| Unit Name | Stratigraphic Code |
|---|
| Raccoon Creek Group | 0 |
| Will Scarlet Shale Member | 0 |
| Coxville Sandstone Member | 0 |
| Wheeler Coal Member or Bed | 0 |
| Bevier Coal Member or Bed | 0 |
| Lagonda Member | 0 |
| Unnamed clastic member - Carbondale Formation | 0 |
| Unnamed gray shale member - Carbondale Formation | 0 |
| Delafield Member | 0 |
| Galatia Member | 0 |
| Absaroka Sequence | 1500 |
| Paleozoic Erathem | 1510 |
| Pennsylvanian Subsystem | 1520 |
| Virgilian Series | 1530 |
| McLeansboro Group | 1540 |
| Mattoon Formation | 1550 |
| Greenup Limestone Member | 1570 |
| Woodbury Limestone Member | 1590 |
| Gila Limestone Member | 1610 |
| Reisner Limestone Member | 1630 |
| Bogota Limestone Member | 1660 |
| Trowbridge Coal Member | 1670 |
| Effingham Limestone Member | 1680 |
| Shumway Limestone Member | 1700 |
| Missourian Series | 1710 |
| Omega Limestone Member | 1730 |
| Bonpas Limestone Member | 1740 |
| Calhoun Coal Member | 1750 |
| Shelbyville Coal Member | 1760 |
| Opdyke Coal Member | 1780 |
| Dix Limestone Member | 1810 |
| Merom Sandstone Member | 1820 |
| Cohn Coal Member | 1850 |
| McCleary's Bluff Coal Member | 1864 |
| Friendsville Coal Member | 1870 |
| Bond Formation | 1880 |
| Millersville Limestone Member | 1890 |
| Livingston Limestone Member | 1900 |
| Coffeen Limestone Member | 1930 |
| Witt Coal Member | 1940 |
| Reel Limestone Member | 1950 |
| Flat Creek Coal Member | 1970 |
| Flannigan Coal Member | 1990 |
| Bunje Limestone Member | 2010 |
| Little Vermilion Limestone Member | 2030 |
| Sorento Limestone Member | 2050 |
| McWain Sandstone Member | 2060 |
| Mt. Carmel Sandstone Member | 2070 |
| La Salle Limestone Member | 2090 |
| Shoal Creek Limestone Member | 2110 |
| Modesto Formation | 2120 |
| New Haven Coal Member | 2130 |
| Hall Limestone Member | 2160 |
| Macoupin Limestone Member | 2170 |
| Womac Coal Member | 2180 |
| Burroughs Limestone Member | 2200 |
| Inglefield Sandstone Member | 2210 |
| Carlinville Limestone Member | 2230 |
| Cramer Limestone Member | 2250 |
| Chapel Coal Member | 2260 |
| Desmoinesian Series | 2300 |
| Trivoli Sandstone Member | 2310 |
| Exline Limestone Member | 2330 |
| Scottville Limestone Member | 2340 |
| Athensville Coal Member | 2350 |
| West Franklin Limestone Member | 2360 |
| Lonsdale Limestone Member | 2370 |
| Gimlet Sandstone Member | 2380 |
| Lake Creek Coal Member | 2390 |
| Pond Creek Coal Member | 2400 |
| Rock Branch Coal Member | 2410 |
| De Graff Coal Member | 2430 |
| Piasa Limestone | 2450 |
| Farmington Shale Member | 2460 |
| Kewanee Group | 2470 |
| Carbondale Formation | 2480 |
| Danville Coal Member | 2490 |
| Galum Limestone Member | 2500 |
| Allenby Coal Member | 2520 |
| Bankston Fork Limestone Member | 2530 |
| Copperas Creek Sandstone Member | 2540 |
| Anvil Rock Sandstone Member | 2550 |
| Lawson Shale Member | 2570 |
| Pokeberry Limestone Member | 2590 |
