the rock is dolomitic limestone.

A trace of pyrite in the "glass rock" unit in 

Schenk hole 7 is the only indication that the rocks of 

the Platteville formation were mineralized.

The Decorah formation, which averages 43 feet 

in thickness, consists of four units. The lowest, or 

Spechts Ferry shale member, is green shale; the 

middle, or Guttenberglimestone member, is brown 

limestone and shale, called "oil rock"; and the upper 

two, which constitute the Ion dolomite member, are 

gray and dark-gray limestone (dolomite in Schenk 

holes 4 through 9) and shale.

In the Tete des Morts area the Galena dolomite, 

225 feet thick, is dolomite throughout, except on the 

Kohlenberg property where the lower 25 to 30 feet 

contain as much as 90 percent limestone and dolomitic 

limestone. The lack of limestone, in the Galena dolomite on the Schenk property shows that the dolomite 

is due apparently to dolomitization associated with 

mineralization, for, if it were due to regional 

dolomitization, these beds on the Kohlenberg land 

would also have been dolomitized.

Several "openings" occur in the Galena dolomite 

in the Dubuque, Iowa, area 15 miles to the northwest 

and in the Galena, 111., area 5 miles northeast of the 

Tete des Morts area; the stratigraphic positions of 

these openings are shown in figure 3. Galena is the 

common mineral in the openings, but in the Dubuque 

area sphalerite and marcasite-pyrite are reported 

from openings that lie below the water table. The 

openings in the upper, noncherty unit of the Galena 

dolomite are commonly filled with clay and dolomite 

sand. However, the "upper flint" opening, the "lower 

flint" opening, and the mineralized zone (here named 

the lower Receptaculites opening) that lies 20 to 30 

feet above the base of the Galena dolomite are 

commonly brangle zones. Even though it has great 

length, the opening type of deposit is relatively narrow, 

and prospecting for this type of ore zone by vertical 

drilling is likely to be disappointing.

No Maquoketa shale was penetrated in the holes 

drilled. In Schenk hole 5, however, phosphatic 

pebbles similar to the material of the depauperate 

zone occurring at the base of the Maquoketa shale 

were found below the surficial material; so the basal 

contact of the Maquoketa was probably within a few 

feet of the depth at which it was logged. Lithologic 

information for the Maquoketa (fig. 3) was derived 

mainly from the study of samples from a well drilled 

.about 2 miles to the south (W. H. Felderman, 

wiNEiSEi sec. 15, T. 87 N., R. 4E., Iowa).

A capping of loess as much as 35 feet thick is 

present on the uplands.

Structure. One of the major reasons for the 

selection of the Tete des Morts area was the occurrence of favorable structures.
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Dolomite, yellowish-buff, finely granular, medium-bedded; interbedded 

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A structure contour map (pi. 1) of the top of the 

cherty unit of the Galena dolomite,prepared before 

drilling,showed two synclines that appeared to join 

near the center of the wi? of sec. 3. Drilling corroborated the presence of both synclines. The northeastward-trending syncline is thought to be the extension 

of the Galena-Shullsburg syncline and has much more 

relief than the narrower northwestward-trending one, 

which is like the Black Jack-Bautsch fold.

Evidence of mineralization

Indications of solution-thinning of the "oil rock" 

(middle part of Decorah formation) and the "glass rock" 

(upper part of Platteville formation) were seen in 

cuttings from one of the holeS( (Schenk 4), drilled 

near the pitch zone noted previously.

Although lines of lead shafts and "sucker holes" 

(diggings) were found, they are thought to be related 

to mining of the vertical or near-vertical "upper-run" 

(in the noncherty unit of the Galena dolomite) or crevice 

deposits and were not given any weight in the planning 

of the drilling because the purpose of this program 

was to explore the "lower-run" or pitch-and-flat type 

of ore body.

Holes 1 through 6 on the Schenk property (sec. 3) 

were spotted, on 125-foot centers, to cut across the 

southeastern projection of the pitch zone in the Tete 

des Morts River. They were drilled on the northeast 

limb of the northwestward-trending structure. Iron 

minerals were the only significant evidence of mineralization in Schenk holes 1 through 6. Holes 2, 3, and 

5 showed an estimated 3. 5 to 4. 7 percent iron for a 

thickness of 16 to 39 feet (pi. 2); all the holes except 

no. 4 had traces of zinc, and hole 3 had a trace of 

lead. The iron minerals were found at the stratigraphic 

ppsition of the upper and lower flint openings. As this 

position is in the upper part of the pitch-type ore 

bodies farther north and east, the occurrence of the 

iron is interpreted as a favorable indication of the 

possible existence of pitch-type lower-run ore bodies 

in the Tete des Morts area. Although no pitch-type 

fractures were found in the drilling, the existence of 

solution-thinning of the "oil rock" and "glass rock" 

with associated concentration of shaly material found 

in Schenk hole 4 is believed to justify further exploration for lower-run zinc-lead deposits.

Holes 7 through 9 on the Schenk property were 

alined across the gently dipping southeast limb of the 

northeastward-trending syncline. In hole 7, iron deposition similar to that in holes 2, 3, and 5 was 

discovered at the same stratigraphic position as in 

holes 1 through 6. In addition, a mineral identified 

as one of the manganese oxides was present at this 

position of the upper flint opening. This cross section, holes 7 through 9, showed less promise than the 

one for holes 1-6.

The alinement of holes drilled on Kohlenberg's 

property crossed the northwestward-trending syncline. 

Hole 1 showed iron deposition estimated at 3 percent 

for 15 feet at the position of the lower Receptaculites 

opening, which is near the base of the Galena dolomite. 

Hole 2 showed traces of zinc, and hole 4 showed the 

manganese mineral, noted in Schenk hole 7, in the 

"gray" beds of the Decorah formation.

The significance of the manganese mineral is 

not known; however, the iron in Kohlenberg hole 1 is 

interpreted as a favorable indication of the possible 

existence of pitch-type lower-run ore bodies in the 

Tete des Morts area.

All holes drilled in the Tete des Morts area were 

completed to the desired depth at or near the base of 

the "glass rock" except Kohlenberg hole 1, which was 

bottomed in the "gray" beds of the Decorah. In the 

lower part of this hole, from 215 to its total depth of 

244 feet, a joint with a strong flow of water caused 

such drilling and sampling difficulties that the hole 

was abandoned.

Recommendations

The exploratory work here described showed 

structure, lithology, and type and position of mineralized zones that are interpreted as favorable indications 

of the possible existence of pitch-type lower-run ore 

bodies. The Tete des Morts and surrounding area 

thus constitute a potential extension of the mining 

district and further exploratory work is recommended.

Outcrop mapping is recommended as a means 

of locating geologic structures along the Mississippi 

River bluff, the Tete des Morts River, and other 

areas where exposures are numerous and structural 

control is good. Where such geologic data are not 

available, it is recommended that favorable structure 

be prospected for by means of drilling, .preferably 

using either a grid, or a series of cross sections 

across syncline trends.

Although the ore bodies are localized along 

structural trends, not all such trends bear ore bodies, 

and any one trend can have both ore-bearing and lean 

or blank areas. Thus, the structural picture must be 

used only as a guide in finding ore, not as a certain 

indication of ore.

Furthermore, it is recommended that any 

exploratory program, in this or similar new areas in 

the district, be planned to include an adequate number 

of drill holes. Recent experience by mining companies 

in the district has shown that limited drilling can give 

only insufficient information regarding any ore discoveries and often it unjustly condemns an area.

THE HIGHLAND AREA, WISCONSIN

The Highland area (fig. 2) in west-central Iowa 

County and the adjoining part of Grant County, Wis., 

includes about 5 square miles. The village of Highland 

lies in the northeast corner of the area. Maximum 

topographic relief is approximately 300 feet. The 

uplands are under cultivation; the valley slopes and 

narrow stream flood plains are grasslands.

Zinc and lead ores in this area have been mined 

from Middle Ordovician rocks of the Platteville,Decorah, 

and Galena formations and lead ore has been taken 

from Lower Ordovician rocks of the Prairie du Chien 

group. The formations that contain these two orebearing zones are separated by the Middle Ordovician 

St. Peter sandstone (fig. 4). Because this part of the 

exploration by the Geological Survey was concerned 

with the lower ore zone, evidence of mineralization
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Limestone, fine- and medium-groined, fossiliferous

Dolomite, gray to buff, medium -grained; phospnatic nodules at base

\Shale, green to gray, arenaceous. Phosphatic nodules and Iron sulfide common

Sandstone, quartz, rounded, fine-to medium-grained, coarse at top and base 

(Deposited In solution channels In underlying rocks)

Dolomite, light-brown, fine-to medium-grained; local giauconite, quartz sand; 

shale, light-green upper 2-3 feet; chert sparse

Dolomite, as above; chert abundant; oolites and giauconite, quartz sand lenses

Dolomite, as above; sparse chert; iocai shale and quartz sand

Dolomite, light brownish-gray, mainly medium -grained; focal glassy chert

Dolomite, as above; chert glassy and parcel an eous, wry abundant. Lead sulfide locally

Dolomite, as above; chert, as above, moderate to sparse

Dolomite, as above; chert, as above, abundant; abundant iron sulfide in middle of zone

Dolomite, as above; chert, sparse to absent. Local shale and quartz sand lenses 

middle and lower part of zone. Abundant iron sulfide in middle of zone

Dolomite, light- to medium-brown, mainly medium-grained} chert glossy, moderate 

\to abundant; oolites common

Dolomite, light-brown, fine- and medium-groined; lower 15 feet arenaceous, oolitic, 

gtauconltic; chert sparse; sandstone, dohmitic, common near base

Sandstone, white, fine-to medium-grained; green shale partings and dotomitic

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Cryptozoon may occur locally throughout the upper 155-165 <Mt 

of the Prairie du Chien formation.

Figure 4. Stratigraphic column of the Highland area, Grant and Iowa Counties, Wis.
in the Prairie du Chien rocks only is discussed. 

Most of the lead ore from this unit was mined from 

about 1850 to 1880, and no records of production are 

available. Areas of diggings (pi. 3) are relatively 

extensive, more so in the Highland vicinity than in 

other places where ore has been mined from the 

Prairie du Chien strata.

The Ohlerking mine, near the center of the 

WiSEisec. 31, T. 7N., R. IE., produced only lead ore. 

It was operated through a shaft about 180 feet deep, 

from which about 275 feet of drift was driven (Chamberlin, 

1882, pp. 516-517). Although the amount of lead ore 

recovered is not known, this was the largest operation 

in the lower ore,zone.

A preliminary survey of the geology of the area, 

including the examination of the old mine dumps, was 

made by Flint before drilling was begun. A geologic 

and structural map (pi. 3) based on information 

gathered during this survey was used for determining 

the location of the drill holes. The topography was 

the only other important factor governing the exact 

location of the holes.

Stratigraphy

Upper Cambrian. The Upper Cambrian 

Trempealeau formation is not exposed in the area 

mapped in the vicinity of Highland but crops out 3 miles 

north. The upper Trempealeau strata are sandstone. 

They consist of white fine and medium subangular to 

subround quartz grains. Green shale partings separate 

the irregular thin sandstone beds.

Lower Ordovician. The Lower Ordovician 

Prairie du Chien group, which includes the mineralized 

zones explored by drilling, conformably overlies the 

Upper Cambrian Trempealeau formation and crops 

out in the northern half of the Wisconsin-Illinois-Iowa 

mining district in the more deeply dissected stream 

valleys. Where observed in the Highland area,this 

group is from 50 to 215 feet thick. Farther west a 

middle sandstone unit separates the dolomite strata 

of the group and permits its division into three formations. An attempt was made to extend this threefold 

division into the area covered by this report; however, 

because of incomplete knowledge of detailed Prairie 

du Chien stratigraphy throughout the mining district, 

it was not possible to identify positively the middle 

formation (fig. 4 and pi. 4), if it is present in the 

Highland area. From the base upward the three formations have been called the Oneota dolomite", New 

Richmond sandstone, and Shakopee .dolomite. Recent 

study by-Flint, however, has shown that these 

members are nor mappable units either in the Highland area or generally in the Wisconsin-Illinois-Iowa 

zinc-lead district.

The Oneota dolomite is mainly a brown-gray 

medium-grained crystalline dolomite. Chert is 

common to abundant 30 to 40 feet above the base and 

in the upper half of the member. Oolitic textures appear 

near the base in both the chert and dolomite. Glauconite 

is common as a minor constituent of the rock. Algal 

(cryptozoon) structures occur locally throughout the 

formation, and near the base two algal zones are 

persistent. Lenses of quartz sandstone and arenaceous 

dolomites occur locally throughout the Oneota, but 

except in the lower 20 feet, approximately, the quartz

represents only a small percentage of the total rock. 

Banded chalcedony and drusy quartz line vugs in both 

the dolomite and chert. Shale is present locally 

throughout the Oneota but does not seem to occupy 

particular stratigraphic zones. Iron sulfide, mainly 

pyrite, is a common constituent of the rock.

In the Highland area the unit designated as New 

Richmond sandstone is an arenaceous shaly bed about 

5 feet thick. In the one exposure where this bed is 

readily identified, a dolomitic sandstone layer about 

1 foot thick, is present. The sand is medium to 

coarse in size and very similar to sand grains of the 

St. Peter sandstone, which is described below.

The Shakopee dolomite is more argillaceous and 

arenaceous than the Oneota. Algal structures are 

common. The beds are generally thin and irregular. 

Shaly and sandy strata are common; locally chert is 

very abundant, and much of it is oolitic.

Middle Ordovician. The Prairie du Chien 

group is overlain by the St. Peter sandstone. 

Where observed in the Highland area, this formation is from 48 to 221 feet thick. The sandstone 

is white to buff, mainly medium grained, but 

coarse at the top and near the base of the formation. The St. Peter is unmineralized except for 

local iron sulfide concentrations.

Above the St. Peter sandstone, the Platteville 

formation has the thin Glenwood shale member at its 

base; the Glenwood is overlain by the Pecatonica 

dolomite member, which is overlain by the McGregor 

limestone member, the highest stratigraphic unit 

penetrated by drilling.

A mantle of residual boulders, sand, clay, and 

soil, which is as much as 8 feet thick, covers the 

area.

Results of geologic mapping

Evidences of mineralization. Considerable 

float galena in many of the stream beds in the Ei 

sec. 3 Land the NWi sec. 32, T. 7 N., R. IE., and 

in the SWjNWi sec. 6, T, 6 N., R. 1 E. was found 

by field investigation of the area before drilling. 

Much of the galena was not broken up and appeared 

to be near its source. In a sharp ravine in the northwest corner of sec. 32, T. 7 N., R. IE., galena was 

found in place, where it is associated with a brown-red 

clay. The dolomite beds are thin and irregular and are 

warped upward into a small dome, the top of which has 

been eroded away exposing the mineral.

