Illinois clay resources for lightweight ceramic block

ILLINOIS GEOLOGICAL
SURVEY LIBRARY

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STATE OF ILLINOIS

DEPARTMENT OF REGISTRATION AND EDUCATION

Illinois Clay Resources for
Lightweight Ceramic Block

W. Arthur White
Ned R. O'Brien

ILLINOIS STATE GEOLOGICAL SURVEY
John C. Frye, Chief URBANA

CIRCULAR 371

1964

Digitized by the Internet Archive

in 2012 with funding from

University of Illinois Urbana-Champaign

http://archive.org/details/illinoisclayreso371whit

ILLINOIS CLAY RESOURCES FOR
LIGHTWEIGHT CERAMIC BLOCK

W. Arthur White and Neal R. O'Brien

ABSTRACT

Seven samples of clays and shales from Illinois were
tested to determine their bonding properties. The clay mate-
rials are composed of illite, kaolinite, montmorillonite, chlo-
rite, or mixed-layer clay minerals. The materials were
ground, mixed with various percentages of water and light-
weight shale aggregate, molded into blocks that measure
8" x 8" x 8", and fired to temperatures of 1850° to 1900°F.
Compressive strengths were then determined.

A mixture of 20 parts clay to 80 parts aggregate, with
16 pounds of water per 100 pounds of mix, appeared to give
optimum results. Blocks made with this composition had com-
pressive strengths greater than 1, 000 pounds per square inch.
Blocks with the greatest compressive strength generally were
obtained from the materials that contained abundant montmoril-
lonite and mixed-layer clay minerals.

INTRODUCTION

Over the last century, there have been various attempts to make lightweight
ceramic products. A lightweight aggregate was patented as early as 1875, but it was
about forty years later, when Stephen Hayde built the first Haydite plant near Kansas
City, that the manufacture of lightweight aggregate from shale was advanced most
significantly. Until the middle 1940's, the industry developed slowly, but since the
end of World War II, there has been increasing interest in the uses of lightweight
aggregate in the building industry. Lightweight aggregate and Portland cement have
been used as a binder for concrete blocks and poured concrete floors and walls.

Bell and McGinnis (1951) first developed a large, lightweight ceramic build-
ing block. They used a sintered lightweight aggregate made from clay materials
bonded with clay. These blocks, which were made on a concrete block machine,
measured 8" x 8" x 16", weighed approximately 25 pounds, and had compressive
strengths of 1,700 pounds per square inch. Bell and McGinnis concluded that:

-1-

2 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 371

"(1) Clay building tile having only slight firing shrinkage and essentially no drying
shrinkage can be made; (2) these tile may be dried and fired very rapidly without
damage; (3) a wide range in the physical properties of these tile may be obtained by
proper selection and blending of the clays and aggregates used." Caruso (1959),
Moffitt (1961), and Robinson (1961; 1962) have discussed the fabrication of light-
weight clay bonded block.

Most of the papers mentioned above were interested in the lightweight ceramic
block as a finished product. The purpose of this investigation is to study the bond-
ing properties of various clay minerals in Illinois, after being fired, and to describe
possible locations of clay materials that would be useful in the manufacture of light-
weight ceramic block. In many respects, however, the finished products and raw
materials cannot be considered separately.

Acknowledgments

The authors wish to express their thanks to Messrs. Poole and Rybicki of
Chisholm, Boyd, and White Company for pressing some of the blocks; to Mr. R. E.
Fieldbinder of Nelsen Concrete Culvert Company for making available the steel
pallets and the pallet rack for drying the block; and to Mr. Gil Montgomery of the
Minerva Company for furnishing the fluorspar used in the study.

The authors are indebted to Professors G. W. Hollon and C. E. Kesler, Uni-
versity of Illinois, who supervised the test, and to Dr. R. E. Grim, University of
Illinois, and Dr. H. E. Risser, Illinois State Geological Survey, for critically
reading the manuscript and making helpful suggestions.

STRATIGRAPHIC OCCURRENCE OF CLAY AND SHALE

In Illinois, clays and shale that can be used in the manufacture of clay bonded
blocks range in age from Ordovician to Pleistocene. Figure 1 shows the outcrop
areas of the bedrock clay and shale deposits that range in age from Ordovician through
Tertiary; figure 2 shows the areas where refractory clays crop out; and figure 3
shows the areas of glacial tills and residual clays. The clays and shales crop out
along stream valleys, in highway and railroad cuts, and in strip mines. Clay and
shale deposits that may be used as bonding materials in the manufacture of light-
weight building block occur in several stratigraphic units. Their relative ages are
shown in the following list.