| Conant Limestone Member | 2600 |
| Jamestown Coal Member | 2610 |
| Brereton Limestone Member | 2630 |
| Anna Shale Member | 2640 |
| Herrin Coal Member | 2660 |
| Spring Lake Coal Member | 2670 |
| Big Creek Shale Member | 2680 |
| Vermilionville Sandstone Member | 2690 |
| Briar Hill Coal Member | 2730 |
| Canton Shale Member | 2750 |
| St. David Limestone Member | 2760 |
| Turner Mine Shale Member | 2770 |
| Dykersburg Shale Member | 2780 |
| Springfield Coal Member | 2790 |
| Covel Conglomerate Bed | 2810 |
| Hanover Limestone Member | 2820 |
| Excello Shale Member | 2830 |
| Houchin Creek Coal Member | 2840 |
| Breezy Hill Limestone Member | 2850 |
| Roodhouse coal bed | 2860 |
| Kerton Creek coal bed | 2870 |
| Pleasantview Sandstone Member | 2880 |
| Purington Shale Member | 2930 |
| Survant Coal Member | 2940 |
| Oak Grove (Limestone) Member | 2960 |
| Mecca Quarry Shale Member | 2970 |
| Francis Creek Shale Member | 3000 |
| Cardiff coal bed | 3010 |
| Colchester Coal Member | 3020 |
| Spoon Formation | 3030 |
| Cheltenham Clay Member | 3040 |
| Abingdon Coal Member or Bed | 3100 |
| Isabel Sandstone Member | 3110 |
| Seelyville Coal Member | 3170 |
| Greenbush Coal Member or Bed | 3200 |
| Dekoven Coal Member or Bed | 3210 |
| Davis Coal Member or Bed | 3250 |
| Seahorne Limestone Member | 3270 |
| Vergennes Sandstone Member | 3280 |
| Stonefort Limestone Member | 3310 |
| Wise Ridge Coal Member | 3320 |
| Mt. Rorah Coal Member | 3330 |
| De Long Coal Member | 3340 |
| Creal Springs Limestone Member | 3350 |
| Murphysboro Coal Member | 3370 |
| Granger Sandstone Member | 3380 |
| New Burnside Coal Member | 3400 |
| Brush Coal Member | 3410 |
| Delwood Coal Member | 3430 |
| O'Nan Coal Member | 3434 |
| Bidwell Coal Member | 3438 |
| Hermon Coal Member | 3450 |
| Seville Limestone Member | 3470 |
| Curlew Limestone Member | 3480 |
| Rock Island Coal Member | 3490 |
| Litchfield Coal Member | 3500 |
| Assumption Coal Member | 3510 |
| Atokan Series | 3520 |
| Abbott Formation | 3540 |
| Bernadotte Sandstone Member | 3550 |
| Murray Bluff Sandstone Member | 3560 |
| Pope Creek Coal Member | 3580 |
| Willis Coal Member | 3590 |
| Grindstaff Sandstone Member | 3610 |
| Tarter Coal Member | 3630 |
| Manley Coal Member | 3650 |
| Babylon Sandstone Member | 3660 |
| Finnie Sandstone Member | 3680 |
| Reynoldsburg Coal Member | 3800 |
| Morrowan Series | 3810 |
| Caseyville Formation | 3820 |
| Pounds Sandstone Member | 3830 |
| Gentry Coal Bed | 3900 |
| Sellers Limestone Bed | 3910 |
| Battery Rock Sandstone Member | 3920 |
| Wayside Member | 3970 |
| Kaskaskia Sequence | 4000 |
| Mississippian Subsystem | 4010 |
| Chesterian Series | 4020 |
| Elviran Stage | 4030 |
| Pope Megagroup | 4040 |
| Grove Church Shale | 4050 |
| Kinkaid Limestone | 4060 |
| Goreville Limestone Member | 4070 |
| Cave Hill Shale Member | 4080 |
| Negli Creek Limestone Member | 4090 |