In the quarry in the NW^NWi sec. 32 some 

galena was recovered as a byproduct in the quarrying 

activities. The lead mineral here occurs near and 

in a honeycombed chert layer 2 to 3 feet thick. Galena 

filling the voids in large free chert blocks may be 

seen near the entrance to the quarry. Abundant float 

galena occurs in the stream valley in the SW^SEl 

sec. 31, T. 7 N., R. IE., and a lesser amount is 

in the stream valley in the SWiNWi sec. 6, T. 6 N., 

R. IE. Two occurrences of galena seen in outcrops 

are in a zone 110 to 125 feet below the top of the 

St. Peter sandstone. A third occurrence also seen in 

an outcrop is in a zone 140 to 150 feet below the top of 

the St. Peter.
The pits and caved shafts of mines other than 

the Ohlerking mine appear to have been no deeper than 

30 or 40 feet; in fact, most were very shallow and 

seem to have been dug to recover only residual galena 

concentrated at the bedrock surface.

Where galena is seen in outcrops,it is associated 

with thick chert layers and with solutional thinning of 

beds.

No zinc mineral was found in any of the exposures.

Structure. The upper surface of the St. Peter 

sandstone was chosen as the datum plane for structure 

contours because of the exceedingly irregular upper 

surface of the Prairie du Chien group. Much of this 

irregularity is primary and not a reflection of warping 

and flexing of the strata after deposition of the Prairie 

du Chien. However, the relief on the upper surface 

of the St. Peter sandstone is believed to represent 

adjustment to stresses applied to the strata, and these 

adjustments account for the fractures that localize 

mineralization.

As seen on the map of the Highland area (pi. 3), 

the basic structure is a southward-dipping homocline. 

Superposed on it are northeastward-trending minor 

corrugations that may be purely superficial because 

stream dissection has produced moderately steepwalled valleys, and the resulting mass movement of 

both surficial material and the sandstone bedrock may 

account for the minor warping. Furthermore, the 

trend of this minor structure locally tends to parallel 

the topography. Nevertheless, this structure was 

prospected because areas of float galena and old lead 

diggings seem to be located along its trend and because 

such gentle' structures localize mineral deposits in 

the upper ore zone in the main part of the mining 

district. Groups of drill holes alined normal to the 

trend of the corrugated structure were drilled at three 

places (pi. 3).

Results of exploratory drilling

Twelve exploratory holes were drilled between 

February 22 and May 17, 1951, five on the Steil 

property, Ni sec. 6, T. 6 N., R. IE., five on the 

Williams property, SEi sec. 31, T. 7 N. , R. IE., 

and two on the Wiest property, Si sec. 29, T. 7 N., 

R. IE. (pi. 3). Samples were taken of cuttings recovered from each 5 feet of drilling and were examined 

through a binocular microscope. (Summary logs are 

included on pp. 11-36.)

Three holes penetrated zones containing galena, 

samples of which assayed as high as 1. 2 percent lead, 

and traces of galena were found in samples from other 

holes (pi. 4 and summary logs, pp. 11-36). Zinc 

sulfide in present in the samples only as traces.

Iron sulfide is a common constituent of Prairie 

du Chien rocks, and significant amounts are present 

in samples from all the exploratory holes except Steil 3 

which penetrated the very thick St. Peter sandstone 

and only 46 feet of dolomite beds of the Prairie du 

Chien group. Concentrations of iron sulfide occur in 

two general zones, one being 150 to 160 feet below 

the top of the St. Peter, the other 195 to 205 feet 

below that surface. Several samples were estimated 

to contain more than 10 percent iron sulfide, and

an estimate that iron sulfide comprised as much as 

25 percent of one of the samples was corroborated by 

assay. The iron sulfide seems to increase slightly 

in amount from northwest to southeast in each property 

as is shown in the cross sections prepared from 

drill-hole data. This trend is significant because in 

the upper mineralized zone in the main part of the 

mining district the larger zinc deposits commonly 

have an iron sulfide halo that extends peripherally for 

some distance beyond the zinc ore.

At least two periods of chert emplacement are 

indicated. The earlier chert, which is similar to 

that common in the Prairie du Chien over a wide area, 

is glassy and is commonly gray or brown; the later chert 

is porcelaneous, white or cream, and is seen in the 

cuttings to have partly or completely Replaced the 

dolomite. In some of the exploratory holes the later 

chert seems to be associated with the iron deposits. 

Considerable drusy quartz and banded chalcedony 

occur locally in the dolomite and chert. Late dolomite 

is present in the vugs also. No obvious relation was 

noted between the late dolomite, the quartz, and the 

zones mineralized with iron sulfide, although one 

may exist.

The general knowledge of Prairie du Chien 

stratigraphy has been augmented by data from the 

drilling. Oolite zones and more poorly defined zones 

of abundant and sparse chert (pi. 4) were recognized 

in the study of the samples. Changes in lithology 

and rock textures were observed, and it was established that the New Richmond sandstone cannot be 

distinguished with certainty in the Highland area. The 

drilling indicated that, as in the southern and central 

parts of the district, the lithology of the Prairie du 

Chien rocks varies laterally in short distances.

Recommendations

Continued district-wide study of Prairie du 

Chien stratigraphy is desirable. At present not enough 

data regarding these strata in and near the mining 

district are available to locate and describe persistent 

zones and stratigraphic markers. Stratigraphic factors 

affected emplacement of lead and zinc in the GalenaDecorah-Platteville ore zone, and probably the same 

is true of mineral zones in the Prairie du Chien. 

Thus a detailed knowledge of the stratigraphy of the 

mineral-bearing rocks is an important and necessary 

consideration for prospecting in this group.

Although some galena-bearing rock was penetrated 

in the area drilled, no conclusions about the presence 

or absence of zinc and lead ore in the, Prairie du Chien 

strata, generally, can be drawn from the limited 

drilling described in this report.

Future investigation of mineral deposition.in the 

Prairie du Chien in the Highland area should include:

1. Additional drill holes southeastward

along the lines of the exploratory holes 

drilled in 1950-51. Such drilling may 

provide data on the increasing concentration of iron sulfide in that direction 

and on the structural possibilities in 

these localities.

10
2. The cleaning out of the shaft and inspection of the old Ohlerking mine workings. 

The shaft reaches a depth at which it 

should penetrate the zones of iron 

deposition recorded in the drill holes 

on the Williams property. Examination 

of stopes and drifts in this mine should 

reveal structural and stratigraphic 

controls, and the manner of mineral 

emplacement. Such information can be 

obtained only partly by drilling.

LITERATURE CITED

Agnew, A. F., and Heyl, A. V., Jr., 1947, Recent 

developments in the Wisconsin-Illinois-Iowa leadzinc district: Iowa Acad. Sci. Proc. 1946, vol. 53. 

p. 228.

Behre, C. H., Jr., 1939, Wisconsin-Illinois district, 

in Bastin, E. S., and others,, Contributions to a 

knowledge of the lead and zinc deposits of the 

Mississippi Valley region: Geol. Soc. America 

Special Paper 24, pp. 67-70.

Chamberlin, T. C., 1882, The ore deposits of southwestern Wisconsin: Wisconsin Geol. Survey, Geology 

of Wisconsin, vol. 4, pp. 516-517.

Heyl, A. V., Jr., Lyons, E. J., and Agnew, A. F., 

1951, U. S. Geological Survey exploratory drilling 

in the Prairie du Chien group: U. S. Geol. Survey 

Circ. 131.

Owen, D. D., 1840, Report of a geological exploration 

of part of Iowa, Wisconsin, and Illinois, 1839: Cong. 

Doc. 26th Cong. 1st sess., H. Ex. Doc. 239, 161 pp.

Thwaites, F. T., and Howell, J. V., 1935, Topography 

of pre-Cambrian surface: Kansas Geol. Soc. 9th 

Ann. Field Conf., fig. 227.

Thwaites, F. T., Howell, J. V., and Jones, D. D., 

1935, Structure of St. Peter sandstone: Kansas Geol. 

Soc. 9th Ann. Field Conf., fig. 230

Whitney, J. D., 1858, _in Hall, James, and Whitney, 

J. D., Report on the geological survey of the State 

of Iowa, vol. 1, pt. 1, Geology, pp. 438-440, 

[Albany, N. Y.]

Willman, H. B., and Reynolds, R. R., 1947, Geological 

structure of the zinc-lead district: Illinois State 

Geol. Survey Rept. Inc. 124, pp. 14-15.

11
GENERALIZED LOGS OF DRILL-HOLE EXPLORATIONS

Tete des Morts area, Jackson 

and Dubuque Counties, Iowa

Schenk 1

Location: 3,470ft north, 1,510ft east of southwest corner, sec. 3, T. 87 N., 

R. 4 E., Iowa.

Driller: John Hauser, Sept. 21 to Oct. 5, 1950.

Collar elevation: 702. 4 ft.

Total depth: 362 ft.

Depth to water: 45,137| ft:- 1

Sample study and logging: A. F. Agnew, Oct. 5, 

1950.

Surficial:

Soil, loess, dark-brown, 

silty.................

Depth 

(feet)

0 - 35 3

Galena dolomite:

Noncherty unit:

Dolomite, light yellowishbuff, medium-granular, 

in part crystalline, 

cinnamon-specked......

Dolomite, orange-brown, 

coarsely crystalline.....

Dolomite, light-brown.....

Dolomite, as above, in 

part medium-granular...

Dolomite, medium - 

granular, in part 

crystalline, dense......

Dolomite, as above,

red-specked............

Cherty unit:

Dolomite, as above; 

chert, estimated as 

30 percent or lesa ......

Dolomite, drab to 

brown, coarsely 

crystalline; drab 

chert, estimated as 

10 percent or less.......

Dolomite, buff-drab, 

coarsely crystalline; 

gray to white chert) 

estimated as 

25 percent or less ......

Dolomite, light-brown 

to grayish-brown; 

brown chert, estimated as 20 percent 

or less ................

Dolomite, brown, 

coarsely crystalline; 

white chert, estimated 

as 25 percent or less

Dolomite, as above; chert, 

estimated as 5 percent 

or less ................

Dolomite, as above; chert, 

estimated as 40 percent 

or less ................

35 - 57i

57~- 70 

70 2 - 92i

92^-100 

100 -

132|-155 

155 -167| 

167|-175

175 -190

190 -197| 

197i-217| 

217|-236

1 Driller's log shows 0-22 feet surficial. 12

Depth 

(feet)

Decorah formation:

Ion dolomite member ("gray" 

and "blue" beds):

Dolomite, light-gray, 

coarsely crystalline, 

silty, 

black-specked........... 236 -246

Dolomite, brown, 

coarsely crystalline, blackspecked; darkgray, mediumcrystalline, and 

coarsely crystalline, mottled darkgray dolomite.......... . 246 -255

Ion and Guttenberg members:

Limestone, gray, dolomitic, 

very black specked 

and mottled; sandy 

with fine to medium 

quartz and fine 

phosphate nodules; 

brownish-gray coarsely 

crystalline slightly dolomitic sandy limestone; 

light-brown coarsely crystalline mottled and specked 

limestone; fossil - 

iferous................. 255.-260

Guttenberg limestone member 

("oil rock"):

Dolomite, brown, fine- to 

medium-crystalline, mottledbrown; fossiliferous...... 260 -262|

Limestone, brown to lightbrown, finely crystalline, dense, red-specked; 

fossiliferous........... . 262^-275

Spechts Ferry shale member 

("clay bed"):

Shale, green, hard, blackspecked ................ 275 -282|

Platteville formation:

Quimbys Mill member ("glass 

rock"):

Limestone, brown to

dark-brown, fine-grained

and crystalline, dense,

black-specked; dark-brown

hard black-specked

shale ................. . 282^-290

McGregor limestone 

member ("Trenton"):

Limestone, dolomite, grayishbrown, silty, slightly 

mottled brown; fossiliferous; trace of gray hard 

shale................... 290 -29?i

Limestone, light-brown, 

fine-grained, dense; 

fossiliferous; grayisholive hard brown-streaked 

shale................... 297i-302|

Limestone, grayish, finegrained, dense, silty..... 302|-307|
Depth 

(feet) 

Platteville formation Continued

McGregor limestone member Con..

Limestone, as above; 

grayish argillaceous 

material abundant....... . 307i-312|

Limestone, grayishdrab, fine-grained, 

very silty, with grayish 

argillaceous material..... 312^-321 

Pecatonica dolomite member:

Dolomite, brown, finely 

granular, sugary, brown 

resinous blebs; trace of 

brownish-gray organic 

shale.......'............. 321 -325

Dolomite, mottled-gray, 

medium-granular, 

black-specked........... . 325 -330

Dolomite, caramel, mediumgranular, crystalline ..... 330 -335

Dolomite, brown, finely 

granular, sugary, very 

silty; black phosphate 

nodules; trace of coarse 

subrounded quartz sand... . 335 -342^ 

Pecatonica and Glenwood members:

Dolomite, as above, also 

sandy with coarse subrounded quartz; phosphate nodules; grayishgreen sandy shale, with 

organic specks; coarse subrounded quartz sandstone; 

argillaceous and pyritic 

cemented ................ 342^-346

St. Peter sandstone:

Sandstone, quartz, medium

to coarse, subrounded;

dolomitic and siliceous

cement .................. 346 -350

Sandstone, quartz, fine

to medium, angular to

subangular............... 350 -352|

Sandstone, quartz, coarse

to very coarse .......... . 352^-358

Sandstone, quartz, fine

to medium.............. . 358 -362

Schenk 2

Location: SE^NWi sec. 3, T. 87 N., R. 4 E.,

Iowa; 123 feet N. 15° E. from Schenk 1.

Drillers: John Hauser, Michael Griffin, Oct. 6 to 

Oct. 17, 1950.

Collar elevation: 730. 0 ft.

Total depth: 350 ft.

Depth to water: 140 ft.

Sample study and logging: A. F. Agnew, Nov. 1950.