Cenozoic Era

Quaternary System
Pleistocene Series

Wisconsinan Stage
Illinoian Stage
Kansan Stage
Tertiary System
Paleocene Series

CLAY RESOURCES FOR LIGHTWEIGHT CERAMIC BLOCK 3

Porters Creek Formation
Mesozoic Era

Cretaceous System
Paleozoic Era

Pennsylvanian System

Mattoon Formation
Bond Formation
Modesto Formation
Carbondale Formation
Spoon Formation
Abbott Formation
Caseyville Formation
Mississippian System
Chesterian Series
Valmeyeran Series

Warsaw Formation
Kinderhookian Series
Hannibal Group

Grassy Creek Formation
Ordovician System

Maquoketa Group
Scales Formation

Orchard Creek Shale

Ordovician Shales

Maquoketa Shale

Maquoketa Shale crops out in Alexander, Calhoun, Carroll, Grundy, Jersey,
Jo Daviess, Kane, Kankakee, Kendall, LaSalle, Lee, Monroe, Ogle, Stephenson,
and Union Counties. The colors of the Maquoketa Shale (Rubey, 1952, p. 22) may
be bluish gray, blue, green, buff, tan, red, maroon, purple, lavender, or white.
The shale may range from massive to fissile. The lithology ranges from an argilla-
ceous dolomite to a slightly calcareous shale, which may have a noncalcareous
portion near the top. In Calhoun County, about 20 feet of noncalcareous, gray,
platy shale is exposed along the east bluff of the Mississippi River, near Batchtown.
In Kankakee County, noncalcareous beds are exposed along the Kankakee River.
The thickness of the Maquoketa Shale ranges from 350 feet, in northern Illinois, to
80 feet, in the southern part of the state (Weller and We Her, 1939, p. 7; Templeton

4 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 371

Figure 1 - Distribution of bedrock clay deposits which crop out in Illinois

CLAY RESOURCES FOR LIGHTWEIGHT CERAMIC BLOCK 5

and Willman, 1963, p. 131). The shale contains illite, chlorite, and some mixed-
layer clay minerals.

Orchard Creek Shale Member of the Scales Formation

The Orchard Creek Shale is 20 feet thick in Alexander County, where it crops
out along the east valley wall of the Mississippi River between Thebes and Fayette-
ville. North of Fayette ville, the shale is green and well laminated. At Fayette ville,
the shale is illitic and contains very little, if any, lime.

Mississippian Shales

Grassy Creek Shale

The Grassy Creek Shale is a black fissile shale that weathers to a bluish or
greenish gray. It is 50 feet thick where it crops out in the Mississippi River bluff
near Rockport and Atlas in Pike County and in the Illinois River bluff near Bedford.
The shale thickens to the north and east (Krey, 1924, p. 34).

Since the fresh shale is fissile and contains organic matter, it is not a good
bonding clay; however, the weathered shale is plastic. The shale is illitic.

Hannibal Shale

The Hannibal Shale ranges in thickness from about 30 feet, near Grafton in
Jersey County, to nearly 100 feet, near the north line of Calhoun County. In Pike
County, the Hannibal Shale rests on the Grassy Creek Shale. To the south, in Cal-
houn and Jersey Counties, the shale is mostly calcareous and nonlaminated, whereas
in the northern part of Pike County, it may be a massive, calcareous sandstone,
becoming more siliceous to the north. The shale has, for the most part, a greenish
gray color.

In some areas of northern Calhoun County, the Hannibal Shale has a low lime
and sand content, which makes it suitable for a bonding clay. The areas of pro-
duction would have to be carefully selected, however, to assure the necessay low
calcium carbonate and sand contents. The shale is illitic.

Chesterian Shale

The Chesterian shales range from calcareous to noncalcareous, and in many
areas, they contain lenses and/or beds of limestone. Their thickness varies from
a few feet to several tens of feet. The Chesterian shales range from thinly laminated
to massive. The colors may be red, green, blue-gray, and dark gray.