| Degonia Sandstone | 4100 |
| Clore Formation | 4110 |
| Ford Station Limestone Member | 4120 |
| Tygett Sandstone Member | 4130 |
| Cora Limestone Member | 4140 |
| Palestine Sandstone | 4150 |
| Menard Limestone | 4160 |
| Allard Limestone Member | 4180 |
| Scottsburg Limestone Member | 4190 |
| Walche Limestone Member | 4200 |
| Waltersburg Formation | 4210 |
| Vienna Limestone | 4230 |
| Tar Springs Sandstone | 4240 |
| Hombergian Stage | 4250 |
| Okaw Group | 4260 |
| Glen Dean Limestone | 4270 |
| Hardinsburg Sandstone | 4280 |
| Golconda Group | 4290 |
| Haney Limestone | 4300 |
| Fraileys Shale | 4320 |
| Big Clifty Sandstone Member | 4330 |
| Gasperian Stage | 4340 |
| Beech Creek Limestone | 4350 |
| West Baden Group | 4360 |
| Cypress Sandstone | 4370 |
| Paint Creek Group | 4380 |
| Ridenhower Formation | 4390 |
| Reelsville Limestone Member | 4400 |
| Sample Sandstone Member | 4410 |
| Beaver Bend Limestone Member | 4420 |
| Bethel Sandstone | 4430 |
| Mammoth Cave Limestone Megagroup | 4450 |
| Cedar Bluff Limestone Group | 4460 |
| Downeys Bluff Limestone | 4470 |
| Yankeetown Sandstone | 4480 |
| Renault Limestone | 4500 |
| Shetlerville Limestone Member | 4510 |
| Popcorn Sandstone Member | 4520 |
| Valmeyeran Series | 5000 |
| Genevievian Stage | 5010 |
| Levias Limestone Member | 5020 |
| Aux Vases Sandstone | 5040 |
| Rosiclare Sandstone Member | 5050 |
| Ste. Genevieve Limestone | 5060 |
| Joppa Member | 5070 |
| Karnak Limestone Member | 5090 |
| Spar Mountain Sandstone Member | 5100 |
| Fredonia Limestone Member | 5110 |
| St. Louis Limestone | 5150 |
| Salem Limestone | 5180 |
| Rocher Member | 5190 |
| Chalfin Member | 5200 |
| Fults Member | 5210 |
| Kidd Member | 5215 |
| Ullin Limestone | 5230 |
| Harrodsburg Limestone Member | 5240 |
| Ramp Creek Limestone Member | 5250 |
| Knobs Megagroup | 5260 |
| Borden Siltstone | 5270 |
| Sonora Formation | 5280 |
| Fort Payne Formation | 5290 |
| Warsaw Shale | 5310 |
| Bilyeu Member | 5320 |
| Keokuk Limestone | 5350 |
| Montrose Chert Member | 5355 |
| Burlington Limestone | 5370 |
| Fern Glen Formation | 5380 |
| Springville Shale | 5390 |
| State Pond Member | 5410 |
| Kinderhookian Series | 5420 |
| Chouteau Limestone | 5430 |
| North Hill Group | 5440 |
| Meppen Limestone | 5445 |
| Starrs Cave Limestone | 5450 |
| Prospect Hill Siltstone | 5460 |
| McCraney Limestone | 5470 |
| New Albany Shale Group | 5480 |
| Hannibal Shale | 5490 |
| Nutwood Shale Member | 5510 |
| Glen Park Formation | 5520 |
| Devonian System | 5800 |
| Upper Devonian Series | 5810 |
| Louisiana Limestone | 5820 |
| Saverton Shale | 5840 |
| Grassy Creek Shale | 5850 |
| Sweetland Creek Shale | 5860 |
| Sylamore Sandstone | 5870 |
| Middle Devonian Series | 5880 |
| Hunton Limestone Megagroup | 5890 |
| Cedar Valley Limestone | 5900 |
| Coralville Member | 5910 |
| Alto Formation | 5920 |