Depth 

(feet) 

Surficial:

Loess.................... . 0 - 40

Loess; trace of buff

granular dolomite......... 40 - 50 l

1 Drillers' log shows 0-40 feet surficial.

Depth 

(feet) 

Galena dolomite:

Noncherty unit:

Dolomite, light-gray,

medium-granular; yellowish

coarsely granular cinnamon

specked dolomite....... . 50- 60

Dolomite, buff to brown,

fine- to medium-grained,

crystalline to

granular................ 60-155

Cherty unit:

Dolomite, as above; white to

brown chert, estimated as

40 percent or less....... 155-180

Dolomite, drab, coarsely

crystalline; chert, estimated

as 25 percent or less... . 180-195 

Dolomite, as above,

mottled-gray; chert, estimated as less than

10 percent............. . 195-210

Dolomite, brown, coarsely

crystalline............ . 210-215

Dolomite, as above; buff,

chert, estimated as

25 percent............. . 215-262

Decorah formation:

Ion dolomite member ("gray" beds):

Dolomite, grayish-brown,

'coarsely crystalline,

 black-specked, silty;

trace of grayish shale...... 262-276

("felue" beds):

Limestone,, gray, coarsely 

crystalline, silty, very 

mottled, fossiliferous...... 276-282

Ion and Guttenberg-members: 

Limestone, light-brown, 

fine-grained, fossiliferous, 

sandy with medium subrounded quartz .......... 282-287

Guttenberg limestone member 

("oil rock"):

Limestone, brown to lightbrown, finely granular to 

dense, yellow-specked, 

very fossiliferous...... . 287-290

Limestone, as above; 

limestone, dark-brown, 

granular, argillaceous.... 290-302

Spechts Ferry shale member 

("clay bed"):

Shale, bluish-green, flaky,*" 

black-specked; gray-brown 

hard shale. Drab very finegrained dense very fossiliferous limestone, with phosphate nodules. White 

limestone............. . 302-309

Platteville formation:

Quimbys Mill member ("glass rock11 ): 

Limestone, brown to darkbrown, medium-granular, 

sugary, fossiliferous; trace 

of dark-brown hard

shale 309-315-

13
Depth 

(feet)

Platteville formation--Continued 

McGregor limestone member 

("Trenton"):

Limestone, gray to grayishbrown, fine-grained, silty; 

trace of grayish-brown brownspecked shale .......... . 315-325

[No sample] .............. . [325-330]

Limestone, gray to olive, 

very fine grained, very 

dense; very fossil - 

iferous; silty, with greenish 

argillaceous areas......... 330-347

Pecatonica dolomite member:

Limestone, dolomitic, grayishbrown, finely granular, 

silty, yellow-specked.... . 347-350

Estimated iron content

Galena dolomite--Continued

Noncherty unit--Continued 

Dolomite, yellowishbuff, medium-granular 

to coarsely-granular, 

crystalline ...........

[No sample] ............

Cherty unit:

Dolomite, brown to drab, 

medium - crystalline; 

brown-mauve -cream 

chert ................

Depth 

(feet)

50 -155 

[155-160]

160-265

Depth 

(feet) Percent

160-165 ................ 2

165-170 ............... 4

17.0-175 ............... 3

175-180 ................ 3

180-185 ............... 4

185-190 ............... 5

Decorah formation:

Ion dolomite member 

("gray"and"blue" beds):

Dolomite, drab, coarsely 

crystalline, gray-specked; 

trace of dark-greenishgray, silty shale ....... .

Guttenberg limestone member 

("oil rock"):

Limestone, brown to 

light-brown, finely 

granular, brownspecked .............. .

Spechts Ferry shale member 

("clay bed"):

Shale, green, fossiliferous; olive hard blackspecked shale............

265-286

286-302

302-307

190-195 

195-200 

200-205 

205-210 

210-215

5 

4 

1 

1 

Tr.

295-300 ............... Tr.

300-304 ................ 2

304-305 .............. 

Schenk 3

Location: SEirNWi sec. 3, T. 87 N., R. 4 E., Iowa;

113 ft S. 20° 45 ft W. from Schenk 1. 

Driller: John Hauser, Oct. 18 to Oct. 27, 1950. 

Collar elevation: 719. 7 ft. 

Total depth: 351 ft. 

Depth to water: 95,145 ft. 

Sample study and logging: A. F. Agnew, Dec. 1950.

Depth 

(feet)

Platteville formation:

Quimbys Mill member ("glass rock"):

Limestone, buff to brown, finely 

granular, crystalline, dense; 

fossiliferous; trace of 

dark-brown brownspecked shale............. 307-315

McGregor limestone member 

("Trenton"):

Dolomite, grayish-brown 

to brown, coarsely granular, 

mostly crystalline........ 315-325

Limestone, brownishgray, fine-grained, dense; 

fossilif erous; 

argillaceous. Grayish 

medium-granular silty % 

dolomite ............. . 325-335

Dolomite, drab, slightly 

mottled gray, finely 

granular, silty........... 335-347

Pecatonica dolomite member:

Dolomite, as above, but 

with brown specks; not 

silty ................. . 347-351

Estimated iron content

Surficial: 

Loess 0-45 1

Galena dolomite:

Noncherty unit:

Dolomite, gray, mediumgranular; yellowish-brown 

coarsely granular very 

cinnamon-specked 

dolomite ............... ,

1 Driller's log shows 0-37 feet surficial.

45-50

Depth 

(feet)

165 -170 

170 -175 

175 -180 

180 -182i 

182i-185 

185 -190 

190 -195 

195 -200

Percent

3

4

3

4

.75

2

2

1

14
Schenk 3--Continued

Estimated iron content Continued

Depth 

(feet)

Depth 

(feet)

200 -205 

205 -210 

210 -215 

215 -220 

220 -225 

225 -230

295 -300 

300 -305 

305 -307i 

307i-310

340 -345 

345 -350

Percent

.25 

Tr. 

.75

1 

Tr.

.5 

1

1.5 

1

.25 

Tr.

Schenk 4

Location: SE|NWl sec. 3, T. 87 N., R. 4 E., Iowa;

216 ft S. 22° W. from Schenk 1. 

Drillers: John Hauser, R. E. Griffin, Oct. 28 to

Nov. 11, 1950. 

Collar elevation: 726. 0 ft. 

Total depth: 335 ft. 

Depth to water: 97 ft. 

Sample study and logging: A. F. Agnew, Dec. 20,

1950.

Surficial:

Loess, brown ............

Loess; glacial sand, quartz, 

chert, quartzite, jasper, 

coarse to very coarse, 

subangular.............. .

Galena dolomite:

Noncherty'unit:

Dolomite, light-gray, 

granular, crystalline; 

light-brown medium - 

granular red-specked sandy 

dolomite; trace of depauperate material ............ .

 Dolomite, buff to brownish, 

otherwise as 

above .................. .

Cherty unit:

Dolomite, as above; gray 

to light-brown 

chert .....................

Dolomite, grayish or 

drab, otherwise as 

above ...................

Dolomite, brown to 

light-brown, 

mottled..................

1 Driller's log shows 0-50 feet surficial.

Depth 

(feet)

0- 35

35- 52 1

Decorah formation:

Ion dolomite member 

("gray" beds): 

Dolomite, gray to buff, 

medium-crystalline, 

black-specked...........

("blue" beds): 

Dolomite, light-gray, 

medium-granular, 

crystalline, very 

black specked; in 

part sandy with medium 

sub rounded quartz and 

medium black phosphate 

nodules.................

Guttenberg limestone member 

("oil rock"): 

Limestone, brown to 

cream, mediumcrystalline, brownspecked; cream to tan 

very fine dense 

red-specked 

limestone ............. .

Spechts Ferry shale member 

("clay bed"):

Shale, green to grayish, 

soft; orange-buff 

fine-grained 

medium-granular, 

crystalline fossiliferous 

limestone; trace of phosphate nodules............

285-298

298-306

306-315

312-321

Platteville formation:

Quimbys Mill member 

("glass rock"): 

Limestone, dark-brown to 

brown, fine-grained, dense, 

dark-brown specked; trace of

dark-brown shale.......

McGregor limestone member 

("Trenton"):

Limestone, buffish-gray, 

mottled, finely granular, 

silty...................

Estimated iron content

321-326

326-335

52- 70

70-170

170-215

215-235

235-285

Depth 

(feet)

50- 55 

55- 60 

60- 65

170-175

175-180.

180-185

185-190

190-195

195-200

200-205

205-210

210-215

215-220

Percent

0.5 

2

Tr.

Tr. 

.25 

2

.75 

Tr. 

.5 

.25 

.75 

.5 

.5

15
Schenk 4--Continued

Estimated iron content--Continued

Depth 

(feet)

Depth 

(feet)

220-225

305-315.

315-320

320-325

Percent

Tr.

Decorah formation--Continued

Spechts Ferry shale member 

("clay bed"):

Shale, green; limestone, 

brown, phosphate 

nodules; trace of 

light-gray 

bentonite............

Schenk 5

Location: SE|NWi sec. 3, T. 87 N. , R. 4 E. , Iowa;

318 ft S. 21° W. from Schenk 1. 

Drillers: John Hauser, R. E. Griffin, Nov. 14

to Nov. 29, 1950. 

Collar elevation: 731. 8 ft. 

Total depth: 340 ft. 

Depth to water: 145 ft. 

Sample study and logging: A. F. Agnew, Jan. 1951.

Platteville formation:

Quimbys Mill member ("glass rock"): 

Limestone, light- to dark-brown, 

finely granular, crystalline,

dark-brown specked

323-330

330-340

Estimated iron content

[ No visible zinc except for a trace at the 65- to 

70-foot -depth.]

Surficial:

Loess, brown............. .

Loess, as above; glacial sand, 

estimated as much as 

70 percent; gray 

till.......................

Till, as above; trace of sand, 

as above; depauperate 

pebbles, estimated as 25 percent or less............. .

Galena dolomite:

Noncherty unit:

Dolomite, brown to lightbrown, finely granular to 

medium-granular, cinnamonspecked. .................

Cherty unit:

Dolomite, light-brown to 

grayish-brown, mediumcrystalline; white to brown 

chert.................. .

Decorah formation:

Ion dolomite member 

("gray" and "blue" beds): 

Dolomite, brown-gray, 

medium-crystalline, 

gray-specked; 

trace of greenish 

shale................... .

Ion and Guttenberg members: 

Limestone, dolomitic, 

grayish-brown, mediumcrystalline, gray-specked; 

sandy with medium subrounded quarts ....... '.. .

Guttenberg limestone member 

("oil rock"):

Limestone, light-brown to 

tan, fine-grained, dense; 

fossiliferous; dark-brown 

argillaceous matter.......

Depth 

(feet)

0-35

35-50

50-58

58-180

180-287

Depth 

(feet)

50-55 

55-60 

60-65 

65-70 

770-75

125-130 

130-135 

135-140

185-190 

190-195 

195-200 

200-205 

205-210

280-285 

285-290 

290-295 

295-300

315-320 

320-325 

325-330 

330-335 

335-340

Percent

Tr.

Tr.

Tr.

.25 

5

4

5 

Tr.

.5

.25

Tr.

Tr. 

.25 

.75 

.25 

Tr.

287-308

308-310

310-323

Schenk 6

Location: SEiNWi sec. 3, T. 87 N., R. 4 E., Iowa;

252 ft N. 24* E. from Schenk 1. 

Driller: John Hauser, Nov. 30 to Dec. 14, 1950. 

Collar elevation: 733. 7 ft. 

Total depth: 315 ft. 

Depth to water: 150 ft. 

Sample study and logging: A. F. Agnew, Dec. 1950.

Depth 

(feet)

1 Drillers' log shows 0-57 feet surficial.

16

Surficial:

Loess, brown) trace of

depauperate pebbles at base.., 0-35
Depth 

(feet)

Schenk 6 Continued

Estimated iron content Continued

Galena dolomite:

Noncherty unit:

Dolomite, yellowishbrown to brown, mediumgranular, mostly 

crystalline .............

Cherty unit:

Dolomite, grayish-drab to 

buff, medium - 

crystalline to coarsely 

crystalline; brown to 

flesh-colored chert 

varying to cotton 

rock...................

35-155

Depth 

(feet)

190-195 

195-200 

200-205

155-264

Decorah formation:

Ion dolomite member 

("gray" beds): 

Dolomite, gray to buff, 

medium-granular, grayspecked. ................. 264-277

("blue" beds):

Limestone, dark-gray to 

- brown, mottled; 

argillaceous; very 

fossiliferous; subrounded 

quartz sand and 

phosphate nodules......... 277-284

Guttenberg limestone-member 

("oil rock"):

Limestone, light-brown, 

medium-crystalline, 

mottled; fossiliferous; 

silty. Light-brown to 

tan fine-grained dense 

argillaceous limestone; 

with brown specks.......

Spechts Ferry shale member 

("clay bed"):

Shale, green to gray-green, 

very fossiliferous. White 

to light grayish-brown 

fine-grained limestone 

containing phosphate nodules and fossils .........

210-215.. 

215-220. 

220-225. 

225-230 . 

230-235 .

265-270 . 

270-275 

275-280 , 

280-285 

285-290 , 290-295

300-305 

305-310 

310-315

Schenk 7

Percent

.75 

Tr.

.25 

Tr. 

.5 

1 

Tr.

Tr. 

.5 

.25 

Tr. 

1 

Tr.

.25 

1 

.5

284-300

Location: NEiSWi sec. 3, T. 87 N., R. 4 E., Iowa;

1, 086 ft S. 32° 30 ft E. from Schenk 1. 

Drillers: John Hauser, Gilbert Reiter, Dec. 21, 1950,

to Jan. 5, 1951. 

Collar elevation: 720.0 ft. 

Total depth: 312ft.' 

Depth to water: - - - 

Sample study and logging: A. F. Agnew, Jan. 16, 1951.

Depth 

(feet)

Surficial:

Loess, brown

300-306

Platteville formation:

Quimbys Mill member:

Limestone, gray-brown, 

fine-grained, dense; 

argillaceous; . 

trace of dark-brown 

shale ...............

Galena dolomite:

Noncherty unit:

Dolomite, yellowish-buff, 

medium-granular, crystalline, cinnamon-specked... 

Cherty unit:

Dolomite, brownish-drab, 

medium-crystalline; gray 

to brown chert...........

0- 25 1

25-150

150-258

306-315

Estimated iron content

[No visible zinc except for a trace at the 285- to 

290-foot depth]

Depth 

(feet)

165-170 ... 

170-175 ... 

175-180 ... 

180-185 .. 

185-190 ....

Percent

0.25

.5

17

Decorah formation:

Ion dolomite member ("gray" beds):

Dolomite, light-gray to brown, 

medium-crystalline, grayspecked; trace of green hard 

silty shale........;...... .

("blue" beds):

Dolomite, calcareous, gray, 

medium-crystalline, 

gray-specked; in part sandy; 

greenish argillaceous 

areas.................... .

1 Drillers' log shows 0-27 feet surficial.

258-273

273-280
Depth 

(feet)

Decorah formation Continued

Guttenberglimestone member ("oilrock"): 

Limestone, cream to 

brown, fossiliferous, 

brown-specked .......... . 280-295

Spechts Ferry shale member 

("clay bed"):

Shale, green; bentonite;

gray limestone ............ 295-301

Platteville formation:

Quimbys Mill member 

("glass rock"):,

Limestone, brown to 

cream, fine-grained, 

fossiliferous; 

brown argillaceous areas; 

trace of dark-brown 

shale ..................