The Chesterian shales crop out in Gallatin, Hardin, Jackson, Johnson, Massac,
Monroe, Pope, Randolph, and Union Counties. In some areas, these shales contain
too much lime for use as a bonding clay. With careful prospecting, portions of the
Chesterian shales that are suitable for bonding clay can be found. The Chesterian
shales are illitic for the most part.

Pennsylvanian Shales and Claystones

The Pennsylvanian shales and underclays are by far the most important bonding
clay resources. These shales crop out over a much larger area of the state than the

ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 371

TstephWsonTwinnTbagoTboone"^ henry " "Ilake""

Figure 2 - Distribution of strippable refractory clays in Illinois.

CLAY RESOURCES FOR LIGHTWEIGHT CERAMIC BLOCK 7

older shales. Although most of the thick Pennsylvanian shales are noncalcareous,
some may contain limestone nodules, lenses, and/or beds. The underclays below
the Colchester (No. 2) Coal are usually noncalcareous, and those above the Summum
(No. 4) Coal are usually calcareous.

The exposed underclays in the Caseyville, Abbott, and Spoon Formations are
refractory (i.e., they fuse above pyrometric cone 15). If these underclays are used
with a nonrefractory aggregate, the addition of a flux is necessary. The Abbott and
Spoon Formations, which crop out in Adams, Brown, McDonough, Pike, Schuyler,
and Warren Counties, also contain shales that are refractory. The refractoriness
decreases from the west edge of the basin, southeastward towards the center of the
basin. For the most part, the shales and underclays of the Carbondale, Modesto,
Bond, and Mattoon Formations are nonrefractory.

Cretaceous Clays and Shales

Clay materials of Cretaceous age occur in southern Illinois in Alexander,
Massac, Pope, Pulaski, and Union Counties. These clays and shales usually con-
tain appreciable percentages of kaolinite, and are, therefore, refractory. A flux is
required to make them a good bonding clay. The clays and shales vary in color from
dark gray to light gray.

Tertiary Clay

Porters Creek Clay

The Porters Creek Clay is a montmorillonite clay that crops out in Pulaski
County in southern Illinois. It is a dark green-gray clay that turns buff when weath-
ered. The Porters Creek Clay is a good bonding clay because of the high montmoril-
lonite content.

Pre -Pleistocene and Early Pleistocene Residual Clays

The residual clays, commonly found in western and southern Illinois, are usu-
ally quite plastic. The clays may be white, red, or yellow in color. Some are quite
cherty. The thickness is variable. Some of the clays contain kaolin and are,
therefore, refractory. A flux is needed to reduce the vitrification range. Some of
these clays contain montmorillonite and/or mixed-layer clay minerals and no flux
would be needed.

Pleistocene Clay

Till might be a suitable source of bonding clay. A till that contains 30 per-
cent clay and few rocks might be considered a bonding clay resource. The Wiscon-
sinan till, which underlies the northeastern one-third of Illinois, is usually calcar-
eous, except for the upper few inches. The till ranges in texture from clayey to
rather sandy and rocky. To make till a useful bonding clay, the calcium carbonate
particles must be removed. The clay mineral in till is chiefly illite.

The Illinoian till (fig. 3) is noncalcareous in the upper few feet only. It could
be used as a bonding clay if the lime and material larger than fine sand were removed.

ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 371

WmiA

EXPLANATION £\ r-S.. ' ' 'f •----'■ . r

Thick loess deposits, \\ *--" "^~S~~1T^Z- -^>7.:\ v ;

greater than 50 in. on till \X; if "" ^~~"~>-... . ^C^~k ■'■

\' I Thin loes deposes on till ' ^t L^/L..^ f \cr V \: ;:i-
'•-Syv' ^ ",'\J tV( ^•-.->-J^..--r

1 ;| Alluvial and lake deposits

| | Residual clays and silts on

| 1 Thin lake clays and silts on 1,11

, ' Wisconslnan till boundary y j^

Miles ^ JS?/

0 10 20 30 40

' 1 I 1 I ^1

Figure 3 - Distribution of surficial clay deposits in Illinois.

CLAY RESOURCES FOR LIGHTWEIGHT CERAMIC BLOCK 9

The older Kansan till crops out in western Illinois. The till is noncalcareous in the
upper few feet. In areas west of the Illinois River, particularly near the Mississippi
River, the Kansan and Illinoian tills are more montmorillonitic (Willman, Glass,
Frye, 1963, p. 23) and are probably the best bonding clays of Pleistocene age.

