Type and Reference Sections of Named Units
A. Principal Reference Section of the Houchin Creek Coal Member, Carbondale Formation
From an unpublished manuscript by Wier (1961, locality 6): Highwall on north side of abandoned strip mine, SE NE SW, Sec. 3, T3S, R7W, Pike County, Indiana. Map of Wier and Stanley (1952) identifies the site as the Blackfoot Mine.
|4.0'||Shale, light to medium gray, thin- to medium-bedded|
|1.5'||Shale, dark gray to black, slightly calcareous, scattered crinoid columnals and small brachiopods, nodules and thin lenses of gray to tan, finely crystalline limestone|
|0.9'||Shale, black, fissile|
|1.2'||Hanover Limestone Member (Stendal Limestone of Wier), black, dense, argillaceous, few fossils (not named), contains lenses of dark gray to tan limestone that is fossiliferous. Unit is lenticular, varies from 0 to 2 feet [0 to 0.6 m] thick.|
|2.2'||Excello Shale Member, black, fissile, alternating hard and soft layers|
|0.5'||Houchin Creek Coal Member, bright banded|
|5.3'||Claystone, light gray, scattered rootlets|
|4.0'||Shale, light gray, weathers brown, sandy|
|1.2'||Sandstone, medium gray, silty, calcareous, single bed|
|28.0'||Sandstone, light gray, fine grained, shaly, mostly thin- to medium-bedded, interlaminated gray sandy shale contains siderite bands. Base under water, close to top of Survant Coal Member, which was mined. Wier and Stanley (1952) report average Survant Coal thickness 2.4 feet at this mine.|
|Total section 48.8 ft (14.9 m).|
B. Type Section of the Hanover Limestone Member
Field notes by S.E. Ekblaw, September 8, 1930: ravine south of road east of Hanover School, SW NW SE and NE SW SE, Sec. 27, T10 N, R11W, Greene County, Illinois. Illinois State Geological Survey, Map Room, open files.
|4'±||Hanover Limestone Member, brownish to bluish gray, nodular structure with brecciated character, massive, in one or two beds. Abundant blue-gray to black nodules in places. Fossils include crinoids, Composita, Squamularia, fusulinids.|
|8"||Shale, greenish gray, slightly calcareous.|
|6"||Clay-shale, bluish gray, noncalcareous.|
|2½"||Clay shale, dark bluish-gray, noncalcareous, poorly bedded, very slickensided, no fossils.|
|1' 6" to 2' 8"||Houchin Creek Coal Member|
|1'||Claystone, black, shaly, leafy.|
|2"||Claystone, gray, noncalcareous.|
|2'||Shale, gray, noncalcareous, evenly bedded, fern leaf and stem impressions.|
C. Type Section of the Delafield Member (New)
From continuous core of Energy Plus borehole no. ME-13, drilled 2,605 ft (794 m) from south line, 1,274 ft (388 m) from west line, Sec. 31, T4S, R6E, Hamilton County, Illinois. Core described by W. John Nelson, January 4–5, 2007.
Table A1 Type section of the Delafield Member (new)
Thickness (ft) Top depth Bottom depth Rock description 4.6 1,043.7 1,048.3 Springfield Coal Member, bright banded, partly removed by company; depths from company log. 4.7 1,048.3 1,053.0 Top of Delafield Member, claystone (underclay), nearly black at top, changing downward to dark gray, olive gray in lower half. Blocky, thoroughly slickensided, lower 3 feet [0.9 m] calcareous, with scattered small limestone nodules. Lower contact gradational. 6.3 1,053.0 1,059.3 Sandstone, medium gray, very fine grained, micaceous, lithic arenite. Brecciated at the top with zigzag fractures extending downward and irregular masses of dark gray dolomite(?) at top. Dark gray siltstone laminae become more numerous downward, outlining wavy and ripple lamination. Lower contact gradational. 35.7 1,059.3 1,095.0 Sandy siltstone and shale, medium gray, mostly planar laminated, some ripples and horizontal burrows in sand-rich interval, possible tidal rhythmites. Interlaminated light gray sandstone is 10 to 30% of rock, reaching a maximum at 1,068–1,076 ft [325.5 to 328.0 m] and decreasing below that point. Trace fossils Teichichnus and Conostichus identified by J.A. Devera. Lower contact gradational. 22.0 1,095/0 1,117.0 Shale, medium-dark gray, silty, becoming darker and finer downward, laminae of very fine sandstone confined to upper part. “Pyrite trails” common, siderite bands and lenses occur in lower 14 feet [4 m]. Lower contact gradational. 6.2 1,117.0 1,123.2 Shale, dark gray, contains little or no silt, very fissile; “pyrite trails” and siderite lenses numerous. Lower contact rapidly gradational, base of Delafield Member. 0.4 1,123.2 1,123.6 Hanover Limestone Member, calcareous shale, grayish black, contains scattered echinoderm and fossil shell fragments; lenses of dark gray, micritic limestone occur near base; lower contact rapidly gradational. 8.4 1,123.6 1,132.0 Excello Shale Member, black, low-density, fissile; phosphatic lenses and pyrite nodules. Concretion of black microgranular dolomite occurs at 1,126.0 to 1,127.7 feet [343.2 to 343.7 m]. Lower contact appears erosive; Houchin Creek Coal is absent. 3.0 1,132.0 1,135.0 Sandstone, medium greenish gray, very fine grained, micaceous, lithic arenite.
D. Type Section of the Galatia Member (New)
Core from Kerr-McGee Corp. borehole # 7629-16 (Sec. 29, T7S, R6E, Saline County, Illinois). This core is in permanent storage at the Samples Library of the Illinois State Geological Survey in Champaign (storage number C-14933).
Table A2 Type section of the Galatia Member (new)
Thickness (ft) Top depth Bottom depth Rock description 8.7 736.5 745.2 Springfield Coal (core removed by company; depths from other logs). 0.2 745.2 745.4 Coal and shale interlaminated, lower contact sharp and uneven. 3.6 745.4 749.0 Top of Galatia Member, sandstone, light olive gray, very fine grained, argillaceous; root traces throughout, masses of granular siderite near base. Lower contact gradational. 5.0 749.0 754.0 Siltstone, light olive-gray, coarse (almost sandstone), moderately fissile, lenses and nodules of siderite common. Lower contact gradational. 8.5 754.0 762.5 Sandstone, medium-light gray, very fine grained, sublitharenite, portions show faint wavy silt and clay laminae, a few siderite lenses. Lower contact gradational. 6.5 762.5 769.0 Siltstone and sandstone, interlayered, lithologies as above. Lamination mostly lenticular and wavy, locally contorted. Rip-up clasts of siltstone in sandstone matrix become more numerous downward. Irregular masses of siderite common. Lower contact gradational. 17.0 769.0 786.0 Sandstone, light gray, very fine to fine-grained, litharenite, micaceous. Shale-pebble conglomerate common in upper 11 feet [3.4 m]. Plant fossils in siltstone at 770.0–770.9 ft [234.7 to 235.0 m]. Basal 6 ft is clean, massive sandstone. Lower contact erosional. Base of Galatia Member (thickness 40.6 feet) 2.0 786.0 788.0 Excello Shale Member, black, hard, thinly fissile, phosphatic lenses and laminae; dense dolomite concretion in mid-lower part. 788.0 End of core, total depth.
Nelson, W.J., S.D. Elrick, W.A. DiMichele, and P.R. Ames, 2020, Evolution of a peat-contemporaneous channel: The Galatia channel, Middle Pennsylvanian, of the Illinois Basin: Illinois State Geological Survey, Circular 605, 85 p., 6 pls.