McGregor limestone member 

("Trenton"):

Limestone, light-gray, 

fine-grained, silty.......

Depth

301-311

311-312

Estimated iron and manganese content

Depth 

(feet)

Percent 

Iron Manganese

145-150 .................... Tr.

150-155 .................... 0.5

155-160 .................... 2 Tr.

160-165 .................... 6 1

165-170'.................... 7 1

170-175 .................... 6 1

175-180 .................... 5 .25

180-185 .................... 4 Tr.

185-190 .................... 3 Tr.

190-195 .................... Tr.

Schenk 8

Location: SEiNWi sec. 3, T. 87 N., R. 4 E., Iowa;

1, 240 ft S. 47° 45 ft E. from Schenk 1. 

Drillers: John Hauser, Robert Dagenhardt, Jan. 10

to Jan. 18, 1951. 

Collar elevation: 718. 4 ft. 

Total depth: 301 ft. 

Depth to water: 125 ft. 

Sample study and logging: A. F. Agnew, Feb. 27, 1951.

Depth 

(feet)

Decorah formation:

Ion dolomite member 

("gray" beds):

Dolomite, gray, mediumgranular, and buff, mediumcrystalline, gray-specked; 

some greenish argillaceous 

matter..................... 250-260

("blue" beds):

Limestone, gray, medium-crystalline, very fossiliferous; in part 

sandy; greenish argillaceous 

and shaly material........... 260-270

Guttenberg' limestone member 

("oil rock"):

Limestone, cream to buff, 

fine-grained, dense, fossiliferous; brown shale........ . 270-285

Spechts Ferry shale member 

("clay bed"):

Shale, green, flaky, soft; 

very fossiliferous. Lightgreenish fine-grained 

limestone containing phosphate nodules ............. . 285-290

Platteville formation:

Quimbys Mill member 

("glass rock"):

Limestone, tan to dark-brown, 

fine-grained, dense; brownish 

argillaceous areas. Darkbrown shale............... . 290-300

McGregor limestone member 

("Trenton"):

Limestone, gray, finely 

granular, sugary........... . 300-301

Schenk 9

Location: SWiNEi sec. 3, T. 87 N., R. 4 E., Iowa;

1, 634 ft S. 62° E. from Schenk 1.

Driller: Robert Dagenhardt, Jan. 20 to Jan. 31, 1951. 

Collar elevation: 720.4 ft. 

Total depth: 305 ft. 

Depth to water: 125 ft. 

Sample study and logging: A. F. Agnew, Feb. 27,

1951.

Depth 

(feet)

Surficial:

Loess, brown.

Surficial:

Loess, brown

Galena dolomite:

Noncherty unit:

Dolomite, yellowish-brown, 

medium-granular, 

crystalline .............

Cherty unit:

Dolomite, grayishbrown; chert............

0- 25 1

25-140 

140-250

Galena dolomite:

Noncherty unit:

Dolomite, lightbrown, mediumgranulaE........

Cherty unit:

Dolomite, grayishbrown; 

grayishbrown 

chert...........

0- 38*

38-140

140-250

1 Drillers' tog shows 0>30 feet surficial. 1 Driller's log shows 0-35 feet surficial.

18
Depth 

(feet)

Decorah formation:

Ion dolomite member 

("gray" beds):

Dolomite, light-gray to 

grayish-brown, mediumcrystalline, gray-specked; 

in part silty.............. . 250-265

("blue" beds):

Limestone, gray, medium-granular, crystalline, grayspecked; fossiliferous; 

in part sandy............... 265-272

Guttenberg limestone member 

(oil rock"):

Limestone, brown to 

buff, fine-grained, dense, 

mottled; fossiliferous; 

brown shale.............. . 272-287

Spechts Ferry shale member: 

Shale, green, very fossiliferous; cream finegrained dense fossiliferous limestone, 

containing phosphate 

nodules ................. . 287-295

Platteville formation:

Quimbys Mill member 

("glass rock"):

Limestone, brown to darkbrown, fine-grained, dense; 

trace of dark-brown 

shale .....................

McGregor limestone member 

("Trenton"):

Limestone, light-brownish 

gray, finely granular, 

sugary, slightly 

mottled ...................

295-301

301-305

Kohlenberg 1

Location: 4, 302 ft north, 504 ft west of southeast

corner, sec. 4, T. 87 N., R. 4 E.,

Iowa. 

Drillers: John Hauser, Gilbert Reiter, Dec. 6 to

Dec. 26, 1950. 

Collar elevation: 732.0 ft. 

Total depth: 244ft. 

Depth to water: 215 ft. 

Sample study and logging: A. F-. Agnew, Jan. 16,

1951.

Surficial:

Loess, brown; 

glacial sand .

Depth 

(feet)

0- 16 1

Galena dolomite:

Noncherty unit:

Dolomite, yellowishbrown, medium-granular; 

in part silty................ 16-60

Dolomite, as above; caramel dull

chert(high-level gravel caved).. 60-105

1 Drillers' log shows 0-15 feet surficial.

Depth 

(feet)

Galena dolomite Continued

Noncherty unit Continued

Dolomite, brown, mottled,

granular,

brown-specked ........ . 105-125

Cherty unit:

Dolomite, as above;

caramel to brown to

pink chert; buff to cream

fine- and medium-grained

limestone; much

calcite ................. 125-155

Dolomite, as above; grayisnbrown medium -crystalline

vuggy dolomite; calcite,

limonite; chert, as above...... 155-205

Dolomite, brown as above; dolomite, calcareous, buff, calcite. 205-210 

[No sample].............. [210-230]

Dolomite, brown and

buff, as above ........ . 230-231

Decorah formation:

Ion dolomite member 

 ("gray" beds):

Limestone, lightbrownish, mediumgranular; in part grayspecked; much calcite; 

trace of olive-green 

black-specked silty 

shale ................

[No sample] ............

[231-240] 

[240-244]

Drillers reported considerable difficulty in the 

lower part of the hole. At 214 feet a "pitchoff" 

(fracture that turned the bit away from vertical) was 

penetrated. The rock was hard drilling until 219 feet, 

where a second pitchoff was struck. From 219 to 

225 feet, soft drilling was accompanied by sanding of 

the hole. At 225 feet the hole was reamed and casing 

was set to stop the sanding. From 225 to 230 feet 

drilling required 2 days (normal footage per,day is 

30 to 40 feet). The hole was reamed to 230 feet and 

casing set at that depth. From 215 to 230 feet no 

cuttings were recovered because flow of water underground washed them away in a fracture. Drilling 

proceeded in soft rock to 244 feet, where two bits and 

the bailer were stuck. After these were recovered, 

rocks and a fence post .thrown into the hole were 

carried away by the underground flow of water, as 

were the cuttings for the 240- to 244-foot interval. 

The hole was abandoned.

The cuttings from 230 to 240 feet indicate that 

the trouble was caused by an "opening" in a crevice 

zone and not by a slump joint.

Estimated iron content

Depth 

(feet)

180-185. 

185-190 

190-195

Percent

Tr.

1

2

19
Kohlenberg I Continued

Estimated iron content Continued

Depth 

(feet)

Depth 

(feet)

195-200 

200-205. 

205-210 

210-215

Kohlenberg 2

Percent

'5 

2 

1 

1

Platteville formation:

Quimbys Mill member ("glass rock"): 

Limestone, cream, finegrained; dolomitic brown 

fine-grained argillaceous 

limestone, containing 

fossils; trace of darkbrown shale ..............

McGregor limestone member 

("Trenton"):

Trace of limestone, light-gray, 

finely granular, sugary.....

235-245

245

Location: NE^NE-? sec. 4, T. 87 N., R. 4 E., Iowa;

442 ft N. 44° E. from Kohlenberg 1. 

Driller: John Hauser, Dec. 28, 1950,to Jan. 9,

1951.

Collar elevation: 689. 0 ft. 

Total depth: 245 ft. 

Depth to water: 110 ft. 

Sample study and logging: A. F. Agnew, Jan. 16,

1951.

Galena dolomite:

Noncherty unit:

Dolomite, yellowishbuff, medium-granular, 

silty .................

Cherty unit:

Dolomite, as above, 

mottled; chert.........

Dolomite, calcareous, 

light-brown, mediumgranular, crystalline; 

white medium-crystal- 

 line limestone;

chert.................

Depth 

(feet)

0- 90 1

90-165

165-192

Kohlenberg 3

Location: SEiSEi sec. 33, T. 88 N. , R. 4 E. , Iowa;

965 ft N. 23° E. from Kohlenberg 1. 

Driller: John Hauser, Jan. 15 to Jan. 23, 1951. 

Collar elevation: 734. 7 ft. 

Total depth: 291 ft. 

Depth to water: 160ft. 

Sample study and logging: A. F. Agnew, Feb. 28,1951.

Depth 

(feet)

Surficial:

Loess, brown,

Galena dolomite:

Noncherty unit:

Dolomite, yellowish-brown, 

medium-granular..........

Cherty unit:

Dolomite, as above; chert....

Dolomite, as above;

in part calcareous ........

0- 15

15-125 

125-21C

210-233

Decorah formation:

Ion dolomite member 

("gray" beds):

Dolomite, gray to 

buff, mediumcrystalline, mottled; 

greenish and brownisholive black-specked 

shale.................. .

("blue" beds):

Limestone, dolomitic, 

gray, mediumcrystalline, argillaceous; 

mottled, silty; 

fossiliferous............

Guttenberg limestone member 

("oil rock"):

Limestone, cream to 

brown, fine-grained, very 

fossiliferous............

Spechts Ferry shale member 

("clay bed"):

Shale, green, splintery; 

phosphate nodules; 

bentonite................

1 Driller's log shows 0-2% feet surficial.

192-207

207-215

215-229

229-235

Decorah formation:

Ion dolomite member 

("gray" and "blue" beds): 

Limestone, brown to 

cream to gray, in part 

mottled olive; trace of 

olive shale............... 233-250

Limestone, as above, 

silty, black-specked, 

fossiliferous; 

fine phosphate 

nodules................... 250-255

Guttenberg limestone member 

("oil rock"):

Limestone, cream to brown, 

fine-grained, dense, brownspecked; brown shale....... 255-275

Spechts Ferry shale member 

("clay bed"):

Shale, green, soft; grayish-brown fine-grained 

fossiliferous limestone, 

containing phosphate 

nodules.................... 275-281

Platteville formation:

Quimbys Mill member ("glass rock"): 

Limestone, light-brown to gray, 

fine-grained, dense, fossil-, 

iferous.................... 281-291

20
Kohlenberg 4 Estimated manganese content

Location: NEiNEi sec. 4, T. 87 N., R. 4 E., Iowa;

42ft N. 44°31 ft W. from Kohlenberg 1. 

Driller: John Hauser, Jan. 25 to Feb. 15, 1951. 

Collar elevation: 734. 5 ft. 

Total depth: 287 ft. 

Depth to water: 

Sample study and logging: A. F. Agnew, Feb. 28,

1951.

Depth 

(feet) Percent

235-240...................... 3

Highland area, Iowa and 

Grant Counties, Wis.

Surficial:

Loess, glacial 

sand .......

Depth 

(feet)

0- 20

Galena dolomite:

Noncherty unit:

Dolomite, buff, mediumgranular, cinnamonspecked; trace of 

Silurian-type 

chert (caving)...........

Cherty unit:

Dolomite, as above;

chert...................

Dolomite, as above; 

white medium - 

crystalline limestone ....

Decorah formation:

Ion dolomite member 

("gray" beds):

Limestone, light-gray to 

buff, mediumcrystalline, grayspecked; green and olive 

silty shale ..............

("blue" beds):

Limestone, light-gray, 

finely crystalline, 

mottled, fossiliferous, 

sandy ..................

Guttenberg limestone member 

("oil rock"):

Limestone, cream to 

tan, finely crystalline, 

granular,

dense, brown-specked, 

fossiliferous............

Spechts Ferry shale member 

("clay bed"):

Shale, green, fossiliferous, 

phosphate nodules........

Platteville formation:

Quimbys Mill member 

("glass rock"):

Calcareous rock flour, 

tan; trace of dark-brown 

shale ..................

McGregor limestone member 

("Trenton"):

Limestone, gray, finely 

granular................

Wiest 1

Location: 1,130 ft north, 1,805 ft east of southwest corner, sec. 29, T. 7 N. , 

R. IE., Wis.

Drillers: J. Hauser, R. Dagenhardt, Mar. 22 to 

Apr. 14, 1951.

Collar elevation: 1, 084. 8 ft.

Total depth: 275 ft.

Depth to water: 115 ft.

Sample study and logging: Arthur E. Flint, Apr. 20, 

1951.

20-130 

130-205 

205-233

[Percentages estimated]

Soil, residual clay,

Platteville formation:

Glenwood shale member:

Shale, gray-green, partly 

arenaceous............

Depth 

(feet)

0- 3

3- 5

233-248

248-253

253-270

270-275

275-286

286-287

St. Peter sandstone:

Sandstone, quartz, lightgray, buff, medium-coarse; 

coarse upper 10 feet, 65 to 

75 feet, and lower 20 feet. 

Many grains show crystal 

overgrowths, local dolomitic 

cement................ .

Prarie du Chien group: 

Shakopee dolomite:

Dolomite, buff, fine- and 

medium-grained; green 

arenaceous shale, very 

common; chert, sparse; 

quartz sand (caved), 

common................

Dolomite, as above; oolitic 

chert, abundant; green 

shale, caving(?) common; 

quartz sand, caved, common; 

iron 1 percent ...........

Dolomite, as above, partly 

arenaceous; chert, as above; 

quartz sand, common; iron 

1 percent...............

Dolomite, buff, fine-grained; 

oolitic chert, very common; 

quartz sand, common; 

iron -|'percent'...........

5-107

107-115

115-120

120-125

125-130

21
Depth 

(feet)

Prairie du Chien group--Continued 

New Richmond sandstone(?): 

Dolomite, brown, very

arenaceous; green

arenaceous shale;

chert, sparse; quartz

sand, abundant; iron

1 percent............... .

Oneota dolomite:

Dolomite, brown,

fine- and medium-grained;

chert, abundant;

green shale and quartz

sand, common;

iron -1 percent...........

Dolomite, as above;

chert, common;

green shale and

quartz sand, sparse;

iron -7f percent...........

Dolomite, as above;

chert, very abundant;

green shale, common;

iron 1 percent........... .

Dolomite, as above;

chert, very abundant;

green shale, sparse;

iron -1 percent.......... .