CLAY MATERIALS INVESTIGATED

The following samples were studied.

Sample 1415 - NE| NW{ sec. 13, T. 6 N., R. 5 W., about 3 miles east of New

Douglas, Bond County, south of blacktop road. The clay is till 5±
feet at top; shale, yellow, plastic 6± feet; and shale, blue, plastic
8 feet at bottom. The till is Illinoian of Pleistocene age and the
shale is from the Bond Formation of Pennsylvanian age. The clay
mineralogy of the shale is illite 4 parts, kaolinite 3, and chlorite
3 parts in 10.

Sample 866 - NEi sec. 11, T. 33 N., R. 8 E., 7 miles east of Morris, Grundy
County. The clay is 3 feet thick under 6 feet of Pleistocene over-
burden. The clay is Spoon Formation of Pennsylvanian age. The
clay mineral components are illite 3, kaolinite 1, and mixed-layer
clay mineral 6 parts in 10.

Sample 2042 - SW| SE^ NE* sec. 15, T. 12 N., R. 9 E., east cut bank of stream
east of road. About \ mile southwest of Sparland, Marshall County.
About 3 feet of underclay beneath Danville (No. 7) Coal in the Carbon-
dale Formation of Pennsylvanian age. The clay mineral components
are illite 3, and mixed-layer clay minerals 7 parts in 10.

Sample 1422 - NW corner sec. 24, T. UN., R. 3 E., about 1 mile southwest of
Shelbyville, Shelby County, on east roadcut of north- south county
road in south valley wall of creek. Six feet of shale is exposed in
roadcut with thin overburden. The shale is in the Bond or Mattoon
Formation of Pennsylvanian age. The clay mineral components are
kaolinite 2, chlorite 1, swelling chlorite 3 to 4, and illite 2 parts in
10.

Sample 996N - NW^ SW^ WN\ sec. 10, I.4S..R.5W., about l\ miles north of
Hadley, Pike County, on north side of old roadcut before road turned
north, in south valley wall of Hadley Creek. Eight feet of clay rests
on Mississippian Limestone and has from 10 to 140 feet of overburden.
The clay occurs in the Spoon or Abbott Formation of Pennsylvanian age.
The clay mineral component is kaolinite.

Sample FE1 13 -NE| SE| sec. 27, T. 15 S., R. IE., southeast of Olmsted, Pulaski
County, on the west cut bank of Ohio River. The clay, about 20 feet
thick with 20 to 40 feet of overburden, is in the Porter Creek Forma-
tion of Tertiary age. The clay mineral components are montmorillon-
ite 5, mixed-layer clay minerals 3, and illite 2 parts in 10.

10 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 371

Sample 2043 - Near center NE| sec. 23, T. IN., R. 12 W. , northeast cut roadbank
in southwest valley of Illinois valley wall above where road crosses
tributary, Schuyler County. The clay is Kansan till of Pleistocene
age and is 5 feet thick. The clay mineral components are illite 1,
kaolinite 1, montmorillonite 4, and mixed-layer clay minerals 4 parts
in 10.

The mineralogy of the clays studied was determined by X-ray diffraction.
Samples composed of illite, montmorillonite, kaolinite, chlorite, and mixed-layer
clay minerals were used in this study.

Procedure

About 500 pounds of clay were collected from each location. Lightweight,
bloated shale aggregate was purchased from Poston Brick and Concrete Products
Company of Springfield and Western Brick Company of Danville. An 8-inch Raymond
hammer mill was used to grind the clay so that it would pass through a .010" x .47"
slot screen. One hundred pounds of dry clay and aggregate were mixed in a plaster
mixer for 4 minutes; water was then added, and mixing was resumed for another 4
minutes. With clays that contained enough kaolinite or quartz to make them more
refractory than the aggregate, it was necessary to add a flux to reduce the fusion
temperature of the clay. In only sample 99 6N, one pound of fluorspar was used for
each 20 lbs. of clay and 80 lbs. of aggregate that were mixed.

The sample blocks were formed on either a concrete block machine or a hy-
draulic press with a vibrating mechanism. The blocks were allowed to dry in air.
They were then placed in an electric kiln and fired to 1850° -1900° F. (1010 to 1038°
C.) for 24-hours. After firing, the blocks were capped. A Riehle compression mach-
ine (300, 000 lbs. maximum capacity) was used to test for compressive strength.
The maximum capacity was applied to the blocks for 2 minutes. The results are given
in table 1.

