14. GS: CIR 332 Coaun Sxxfi>OLu STATE OF ILLINOIS OTTO KERNER, Governor DEPARTMENT OF REGISTRATION AND EDUCATION WILLIAM SYLVESTER WHITE, Director LOWER PENNSYLVANIAN CLAY RESOURCES OF ROCK ISLAND, MERCER, AND HENRY COUNTIES, ILLINOIS Walter E. Parham ILLINOIS GEOLOGICAL SURVEY LIBRARY NOV 201961 DIVISION OF THE ILLINOIS STATE GEOLOGICAL SURVEY JOHN C. FRYE, Chief URBANA CIRCULAR 322 1961 ILLINOIS STATE GEOLOGICAL SURVEY 3 3051 00004 1677 URBANA LOWER PENNSYLVANIAN CLAY RESOURCES OF ROCK ISLAND, MERCER, AND HENRY COUNTIES, ILLINOIS Walter E. Parham ABSTRACT Some 95 samples of the underclays occuring in the Spoon and Abbott Formations (lower Pennsylvanian) of Rock Island, Mer- cer, and Henry Counties, Illinois, were tested to determine their suitability for use in making fired clay products. This area of Illinois contains underclay deposits of good quality capable of a wide variety of uses. The overburden is less than 40 feet thick over 50 percent of the underclays. At present, only one underclay and one shale pit are in operation in the three counties . All of the samples have fusion temperatures below PCE cone 28, and about half of the clays tested have light firing colors. Var- ious samples are suitable for stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery, bonding clay, and lightweight aggregate. INTRODUCTION This report on the clay resources of the Spoon and Abbott Formations of the Pennsylvanian System in Rock Island, Mercer, and Henry Counties, Illinois, is the third in a series of guides to locating and exploiting new light-burning clay deposits. Reports on the clay resources of LaSalle and Knox Counties already have been published (Parham, 1959, 1960). Most of Rock Island, Henry, and Mercer Counties is covered by Pleistocene glacial deposits. The older coal-bearing rocks of the Pennsylvanian System and their associated clays are exposed in the streams along the bluffs of the Rock and Mississippi Rivers and in other streams that have cut through the region's wide- spread glacial deposits. The type of clay sampled for this report is called under- clay and generally is found directly beneath coal beds. Underclays are nonlami- nated, gray, fine grained, sedimentary rocks. They can vary in thickness from a few inches to ten or fifteen feet. Sampling was limited to underclays of the Spoon and Abbott Formations. However, preliminary investigations of the spores of some coals of western Rock Island County by R. M. Kosanke of the Illinois State Geological Survey have shown that there are at least two coals in this region containing spores like those found in coals of the Caseyville Formation of southern Illinois. It is possible that some of the underclays of western Rock Island County listed in this report as being in [1] [ . ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 the lower Abbott Formation will be found to belong to the Caseyville Formation when the current spore study has been completed. A total of 95 samples, two of which are shale, were studied. The samples were taken from the locations shown in figure 1 . A few of them were obtained from underground mines of the Rock Island (No. 1) Coal, but most were from outcrops. GENERAL GEOLOGY OF THE AREA The Pennsylvanian rocks of Rock Island, Mercer, and Henry Counties appear to lie flat in most areas, but they actually dip very gently to the southeast. The thickness of the Pennsylvanian underclays may be extremely variable within a small area. Careful geologic correlation and measurement of the exposed rocks in the prospect area, coupled with the study of cores of the same rocks from the covered intervals, should be made before attempting to exploit such deposits. Wanless (1952) stated that some of the rocks in this region were deposited in estuaries a few hundred yards wide and several miles long. The Rock Island (No. 1) Coal, and the limestone above it, can vary from 1 to 5 feet in thickness in less than 100 yards near the edges of these estuaries. Such variation causes equivalent geologic sections to differ greatly in appearance even though they may be quite close together. Small faults of five- or ten-foot displacement have been observed in west- ern Rock Island County. In addition, in some places throughout the region young- er Pennsylvanian sandstones have cut through the older layers of Pennsylvanian rocks. Either of these factors may account for the sudden termination of an appar- ently continuous underclay unit. The delineation of such a deposit thus can be- come very complex. It is recommended that competent geological assistance be utilized during the initial development of underclay resources . At present, only one deposit of underclay and one of shale are being used commercially in the three counties. Earlier in the 1900 's underclays were used locally in all of these counties, but little trace of this activity is left today. A deposit in western Rock Island County was mined from time to time and the raw material was hauled by wagon to Muscatine, Iowa (Lines, 1917), for the manufac- ture of drain tile. At Sears, in Rock Island County, clay was mined for use in the manufacture of fire brick. In 1925 underclay was mined at Griffin in Mercer County, but this operation has long since been abandoned. Other ceramic and mineralogi- cal data regarding clays and shales from this area can be found in Lines (1917), Parmelee and Schroyer (1921), Grim et al. (1957), White and Lamar (1960), and White (1960). A detailed geologic account of this region is found in the publications by Green (1870), Savage and Udden (1921), Shaw (1873), Wanless (1929, 1952), and Worthen and Shaw (1873) . The formation names used in this report are those used in the Illinois State Geological Survey's "Classification of the Pennsylvanian Strata of Illinois" (Kosanke et al., 1960). Owing in part to the rapid lateral variations in the thickness of the rocks involved and in part to the lack of detailed geological information in parts of the counties studied, it was difficult, in places throughout the area, to determine exactly what unit was being sampled. The stratigraphic relationships of these rocks is being investigated by Neal O'Brien, Illinois Geological Survey, who also aided in identifying the various stratigraphic units in this report. CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 3 REPORT OF TESTS Included in this report on existing clay deposits in Rock. Island, Mercer, and Henry Counties is information concerning sample locations, thickness, over- burden, type of underlying and overlying sediment, results of tests on the physical properties, and suggestions for uses. The test results include the drying and fir- ing shrinkage of the clay, water of plasticity, fired colors, and bonding properties. The clay minerals in each sample were identified by x-ray techniques. The x-ray analyses were used as a basis for selecting samples for bonding tests and for fusion temperature tests. Extrusion and Firing of Test Bars Each sample of clay was air dried and crushed to particles approximately one-fourth inch or less in diameter. The sample then was mixed with sufficient water to develop plasticity. The percentage of water added in each case was determined and recorded as water of plasticity. The plastic clay was extruded into three individual test bars, each 1 by 1 by 6 inches. The bars were air dried for at least two days, then measured to determine the percentage of drying shrink- age. The first bar was fired at 1832° F, the second at 2012°F, and the third at 2200 c F. After each firing, the test bars were measured to determine the percent- age of firing shrinkage. Most of the samples in this study were obtained from outcrops, and weathering probably has altered the burning color of the clay. A weathered, light- burning clay generally burns darker than