Dolomite, as above; chert,

very abundant; shale, as

above; iron -1 percent......

Dolomite, as above;

chert, very abundant;

limonite and hematite

estimated as

3 percent............... .

Dolomite and chert, as

above; green shale, very

common; iron -^ percent... 

Dolomite and chert, as

above;trace of

glauconite .............. .

Dolomite, as above; chert

estimated as 90 percent

of sample; green shale,

sparse ................ .

Dolomite, as above; chert,

very abundant; iron

1 percent.................

Dolomite, gray, fine- and

medium-grained; chert,

common; iron

-1 percent ............. .

Dolomite, as above,

medium-grained; chert,

common; trace of

glauconite................

Dolomite, as above;

chert, common to sparse;

iron -1 percent...........

Dolomite, brown, mediumgrained, granular; chert,

as above; iron

I percent............... .

Dolomite, as above; chert,

abundant; iron

4 percent ................

130-135

135-140

140-145 

145-150

150-155 

155-160

160-165 

165-170 

170-175

175-180 

180-185

185-190

190-195 

195-200

200-205 

205-210

Prairie du Chien group Continued 

Oneota dolomite Continued

Dolomite, as above; chert, 

sparse; iron 

1 percent..................

Dolomite, as above; browngreen shale, common; 

iron 1 percent............ .

Dolomite, as above; chert 

and shale, sparse......... .

Dolomite, as above; green 

shale, sparse............ .

Dolomite, as above; oolitic 

chert, abundant............

Dolomite, as above, 

granular; green shale, 

common .................. .

Dolomite, as above, partly 

oolitic; green shale, oolitic 

chert, and quartz sand, 

sparse................... .

Dolomite, as above,

arenaceous; chert, as above; 

green shale and quartz 

sand, sparse ..............

Dolomite, as above; mediumcoarse rounded quartz 

sa'ndstone, abundant.........

Dolomite, as above; chert, 

sparse; sandstone, as above, 

abundant................. .

Depth 

(feet)

210-215

215-220 

220-230 

230-235 

235-245

245-255 

255-260

260-265 

265-270 

270-275

Wiest 2

Location:. Sec. 29. T. 7N., R. 1 E., Wis.; 315 ft S. 52°E.

from Wiest 1. 

Drillers: R. Dagenhardt, J. Dagenhardt, May 3 to

May 17, 1951.

Collar elevation: 1, 083. 4 ft. 

Total depth: 235 ft. 

Depth to water: 

Sample study and logging: Arthur E. Flint, May 27, 1951.

[Percentages estimated]

Soil, residual clay,

St. Peter sandstone:

Sandstone, quartz, lightgray and buff, medium and 

medium-coarse except 

coarse near top andbase..,

Depth 

(feet)

0- 4

4-62

Prairie du Chien group: 

Shakopee dolomite:

Shale, buff, very abundant; 

oolitic chert, abundant; 

brown- gray dolomite, 

sparse ..................

Dolomite, brown, fine- and 

medium-grained; buff shale, 

very abundant; quartz sahd, 

very common (caving)......

62-65

65-70

22
Depth 

(feet)

Depth 

(feet)

Prairie du Chien group Continued 

Shakopee dolomite Continued 

Dolomite, as above,

fine- and medium-grained; 

oolitic chert, abundant; 

quartz sand, sparse; iron

-1 percent...............

Dolomite, chert, and

quartz sand, as

above .................. .

Dolomite, as above; partly

oolitic chert; quartz sand

as above; iron

-1 percent ...............

Dolomite and chert, 

as above; quartz sand, 

common; green shale, 

sparse; iron

-1 percent ...............

Dolomite, as above; chert,

as above, abundant;

red-brown shale, very

common; quartz sand,

sparse;iron

1 percent................

Dolomite, as above, partly

arenaceous; chert, common;

iron -1 percent............

Dolomite, as above; chert,

very common; green shale

and quartz sand,

sparse ................. .

Dolomite, nonarenaceous,

and chert, as above;

quartz sand, sparse;

iron -1 percent'.......... .

Dolomite, brown, fineand medium-grained;

chert, common;

iron +1 percent ..........

Dolomite and chert,

as above; quartz sand,

common; iron

-1 percent ...............

New Richmond sandstone(?): 

Dolomite, as above, 

partly arenaceous; 

green-brown arenaceous 

shale, common; chert, 

common; iron

-1 percent.............. .

Oneota dolomite:

* Dolomite, as above; chert, 

abundant; iron

-1 percent.............. .

Dolomite, brown,

fine- and medium-grained; 

chert, common ...........

Dolomite, as above; chert, 

as above, sparse to 

common................ .

Dolomite, as above; 

chert, as above; 

iron -1 percent.......... .

Dolomite, as above; 

chert, abundant; redbrown shale, sparse to common; iron 3 percent ...... .

70-75 

75-80

80-85 

85-90

90-95 

95-100

100-105 

105-110 

110-115 

115-120

120-125

125-130 

130-135 

135-140 

140-145

145-150

Prairie du Chien group Continued 

Oneota dolomite Continued 

Dolomite, gray-brown, 

fine- and medium-grained; 

chert, abundant; iron

5 percent.............. .

Dolomite, as above; chert, 

very abundant; iron

6 percent............. .

Dolomite, as above; chert, 

abundant; iron 2 percent; 

trace of zinc ........... .

Dolomite, gray, mediumgrained; chert, very 

abundant; iron 1.percent; 

trace of zinc............

Dolomite and chert, as

above; iron 1 percent; trace 

of zinc .................

Dolomite, as above; chert, 

sparse to common; iron 

._ +1 percent............ .

Dolomite, as above; chert, 

sparse;, iron 

+ 1 percent..............

Dolomite and chert, as 

above; iron

-1 percent............ .

Dolomite, as above; iron

-1 percent............. .

Dolomite, as above;

chert, sparse to

common.............. .

Dolomite, as above;

chert, sparse.......... .

Dolomite and chert, as

above;iron

1 percent...............

Dolomite, as above; gray

shale, very common;

iron -1 percent......... .

Dolomite, gray, medium- 

. grained, granular; gray

shale, abundant..........

Dolomite, as above; chert,

sparse................ .

Dolomite, as above; chert,

sparse to common; iron

\ percent ............. .

Dolomite, as above; chert,

sparse................ .

150-155 

155-160 

160-165

165-170 

170-175 

175-180 

180-185

185-190 

190-195

195-200 

200-205

205-210 

210-215

215-220 

220-225

225-230 

230-235

Williams 1

Location: 1,455 ft north, 1, 700 ft west of southeast 

corner, sec. 31, T. 7 N., R. IE., Wis.

Driller: R. Dagenhardt, Feb. 22 to Mar. 5, 1951.

Collar elevation: 1,116. 6 ft.

Total depth: 330ft.

Depth to water: 50 ft.

Sample study and logging: Arthur'E. Flint, Mar. 10, 

1951.

23

[Percentages estimated]

Soil, residual clay, weathered limestone fragments.........

Depth 

(feet)

0-5
Depth 

(feet)

Depth 

(feet)

Platteville formation:

McGregor limestone member: 

Limestone, brown and 

gray, medium- and 

fine-grained, 

fossiliferous..........

Pecatonica dolomite member: 

Dolomite, gray and buff, 

medium-granular, 

arenaceous in lower 

2 feet; phosphatic 

nodules common 

near base.............

Glenwood shale member: 

Shale, gray-green; a 

few phosphatic nodules; 

limonite common.......

5- 32

32- 47

47- 50

St Peter sandstone:

Sandstone, quartz, 

light-gray and buff, 

medium-grained 

except coarse near base 

in the 85- to 90-foot 

sample and near top of 

formation; limonite common 

near base............... .

Prairie du Chien group: 

Shakopee dolomite:

Shale, light-green and 

gray; oolitic and 

arenaceous chert, 

common; limonite, 

common................ .

Dolomite and dolomitic 

siltstone, buff, finegrained; oolitic chert, 

very abundant; green 

shale, common; quartz 

sand (caving) and limonite, 

common; trace of 

glauconite .............. .

Dolomite, light-brown, 

some arenaceous, 

fine- and mediumgrained; chert, much is. 

oolitic, abundant; gray 

and green shale, very 

common................ .

Dolomite, as above; 

chert, some oolitic, 

very common ........... .

Dolomite, as above; chert, 

very common; quartz 

sand cememted with 

silica, very common......

Dolomite, as above, 

much is arenaceous, 

and dolomitic sandstone; chert, sparse; 

quartz sand, common..... 

New Richmond sandstone(?):

Dolomite, as above; chert, 

sparse; green shale, common; 

quartz sand cemented with 

limonite, common ..... .

50-123

123-125

125-130

130-135

135-140

140-145

145-150

150-155

Prairie du Chien group--Continued 

Oneota dolomite:

Dolomite, as above,

some medium-grained;

chert, sparse to common;

quartz sand,

common .............. .

Chert, light-gray,

glassy, estimated as

80 percent of sample;

dolomite, as above ......

Dolomite, as above,

medium-grained; chert,

as above, abundant ......

Dolomite, as above;

chert, some oolitic,

very abundant.......... .

Dolomite, as above;

chert, some oolitic,

very abundant;

green shale,

sparse................ .

Dolomite, as above;

chert, some oolitic,

very abundant.......... .

Dolomite, as above;

chert, some oolitic,

common .............. .

Dolomite, as above;

chert, some oolitic,

common .............. .

Dolomite, gray,

medium-grained; chert,

some is oolitic,

very abundant; iron,

trace................. .

Dolomite, as above;

chert, some

arenaceous, very

abundant; green shale,

very common; iron

+2 percent............ .

Dolomite, as above;

chert, very abundant;

quartz sand, common;

iron +2 percent........ .

Dolomite, as above;

chert, very abundant; iron

2 percent............. .

Dolomite, as above; chert

abundant; quartz sand,

common; iron

+2 percent ..............

Dolomite, as above; chert,

very common; quartz sand,

as above; iron

-1 percent ..............

Dolomite, as above; chert,

sparse,to common;

quartz sand, as above;

iron -j percent ........ .

Dolomite, as above;

chert, sparse to common;

iron -1 percent......... .

Dolomite, as above; chert,

sparse;iron

-1 percent ............ .

155-160

160-165 

165-170 

170-175

175-180 

180-185 

185-190 

190-195

195-200

200-205

205-210 

210-215

215-220 

220-225

225-230 

230-235 

235-245

24
Prairie du Chien group Continued 

Oneota dolomite--Continued

Dolomite, as above; 

chert, very common; 

iron 2percent............

Dolomite, brown, mediumgrained; chert, sparse; 

iron 1 percent ............

Dolomite, as above; 

chert, some oolitic, 

common; green shale, 

common; iron 

1 percent............... .

Dolomite, gray, medium- 

 grained; green shale, 

very common; chert, 

sparse; iron 

1 percent............... .

Dolomite, as above; 

chert, sparse; 

iron -1 percent ......... .

Dolomite, brown, mediumgrained; chert, some 

oolitic, sparse to 

common; quartz sand, 

common ............... .

Dolomite, as above; chert, 

sparse; gray arenaceous 

shale, sparse to common; 

quartz sand, 

common ............... .

Dolomite, as above; chert, 

sparse; quartz sand, 

very common........... .

Dolomite, as above; chert, 

. oolitic, very common; 

quartz sand, 

sparse...................

Dolomite, as above; chert, 

partly oolitic, 

abundant ............... .

Dolomite, as above; chert, 

nonoolitic, very 

common................ .

Dolomite, as above; chert, 

a little is oolitic, common; 

quartz sand, 

common................ .

Dolomite, as above,

arenaceous; quartz sand, 

common .................

Dolomite, buff, arenaceous, 

oolitic,, and dolomitic 

sandstone; chert, sparse 

to common ............. .

Dolomite and dolomitic 

sandstone, as above;. 

chert, sparse; quartz 

sand estimated as 

30 percent of sample; 

trace of green shale ...... .

Sandstone, dolomitic, 

buff, mediumcoarse, rounded, 

and arenaceous 

dolomite; quartz sand, 

abundant; trace 

of glauconite............ .

Depth 

(feet)

245-250 

250-255

255-260

260-265 

265-270

270-275

275-280 

280-285

285-290 

290-295 

295-300

300-305 

305-310

310-315 

315-320

Depth 

(feet)

Trempealeau formation (Cambrian): 

Jordan sandstone member:

Sandstone, quartz, clear, 

medium-grained, poorly 

sorted, some dolomitic 

cement................ 325-330

Williams 2

Location: Sec. 31, T. 7 N., R. 1 E., Wis.;

335 ft N. '318 10 ft W. from Williams 1. 

Driller: R. Dagenhardt, Mar. 7 to Mar. 16, 1951. 

Collar elevation: 1,097. 1 ft. 

Total depth: 295 ft. 

Depth to water: 105 ft. 

Sample study and logging: Arthur E. Flint, Mar. 20,

1951.

[Percentages estimated]

Soil, residual clay, 

weathered limestone.

Platteville formation:

McGregor limestone member: 

Limestone, gray-brown, 

fine- and medium-grained, 

fossiliferous........... .

Pecatonica dolomite member: 

Dolomite, gray and buff, 

medium-grained, 

arenaceous in lower 

3 feet; phosphatic nodules 

and limonite common 

near base............. .

Glenwood shale member: 

Shale, gray-green, 

arenaceous in part; 

phosphatic nodules and 

marcasite partly oxidized, 

common,................

St. Peter sandstone:

Sandstone, quartz, lightgray and buff, mediumgrained except coarse at 

top and through lower 

20 feet, rounded, some 

grains frosted, 

pitted................. .

Depth 

(feet)

0- 5

5- 11

11- 29

29- 31

31- 97

320-325

25

Prairie du Chien group: 

Shakopee dolomite:

Shale, gray; brown-gray

dolomite, sparse......... 97-100

Dolomite, brown-gray,

fine- and medium-grained,

some is arenaceous; oolitic

chert, very abundant;

some caving

sandstone............. . 100-105

Dolomite and chert, as above;

gray-green shale, common;

trace of glauconite......... 105-110
Prairie du Chien group Continued 

Shakopee dolomite Continued

Dolomite, as above, 

much is arenaceous; 

chert, some is oolitic, 

abundant; shale, as 

above, common to 

very common ..............

Dolomite, gray, as above, 

little is arenaceous; chert, 

as above, common; trace 

of glauconite; shale, as 

above,, common........... .

Dolomite, as above; chert, 

sparse to common; shale, 

as above, very common; 

trace of glauconite ........ .

Dolomite, as above; chert, 

sparse; shale, as above, 

common................. .

New Richmond sandstone(?):

Dolomite, gray and 

brown, fine- and 

medium-grained, 

much is arenaceous; 

chert, sparse; green 

shale, common; a little 

quartz sand............... .