Fragments of the crushed tile were placed in cold water for 24 hours. The
samples were then weighed and placed in an oven at 110° C, overnight. The sam-
ples were weighed again to determine the porosity.

Test Results

Forming Properties

The strongest blocks were made from mixtures in which 20 percent clay and
80 percent aggregate (l/l 6"-0) were mixed dry and about 16 percent water added and
mixed. FE113 was an exception, however. Good blocks were obtained with only
10 percent clay (FE113). To use a larger percentage of clay, more water would be
necessary. An excess of water, however, caused the mix to stick to the machine;
an insufficiency of water caused the blocks to be crumbly when air dried. When less

CLAY RESOURCES FOR LIGHTWEIGHT CERAMIC BLOCK

than 16 percent of water was used, a reduction in block strength resulted. This
suggests that there was not enough water to allow the bonding mechanism of the
clay to develop fully. This bonding mechanism is probably due to the development
of a wedge-shaped mass of clay at the junctions of the aggregate grains (Grim and
Cuthbert, 1946, p. 15) and the formation of a glassy phase, which bonds the vitri-
fied clay wedge and the aggregate together. The clay must be lubricated with water
so that it can coat the particles of aggregate to give the best bond structure when
the blocks are fired.

Drying Properties

The sample blocks were dried in air; however, the open-pore structure of the
blocks would allow them to be dried without difficulty at a more rapid rate. Bell and
McGinnis (1951, p. 338) state that no difficulty was encountered in drying blocks
at above 212° F.

Firing Properties

The samples were fired for 24 hours at 1850-1900° F. Bell and McGinnis
(1951, p. 338) used a l\ hour schedule, whereas Caruso (1959, p. 80) used a tunnel
kiln with a 5 hour and 40 minute firing schedule.

The total shrinkage in this study ranged from 5 to 13 percent (table 1).

Block can be flashed in the same manner as brick. One group of blocks was
fired in an atmosphere of insufficient oxygen; these samples did not bloat. The color
of the blocks in this group was much lighter, and some of the blocks were pink
instead of the red produced in a completely oxidizing atmosphere. The strength of
these blocks was similar to the strength of those burned in an oxidizing atmosphere.

Other Properties

The sample blocks (figs. 4 and 5) had a pleasing appearance. The colors
were similar to those found in brick. Color can be changed by additives, flashing
in kiln, or varying the temperature of the kiln. Blocks can be glazed to obtain
colors that cannot be produced by the above processes.

Ceramic blocks show a thermal expansion more nearly equal to that of brick
than do concrete blocks. Texture can be changed by increasing or reducing the per-
centage of the fines and by using a larger aggregate size. The clay block will not
shrink .

If a white burned product is desired, the white burning clay should be used
as a glaze or terra sigillatta on the surface of the block. When a white burning clay
is used as a bonding clay, it only lightens the burning color of the aggregate.

Clays containing montmorillonite may require less clay to give the desired
strength (sample FE113) or more nonclay material can be tolerated (sample 2043).

All seven clays tested produced blocks that had a strength of over 1,000
pounds per square inch. Five of the clays had an average strength of over 1, 400
pounds. The average strength of blocks from one clay (sample 1415) was over 1,700
pounds per square inch, and some of these blocks had a strength of 1900 psi.

Blocks fired to 1850° F. were soft enough that nails driven into them did not
bend (fig. 5), and they could be sawed with a handsaw.

ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 371

TABLE 1 - POROSITY AND STRENGTH OF CLAY AND AGGREGATE MIXES

Mixture Percent

H20
Percent

After Firing

Sample

PSI

Percent
Porosity

No.