| Rapid Member | 5950 |
| Lingle Formation | 5970 |
| Walnut Grove Limestone Member | 5980 |
| Rendleman Oolite Bed | 5990 |
| Solon Member | 6000 |
| Hoing Sandstone Member | 6010 |
| Misenheimer Shale Member | 6020 |
| Wapsipinicon Limestone | 6030 |
| Davenport Member | 6040 |
| Tripp Limestone Member | 6050 |
| Blocher Shale | 6060 |
| Howardton Limestone Member | 6070 |
| Grand Tower Limestone | 6080 |
| Tioga Bentonite Bed | 6090 |
| Spring Grove Member | 6100 |
| Cooper Limestone Member | 6110 |
| Kenwood Member | 6120 |
| Otis Member | 6130 |
| Coggan Member | 6135 |
| Geneva Dolomite Member | 6140 |
| Dutch Creek Sandstone Member | 6150 |
| Tippecanoe Sequence | 6160 |
| Lower Devonian Series | 6170 |
| Clear Creek Chert | 6180 |
| Backbone Limestone | 6190 |
| Grassy Knob Chert | 6200 |
| Bailey Limestone | 6210 |
| Silurian System | 6700 |
| Cayugan Series | 6720 |
| Niagaran Series | 6740 |
| Moccasin Springs Formation | 6770 |
| Racine Formation | 6780 |
| St. Clair Limestone | 6820 |
| Sugar Run Formation | 6840 |
| Joliet Formation | 6860 |
| Marcus Formation | 6864 |
| Romeo Member | 6868 |
| Markgraf Member | 6872 |
| Brandon Bridge Member | 6876 |
| Alexandrian Series | 6880 |
| Kankakee Formation | 6900 |
| Sweeney Formation | 6921 |
| Sexton Creek Limestone | 6940 |
| Plaines Member | 6944 |
| Troutman Member | 6948 |
| Offerman Member | 6952 |
| Drummond Member | 6956 |
| Edgewood Formation | 6960 |
| Elwood Formation | 6965 |
| Blanding Formation | 6970 |
| Wilhelmi Formation | 6975 |
| Tete de Morts Formation | 6985 |
| Birds Member | 6990 |
| Schweizer Member | 6995 |
| Mosalem Formation | 7010 |
| Noix Oolite Member | 7020 |
| Ordovician System | 7360 |
| Cincinnatian Series | 7370 |
| Richmondian Stage | 7380 |
| Maquoketa Shale Group | 7390 |
| Neda Formation | 7400 |
| Brainard Shale | 7410 |
| Girardeau Limestone | 7420 |
| Fort Atkinson Limstone | 7430 |
| Scales Shale | 7440 |
| Clermont Shale Member | 7450 |
| Maysvillian Stage | 7460 |
| Elgin Shale Member | 7470 |
| Edenian Stage | 7480 |
| Orchard Creek Shale Member | 7490 |
| Thebes Sandstone Member | 7500 |
| Ottawa Limestone Megagroup | 7510 |
| Cape Limestone | 7520 |
| Champlainian Series | 7530 |
| Trentonian Stage | 7540 |
| Galena Group | 7550 |
| Dubuque Formation | 7560 |
| Kimmswick Subgroup | 7570 |
| Wise Lake Formation | 7580 |
| Stewartville Member | 7590 |
| Sinsinawa Member | 7600 |
| Dunleith Formation | 7610 |
| Wyota Member | 7620 |
| New London Member | 7630 |
| Wall Member | 7640 |
| Sherwood Member | 7650 |
| Moredock Member | 7660 |
| Rivoli Member | 7670 |
| Mortimer Member | 7680 |
| Fairplay Member | 7690 |
| Eagle Point Member | 7700 |
| Beecher Member | 7710 |
| St. James Member | 7720 |
| Buckhorn Member | 7730 |
| Decorah Subgroup | 7740 |
| Guttenberg Formation | 7750 |
| Glenhaven Member | 7760 |
| Garnavillo Member | 7770 |
| Kings Lake Formation | 7780 |