Oneota dolomite;

Dolomite, as above; chert 

and gray shale, sparse..... .

Dolomite, as above,

partly arenaceous; chert, 

abundant................. .

Dolomite, brown and buff, 

fine- and medium-grained; 

chert, abundant; gray-green 

shale, sparse; lead 

i percent ................ .

Dolomite, as above; chert, 

common; green shale, 

sparse; trace of lead....... .

Dolomite, as above,

partly arenaceous; graygreen shale, sparse to 

common; chert, sparse......

Dolomite, as above, nonarenaceous; chert, abundant; 

trace of green shale; 

iron 1 percent..............

Dolomite, as above; chert, 

abundant; iron 1 percent.....

Dolomite, as above; chert, 

very common...............

Dolomite, gray, fine- and 

medium-grained; chert, very 

common; green shale, sparse 

to common; iron +3 percent...

Dolomite, as above; chert, 

abundant; iron+3 percent ....

Depth Depth 

(feet) (feet)

Prairie du Chien group Continued 

Oneota dolomite Continued

Dolomite, as above; chert, 

abundant; iron 

+2 percent ............... 190-195

Dolomite, as above:

chert, sparse to common; 

110-120 iron +2percent.......... . 195-200

Dolomite, as above; chert, 

common to sparse; 

iron -1 percent; trace of 

lead..................... 200-205

120-125 Dolomite, as above; chert,

sparse; iron 

i percent............... . 205-210

Dolomite, as above; chert, 

125-130 common to sparse........ 210-215

Dolomite, as above;

chert, sparse; iron 

130-135 1 percent.................. 215-220

Dolomite, as above; chert, 

sparse; iron -1 percent; 

trace of lead.............. 220-225

Dolomite, brown, mediumgrained; chert, sparse to 

common; iron 

-1 percent ............. . 225-230

135-140 Dolomite and chert, as

above; gray-green shale, 

very common; quartz sand, 

140-145 common; trace of glauconite;

iron -1 percent.......... . 230-235

Dolomite, as above; chert 

145-150 and shale;sparse........ . 235-240

Dolomite, gray, fine- and

medium-grained ........ . 240-245

Dolomite, as above;

trace of arenaceous

150-155 green shale; dolomitic

sandstone, common to 

sparse ................. . 245-250

155-160 Dolomite, brown, mediumgrained; green arenaceous 

shale, common; quartz 

sand, sparse............ . 250-255

160-165 Dolomite, as above; trace

of chert and green shale; 

quartz sand, 

sparse ................. . 255-265

165-170 Dolomite, as above; chert,

partly oolitic, very 

170-175 common............... . 265-275

Dolomite, as 

175-180 above.................. . 275-280

Dolomite, as above,

arenaceous............... 280-290

Dolomite, as above, 

180-185 arenaceous and oolitic;

trace of chert, 

185-190 oolitic................... 290-295

26
Williams 3

Location: Sec. 31, T. 7 N., R. IE., Wis.;

265 ft S. 43° E. from Williams 1. 

Driller: R. Dagenhardt, Mar. 17 to Mar. 30, 1951. 

Collar elevation: 1,093. 3 ft. 

Total depth: 290 ft. 

Depth to water: 155 ft. 

Sample study and logging: Arthur E. Flint, Mar. 3,

1951.

Depth 

(feet)

[Percentages estimated]

Soil, residual clay, 

weathered limestone,

Depth 

(feet)

0- 8

Platteville formation:

McGregor limestone member: 

Limestone, brown-gray, 

fine -grained ..........

Pecatonica dolomite member: 

Dolomite, gray and buff, 

medium-grained, 

arenaceous near 

. base .................

Glenwood shale member:

Shale, gray-green, a few 

phosphatic nodules.....

12- 26 

26- 28

St. Peter sandstone:

Sandstone, quartz, lightgray and buff, rounded, 

medium-grained except 

coarse in upper 8 feet 

and lower 10 feet....... 28- 72

Prairie du Chien group: 

Shakope'e dolomite:

Dolomite,; buff, 

fine- and mediumgrained; oolitic chert, 

common; green glauconitic 

shale, common...........

Dolomite, as above;

chert, sparse.............

Dolomite, buff,

medium-grained .........

Dolomite, brown,

fine- and medium-grained;

chert, sparse to

common ................

Dolomite, as above, 

partly oolitic; chert, 

sparse...................

Dolomite, as above,

nonoolitic; oolitic chert, 

very abundant; green 

arenaceous shale, 

common.................

Dolomite, as above; 

oolitic chert, abundant; 

gray-green shale and 

quartz sand, common......

72- 75 

75- 85 

85- 90

90- 95 

95-100

100-105 

105-110

Prairie du Chien group Continued 

Shakopee dolomite Continued

Dolomite, as above,

but fine-grained, dense; 

oolitic chert, very abundant; 

shale and quartz sand, as 

above.................. .

Dolomite, as above, fineand medium-grained; chert, 

common to sparse........ .

Dolomite, as above, fine- and 

medium-grained......... .

New Richmond sandstone(?):

Dolomite, brown, mediumgrained; chert, 

sparse................. .

Oneota dolomite:

Dolomite, as above; chert, 

very abundant........... .

Dolomite, as above; chert, 

very abundant ............

Dolomite, gray, fine- and 

medium-grained; chert, 

abundant .................

Dolomite, brown, fine- and 

medium-grained; chert, 

sparse to common.........

Dolomite, gray, fine- and 

medium-grained; chert, 

common................ .

Dolomite, as above; chert, 

abundant................ .

Dolomite,as above; chert, abundant; iron 2 percent..........

Dolomite, as above; chert, 

common................ .

Dolomite, as above; chert, 

abundant.................

Dolomite, gray, mediumgrained; chert, 

abundant.................

Dolomite, as above; chert, 

abundant................ .

Dolomite, as above; chert, 

abundant; iron 

+ 1 percent.............. .

Dolomite, brown, mediumgrained; chert, abundant; 

iron -1 percent.......... .

Dolomite, gray, mediumgrained; chert, sparse 

to common; iron

- § percent...............

Dolomite, as above;

chert, sparse ............

Dolomite, as above; chert,

abundant; iron

3 percent............... .

Dolomite, as above; chert,

abundant; iron

2 percent .............. .

Dolomite, as above; chert,

sparse; iron

-i percent...............

110-115

115-120 

120-130

130-135

135-140 

140-145

145-150 

150-165

165-170 

170-175 

175-180 

180-185 

185-190

190-195 

195-200

200-205 

205-210

210-215 

215-220

220-225 

225-230 

230-235

27
Prairie du Chien Continued

Oneota dolomite Continued

Dolomite, gray, granular; 

chert, partly oolitic, 

sparse................

Dolomite, as above;

trace of chert..........

Dolomite, brown, 

medium-grained, 

arenaceous; angular 

quartz sand, very 

abundant ..............

Dolomite, as above, 

nonarenaceous; quartz 

sand, as above, 

very abundant..........

Dolomite, as above;

chert, abundant........

Dolomite, as above, 

partly oolitic; oolitic 

chert, abundant; quartz 

sand, sparse to 

common ..............

Dolomite, as above; 

partly oolitic chert, 

abundant; quartz 

sand, as above .........

Dolomite, as above, 

partly arenaceous and 

oolitic;chert and 

quartz sand, 

sparse ...............

Dolomite, as above, 

arenaceous and oolitic; 

oolitic chert, common; 

quartz sand, sparse; 

iron I percent..........

Dolomite, as above,

arenaceous, glauconitic; 

chert and quartz sand, 

sparse.................

Depth 

(feet)

235-240 

240-245

245-250

250-260 

260-265

265-270 

270-275

275-280

280-285 

285-290

Depth 

(feet)

Williams 4

Location: Sec. 31, T. 7 N., R. 1 E., Wis.;

525 ft S. 45°50 ft E. frpm Williams 1. 

Driller: R. Dagenhardt, Apr. 6 to Apr. 17, 1951. 

Collar elevation: 1,080. 2 ft. 

Total depth: 280 ft. 

Depth to water: 145 ft. 

Sample study and logging: Arthur E. Flint, Apr. 20,

1951.

[Percentages estimated, except where assay values 

are indicated]

Soil, residual clay 

and chert........

Platteville formation:

Glenwood shale member: 

Shale, gray-green, 

oxidized in part 

to red .........

Depth 

(feet)

0- 8

8-10 28

St. Peter sandstone:

Sandstone, quartz, licrhtgray and buff, rounded, 

many grains frosted, 

medium-grained except 

coarse in upper 10 feet and 

lower 8 feet, traces of white 

porcellaneous'chert in lower 

30 feet (may be caved).....

Prairie du Chien group: 

Shakopee dolomite:

Shale, brown-buff;

dolomite, buff,

sparse................. .

Dolomite, brown,

fine- and medium-grained;

oolitic chert, sparse;

quartz sand (caving)...... .

Dolomite, as above,

partly arenaceous;

chert, sparse;

quartz sand, as

above ................... .

Dolomite, as above,

fine- and

medium-grained ........ .

Dolomite, as above,

partly oolitic; partly

oolitic chert,

very common; brown

shale, sparse.............

Dolomite, as above,

nonoolitic; partly

oolitic chert,

abundant............... .

Dolomite, as above,

partly arenaceous;

very oolitic chert,

abundant; green

arenaceous shale,

common................ .

Dolomite, as above,

some very finegrained; partly

oolitic chert, abundant;

quartz sand and green

shale, sparse to

common ............... .

Dolomite, as above,

partly arenaceous;

quartz sand, sparse;

trace of glauconite....... .

New Richmond sandstone(?): 

Dolomite, brown, partly

arenaceous, and dolomitic

sandstone; green shale,

sparse to common....... .

Oneota dolomite:

Dolomite, brown, fine- and

medium-grained..........

Dolomite, brown

and gray, medium -

and fine -grained;

chert, abundant......... .

Dolomite, as-above;

chert, very

common................ .

10- 56

56- 60 

60- 65

65- 75 

75- 80

80- 85 

85- 90

90- 95

95-100 

100-105

105-110 

110-115

115-120 

120-125
Prairie du Chien group--Continued 

Oneota dolomite--Continued 

Dolomite, as above;

chert, sparse; trace

of lead .................

Dolomite, gray,

medium-grained;

chert, sparse.......... .

Dolomite, as above,

fine- and mediumgrained; glauconitic

chert, abundant..........

Dolomite, brown,

ve.i*y fine and

medi um - grained,

partly arenaceous; chert,

abundant.............. .

Dolomite, as above;

chert, very abundant;

iron 2 percent; lead

if percent...............

Dolomite, as above;

chert, very abundant;

green shale, sparse;

iron 2 percent;

trace of lead............

Dolomite and chert, as

above; iron I percent;

lead i percent...........

Dolomite, as above;

chert, abundant; iron

 | percent; trace of

lead.................. .

Dolomite and chert,

as above; iron

if percent...............

Dolomite, as above;

chert, very common;

iron f percent;

trace of lead ............

Dolomite, gray, fineand medium-grained;

chert, sparse; trace

of lead................ .

Dolomite, as above,

medium-grained; chert,

sparse..................

Dolomite, as above;

chert, common to

sparse; iron assayed

12. 65 percent of sample;

zinc assayed

trace................. .

Dolomite and chert,

as above; iron

8 percent ............. .

Dolomite and chert,

as above; iron

6 percent ............. .

Dolomite, as above;

chert, sparse;

iron 2 percent.......... .

Dolomite and chert,

as above; iron

1 percent............. .

Dolomite and chert,

as above; iron 2 percent...

Depth 

(feet)

125-130 

130-140

140-150

150-155 

155-165

165-175 

175-180

180-185 

185-190

190-195

195-200 

200-205

205-210 

210-215 

215-220 

220-225

225-230 

230-235

Depth 

(feet)

Prairie du Chien Continued

Oneota dolomite Continued

Dolomite, brown,

medium-grained; chert,

sparse;iron

1 percent...............

Dolomite, as

above..................

Dolomite, as above; 

partly oolitic chert, 

very abundant...........

Dolomite, as above; 

chert and quartz sand, 

sparse to 

common ...............

Dolomite, as above; 

partly oolitic chert, 

common; quartz sand, 

sparse .................

Dolomite, as above; 

partly oolitic chert, 

common to 

sparse..................

Dolomite, brown, mediumgrained, arenaceous, 

partly glauconitic; 

quartz sand common; 

trace of iron............

Dolomite, as above,

arenaceous, and oolitic; 

partly oolitic chert, 

sparse; quartz sand, 

sparse.................

235-240 

240-250

250-255 

255-260 

260-265 

265-270

270-275 

275-280

Williams 5

Location: Sec. 31, T. 7 N., R. IE., Wis.;

860ft S. 46°45ftE. from Williams 1. 

Driller: R. Dagenhardt, Apr. 18 to Apr. 28, 1951. 

Collar elevation: 1, 072. 2 ft. 

Total depth: 275 ft. 

Depth to water: 25 ft. 

Sample study and logging: Arthur E. Flint, Apr. 30,

1951.

[Percentages estimated]

Soil, alluvium, silt and 

fine quartz sand......

Depth 

(feet)

0- 5

St. Peter sandstone:

Sandstone, quartz, lightgray and buff, medium - 

grained exeept coarse 

in upper 5 feet, 

35- to 50-foot 

sample, and lower 

17 feet, rounded, 

some grains frosted, 

overgrowths on 

grains in 

upper 15 feet 

common............... 5-82

29
Depth 

(feet)

Depth 

(feet)

Prairie du Chien group: 

Shakopee dolomite:

Shale, green; 

oolitic chert, 

common; arenaceous 

fine- and mediumgrained dolomite, 

sparse................ .

Dolomite, buff, fineand medium-grained, 

arenaceous; oolitic 

chert, abundant; 

buff arenaceous shale, 

common; quartz sand 

(caving), common ..... .

Dolomite, brown, as 

above; oolitic chert, 

very common; quartz 

sand, sparse .......... .

Dolomite, as above; 

oolitic chert, sparse 

to common; green 

glauconitic shale, 

common; quartz sand, 

sparse .................

Dolomite, as above, 

partly arenaceous; 

chert and quartz 

sand, sparse; iron 

-1 percent..............

New Richmond sandstp,ne(?):

Dolomite, as above; 

green arenaceous 

shale, very 

common; quartz sand, 

sparse; iron 

+1 percent ..............

Oneota dolomite:

Dolomite, as above; 

chert, abundant; 

green shale, sparse; 

iron 1 percent...........

Dolomite, gray,

nonarenaceous; chert, 

abundant; green shale, 

common; trace of 

lead ....................

Dolomite and chert, 

as above; shale, as 

above, sparse; trace 

of lead .................