the unweathered clay from the same de- posit, owing to the oxidation of pyrite in the clay and to the fine dissemination of iron throughout the clay deposit. For a better indication of true burning color, it would be necessary to obtain unweathered samples of the clay from drill holes near the area in question. In some clays, soluble iron salts will migrate outward to the surface of an unfired brick during the drying period. When the brick is fired, the high concen- tration of iron will be on that surface of the brick through which the most drying has taken place, and the fired color generally will be dark brick red on that sur- face, whereas the other surfaces may be considerably lighter. Samples 1581, 1627, 1629, 1703, 1707, and 1718 displayed this iron dis- coloration, but the fired colors, which are listed in the tables for the various firing temperatures, are taken from the surfaces not discolored by the iron. High-Temperature Properties The 10 samples that proved to have, on the basis of mineralogical data ob- tained by x-ray analyses of each sample, the largest amounts of kaolinite were selected for tests to determine whether their fusion points were PCE (pyrometric cone equivalent) 28 or greater. A small cone was made from each sample and mounted in a gas furnace with standard cones of PCE 28, 29, 30, and 31. The sample was heated to its fusion point and compared with the standard cones. The fusion point of all samples tested fell below PCE cone 28, making them unacceptable for use as medium heat duty refractories, which require materials with PCE values of at least 29 (Parham, 1959, p. 7). ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 KEY • Outcrop sampled y Mine 1660 Sample number SCALE 12 3 4 Miles JALEDO r 1706 1717* 1710 -I— W- 1712 VIOLA 1581 1711 Fig. 1 - Map of area studied showing CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 5 HENRY CO. locations from which samples were taken. 6 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 Bonding Tests Some underclays have been found to be satisfactory for use as bonding clays for foundry sands. The clay mineralogy of an underclay may be used effectively in predicting its bonding properties. About one-fourth of the samples were selected for bonding tests, on the basis of x-ray analyses of their clay minerals. Mixtures of 92 percent foundry sand and 8 percent clay were made and mixed with varying amounts of water. The tests were then run in a manner described in the "Foundry Sand Handbook" (American Foundrymen's Society, 1952). The green compression strength of each sample tested, in pounds per square inch (GCS psi), is listed in the following tables under "Bonding properties." It is the maximum green strength developed by the clay at its optimum water content. Suggested Uses Many clay deposits may be satisfactory for use in more than one variety of fired clay product. Some types of clay products require clay with specific physical properties, but others can be made from several types of clay. Refractories made from underclays, for instance, can be made only from clays with a high kaolinite content, whereas the latitude of properties of clays used in stoneware is somewhat less restricted. Structural clay products, sewer pipe, and drain tile can be made from a wider variety of clays than either of the first two categories, and the require- ments for flower pot clay are the least stringent. The sequence, then, running from products that demand clay having specific properties to products that can use clay of several types is (1) refractories, (2) stoneware, (3) structural clay products, sewer pipe, and drain tile, and (4) flower pots. In the following tables under "Suggested uses" for each clay, the product listed first is the one highest in this sequence. The samples also may be acceptable for products (listed next) that are found lower in the sequence, but may not be satisfactory for use in products found higher in the sequence. Lightweight aggregate and bonding clay are not included in the above list of products but are listed in the following tables for samples suitable for such use. All of the underclays tested are suitable for some form of art pottery (Jonas, 1957). 1957). Results of all tests made during this investigation appear in the following tables. RESULTS OF TESTS ROCK ISLAND COUNTY SAMPLE 1593 NE| NE\ SWi sec. 28, T. 17 N., R. 1 W. Thickness: Ft. In Overburden Overlying rocks 57 Rock Island (No. 1) Coal 2 6 Underclay (sample 1593) 2 6 Shale Extrusion properties Good Water of plasticity, percent 16.9 Linear drying shrinkage, percent 3.5 The underclay is in the lower part of the Spoon Formation. Firing temperature 1832°F 2012°F 2200°F Linear firing shrinkage, percent 1.2 5.5 5.0 Total linear shrinkage, percent 4.7 9.0 8.5 Fired color Cream Tan Tan Surface texture of fired test bar: Bloating started at 2200 °F. Bonding properties: 4.70 (GCS psi); 1.50 (Optimum H 2 0). Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1594 SW{ SE{ NW| sec. 31, T. 17 N., R. 1 W. Extrusion properties Good Water of plasticity, percent 17.4 Linear drying shrinkage, percent 3.0 Overburden Ft. In Overlying rocks 100 Coal 1 44 Underclay (sample 1594) 1 8+ Base covered The underclay is in the middle part of the Abbott Formation. Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Has rough edges at all firing temperatures. Bloat- ing started at 2200 °F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 0.0 5.0 5.7 3.0 8.0 8.7 Salmon Salmon Tan ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1595 NE| NE4- SE± sec. 14, T. 17 N., R. 2 W. Extrusion properties Fair Water of plasticity, percent 20.2 Linear drying shrinkage, percent 3.0 Overburden Ft. In. Overlying rocks 79 Coal 1 Underclay (sample 1595) (lower [?] part of Spoon Formation) 2 6 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Has rough edges at all firing temperatures. Bloat- ing started at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1596 NW| NE± SE± sec. 25, T. 17 N., R. 1 W. 1832°F 2012°F 2200°F 1.4 6.7 5.0 4.4 9.7 8.0 Salmon Salmon Brown Extrusion properties Fair Water of plasticity, percent 16.9 Linear drying shrinkage, percent 3.5 Overburden Ft . In . Overlying rocks 55 Coal 10 Underclay (sample 1596) (lower part of Spoon Formation) 5 Sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Bonding properties: 6.46 (GCS psi); 1.70 (Optimum H 2 0) . Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 1.2 5.0 6.7 4.7 8.5 10.2 Salmon Salmon Brown SAMPLE 1597 SW| SE| NE± sec. 25, T. 17 N., R. 1 W. Overburden Ft Overlying rocks 55 Coaly shale Underclay (sample 1597) (lower part of Spoon . Formation) 7 Coaly seam 1 In. Extrusion properties Good Water of plasticity, percent 22.9 8 Linear drying shrinkage, percent 3.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 0.9 4.4 Salmon 2012°F 4.7 8.2 Salmon 2200 "F 7.9 11.4 Tan Surface texture of fired test bar: Normal. Bonding properties: 3.85 (GCS psi); 1.45 (Optimum H 2 0) . Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 9 SAMPLE 1598 SW{ SE} NE| sec. 25, T. 17 N., R. 1 W, Overburden Overlying rocks Coaly seam Underclay (sample 1598) (upper [?] part of Abbott Formation) Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Ft. In. Extrusion properties Fair 65 Water of plasticity, percent 17.9 1 6 Linear drying shrinkage, percent 2.5 2+ (exposed) 1832°F 0.2 2.7 Salmon 2012°F 2.6 5.1 Salmon 2200°F 7.7 10.2 Brown ,0) Surface texture of fired test bar: Normal. Bonding properties: 3.25 (GCS psi); 1.50 (Optimum H 2 > Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1599 SE{ NE± SE{ sec. 5, T. 17 N. R. 1 E. Ft. In. Extrusion properties Good 27 Water of plasticity, percent 13.7 6 Linear drying shrinkage, percent 3.5 Overburden Overlying rocks Ironstone nodules Underclay (sample 1599) (upper [?] part of Abbott Formation) Sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 10+ (exposed) 1832°F 2012°F 2200°F 0.3 2.5 3.4 3.8 6.0 6.9 Buff Buff Tan SAMPLE 1600 SE± NEi SEj sec. 5, T. 17 N, R. 1 E, Overburden Overlying rocks Coaly ironstone shale Underclay (sample 1600) (upper [?] part of Abbott Formation) Shale Ft. 25 1 0-10 In. Extrusion properties Good Water of plasticity, percent 14.0 Linear drying shrinkage, percent 3.0 1832°F 2012°F 2200°F 0.2 1.7 3.1 3.2 4.7 6.1 Salmon Salmon Tan Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Bonding properties: 2.32 (GCS psi); 1.40 (Optimum H 2 0). Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 10 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1601 NE{ NW{ NW{ sec. 4, T. 17 N, R. 1 E. Overburden Ft . In , Overlying rocks 60 Coal streak 3 Underclay (sample 1601) (lower part of Spoon Formation) 2 Silty shale Firing temperature 1832°F Linear firing shrinkage, percent 0.7 Total linear shrinkage, percent 3.7 Fired color Salmon Extrusion properties Fair Water of plasticity, percent 16.4 Linear drying shrinkage, percent 3.0 2012°F 2.9 5.9 Salmon 2200°F 4.8 7.0 Tan Surface texture of fired test bar: Normal. Bonding properties: 3.12 (GCS psi); 2.14 (Optimum H 2 0) . Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1602 SWi NW± SW{ sec. 8, T. 17 N, R. 1 E, Overburden Overlying rocks Underclay (sample 1602) (lower [?] part of Spoon Formation) Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Ft. In. Extrusion properties Good 60 Water of plasticity, percent 15.9 Linear drying shrinkage, percent 3.5 2+ (exposed) 1832°F 1.2 4.7 Salmon 2012°F 3.4 6.9 Salmon 2200°F 4.1 7.6 Tan Surface texture of fired test bar: Normal. Bonding properties: 4.18 (GCS psi); 1.33 (Optimum H 2 0) . Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1603 SE± NW| NW| sec. 9, T. 17 N. Overburden Ft. In. Overlying rocks 40 Coal 1 Underclay (sample 1603) (lower part of Spoon Formation) 2+ (exposed) Base covered R. 1 E. Extrusion properties Fair Water of plasticity, percent 20.0 Linear drying shrinkage, percent 4.0 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Bloating started at 2200° F. Suggested uses: Lightweight aggregate, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200 0.9 5.0 +0.5 4.9 9.0 3.5 Salmon Brown Tan CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 11 SAMPLE 1604 SE± NW{ NW| sec. 9, T. 17 N., R. IE. Overburden Ft. 45 In. Extrusion properties Good Overlying rocks Coal Underclay (sample 1604) (lower part of Spoon Formation) 1 Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Water of plasticity, percent 18.3 Linear drying shrinkage, percent 3.0 6+ (exposed) 1832 °F 2012°F 2200°F 0.3 3.4 5.5 3.3 6.4 8.5 Buff Buff Tan Surface texture of fired test bar: Bonding properties: Normal, 3.70 (GCS psi); 1.45 (Optimum H 2 0) . Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1605 NW{ NW± SW± sec. 9, T. 17 N., R. 1 E, Overburden Overlying rocks Rock Island (No. 1) Coal Underclay (sample 1605) (lower part of Spoon Formation) Shale Ft. In. Extrusion properties Good 80 Water of plasticity, percent 22.2 1 8 Linear drying shrinkage, percent 3.0 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Bloating started at 2200 °F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 0.7 7.4 3.3 3.7 10.4 6.3 Salmon Brick red Brown SAMPLE 1606 NE| NW| SEi sec. 26, T. 17 N, R. 4 W. Overburden Ft . In . Overlying rocks 33 Coal 1 1 Underclay (sample 1606) 3 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Extrusion properties Good Water of plasticity, percent 18.3 Linear drying shrinkage, percent 4 .0 1832°F 0.7 4.7 Buff 2012°F 4.3 8.3 Buff 2200°F 5.1 9.1 Tan Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 12 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1607 NE± NW{ SE± sec. 26, T. 17 N. R. 4 W. Extrusion properties Good Water of plasticity, percent 24.0 Linear drying shrinkage, percent 3.5 Overburden Ft . In . Overlying rocks 18 Thin coal streak Underclay (sample 1607) 2 7 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Bonding properties: 3.10 (GCS psi); 1.50 (Optimum H 2 0) . Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1608 NE± SEj SW| sec. 35, T. 17 N., R. 4 W. 1832°F 2012°F 2200°F 0.2 1.6 3.3 3.7 5.1 6.8 Cream Cream Buff Extrusion properties Good Water of plasticity, percent 21. 6 Linear drying shrinkage, percent 6.0 Overburden Ft . In . Overlying rocks 40 Coal 5 Underclay (sample 1608) 3 6 Black shale Firing temperature 1832° Linear firing shrinkage, percent 1.0 Total linear shrinkage, percent 7.0 Fired color Pink Surface texture of fired test bar: Normal. Bonding properties: 5.90 (GCS psi); 2.20 (Optimum H 2 0). Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 2012°F 2200°F 4.2 6.3 10.2 11.3 Tan Greenish tan SAMPLE 1609 NEJ SEi SW{ sec. 35, T. 17 N., R. 4 W. Overburden Ft . In , Overlying rocks 27 Coaly streak 3 Underclay (sample 1609) 11 Coal 5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Extrusion properties Good Water of plasticity, percent 17.6 Linear drying shrinkage, percent 4.5 1832°F 0.8 5.3 Cream 2012°F 2.2 6.7 Cream 2200°F 3.3 7.8 Cream Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 13 SAMPLE 1610 NWi NW{ NEj sec. 34, T. 17 N., R. 1 W. Overburden Ft . In , 8 Extrusion properties Good Water of plasticity, percent 20.8 Linear drying shrinkage, percent 4.0 Overlying rocks Coal Underclay (sample 1610) (middle [?] part of Spoon Formation) Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 0.9 3.7 7.6 4.9 7.7 11.6 Salmon Brick red Brown SAMPLE 1612 SE| SEi SW$ sec. 32, T. 17 N., R. 1 W. Overburden Overlying rocks Shaly coal Underclay (sample 1612) Base covered Ft. In. Extrusion properties Good 10-40 Water of plasticity, percent 15.7 10 Linear drying shrinkage, percent 3.0 2+ (exposed) 1832°F 2012°F 2200°F +0.5 0.2 2.1 2.5 3.2 5.1 Cream Cream Buff Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Bonding properties: 2.15 (GCS psi); 1.16 (Optimum H 2 0). Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1613 Center of E section line, sec. 11, T. 17N., R. 1W. Overburden Ft. In, Overlying rocks 40 Coal 8 Underclay (sample 1613) 3 4 Shale Firing temperature 1832°F Linear firing shrinkage, percent 1.2 Total linear shrinkage, percent 5.2 Fired color Salmon Extrusion properties Fair Water of plasticity, percent 19.3 Linear drying shrinkage, percent 4.0 2012°F 4.5 8.5 Brick red 2200°F 5.2 9.2 Brown Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 14 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1614 SE| NE| SW{ sec. 29, T. 17 N., R. 3 W. Extrusion properties Fair Water of plasticity, percent 18.8 Linear drying shrinkage, percent 4.5 Overburden Ft. In. Overlying rocks 40 Coal 5 Underclay (sample 1614) (middle part of Abbott Formation) 3 9 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Bloating started at 2200 °F. Bonding properties: 5.55 (GCS psi); 1.80 (Optimum H 2 0) . Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1615 NW± NE£ SE£ sec. 21, T. 16 N., R. 4 W. 1832°F 2012°F 2200°F 1.9 6.3 5.1 6.4 10.8 9.6 Salmon Brown Brown Overburden Ft . In . Overlying rocks 16 Coal 1 2 Underclay (sample 1615) 4 2 Shale Firing temperature 1832°F Linear firing shrinkage, percent 0.9 Total linear shrinkage, percent 4.4 Fired color Buff Extrusion properties Good Water of plasticity, percent 16.8 Linear drying shrinkage, percent 3.5 2012°F 3.8 7.2 Buff 2200°F 5.5 9.0 Tan Surface texture of fired test bar. Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . Rocks dipping 30° to 35° to N.E. Coal Underclay (sample 1616) Shale SAMPLE 1616 NWi SWi NW| sec. 27, T. 16 N., R. 5 W. Extrusion properties Good Water of plasticity, percent 13.9 9 Linear drying shrinkage, percent 3.0 13 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200°F +0.5 1.0 3.4 2.5 4.0 7.4 Cream Buff Tan CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 15 SAMPLE 1617 SEi SE^ SW£ sec. 30, T.. 17 N., R. 3 W. Overburden Overlying rocks Coal Underclay (sample 1617) Sandstone ? Ft. In. Extrusion properties Good 16 Water of plasticity, percent 15.7 10 Linear drying shrinkage, percent 4.5 1+ (exposed) Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Bloating started at 2200°F. Suggested uses: Lightweight aggregate, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200°F 1.1 4.3 2.1 5.6 8.8 6.6 Salmon Brick red Tan SAMPLE 1618 NEi NW| NE| sec. 36, T. 17 N., R. 4 W. Overburden Overlying rocks 55 Sandstone 1 Underclay (sample 1618) (lower part of Spoon Formation) 3 Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Ft. In. Extrusion properties Good Water of plasticity, percent 19.3 7 Linear drying shrinkage, percent 3.5 8+ (expose ■d) 1832°F 2012°F 2200°F 0.0 1.0 3.1 3.5 4.5 6.6 Cream Cream Buff Surface texture of fired test bar. Normal. Bonding properties: 3.33 (GCS psi); 1.33 (Optimum H 2 0) . Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1619 SE± NE| SE£ sec. 36, T. 17 N., R. 4 W. Ft. In. Extrusion properties Good Water of plasticity, percent 25.9 Linear drying shrinkage, percent 6.5 Overburden Overlying rocks 22 Shaly limestone 3 Underclay (sample 1619) (middle part of Spoon Formation) 3 Coal 4 Firing temperature 1832°F Linear firing shrinkage, percent 3.8 Total linear shrinkage, percent 10.3 Fired color Brick red 2012°F 7.1 13.6 Brick red 2200°F Surface texture of fired test bar: Bloating started at 2012°F. Bonding properties: 9.50 (GCS psi); 1.85 (Optimum H 2 0) . Suggested uses: Bonding clay, sewer pipe, drain tile, flower pots, art pottery, 16 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1620 SE± NE£ SE| sec. 36, T. 17 N., R. 4 W. Ft. 30 In. Overburden Overlying rocks Coal Underclay (sample 1620) (middle part of Spoon Formation) 3+ (exposed) Base covered Extrusion properties Good Water of plasticity, percent 16.6 Linear drying shrinkage, percent 4.0 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 0.9 4.7 5.9 4.9 8.7 9.9 Salmon Salmon Tan SAMPLE 1621 NW| SW| SW± sec. 30, T. 17 N., R. 3 W. Overburden Ft . In . Overlying rocks 50 Coal 1 Underclay (sample 1621) (lower [ ? ] part of Spoon Formation) 3 Sandstone Firing temperature 1832°F Linear firing shrinkage, percent 1.2 Total linear shrinkage, percent 5.2 Fired color Salmon Extrusion properties Good Water of plasticity, percent 17.3 Linear drying shrinkage, percent 4.0 2012°F 6.1 10.1 Salmon 2200°F 2.4 6.4 Tan Surface texture of fired test bar: Bloating started at 2200°F. Suggested uses: Lightweight aggregate, structural clay products, sewer pipe, drain tile, flower pots, art pottery. Overburden SAMPLE 1622 SW| SWi SW{ sec. 30, T. 17 N., R. 3 W. Ft. In. Extrusion properties Overlying rocks 19 Coal 1 4 Underclay (sample 1622) (lower [ ?] part of Spoon Formation) 2 8 + (exposed) Base covered Firing temperature 1832°F Linear firing shrinkage, percent 0.2 Total linear shrinkage, percent 2.7 Fired color Cream Water of plasticity, percent Linear drying shrinkage, percent Fair 15.0 2.5 2012°F 2.7 5.2 Buff 2200°F 5.1 7.6 Tan Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 17 SAMPLE 1623 NEi NE| SE| sec. 35, T. 17 N., R. 4 W. Extrusion properties Poor Water of plasticity, percent 14.4 Linear drying shrinkage, percent 3.0 Overburden Ft . In Overlying rocks 55 Shale Underclay (sample 1623) (Abbott [ ? ] Formation) 3 1 Sandy shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1624 NW| SE| SE} sec. 29, T. 17 N., R. 3 W. 1832°F 2012°F 2200°F 0.7 4.1 5.5 3.7 7.1 8.5 Cream Cream Tan Overburden Ft. In. Extrusion properties Good Water of plasticity, percent 14.6 Linear drying shrinkage, percent 3.0 Overlying rocks 70 Shale 5 Underclay (sample 1624) (middle part of Abbott Formation) 4 Sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. L832°F 2012°F 2200°F 0.5 4.0 5.7 3.5 7.0 8.7 Buff Buff Tan SAMPLE 1625 NE± NW± SW{ sec. 4, T. 16 N., R. 3 W. In. Overburden Ft . Overlying rocks 27 Coal 2-3 Underclay (sample 1625) (middle part of Spoon Formation) 2 7+ (exposed) Base covered Extrusion properties Good Water of plasticity, percent 24.3 Linear drying shrinkage, percent 6.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 4.3 10.8 Brick red 2012°F 4.6 11.1 Brick red 2200°F Surface texture of fired test bar: Bloating started at 201 2 °F. Bonding properties: 8.22 (GCS psi); 1.90 (Optimum H 2 0) . Suggested uses: Bonding clay, sewer pipe, drain tile, flower pots, art pottery. 18 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1626 NEJ NWJ SWi sec. 4, T. 16 N., R. 3 W. Extrusion properties Good Water of plasticity, percent 24.2 Linear drying shrinkage, percent 6.0 2200°F Overburden Ft . In . Overlying rocks 24 Shale 1 Underclay (sample 1626) (middle part of Spoon Formation) 2 Coal 2-3 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight bloating at 201 2 °F. Bonding properties: 8.52 (GCS psi); 1.90 (Optimum H 2 0). Suggested uses: Bonding clay, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2.5 3.9 8.5 9.9 Brick red Brick red SAMPLE 1627 NW{ SE| SE{ sec. 32, T. 17 N., R. 3 W. Ft, 90 In. Overburden Overlying rocks Organic shale Underclay (sample 1627) (middle part of Abbott Formation) 2+ (exposed) Base covered Extrusion properties Good Water of plasticity, percent 18.9 Linear drying shrinkage, percent 3.5 1832°F 2012°F 2200°F +0.2 3.6 6.4 3.3 7.1 9.9 Buff Salmon Tan Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Iron discoloration on top surface at all firing tem- peratures. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1628 SEj NW| SE{ sec. 32, T. 17 N., R. 3 W. Extrusion properties Good Water of plasticity, percent 19.1 Linear drying shrinkage, percent 4.5 Overburden Ft . In . Overlying rocks 90 Organic clay shale 2 4 Underclay (sample 1628) (middle part of Abbott Formation) 3 8 Black shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight bloating at 2200 "F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 1.0 6.4 5.6 5.5 11.0 10.1 Salmon Brick red Brown CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 19 SAMPLE 1629 NEl SW{ NWi sec.9, T. 17N..R. IE, Overburden Ft . In , Overlying rocks 50 Black fissile shale 6 Underclay (sample 1629) (lower part of Spoon Formation) 3 6 Shale Firing temperature 1832°F Linear firing shrinkage, percent +0.3 Total linear shrinkage, percent 2.7 Fired color Salmon Extrusion properties Water of plasticity, percent Linear drying shrinkage, percent Good 13.8 3.0 2012°F 2.2 5.2 Salmon 2200°F 5.5 8.5 Tan Surface texture of fired test bar: Iron discoloration on top surface at all firing tem- peratures . Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1630 NE{ SW{ SW{ sec. 9, T. 17 N., R. 1 E. Overburden Overlying rocks Black shale Underclay (sample 1630) (lower part of Spoon Formation) 4 Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Ft. In. Extrusion properties Good 80 Water of plasticity, percent 17.4 5 Linear drying shrinkage, percent 2.0 2+ (expose d) 1832°F 2012°F 2200"F 0.2 4.3 6.8 2.2 6.3 8.8 Salmon Brick red Brown Surface texture of fired test bar: Slight bloating at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1631 SE± SEi NW{ sec. 32, T. 17 N., R. 3 W. Overburden Overlying rocks 120 Black shale 6+ Underclay (sample 1631) (lower part of Spoon Formation) 7 Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Ft. In. Extrusion properties Fair Water of plasticity, percent 15.8 Linear drying shrinkage, percent 2.0 7+ (expose d) 1832°F 2012°F 2200°F 0.7 4.4 5.8 2.7 6.4 7.8 Buff Salmon Tan Surface texture of fired test bar. Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 20 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1632 NE± NE± SW| sec. 25, T. 17 N., R. 4 W. Overburden Ft . In . Overlying rocks 25 Coaly shale 8 Underclay (sample 1632) (middle part of Abbott Formation) 3 Shale Firing temperature 1832°F Linear firing shrinkage, percent 1.4 Total linear shrinkage, percent 5.9 Fired color Salmon Extrusion properties Good Water of plasticity, percent 18.5 Linear drying shrinkage, percent 4.5 2012°F 4.4 8.9 Brick red 2200°F 4.0 8.5 Brown Surface texture of fired test bar: Slight bloating at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1633 SW{ NW{ NE{ sec. 5, T. 16 N., R. 3 W. Overburden Ft. Overlying rocks 65 Coal Underclay (sample 1633) (middle part of Spoon Formation) 3 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color In. i-i Extrusion properties Good Water of plasticity, percent 26.2 Linear drying shrinkage, percent 5.5 1832°F 0.2 5.7 Salmon 2012°F 4.9 10.4 Brown 2200°F +0.4 5.1 Tan Surface texture of fired test bar: Bloating started at 2200°F. Bonding properties: 7.04 (GCS psi); 1.80 (Optimum H 2 0). Suggested uses: Bonding clay, lightweight aggregate, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1634 NEi SE| NE{ sec. 31, T. 17 N., R. 3 W. In. Overburden Ft . Overlying rocks 40 Shale Underclay (sample 1634) (lower part of Spoon Formation) 7 6+ (exposed) Base covered Extrusion properties Good Water of plasticity, percent 15.3 Linear drying shrinkage, percent 3.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 0.0 3.5 Buff 2012°F 1.9 5.4 Salmon 2200°F 4.0 7.5 Tan Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 21 SAMPLE 1635 NWi SEi NEJ sec. 31, T. 17 N., R. 3 W. Extrusion properties Fair Water of plasticity, percent 12.8 Linear drying shrinkage, percent 2.0 Overburden Ft. In. Overlying rocks 80 Sandstone 1 Underclay (sample 1635) (upper part of Abbott Formation) 3 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar. Small blisters on surface at 2012°F. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1636 NW{ NE{ SE{ sec. 30, T. 17 N., R. 1 W. 1832°F 2012°F 2200°F 0.0 1.0 1.5 2.0 3.0 3.5 Cream Salmon Tan Overburden Ft . In . Overlying rocks 65 Glacial till Shale (sample 1636) (lower part of Abbott Formation) 10 Sandstone Firing temperature 1832°F Linear firing shrinkage, percent 1.2 Total linear shrinkage, percent 5.7 Fired color Salmon Extrusion properties Good Water of plasticity, percent 22.5 Linear drying shrinkage, percent 4.5 2012°F 7.0 11.5 Brick red 2200°F Surface texture of fired test bar: Surface blistered at 2012°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1669 SEi NW{ SW± sec. 25, T. 17 N., R. 4 W. Extrusion properties Fair Water of plasticity, percent 20.6 Linear drying shrinkage, percent 5.0 Overburden Ft . In . Overlying rocks 40 Coal 1 Underclay (sample 1669) (middle part of Abbott Formation) 1 6 Green clay band Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200°F 2.3 4.8 4.8 7.3 9.8 9.8 Salmon Tan Buff 22 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1670 NE| SW± SW{ sec. 25, T. 17 N., R. 4 W. Overburden Ft. In. Extrusion properties Fair Overlying rocks 70 Water of plasticity, percent 15.1 Coal 1 Linear drying shrinkage, percent 3.5 Underclay (sample 1670) (upper part of Abbott Formation) 3+ (exposed) Base covered Firing temperature 1832°F Linear firing shrinkage, percent 2.0 Total linear shrinkage, percent 5.5 Fired color Cream 2012°F 2200°F 4.4 4.5 7.9 8.0 Tan Greenish tan Surface texture of fired test bar: Surface scumming at 2012 °F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1671 NE± NEi SEi sec. 2, T. 16 N., R. 5 W. Overburden Overlying rocks Coal Underclay (sample 1671) Shale Ft. 78 2 3 In. Extrusion properties Good Water of plasticity, percent 19.5 Linear drying shrinkage, percent 4.0 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 2012°F 2200°F 4.2 5.3 6.0 7.0 9.4 10.3 Salmon Buff Greenish tan Surface texture of fired test bar: Pock-marked by pyrite at all firing temperatures, Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots. SAMPLE 1672 NE| NW{ SE| sec. 2, T. 16 N., R. 5 W. Ft. In. Extrusion properties Good 100 Water of plasticity, percent 15.5 6 Linear drying shrinkage, percent 3.5 Overburden Overlying rocks Coal Underclay (sample 1672) (middle [ ? ] part of Abbott Formation) Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Surface scum at all firing temperatures. Slight warping at 2200°F. Pyrite pockmarks at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 4+ (exposed) 1832°F 2012°F 2200°F 1.1 2.6 2.9 4.6 6.1 6.4 Salmon Brick red Brick red CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 23 SAMPLE 1673 SW{ SE{ NE| sec. 2, T. 16 N., R. 5 W. Ft. 150 In, 10 Overburden Overlying rocks Coal Underclay (sample 1673) (lower part of Abbott Formation) 4+ (exposed) Base covered Extrusion properties Good Water of plasticity, percent 17.8 Linear drying shrinkage, percent 3.5 1832°F 2012°F 2200°F 1.1 3.6 6.0 4.6 7.1 9.5 Buff Salmon Brown Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1674 SW{ SE} NE{ sec. 3, T. 16 N., R. 5 W. Extrusion properties Water of plasticity, percent Linear drying shrinkage, percent Good 20.0 4.5 Overburden Ft . In . Overlying rocks 60 Coal 1 Underclay (sample 1674) (middle [?] part of Abbott Formation) 1-5 Sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1675 NW± NW± NW{ sec. 11, T. 16 N., R. 5 W. In 1832°F 2012°F 2200°F 2.1 5.5 5.7 6.6 10.0 10.2 Salmon Brick red Brown Extrusion properties Good Water of plasticity, percent 17.5 Linear drying shrinkage, percent 3.5 Overburden Ft Overlying rocks 80 Ironstone nodular layer 1 Underclay (sample 1675) (upper part of Abbott Formation) 3 Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 6+ (expose d) 1832°F 2012°F 2200°F 1.5 3.5 5.1 5.0 7.0 8.6 Buff Buff Greenish tan 24 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1679 SEi NEi SW± sec. 6, T. 16 N., R. 4 W. Overburden Ft . Overlying rocks 100 Coal 2 Underclay (sample 1679) 5 Shale In. Extrusion properties Good Water of plasticity, percent 18.1 Linear drying shrinkage, percent 4.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 2012°F 2200°F 0.5 3.6 5.8 5.0 8.1 10.3 Buff Buff Greenish tan Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1680 SE± SW± NE| sec. 6, T. 16 N., R. 4 W. Overburden Ft. In. Extrusion properties Overlying rocks 90 Water of plasticity, percent Coal streak Linear drying shrinkage, percent Underclay (sample 1680) 3+ (exposed) Base covered Good 19.0 4.0 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight warping at all firing temperatures. Suggested uses: Drain tile, flower pots. 1832°F 2012°F 2200°F 1.4 3.1 4.3 5.4 7.1 8.3 Pink Buff Greenish tan SAMPLE 1681 NWi SE| NW| sec. 11, T. 16 N., R. 5 W. Overburden Ft . In . Overlying rocks 75 Black shale 1 6 Underclay (sample 1681) (upper [ ? ] part of Abbott Formation) 6 Coal 1 Firing temperature 1832°F Linear firing shrinkage, percent 1.9 Total linear shrinkage, percent 5.4 Fired color Buff Extrusion properties Good Water of plasticity, percent 18.8 Linear drying shrinkage, percent 3.5 2012' 4.0 7.5 Buff 2200°F 5.6 9.1 Greenish tan Surface texture of fired test bar: Slight surface scum at 2012°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 25 SAMPLE 1682 NE^ SE{ NW{ sec. 11, T. 16 N., R. 5 W. Overburden Overlying rocks Coal Underclay (sample 1682) (lower [ ?] part of Spoon Formation) Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Ft. In. Extrusion properties Good 75 Water of plasticity, percent 18.2 1 5 Linear drying shrinkage, percent 4.0 3+ (exposed) 1832°F 2012°F 2200°F 1.3 3.6 4.6 5.3 7.6 8.6 Cream Cream Cream Surface texture of fired test ban Slight surface scum at 2012°F. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1684 SEi NE£ SW{ sec. 28, T. 17 N., R. 3 W. Ft. In. Extrusion properties Good 60 Water of plasticity, percent 14.5 6 Linear drying shrinkage, percent 3.5 Overburden Overlying rocks Ironstone nodular layer Underclay (sample 1684) (middle [?] part of Abbott Formation) Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 5+ (exposed) 1832°F 2012°F 2200°F 0.7 1.7 4.1 4.1 5.2 7.6 Cream Buff Greenish tan SAMPLE 1685 SE± NE\ SWi sec. 1, T. 16 N., R. 5 W. Extrusion properties Fair Water of plasticity, percent 24.8 Linear drying shrinkage, percent 3.5 Overburden Ft. In, Overlying rocks 100 Ironstone nodular layer 6 Underclay (sample 1685) (middle [ ? ] part of Abbott Formation) 3 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight bloating started at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art p ottery . 1832°F 2012°F 2200°F 3.0 6.1 6.5 6.5 9.6 10.0 Salmon Brick red Brown 26 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1686 SW± NE| NE| sec. 6, T. 16 N., R. 4 W. Overburden Ft . In. Extrusion properties Good Overlying rocks 6 Water of plasticity, percent 23.0 Coal 6 Linear drying shrinkage, percent 4.5 Underclay (sample 1686) 3 Coal 2 Firing temperature 1832°F 2012°F 2200°F Linear firing shrinkage, percent 4.1 7.2 6.1 Total linear shrinkage, percent 8.6 11.7 10.6 Fired color Salmon Brick red Brick red Surface texture of fired test bar: Slight surface scum at 1832°F and 2012°F. Slight bloating at 2200 °F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1687 SWi NEJ NE± sec. 6, T. 16 N., R. 4 W. Overburden Overlying rocks Coal Underclay (sample 1687) Base covered Ft. 10 In. Extrusion properties Good Water of plasticity, percent 21.0 2 Linear drying shrinkage, percent 4.5 2+ (exposed) Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar. Normal. Suggested uses* Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200°F 3.1 5.4 5.3 7.0 10.0 10.1 Salmon Tan Greenish tan SAMPLE 1688 NW{ NWi NW± sec. 8, T. 16 N., R. 4 W. Overburden Ft . In . Overlying rocks 90 Coal 1 Underclay (sample 1688) 3 10 Sandstone Firing temperature 1832°F Linear firing shrinkage, percent 0.1 Total linear shrinkage, percent 3.6 Fired color Salmon Extrusion properties Poor Water of plasticity, percent 13.7 Linear drying shrinkage, percent 3.5 2012°F 1.7 5.2 Salmon 2200°F 2.9 6.4 Buff Surface texture of fired test bar: Lime pits at 2200 °F. Bonding properties: 4.10 (GCS psi); 1.30 (Optimum H 2 0) . Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 27 SAMPLE 1689 NW± NW\ NW{ sec. 8, T. 16 N., R. 4 W. Extrusion properties Good Water of plasticity, percent 17.5 Linear drying shrinkage, percent 4.0 Overburden Ft . In . Overlying rocks 50 Sandstone Underclay (sample 1689) 2 6 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200°F 0.6 2.1 4.1 4.6 6.1 8.1 Pink Cream Cream SAMPLE 1708 NW{ SE± SW± sec. 32, T. 17 N., R. 4 W. Overburden Ft . Overlying rocks 100 Coal streak Underclay (sample 1708) 1 Base covered In. Extrusion properties Fair Water of plasticity, percent 17.0 \ Linear drying shrinkage, percent 3.5 6+ (exposed) Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 2.5 3.5 5.1 6.0 7.0 8.6 Cream Buff Greenish tan SAMPLE 1709 NEi NE± SWJ sec. 28, T. 17 N., R. 3 W Overburden Ft . In Overlying rocks 50 Coal Underclay (sample 1709) 1 Base covered Extrusion properties Fair Water of plasticity, percent 15.5 8 Linear drying shrinkage, percent 4.0 6+ (exposed) Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight surface scum at 1832°F and 2012°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 1.8 3.4 4.8 5.0 8.0 7.8 Salmon Brick red Red brown 28 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 MERCER COUNTY SAMPLE 1581 SW| NW± SW± sec. 23, T. 14 N., R. 2 W. Overburden Ft . In . Overlying rocks 20 6 Colchester (No. 2) Coal 1 4 Underclay (sample 1581) (upper part of Spoon Formation) 3 Silty shale Firing temperature 1832°F Linear firing shrinkage, percent +0.2 Total linear shrinkage, percent 3.3 Fired color Pink Extrusion properties Good Water of plasticity, percent 18.0 Linear drying shrinkage, percent 3.5 2012 8 F 1.7 5.2 Tan 2200°F 3.1 6.6 Brick red Surface texture of fired test bar: Iron discoloration on top surface at all firing tem- peratures. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1706 SE| NEJ NW| sec. 32, T. 14 N., R. 2 W. Overburden Ft . In . Overlying rocks 39 Rock Island (No. 1) Coal 1 6 Underclay (sample 1706) (lower part of Spoon Formation) 2 Sandstone Extrusion properties Fair Water of plasticity, percent 18.5 Linear drying shrinkage, percent 3.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 1.7 5.2 Salmon 2012°F 2200°F 5.3 6.7 8.8 10.2 Brick red Brick red nd 2200°F. Iron discolora Surface texture of fired test bar. Surface scum at 2012°F and 2200°F. tion on top surface at 2200 °F. Structural clay products, sewer pipe, drain tile, flower pots, art pottery . Suggested uses: SAMPLE 1707 NW± SW{ 8EJ sec. 5, T. 14 N., R. 2 W. Overburden Ft. In. Extrusion properties Overlying rocks 36 Water of plasticity, percent Rock Island (No. 1) Coal 3 6 Linear drying shrinkage, percent Underclay (sample 1707) (lower part of Spoon Formation) 4+ (exposed) Base covered Fair 18.0 3.0 1832°F 2012°F 2200°F 1.6 5.8 6.1 4.6 8.8 9.1 Salmon Salmon Brown Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Iron discoloration on top surface at all firing tem- peratures. Slight bloating at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 29 SAMPLE 1710 SEi NW} SE{ sec. 33, T. 14 N, R. 2 W. Extrusion properties Good Water of plasticity, percent 19.5 Linear drying shrinkage, percent 4.5 Overburden Ft. In. Overlying rocks 7 Rock Island (No. 1) Coal 4 Underclay (sample 1710) (lower part of Spoon Formation) 5 Black shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Bonding properties: 3.56 (GCS psi); 1.40 (Optimum H 2 0). Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1711 SW± SE± NWi sec. 1, T. 13 N., R. 2 W. 1832°F 2012°F 2200°F 0.2 2.2 3.8 4.7 6.7 8.3 Cream Cream Cream Overburden Overlying rocks Colchester (No. 2) Coal Underclay (sample 1711) (upper part of Spoon Formation) Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Ft. In. Extrusion properties Good 60 Water of plasticity, percent 21.8 1 6 Linear drying shrinkage, percent 6.5 2+ (exposed) 1832°F 0.7 7.2 Cream 2012°F 3.5 10.0 Cream 2200°F 2.6 9.1 Cream Surface texture of fired test bar: Few dark pyrite spots on surfaces. Bonding properties: 6.15 (GCS psi); 1.62 (Optimum H 2 0) . Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1712 NE{ NE± NEi sec. 5, T. 13 N., R. 2 W. Extrusion properties Poor Water of plasticity, percent 20.0 Linear drying shrinkage, percent 4.5 Overburden Ft . In . Overlying rocks 25 Coal 2 Underclay (sample 1712) (upper part of Abbott Formation) 3 Silty shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight warping at all firing temperatures. Suggested uses: Drain tile, flower pots. 1832°F 2012°F 2200°F 2.0 5.0 5.5 6.5 9.5 10.0 Salmon Salmon Greenish tan 30 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1713 SE{ NW{ SWi sec. 33, T. 15 N., R. 3 W. In. Extrusion properties Good Water of plasticity, percent 16.5 6 Linear drying shrinkage, percent 3.3 Overburden Ft . Overlying rocks 50 Sandstone 1 Underclay (sample 1713) (lower [ ? ] part of Spoon Formation) 3 Coal streak Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Bonding properties: 3.30 (GCS psi); 1.17 (Optimum H 2 0). Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1714 NEi NW| SE{ sec. 35, T. 15 N., R. 3 W. 3* 1832°F 2012°F 2200°F 0.0 1.7 2.0 3.3 5.0 5.3 Cream Cream Cream In. Extrusion properties Good Water of plasticity, percent 22.4 2 Linear drying shrinkage, percent 4.5 Overburden Ft . Overlying rocks 13 Coal streak Underclay (sample 1714) (lower [ ? ] part of Spoon Formation) 3 Coal streak Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar. Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1715 NE± NW± SE{ sec. 35, T. 15 N., R. 3 W. Extrusion properties Fair Water of plasticity, percent 17.3 Linear drying shrinkage, percent 3.0 1 4 1832°F 2012°F 2200°F 1.8 5.5 6.0 6.3 10.0 10.5 Pink Buff Greenish tan Overburden Ft. In Overlying rocks 17 Coal streak i 4 Underclay (sample 1715) (lower [?] part of Spoon Formation) 4 6 Sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832° 1.6 4.6 Pink 2012°F 4.0 7.0 Cream 2200°F 5.3 8.3 Buff Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 31 SAMPLE 1716 NE± NW{ SEi sec. 35, T. 15 N., R. 3 W. Overburden Ft . In . Overlying rocks 22 Sandstone 6 Underclay (sample 1716) (lower [?] part of Spoon Formation) 4 Shale Firing temperature 1832° Linear firing shrinkage, percent 1.2 Total linear shrinkage, percent 4.7 Fired color Pink Extrusion properties Water of plasticity, percent Linear drying shrinkage, percent Good 16.5 3.5 2012°F 3.2 6.7 Cream 2200°F 4.3 7.8 Buff Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1717 SW$ NW{ SW| sec. 32, T. 14 N., R. 2 W. Extrusion properties Good Water of plasticity, percent 17.2 Linear drying shrinkage, percent 3.5 Overburden Ft . In , Overlying rocks 70 Coal 1 ? Underclay (sample 1717) (lower part of Spoon Formation) 11 Black shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight warping at 2012°F and 2200°F. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1718 NWi SE| SE± sec. 26, T. 14 N., R. 1 W. 1832°F 2012°F 2200°F 0.1 1.9 3.3 3.6 5.4 6.8 Salmon Salmon Buff Extrusion properties Good Water of plasticity, percent 23.9 Linear drying shrinkage, percent 5.0 Overburden Ft . In . Overlying rocks 150 Rock Island (No. 1) Coal 4 Underclay (sample 1718) (lower part of Spoon Formation) 3 6 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Iron discoloration on top surface at all firing tem- peratures. Bloated at 2200°F. Suggested uses: Lightweight aggregate, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200°F 4.6 6.9 +20.5 9.6 11.9 + 15.5 Salmon Brick red Greenish tan 32 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 HENRY COUNTY SAMPLE 1611 NEi NW± SW| sec. 19, T. 17 N., R. 1 E Extrusion properties Fair Water of plasticity, percent 16.7 Linear drying shrinkage, percent 3.5 Overburden Ft . In . Overlying rocks 25 Rock Island (No. 1) Coal 4 Underclay (sample 1611) (lower part of Spoon Formation) 6 6 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight bloating at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1676 SE£ SW± SEj sec. 30, T. 17 N., R. IE. 1832°F 2012°F 2200°F 0.7 5.7 4.8 4.2 7.2 8.3 Salmon Brick red Brick red Overburden Ft . In. Extrusion properties Good Overlying rocks 20 Water of plasticity, percent 24.4 Coal 5 Linear drying shrinkage, percent 5.0 Underclay (sample 1676) (middle part of Spoon Formation) 1 4 Coal i 2 Firing temperature 1832°F 2012°F 2200°F Linear firing shrinkage, percent 3.0 6.1 6.8 Total linear shrinkage, percent 8.0 11.1 11.8 Fired color Salmon Brick red Brick red Surface texture of fired test bar: Normal . Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1677 SE{ SWi SE| sec. 30, T. 17 N., R. 1 E, Overburden Ft . Overlying rocks 22 Coal Underclay (sample 1677) (middle part of Spoon Formation) 2 Coal Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color In. Extrusion properties Good Water of plasticity, percent 31.8 Linear drying shrinkage, percent 8.0 1832°F 5.0 13.0 Salmon 2012°F 7.8 15.8 Brick red 2200°F 7.0 15.0 Brick red Surface texture of fired test bar: Slight warping and bloating at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 33 SAMPLE 1678 SEi SW± SE{ sec. 30, T. 17 N., R. 1 E, Overburden Ft , Overlying rocks 24 Coal Underclay (sample 1678) (middle part of Spoon Formation) 2 Sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color In. Extrusion properties Good Water of plasticity, percent 34.4 Linear drying shrinkage, percent 6.5 1832°F 5.1 11.6 Salmon 2012°F 9.9 16.4 Brick red 2200°F 9.9 16.4 Brick red Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1683 SW{ NE{ NE} sec. 33, T. 14 N., R. 1 E. Extrusion properties Poor Water of plasticity, percent 13.2 Linear drying shrinkage, percent 2.5 Overburden Ft . In , Overlying rocks 260 Rock Island (No. 1) Coal 4 6 Underclay (sample 1683) (lower part of Spoon Formation) 4 Silty sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight bloating and small pyrite blisters at 2200°F, Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 2.1 3.8 5.4 3.8 7.1 8.1 Brick red Brick red Brown SAMPLE 1690 NW{ SE{ SEi sec. 21, T. 17 N., R. 1 E. Overburden Ft . In. Overlying rocks 16 Coal 6 Underclay (sample 1690) (lower part of Spoon Formation) 3 Shale Extrusion properties Good Water of plasticity, percent 21.6 Linear drying shrinkage, percent 4.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 2.5 7.0 Salmon 2012°F 5.7 10.2 Salmon 2200°F 6.3 10.8 Brown Surface texture of fired test bar: Slight surface scum at 2012°F. Slight blistering at 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 34 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 Extrusion properties Good Water of plasticity, percent 25.0 Linear drying shrinkage, percent 4.5 SAMPLE 1691 NE{ SE| NW| sec. 21, T. 17 N., R. 1 E. Overburden Ft . In . Overlying rocks 15 Black shale 1 Underclay (sample 1691) (lower part of Spoon Formation) 3 4 Sandy clay Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Bonding properties: 8.00 (GCS psi); 2.20 (Optimum H 2 0) . Suggested uses: Bonding clay, structural clay products, sewer pipe, drain tile, flower pots, art pottery. .832°F 2012°F 2200°F 2.5 6.9 8.5 7.0 11.4 13.0 Pink Salmon Tan SAMPLE 1692 SE{ SW| SW| sec. 27, T. 17 N., R. 2 E. Ft. In. Extrusion properties Fair 55 Water of plasticity, percent 15.2 5 Linear drying shrinkage, percent 3.0 Overburden Overlying rocks Sandstone Shale (sample 169 2) (upper part of Spoon Formation) 20+ (exposed) Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar. Slight bloating at 2200 °F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 2.5 7.2 5.9 6.5 10.2 8.9 Brick red Brick red Red-brown SAMPLE 1693 NE{ NE± SW| sec. 28, T. 17 N., R. 2 E. Overburden Overlying rocks 35 Sandstone 2 Underclay (sample 169 3) (middle part of Spoon Formation) 3 Base covered Ft. In. Extrusion properties Water of plasticity, percent Linear drying shrinkage, percent Good 23.5 5.0 6+ (exposed) Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 2.0 7.0 Cream 2012°F 5.0 10.0 Cream 2200°F 5.5 10.5 Greenish tan Surface texture of fired test bar: Warping at 2200 °F. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 35 SAMPLE 1694 NWl NW| NEi sec. 28, T. 17 N., R. 2 E. In. Extrusion properties Good Water of plasticity, percent 23.4 3 Linear drying shrinkage, percent 3.5 Overburden Ft . Overlying rocks 20 Coal 1 Underclay (sample 1694) (middle part of Spoon Formation) 5 Coal streak Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1695 NE± NWi NW| sec. 28, T. 17 N., R. 2 E. 6 1 1832°F 3.0 6.5 Salmon 2012°F 7.5 11.0 Brick red 2200°F 8.1 11.6 Brick red Extrusion properties Good Water of plasticity, percent 24.2 Linear drying shrinkage, percent 3.5 Overburden Ft. In, Overlying rocks 4 Coal 2 Underclay (sample 1695) (lower part of Spoon Formation) 6 Black shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight warping at 2012°F and 2200°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 1.7 5.7 8.1 4.7 9.5 12.2 Salmon Brick red Brick red SAMPLE 1696 SW£ NW± SW£ sec. 34, T. 17 N., R. 2 E. Overburden Ft . In . Overlying rocks 12 Sandstone 3 4 Underclay (sample 1696) (middle part of Spoon Formation) 5+ (exposed) Base covered Extrusion properties Fair Water of plasticity, percent 22.6 Linear drying shrinkage, percent 3.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight surface scum at 2012°F. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. 