Clay 1 Aggregate

Remarks

15.0

603

20.0

1406

25.2

10.0

—

—

20.0

356

—

10.0

—

—

10.6

262

—

20.0

1442

26.2

Too wet

15.0

1124

22.0

15.0

635

—

20.0

1880

22.6

9.0

374

—

Too dry

20.0

1304

__

10.0

740

—

Coarser Aggregat

10.0

360

32.0

Finer Aggregate

20.0

—

32.0

15.0

1439

28.0

10.0

509

—

9.0

300

10.0

278

—

5.0

—

—

Too dry

15.0

1714

13.5

15.0

1292

19.0

10.0

<252

31.5

Too dry

11.0

596

—

Too dry

15.0

774

25.5

15.0

1109

17.3

10.0

<400

28.0

12.3

850

—

5.0

184

__

Too dry

15.0

1092

29.0

20.0

—

—

Too wet

10.0

275

—

15.0

1033

—

10.0

979

25.6

20.0

780

—

15.0

760

—

10.0

430

—

10.3

603

—

10.0

480

__

15.0

1472

30.0

10.0

900

25.5

15.0

967

—

11.0

313

—

CLAY RESOURCES FOR LIGHTWEIGHT CERAMIC BLOCK 13

Figure 4 - Lightweight block made from various Illino:

ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 371

CONCLUSIONS

Many of the deposits of clay and shale in Illinois could be used in the manufac-
ture of lightweight ceramic blocks .

Either the brick industry or the concrete block industry could produce ceramic
blocks as a second product with a minimum of additional equipment. Brick
manufacturers already have the processing machinery for preparing the clay
and the kiln for firing the finished product, whereas a plant that manufactures
concrete block would have the mixing equipment and the shaping machinery.

The blocks make excellent building materials because they are strong and
aesthetically pleasing.

Clay block can be used in most places where concrete block can be used.

Clay blocks will not shrink.

A curing period is not required.

Clay blocks would be more compatible with the thermal and permanent expansion
of brick than would concrete blocks.

Generally, clay material with abundant montmorillonite and mixed-layer clay
minerals are good bonding clays. If clays containing montmorillonite are used,
less clay may be required to give the desired strength (sample FE113). Clay
materials that contain abundant nonclay material (sample 2043) may require a
higher ratio of clay to aggregate than clays with less nonclay components.

Bell, W. C, and McGinnis, D. H., 1951, The development of large lightweight
structural clay building units. II. Lightweight clay-aggregate building units:
Am. Ceramic Soc. Bull., v. 30, no. 12, p. 336-339.

Caruso, P. A., 1959, New design data for clay bonded block: Brick and Clay Rec,
v. 135, no. 4, p. 69-87.

Grim, R. E., and Cuthbert, F. L., 1946, The bonding action of clays. Part II -
Clays in dry molding sands: Illinois Geol. Survey Rept. Inv. 110, 36 p.

Krey, Frank, 1924, Structural reconnaissance of the Mississippi Valley area from
Old Monroe, Missouri, to Nauvoo, Illinois: Illinois Geol. Survey Bull. 45, 86 p.

Moffitt, R. B.3 1961, Determine firing schedule of ceramic block: BrickandClay
Rec, v. 139, no. 5, p. 60-83.

Robinson, G. C, 1961, Clay block on concrete block machine: Brick and Clay Rec.
v. 139, no. 5, p. 43-47.

Robinson, G. C, 1962, Clay block on concrete block machines: Brick and Clay
Rec, v. 140, no. 1, p. 66-87.

Rubey, W. W. , 1952, Geology and mineral resources of Hardin and Brussels Quad-
rangles (in Illinois): U. S. Geol. Survey Prof. Paper 218, 179 p.

CLAY RESOURCES FOR LIGHTWEIGHT CERAMIC BLOCK 15

Templeton, J. S., and Willman, H. W., 1963, Champlainian Series (Middle Ordo-
vician) in Illinois: Illinois Geol. Survey Bull. 89, 260 p.

Weller, Stuart, and Weller, J. M., 1939, Preliminary geological maps of the pre-
Pennsylvanian Formations in part of southern Illinois - Waterloo, Kimmswick,
New Athens, Crystal City, Renault, Baldwin, Chester, and Campbell Hill Quad-
rangles: Illinois Geol. Survey Rept. Inv. 59, 15 p.

Willman, H. B., Glass, H. D., and Frye, J. C, 1963, Mineralogy of glacial tills
and their weathering profiles in Illinois. Part I - Glacial tills: Illinois Geol.
Survey Circ. 347, 55 p.

Illinois State Geological Survey Circular 371
15 p., 5 figs., 1 table, 19 64

Printed by Authority of State of Illinois, Ch . 127, IRS, Par. 58.25.

CIRCULAR 371

ILLINOIS STATE GEOLOGICAL SURVEY

URBANA