Dolomite, as above; 

chert, sparse; quartz 

sand, sparse.......... .

Dolomite, as above, 

partly arenaceous; 

chert and shale, 

sparse .................

Dolomite, as above; 

chert, common to 

sparse; trace of 

lead ...................

Dolomite, gray, 

granular, mediumgrained; green-brown 

shale, very common; 

chert, sparse; trace of 

glauconite; iron -^ percent.

82- 85

85- 90

90- 95

95-100

100-105

105-110 

110-115

115-120

120-125 

125-130

130-135 

135-140

140-145

30

Prairie du Chien group--Continued 

Oneota dolomite--Continued 

Dolomite, brown, gray,

fine- and medium -

grained; chert,

common ............... .

Dolomite, as above; chert,

very abundant; green

shale, very common......

Dolomite, as above,

partly medium-grained;

chert, abundant; green

shale, common; iron

2 percent............... .

Dolomite, as above;

chert, very abundant; iron

+ 1 percent.............. .

Dolomite, as above,

medium-grained; chert,

abundant; iron

\ percent............... .

Dolomite and chert,

as above ............... .

Dolomite, as above;

chert, sparse........... .

Dolomite, gray, mediumgrained; chert, sparse;

iron4 percent.............

Dolomite, as above;

iron 5 percent........... .

Dolomite, as above;

iron 2 percent .......... .

Dolomite, gray-brown,

medium-grained; iron

+1 percent.............. .

Dolomite, gray, mediumgrained; iron

~\ percent...............

Dolomite, light-buff,

medium-grained; white

decomposed chert, sparse;

iron \ percent........... .

Dolomite, brown-gray,

medium-grained; chert,

sparse ................. .

Dolomite, as

above.................. .

Dolomite, as above; oolitic

chert, very common;

green-brown arenaceous

glauconitic shale, common;

trace of glauconite....... .

Dolomite, brown, mediumgrained, partly arenaceous;

green glauconitic arenaceous

shale, common...........

Dolomite, as above, arenaceous

and oolitic; shale, as above,

common; chert, sparse;

iron -\ percent.......... .

Dolomite, as above, very

arenaceous and glauconitic;

iron 2 percent.............

Dolomite, as above,

arenaceous and oolitic;

oolitic chert,

sparse; iron

-i percent ............. .

145-150 

150-155

155-160 

160-165

165-170 

170-175 

175-200

200-205 

205-210 

210-215

215-220 

220-225

225-230

230-235 

235-245

245-250 

250-255

255-260 

260-270

270-275
Steil 1

Location: 165 ft south, 1, 685 ft east of northwest corner, sec. 6, T. 6 N., R. 1 E., 

Wis.

Driller: John Hauser, Feb. 22 to Mar. 1, 1951.

Collar elevation: 1,119. 8 ft.

Total depth: 350ft.

Depth to water: 45 ft.

Sample study and logging: Arthur E. Flint, Mar. 8, 

1951.

Depth 

(feet)'

[Percentages estimated]

Depth 

(feet)

Soil, residual clay and 

weathered limestone (Quimbys 

Mill?) in lower 

8 feet.................. 0-15

Platteville formation:

McGregor limestone member: 

Limestone, mediumgray, mediumgrained 20 to 33 feet; 

otherwise fine- and 

very fine grained; 

fossiliferous .........

Pecatonica dolomite member: 

Dolomite, mediumgray, weathers buff; 

quartz sand and 

phosphatic nodules 

at base...............

Glenwood shale member: 

Shale, gray-green, 

arenaceous; limonite, 

phosphatic nodules, 

very common.........

15- 50

50- 61

61- 64

St. Peter'sandstone:

Sandstone, quartz, lightgray, rounded, mediumfine except coarse in 

upper 10 feet and lower 

15 feet................

Prairie du Chien group: 

Shakopee dolomite:

Shale, green, 

arenaceous 151 

to 153 feet; graybrown fine- and mediumgrained dolomite; some 

arenaceous oolitic chert; 

glauconite, common._,....

Dolomite, as above, 

nonarenaceous; quartz 

sand (mostly caving), 

15 percent of sample; 

trace of green 

shale................. .

Dolomite, as above, some 

arenaceous; oolitic 

chert, abundant........ .

Dolomite, as above; chert, 

a*s above, partly oolitic, 

abundant; sparse green 

shale and quartz sand 

(caving)...............

64-151

151-155

155-160 

160-165

165-170

Prairie du Chien group--Continued 

Shakopee dolomite Continued

Dolomite, as above; 

chert, as above, some 

oolitic, common; quartz 

sand, sparse ........... .

New Richmond sandstone(?):

Dolomite, buff and light 

brownish-gray, fine- and 

very fine grained, partly 

arenacous; light-gray and 

light-yellow chert, much 

is oolitic, abundant; green 

shale, sparse; quartz sand, 

common ............... .

Oneota dolomite:

Dolomite, buff, fine- and 

medium-grained; partly 

oolitic chert, common; 

quartz sand, common 

(caving from New Richmond?); 

iron 1 percent.............

Dolomite, light -brown - 

gray, mainly fine-grained; 

chert, common.......... .

Chert, light-gray, 

80 percent of sample; 

dolomite, as 

above.................. .

Dolomite, as above;

chert, common.......... .

Dolomite, light brownishgray, medium-grained; 

chert, abundant; quartz 

sand, sparse; iron 

1 percent............... .

Dolomite, as above; chert, 

common; trace of 

glauconite .............. .

Dolomite, light browngray, fine- and mediumgrained; chert, 

as above .................

Dolomite, light to medium 

brown-gray, mediumgrained; chert, common; 

iron -1 percent......... .

Dolomite, as above;

chert, abundant; quartz sand,

common; iron

1 percent................

Dolomite, as above; chert, 

as above, abundant; quartz 

sand, common; iron 

3 percent.................

Dolomite and chert, as 

above; quartz sand and 

green shale, common; 

iron 3 percent.. ..........

Dolomite, as above; 

chert, abundant; quartz 

sand, common (part is 

caving); iron 

+1 percent.............. .

Dolomite, as above; chert,common; quartz sand and green 

shale, sparse; 

iron -1percent.......... .

170-175

175-180

180-185 

185-195

195-200 

200-205

205-210 

210-215

215-220 

220-225 

225-230 

230-235 

235-240

240-245 

245-250

31
Depth 

(feet)

Depth 

(feet)

Prairie du Chien group Continued 

Oneota dolomite Continued

Dolomite, as above; 

chert, very common; 

yellow-buff shale 

and quartz sand (caving?), 

common; iron 

-1 percent ............ .

Dolomite, as above; 

chert, as above; 

quartz sand, as 

above;iron 

+2 percent..............

Dolomite, as above; 

chert, common; quartz 

sand, as above; 

iron +1 percent......... .

Dolomite, as above; 

chert and quartz sand, 

sparse to common; 

iron 1 percent ......... .

Dolomite, as above; 

chert and quartz sand,

, sparse ............... .

Dolomite, as above; 

green-gray shale, 

abundant;' trace of 

glauconite............. .

Dolomite, light- and 

medium -b rown, 

medium-grained; 

shale, as above, 

common .............. .

Dolomite, as above........

Dolomite, as above;

chert, sparse.......... .

Dolomite, as above; 

chert, much is 

oolitic, very 

common............... .

Dolomite, as above; 

chert, very 

common............... .

Dolomite, as above; a 

little greenish-gray 

siltstone; chert, 

common ...............

Dolomite, as above; 

chert, sparse to 

common; quartz sand, 

very common ...........

Dolomite, as above, much 

is arenaceous and 

oolitic; oolitic chert, 

common; quartz sand, 

common; trace of 

glauconite............. .

Dolomite, as above, most 

is arenaceous and 

oolitic; arenaceous 

and oolitic chert, 

common; quartz sand, 

abundant; light-green 

shale, common .........

250-255

255-260 

260-265

265-270 

270-275

275-280

280-285 

285-290

290-295

295-300 

300-305

305-310 

310-320

320-325

Prairie du Chien group Continued 

Oneota dolomite Continued

Dolomite, as above; 

chert, sparse; quartz 

sand, abundant; 

iron 3 percent ..........

Sandstone, quartz, 

fine to coarse-, 

poorly sorted; dolomite, 

arenaceous 20 percent 

of sample.,.............

330-335

335-337

Trempealeau formation:

Jordan sandstone member: 

Sandstone, quartz, fine 

to coarse, poorly sorted, 

in part dolomitic 

cemented............... 337-350

Steil 2

Location: Sec. 6, T. 6 N., R. IE., Wis., 

245 ft N. 63°30 ft W. from Steil 1.

Driller: John Hauser, Mar. 3 to Mar. 16, 1951.

Collar elevation: 1,113. 8 ft.

Total depth: 325ft.

Depth to water: 225 ft.

Sample study and logging: Arthur E. .Flint, Mar. 18, 

1951.

[Percentages estimated, except where assay values 

are indicated]

Soil, residual clay, decomposed 

buff limestone........... .

Platteville formation:

McGregor limestone member:

Limestone, gray, weathers 

buff, fine- and mediumgrained, fossiliferous,.....

Pecatonica dolomite member: 

Dolomite, medium-gray, 

medium-grained, 

arenaceous near 

base ................... .

Glenwood shale member: 

Shale, grayish-green,

iron,common..............

Depth 

(feet)

0- 10

10- 37

37- 54 

54- 56

St. Peter sandstone:

Sandstone, quartz, rounded; 

many grains frosted, pitted, 

medium-fine except coarse 

in upper 10 feet and mediumcoarse in lower 12 feet .....

325-330

Prairie du Chien group: 

Shakopee dolomite:

Shale, light-buff; dolomite, 

buff, arenaceous; chert, 

sparse; limonite, common..

56-137

137-140

32
Depth 

(feet)

Depth 

(feet)

Prairie du Chien group Continued 

Shakopee dolomite Continued

Dolomite, brown-gray 

and buff, fine- and 

medium-grained; 

chert, much is 

oolitic, very common; 

quartz sand 

(caving), common.......

Dolomite, light-buff, 

some oolitic, very 

common; light-gray 

chert, much is oolitic, 

70 percent of sample; 

glauconitic shale and 

quartz sand, 

sparse................

Dolomite, as above; 

partly oolitic chert, 

very common; traces 

of quartz sand and 

glauconite.............

Dolomite, as above,

some arenaceous; chert, 

as above, very common; 

traces of quartz sand 

and green shale........

Dolomite, as above; chert, 

common; iron

-1 percent; lead assayed 

0. 45 percent...........

New Richmond sandstone(?):

Dolomite, as above; 

chert, common to 

sparse; shale and 

quartz sand, common; 

iron +1 percent; lead 

assayed 

0. 6 percent............

Oneota dolomite:

Dolomite, as above; some 

chert; traces of 

glauconite; lead assayed 

0. 5 percent.............

Dolomite as above; chert, 

as above; lead assayed 

(175 to 177|feet) 

1. 25 percent; 

(177i-180 feet) 

1. 20 percent...........

Dolomite, as above, 

medium-grained; chert, 

much is oolitic, very 

common; lead assayed 

(180 to 182| feet) 

0. 5 percent; 

(182f to 185 feet) 

0. 85 percent...........

Dolomite, as above; 

chert, common; 

lead 0. 25 percent......

Dolomite, as above; 

chert, common; iron

-1 percent; trace of 

lead ..................

Dolomite, as 

above; chert, 

abundant.............. .

140-145

145-150

150-155

155-160

160-165

165-170

170-175

175-180

180-185 

185-190

190-195 

195-200

Prairie du Chien group Continued 

Oneota dolomite Continued

Dolomite, as above, 

a little is arenaceous; 

chert, sparse; trace of 

glauconite .............. .

Dolomite, light-brown, 

medium-grained; chert, 

abundant; iron 2 percent; 

trace of glauconite........

Dolomite, as above; chert, 

very abundant; iron 

2 percent................

Dolomite, brown and 

medium-gray, mediumgrained; chert very 

abundant; light-gray 

shale, common; iron 

4-1 percent.............. .

Dolomite, as above; chert, 

common..................

Dolomite, gray, mediumgrained; chert, 

common..................

Dolomite, as above; chert, 

sparse;trace of 

zinc ................... .

Dolomite, as above; 

chert, sparse; iron 

4-1 percent.............. .

Dolomite, as above; trace 

of chert; iron

1 percent................

Dolomite and chert,

as above;trace of

iron ................... .

Dolomite and chert, as above;

iron 4 percent.......... .

Dolomite and chert, as

above; iron 3 percent......

Dolomite, light-gray,

granular; chert, sparse;

iron 2 percent; trace of

zinc ................... .

Dolomite, brown-gray,

medium-grained; chert,

sparse;iron

2 percent............... .

Dolomite, as above; chert, 

sparse; gray shale, sparse; 

iron 1 percent........... .

Dolomite, as above; chert, 

sparse; iron -1 percent; 

trace of zinc............. .

Dolomite, as above; chert, 

sparse; some graygreen shale............. .

Dolomite, brown,

medium-grained......... .

Dolomite, as above........ .

Dolomite, as above; but 

partly oolitic and arenaceous; light-brown chert, 

common................ .

Dolomite, as above; chert, 

some is oolitic, common; 

quartz sand, 5 percent of sample; trace of glauconite ....

200-205

205-210 

210-215

215-220 

220-225

225-230 

230-235 

235-240 

240-245

245-250 

250-255 

255-260

260-265

265-270 

270-275 

275-280

280-285

285-290 

290-300

300-305 

305-310

33
Depth 

(feet)

Depth 

(feet)

Prairie du Chien group--Continued 

Oneota dolomite--Continued

Dolomite, as above, much 

is oolitic, arenaceous, 

and glauconitic; oolitic 

and arenaceous chert, 

very common; quartz 

sand, 5 percent of 

sample ................

Dolomite, as above; 

chert, as above, 

common; quartz sand 

10 percent of 

sample............... ,

Dolomite, brown,

arenaceous; chert, as 

above (caving?), sparse; 

quartz sand 20 percent 

of sample..............

310-315

315-320

320-325

Note: Bottom of hole is at or very near the 

Cambrian-Ordovician boundary.

Steil 3

Location: Sec. 6, T. 6 N., R. 1 E., Wis.;

210 ft S. 60° 33 ft E. from Steil 1. 

Driller: John Hauser, Mar. 16 to Mar. 21, 1951. 

Collar elevation: 1,103. 7 ft. 

Total depth: 310ft. 

Depth to water: 200 ft. 

Sample study and logging: Arthur E. Flint, Mar. 25,

1951.

Prairie du Chien group: 

Oneota(?) dolomite:

Shale, light-gray and 

green; light-brown 

and gray chert, common; 

iron,common............ .