1832°F 2012°F 2200°F 1.5 6.0 7.1 5.0 9.5 10.6 Pink Tan Greenish tan 36 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1697 NE± SE| NW| sec. 21, T. 17 N., R. 1 E. Extrusion properties Good Water of plasticity, percent 25.0 Linear drying shrinkage, percent 4.0 Overburden Ft. In, Overlying rocks 10 Coal 1 Underclay (sample 1697) (middle part of Spoon Formation) 3 Coaly shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight warping at 2200 "F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1698 SE± NEJ SWi sec. 27, T. 17 N., R. 1 E. 1832°F 2012°F 2200°F 3.2 6.8 7.6 7.2 10.8 11.6 Pink Salmon Brown Overburden Ft. In. Extrusion properties Good Overlying rocks 18 Water of pla isticity, percent 12.5 Coal 10 Linear drying shrinkage, percent 4.0 Underclay (sample 1698) (middle [?] part of Spoon Formation) 2 6+ (exposed) Base covered Firing temperature 1832°F 2012°F 2200°F Linear firing shrinkage, percent 1.8 4.1 5.6 Total linear shrinkage, percent 5.8 8.1 9.6 Fired color Cream Buff Greenish tan Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1699 NE± NE| NW± sec. 22, T. 17 N., R. 1 E. In. Extrusion properties Good Water of plasticity, percent 18.0 6 Linear drying shrinkage, percent 4.5 Overburden Ft. Overlying rocks 80 Ironstone nodular layers 1 Underclay (sample 1699) (upper part of Abbott Formation) 2 Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Slight surface scum at 1832°F and 2012°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 6+ (expose d) 1832°F 2012"F 2200°F 2.0 4.6 5.3 7.0 8.6 10.3 Salmon Brick red Brown CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 37 Overburden Overlying rocks Coal streak Underclay (sample 1700) (lower part of Spoon Formation) Coal Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Normal. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1701 NEi SW± SW{ sec. 15, T. 18 N., R. 3 E. In SAMPLE 1700 H sec . 15, T. 18 N., R. 3 E. Ft. In Extrusion properties Fair 30 Water of plasticity, percent 19.3 i 2 Linear drying shrinkage, percent 3.5 3 1 6 1832°F 2012°F 2200°F 2.5 5.6 6.5 6.0 9.1 10.0 Cream Cream Greenish tan Extrusion properties Good Water of plasticity, percent 17.3 Linear drying shrinkage, percent 3.0 Overburden Ft . Overlying rocks 35 Coal 1 Underclay (sample 1701) (lower part of Spoon Formation) 3 Shale Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Iron discoloration on top surface at all firing tem- peratures. Suggested uses: Stoneware, structural clay products, sewer pipe, drain tile, flower pots, art pottery. SAMPLE 1702 SL\ NW| SW| sec. 15, T. 18 N., R. 3 E. 1832°F 2012°F 2200°F 0.4 3.3 5.0 3.4 6.3 8.0 Salmon Salmon Tan Overburden Ft . In , Overlying rocks 40 Coal 8 Underclay (sample 1702) (lower part of Spoon Formation) 4+ (exposed) Base covered Extrusion properties Poor Water of plasticity, percent 15.0 Linear drying shrinkage, percent 2.5 Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color 1832°F 2.1 4.6 Cream 2012°F 4.5 7.0 Cream 2200°F 6.1 8.6 Cream Surface texture of fired test bar: Normal. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 38 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 SAMPLE 1703 NW{ NE± SE{ sec. 24, T. 18 N., R. 2 E Overburden Ft. In. Extrusion properties Water of plasticity, percent Linear drying shrinkage, percent Good 12.8 3.0 Overlying rocks 70 Rock Island (No. 1) Coal 3 Underclay (sample 1703) (lower part of Spoon Formation) 2 Base covered Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Iron discoloration on top surface at all firing tem- peratures. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . SAMPLE 1704 SE{ NW{ NE{ sec. 23, T. 17 N., R. 1 E. 6+ (expose d) 1832°F 2012°F 2200°F 0.5 2.2 4.9 3.5 5.2 7.9 Salmon Salmon Tan Extrusion properties Fair Water of plasticity, percent 20.0 Linear drying shrinkage, percent 5.0 Overburden Ft. In, Overlying rocks 40 Coal 7 Underclay (sample 1704) (middle part of Spoon Formation) 3 Silty sandstone Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Surface scum at 2012°F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 2.3 4.8 5.2 7.3 9.8 10.2 Buff Tan Greenish tan SAMPLE 1705 NWi SWJ SEJ sec. 30, T. 17 N., R. 1 E In. Extrusion properties Good Water of plasticity, percent 24.4 Linear drying shrinkage, percent 5.5 Overburden Ft Overlying rocks 38 Coal 1 Underclay (sample 1705) (middle part of Spoon Formation) 4 Sandy clay Firing temperature Linear firing shrinkage, percent Total linear shrinkage, percent Fired color Surface texture of fired test bar: Warping and bloating at 2200 °F. Suggested uses: Structural clay products, sewer pipe, drain tile, flower pots, art pottery . 1832°F 2012°F 2200°F 3.3 6.0 2.2 8.3 11.0 8.6 Salmon Brick red Tan CLAYS OF ROCK ISLAND, MERCER, AND HENRY COUNTIES 39 SUMMARY Generally, an underclay with a light firing color will tend to be more refractory than clays that fire darker. Approximately half of the samples tested are light burn- ing. However, none has a fusion temperature of PCE cone 28 or above, thus making their use as medium heat duty refractories unacceptable: Samples 1607, 1609, 1612, 1618, 1682, 1710, 1711, and 1713, based on their fired colors and mineralogical data, will have the highest fusion temperatures. Samples 1619, 1625, 1626, 1633, and 1691 were found to have the greatest bonding strength. The overburden for the outcrop samples varied from 6 to 150 feet. Fifty per- cent of the sample areas have overburden of 40 feet or less. The test results show that there are many underclay deposits of commercial quality in the area of Rock Island, Mercer, and Henry Counties. Some of the thinner deposits of good quality that have thicknesses of overburden so great as to make them uneconomical today for industrial use may be of value locally to individuals or schools interested in making small amounts of art pottery. 40 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 322 REFERENCES American Foundrymen's Society, 1952 (6th ed.), Foundry sand handbook: American Foundrymen's Society, p. 17-28, 85-89, 93-95. Green, H. A., 1870, Geology of Mercer County, in Worthen et al . , Geology and paleontology, vol. IV, p. 301-312, Geol . Survey of Illinois . Grim, Ralph E., Bradley, William F., and White, W. Arthur, 1957, Petrology of the Paleozoic shales of Illinois: Illinois Geol. Survey Rept . Inv. 203. Jonas, Edward C, 1957, Pottery clay resources of Illinois: Illinois Geol. Survey Circ. 233. Kosanke, R. M., Simon, J. A., Wanless, H. R., and Willman, H. B., 1960, Classification of the Pennsylvanian strata of Illinois: Illinois Geol. Survey Rept. Inv. 214. Lines, Edwin H., 1917, Pennsylvanian fireclays of Illinois, in DeWolf et al., Biennial report: Illinois Geol . Survey Bull. 30, p. 61. Parham, Walter E., 1959, Light-burning clay resources in LaSalle County, Illinois: Illinois Geol. Survey Circ. 277. Parham, Walter E., 1960, Lower Pennsylvanian clay resources of Knox County, Illinois: Illinois Geol . Survey Circ. 302. Parmelee, C. W., and Schroyer, C. R., 1921, Further investigations of Illinois fire-clays: Illinois Geol . Survey Bull . 38-D. Savage, T. E., and Udden, J. A., 1921, Geology and mineral resources of the Edgington and Milan quadrangles: Illinois Geol. Survey Bull. 38-C. Shaw, James, 1873, Geology of Henry County, in Worthen et al . , Geology and paleontology, vol. V, p. 185-201, Geol. Survey of Illinois . Wanless, H. R., 1929, Geology and mineral resources of the Alexis quadrangle: Illinois Geol. Survey Bull. 57. Wanless, H. R., 1952, Studies of field relations of coal beds: Second Conference on the Origin and Constitution of Coal, Nova Scotia Research Foundation, p. 148-175. White, W. Arthur, 1960, Lightweight aggregate from Illinois shales: Illinois Geol. Survey Circ. 290. White, W. Arthur, and Lamar, J. E., 1960, Ceramic tests of Illinois clays and shales: Illinois Geol. Survey Circ . 303. Worthen, A. H., and Shaw, James, 1873, Geology of Rock Island County in Worthen, et al . , Geology and paleontology, vol. V, p. 217-234, Geol. Survey of Illinois. Illinois State Geological Survey Circular 32 2 40 p., 1 fig., 95 tables, 1961 CIRCULAR 322 ILLINOIS STATE GEOLOGICAL SURVEY URBANA