| Tyson Member | 7790 |
| Mincke Member | 7800 |
| Spechts Ferry Formation | 7810 |
| Glencoe Member | 7820 |
| Castlewood Member | 7830 |
| Blackriveran Stage | 7840 |
| Platteville Group | 7850 |
| Plattin Subgroup | 7860 |
| Quimbys Mill Formation | 7870 |
| Strawbridge Member | 7880 |
| Shullsburg Member | 7890 |
| Hazel Green Member | 7900 |
| Nachusa Formation | 7910 |
| Everett Member | 7920 |
| Elm Member | 7930 |
| Eldena Member | 7940 |
| Grand Detour Formation | 7950 |
| Forreston Member | 7960 |
| Victory Member | 7970 |
| Hely Member | 7980 |
| Clement Member | 7990 |
| Stillman Member | 8000 |
| Walgreen Member | 8010 |
| Dement Member | 8020 |
| Mifflin Formation | 8030 |
| Briton Member | 8040 |
| Hazelwood Member | 8050 |
| Establishment Member | 8060 |
| Brickeys Member | 8070 |
| Blomeyer Member | 8080 |
| Pecatonica Formation | 8090 |
| Oglesby Member | 8100 |
| Medusa Member | 8110 |
| New Glarus Member | 8120 |
| Dane Member | 8130 |
| Chana Member | 8140 |
| Hennepin Member | 8150 |
| Ancell Group | 8160 |
| Glenwood Formation | 8170 |
| Joachim Dolomite | 8180 |
| Harmony Hill Shale Member | 8190 |
| Metz Member | 8200 |
| Loughridge Sandstone Member | 8210 |
| Matson Member | 8220 |
| Nokomis Sandstone Member | 8230 |
| Daysville Dolomite Member | 8240 |
| Defiance Member | 8250 |
| Kingdom Sandstone Member | 8260 |
| Boles Member | 8270 |
| Augusta Member | 8280 |
| Abernathy Member | 8290 |
| Dutchtown Limestone | 8300 |
| Sharpsboro Member | 8310 |
| Gordonville Member | 8320 |
| St. Peter Sandstone | 8330 |
| Starved Rock Sandstone Member | 8340 |
| Tonti Sandstone Member | 8350 |
| Kress Member | 8360 |
| Sauk Sequence | 8370 |
| Chazyan Stage | 8380 |
| Knox Dolomite Megagroup | 8390 |
| Everton Dolomite | 8400 |
| Canadian Series | 8410 |
| Prairie du Chien Group | 8420 |
| Shakopee Dolomite | 8430 |
| New Richmond Sandstone | 8440 |
| Oneota Dolomite | 8450 |
| Blodgett Member | 8460 |
| Arsenal Member | 8470 |
| Gunter Sandstone | 8480 |
| Cambrian System | 8550 |
| Croixan Series | 8560 |
| Trempealeauan Stage | 8570 |
| Eminence Formation | 8580 |
| Jordan Sandstone | 8590 |
| Momence Sandstone Member | 8600 |
| Potosi Dolomite | 8610 |
| Franconian Stage | 8620 |
| Derby-Doerun Member | 8640 |
| Potsdam Sandstone Megagroup | 8650 |
| Franconia Formation | 8660 |
| Davis Member | 8670 |
| Ironton Sandstone | 8680 |
| Mooseheart Member | 8700 |
| Marywood Member | 8710 |
| Fox Valley Member | 8720 |
| Buelter Member | 8730 |
| Dresbachian Stage | 8740 |
| Galesville Sandstone | 8750 |
| Eau Claire Formation | 8760 |
| Proviso Siltstone Member | 8780 |
| Lombard Dolomite Member | 8790 |
| Elmhurst Sandstone Member | 8800 |
| Mt. Simon Sandstone | 8810 |
| Charter Member | 8820 |
| Gunn Member | 8830 |
| Lacey Member | 8840 |
| Mayfield Member | 8850 |
| Lovell Member | 8860 |
| Kenyon Member | 8870 |
| Crane Member | 8880 |