Dolomite, light-gray

and light-brown, granular; 

light-brown and white 

chert, sparse to common; 

iron 4 percent............

Dolomite, as above;

iron 3 percent.............

Dolomite, as above; 

chert, sparse; trace of 

glauconite. ............. .

Dolomite, as above; 

traces of chert and 

green shale............. .

Dolomite, as above; 

oolitic chert, common; 

glauconite, common in 

dolomite.................

Dolomite, light-brown, 

arenaceous, oolitic; 

traces of chert, green 

shale, and glauconite; 

quartz sand, 

sparse................. .

Dolomite, as above, but 

very arenaceous and 

glauconitic; oolitic chert, 

sparse; quartz sand, common; 

trace of green shale.......

264-266

266-270 

270-275

275-280 

280-290

290-295

295-305 

305-310

[Percentages estimated]

Soil, residual clay and 

weathered limestone

Depth 

(feet)

0- 5

Platteville formation:

McGregor limestone member: 

Limestone, gray-brown, 

fine- and medium-grained, 

fossiliferous ........... 5-25

Pecatonica dolomite member: 

Dolomite, medium-gray, 

weathered, buff, medium - 

grained................. 25- 42

Glenwood shale member: 

Shale, gray-green; 

phosphatic nodules and 

iron, common........... 42- 43

St. Peter sandstone:

Sandstone, light-gray

and buff, medium-grained,

locally medium-coarse;

gray-green shale, 150 to

175 feet, abundant, and

traces in most samples;

bright-red hematite occurs

with much of shale; iron

common in lowest

3 feet................. . 43-264

Steil 4

Location: Sec. 6, T. 6 N., R. IE., Wis.;

710 ft. S. '67° 30 ft E. from Steil 1. 

Driller: R. Dagenhardt, Apr. 28 to May 4, 1951 

Collar elevation: 1,073. 9 ft. 

Total depth: 230 ft. 

Depth to water: 155 ft. 

Sample study and logging: Arthur E. Flint, May 9,

1951.

[Percentages estimated]

Soil and residual clay.

Depth 

(feet)

0- 5

Platteville formation:

Pecatonica dolomite member: 

Dolomite, medium-gray, 

weathered, buff, 

medium -grained, 

some limonite 

mottling..............

Glenwood shale member: 

Shale, green; 

traces of 

limonite and 

pyrite; a few 

quartz sand 

grains...............

5-18

18-20

34
Depth 

(feet)

Depth 

(feet)

St. Peter sandstone:

Sandstone, quartz, 

light-gray, rounded, 

some frosting of 

grains, medium 

except coarse in 

upper 5+ feet, 

lower 7 to 8 feet 

and in sample 45 

to 50 feet. ........... 20- 72

Prairie du Chien group: 

Shakopee dolomite:

Shale, light-buff 

and green; chert, 

brown, arenaceous; 

sandstone, quartz, 

common (caving?) .....

Dolomite, light-buff, 

fine-grained; lightgray oolitic chert, 

abundant; light-buff 

shale, common (caving); 

quartz sand (caving), 

common .............

Dolomite, as above, a 

little arenaceous; 

chert, sparse; traces 

of limonite and 

glaucoriite; quartz sand, 

sparse................

Dolomite, light-brown 

and buff, fine- and 

medium-grained; 

chert, sparse; 

limonite, glauconite, 

and quartz sand, 

as above...............

Dolomite, mediumgray-brown, fine- and 

medium-grained; 

chert, sparse..........

Dolomite, as above; 

light-gray oolitic 

chert, abundant; 

quartz sand, 

common ..............

Dolomite, as above, 

some arenaceous; 

chert, as above, 

some oolitic, abundant; 

green shale, common; 

a little quartz sand 

(partly caving).........

Dolomite, as above, 

some arenaceous; 

chert, as above, 

very common; 

shale, as above, 

common ..............

Dolomite, as above, 

some arenaceous; 

light-gray chert, 

much is oolitic, 

very common .........

72- 75

75- 80

80- 85

85-100

100-105

105-110

110-115

115-120

120-125

Prairie du Chien group Continued 

New Richmond sandstone(?): 

Dolomite, as above,

very arenaceous;

shale, as above,

common; quartz sand,

10 percent of

sample................. , Oneota dolomite:

Dolomite, light-buff

and light-brown,

fine- and medium

grained, a little

arenaceous; green

shale and quartz

sard, sparse ............

Dolomite, as above,

some medium-grained;

traces of chert, shale,

and quartz

sand ....................

Dolomite, as above;

chert, very abundant;

trace of

iron....................

Dolomite, as above, fineand medium-grained;

chert as above, very

abundant; trace of

iron....................

Dolomite, as above;

chert, as above, sparse;

trace of iron............

Dolomite, light-gray,

medium-grained; chert,

as above, common; iron

2 percent...............

Dolomite, as above;

chert, very abundant;

iron 7 percent..........

Dolomite, light-gray,

very dense, fine-grained;

chert, as above, common;

iron 5 percent...........

Dolomite, brown, mediumgrained; chert, abundant;

iron 2 percent ...........

Dolomite, light- and

medium-gray, mediumgrained; chert, as above,

sparse; iron

+ 1 percent..............

Dolomite, as above,

medium-grained; chert,

sparse; iron

1 percent...............

Dolomite and chert,

as above; iron

+ 1 percent.............

Dolomite, as above;

chert, sparse; iron

i percent...............

Dolomite, as above;

chert,

sparse .................

125-130

130-135

135-140 

140-145

145-150 

150-160

160-165 

165-170

170-175 

175-180

180-185

185-190 

190-200 

200-205 

205-210

35
Depth 

(feet)

Depth 

(feet)

Prairie du Chien group--Continued 

Oneota dolomite--Continued 

Dolomite, gray-brown,

medium-grained; chert,

common;

iron i percent.........

Dolomite, as above;

chert, sparse to

common; green

shale, sparse;

quartz sand (caving?),

common ..............

Dolomite, as above;

chert, common........

Steil 5

210-220

220-225 

225-230

Location: Sec. 6, T. 6 N., R. IE., Wis.;

1,475 ft S. 74°32 ft E. from Steil 1. 

Driller: R. Dagenhardt, May 4 to May 12, 1951. 

Collar elevation: 1, 070. 7 ft. 

Total depth: 235 ft. 

Depth to water: 135 ft. 

Sample study and logging: Arthur E. Flint, May 14,

1951.

[Percentages estimated]

Soil, residual clay, 

dolomite sand ...

Depth 

(feet)

0- 5

Platteville formation:

Pecatonica dolomite member: 

Dolomite, buff and gray, 

medium-grained, 

arenaceous at 

base .................

Glenwood shale member: 

Shale, gray-green; 

phosphatic nodules, 

limonite and marcasite, 

common ..............

5- 24

24- 26

St. Peter sandstone:

Sandstone, quartz, 

light-gray and 

buff, medium except 

coarse near top and 

base............... 26-106

Prairie du Chien group: 

Shakopee dolomite:

Shale, green and lightbuff; light-brown 

chert and light-brown 

dolomite, 

sparse .............

Dolomite, gray-brown-, 

fine- and mediumgrained; quartz 

sand (caving), very 

common.............

106-110

110-115

Prairie du Chien group Continued 

Shakopee dolomite Continued

Dolomite, as above; brown 

oolitic chert, very 

abundant; trace of green 

shale....................

Dolomite, as above; chert, 

as above, partly oolitic, 

abundant; green shale, 

common; quartz sand, 

common .................

Dolomite, as above;

chert, as above, common; 

quartz sand, common; 

iron -1 percent.......... .

New Richmond sandstone(?):

Dolomite, as above, some 

is arenaceous; dolomitic 

quartz sandstone, common; 

chert, as above, oolitic, 

abundant; quartz sand 

30 percent of sample; iron 

+1 percent.............. .

Oneota dolomite:

Dolomite, as above, a little 

is arenaceous; chert, as 

above, a little is oolitic, 

common; brown and green 

shale, common; quartz sand 

5 percent of sample; trace of 

glauconite.............. .

Dolomite, as above; chert, as 

above, common; traces of 

green shale and quartz 

sand................... .

Dolomite, as above; chert, 

sparse to common; shale 

and quartz sand, 

as above............... .

Dolomite, as above; chert, 

very abundant............

Dolomite, as above; chert, 

very abundant .......... .

Dolomite, as above, 

chert, sparse to 

common................ .

Dolomite, as above; 

chert, very 

abundant............... .

Dolomite, as above; 

chert, sparse to 

common................ .

Dolomite, brown, fine- and 

medium-grained; chert, 

abundant; iron 

1 percent............... .

Dolomite, as above; chert, 

very abundant, iron 

+ 1 percent.............. .

Dolomite, as above, mediumgrained; chert, 

very abundant, 

iron 

1 percent .............. .

115-120

120-125

125-130

130-135

135-140 

140-145

145-150 

150-155 

155-160

160-165 

165-170 

170-175

175-180 

180-185

185-190

36
Prairie da Chien Continued

Oneota dolomite Continued

Dolomite, as above; 

chert, very abundant; 

iron 1 percent.........

Dolomite, as above; 

fine- and mediumgrained; chert, very 

abundant; iron 

2 percent.............

Dolomite, as above, 

medium-grained; chert, 

sparse to 

common ..............

Dolomite, as above; 

chert, sparse; iron 

1 percent .............

Dolomite, as abpve; 

chert, sparse; iron 

9 percent .............

Depth 

(feet)

190-195

195-200

200-205

205-210

210-215

Depth 

(feet)

Prairie du Chien Continued

Oneota dolomite Continued

Dolomite, gray, mediumgrained; chert, common;

quartz sand 25 percent

of sample; iron

5'percent ...............

Dolomite, as above; cnert,

sparse to common;

quartz sand 25 percent

of sample; iron

4 percent...............

Dolomite, as above;

chert, common;

quartz sand 7 to

8 percent of sample ;

iron 2 percent ..........

Dolomite, as above;

chert, sparse to common;

iron 3 percent...........

215-220

220-225

225-230

230-235

37 IHT.-DOP. SET... WASH.. D.C.389J7
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PREPARED IN COOPERATION WITH THE 

WISCONSIN GEOLOGICAL AND NATURAL HISTORY SURVEY CIRCULAR f»l PLATE 1

EXPLANATION

Om-* _i. /

Maquaketa shale

Og 

Galena dolomite

Structure contour on top of chert, Galena dolomite 

Dashed where approximately located

Strike and dip of beds

Geologic contact, approximately located

Strike and dip of joints 

and strike of vertical joints

COUNTY 

COUNTY

Outcrop elevation at top of chert, 

Galena dolomite

Churn-drill hole 

Drilled by U. S. Geological Survey

e: number of hole 

733.6: elevation at top of collar 

57ft elevation at top of chert

*Q

6O5 ,@732.O 

6O7

H. H. GHER'S DIGGINGS

PROPERTY

GAYLOR PROPERTY

INDEX MAP 

SHOWING EXTENT 

OF PROPERTIES

MAP OF THE TETE DES MORTS AREA SHOWING THE LOCATION OF THE HOLES

DRILLED BY THE U S. GEOLOGICAL SURVEY 

DUBUQUE AND JACKSON COUNTIES, IOWA

Geology by Alien F Agnew and Arthur E.Flint, 1950

200 200 400 6OO F««t
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY CIRCULAR 231 PLATE 2

Center of 

east 1/2 sec. 3, 

T87N., R.4E.

300 feet south to

center sec. 3, T.87N.,R.4E.

Elevations are in feet, 

datum is mean sea level

'"Drab"

(nonc herty)

Glass rock1

T.D. 

245 FT.

EXPLANATION

"Clay bed1 

rock"

Zone containing iron-, iron as sulfide,oxide,or both 

Shows the estimated percent of iron

Zone containing manganese oxide 

Shows the estimated percent of manganese

4

0 200 400

SCALE IN FEET Total depth Drill hole

CROSS SECTIONS OF THE HOLES DRILLED BY THE 

U.S. GEOLOGICAL SURVEY IN THE TETE DES MORTS AREA

DUBUQUE AND JACKSON COUNTIES, IOWA
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PREPARED IN COOPERATION WITH THE 

WISCONSIN GEOLOGICAL AND NATURAL HISTORY SURVEY CIRCULAR 231 PLATE 3

EXPLANATION

Galena-Decorah and Platteville formation! 

undivided

Prairie du Chien group

Zn.. 

MANNING DIGGINGS

Ogdp

Geologic contact 

Dotted where concealed

INDEX MAP 

SHOWING EXTENT 

OF PROPERTIES Outcrop elevation at top of St. Peter sandstone 

Elevation to the nearest foot

Churn-drill hole

Drilled by the U. S Geological Survey 

Shows elevation at top of St. Peter sandstone

Structure contour on top of St. Peter sandstone

HIGHLAN

9O 90

Strike of vertical joints

Temporary bench mark and elevation 

Established by the U. S. Geological Survey

Mine shaft 

G: denotes shaft in Galena1 Decorah, and

Platteville formations 

Zn: denotes zinc; otherwise lead

Diggings 

Zn: denotes zinc; otherwise lead

// HORNSNOGGLE 

ft ..;. :..DIGGINGS

MAP OF HIGHLAND AREA SHOWING THE LOCATION OF THE HOLES

DRILLED BY THE U. S. GEOLOGICAL SURVEY

GRANT AND IOWA COUNTIES, WISCONSIN

Geology by Arthur E. Flint, I960

1000 IOOO 2000 3000 Feet
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PREPARED IN COOPERATION WITH THE 

WISCONSIN GEOLOGICAL AND NATURAL HISTORY SURVEY CIRCULAR 231 PLATE 4

WIEST 

/

PROPERTY

N 3 corner, 

sec.6,T6N., R. I E. \

PROPERTY \

/Center SWsec. 29, 

T.7N., R. IE.

r~-4---"

Abundant liehert,oolitic

chert, oolitic

Abundant 

chert

Sparse chert

Abundant chert, T.D. 

Sparse oolitic 235 FT

chert II Sparse 

chert

Noncherty, 

shaly 230 FT.

EXPLANATION Abundant flchert,oolitic 

II Arenaceous, 

oolitic

Arenaceous* Uoolitic 

T.D.

29p_F_L_

T.D. T.D. 

325 FT. 350 FT. Zone containing lead sulfide

Zone containing iron: 

iron as sulfide,oxide,or both

o 300 eoo 

SCALE IN FEET

Total depth

CROSS SECTIONS OF THE HOLES DRILLED BY THE 

U. S GEOLOGICAL SURVEY IN THE HIGHLAND AREA

GRANT AND IOWA COUNTIES, WISCONSIN

Geology by Arthur E.Flint, 1951