| Tama | TM-A2 | 140 | 17 | Mississippian (Lower) | Maynes Creek Cream | | Q |
| Tama | TM-A2+ | 140 | 17 | Mississippian (Lower) | Maynes Creek Cream | + | Q |
| Tama | TM-C1 | 84 | 18 | Mississippian (Lower) | Maynes Creek Cream | | Q |
| Tama | TM-C1+ | 84 | 18 | Missisippian (Lower) | Maynes Creek Cream | + | Q |
| Tama | TM-B2+ | 138 | 17 | Mississippian (Lower) | Maynes Creek Fossiliferous | + | Q |
| Tama | TM-C2+ | 141 | 18 | Mississippian (Lower) | Maynes Creek Fossiliferous | + | |
| Tama | TM-A1+ | 122 | 17 | Mississippian (Lower) | Maynes Creek Gray | + | Q |
| Tama | TM-B1 | 83 | 17 | Mississippian (Lower) | Maynes Creek Gray | | Q |
| Tama | TM-B1+ | 83 | 17 | Mississippian (Lower) | Maynes Creek Gray | + | Q |
| Tama | TM-C3+ | 142 | 18 | Mississippian (Lower) | Maynes Creek Gray | + | |
| Union | UN-A | 315 | 7 | Pennsylvanian | Cement City | | Q |
| Union | UN-A+ | 315 | 7 | Pennsylvanian | Cement City | + | Q |
| Union | UN-A1 | 165 | 8 | Pennsylvanian | Hertha | | Q |
| Union | UN-A1+ | 165 | 8 | Pennsylvanian | Hertha | + | Q |
| Van Buren | VB-G | 103 | 12 | Mississippian (Middle) | Croton Banded | | S |
| Van Buren | VB-G+ | 103 | 12 | Mississippian (Middle) | Croton Banded | + | S |
| Van Buren | VB-M | | 12 | Mississippian (Middle) | Croton Banded | | |
| Van Buren | VB-M+ | | 12 | Mississippian (Middle) | Croton Banded | | |
| Van Buren | VB-C | 210 | 11 | Mississippian (Middle) | Croton Chalcedonic | | |
| Van Buren | VB-C+ | 210 | 11 | Mississippian (Middle) | Croton Chalcedonic | + | |
| Van Buren | VB-E | 212 | 11 | Mississippian (Middle) | Croton Chalcedonic | | |
| Van Buren | VB-E+ | 212 | 11 | Mississippian (Middle) | Croton Chalcedonic | + | |
| Van Buren | VB-F | 102 | 11 | Mississippian (Middle) | Croton Chalcedonic | | S |
| Van Buren | VB-F+ | 102 | 11 | Mississippian (Middle) | Croton Chalcedonic | + | S |
| Van Buren | VB-L | 118 | 9 | Pennsylvanian | Hematite | | |
| Van Buren | VB-L+ | 118 | 9 | Pennsylvanian | Hematite | + | |
| Van Buren | VB-A+ | 149 | 13 | Mississippian (Middle) | Keokuk | + | S |
| Van Buren | VB-H | 123 | 13 | Mississippian (Middle) | Keokuk | | S |
| Van Buren | VB-H+ | 123 | 13 | Mississippian (Middle) | Keokuk | + | S |
| Van Buren | VB-I | 124 | 13 | Mississippian (Middle) | Keokuk | | O |
| Van Buren | VB-I+ | 124 | 13 | Mississippian (Middle) | Keokuk | + | O |
| Van Buren | VB-K | 205 | 13 | Mississippian (Middle) | Keokuk | | O |
| Van Buren | VB-K+ | 205 | 13 | Mississipian (Middle) | Keokuk | + | O |
| Van Buren | VB-E | 212 | 10 | Mississippian (Middle) | Keokuk | | Q |
| Van Buren | VB-E+ | 212 | 10 | Mississippian (Middle) | Keokuk | + | Q |
| Wapello | WP-A | 523 | 9 | Pennsylvanian | Bog Iron | | |
| Wapello | WP-A+ | 523 | 9 | Pennsylvanian | Bog Iron | + | |
| Washington | WS-B1 | 189 | 12 | Mississippian (Middle) | Croton Banded | | S |
| Washington | WS-B1+ | 189 | 12 | Mississippian (Middle) | Croton Banded | + | S |
| Washington | WS-A | 166 | 11 | Mississippian (Middle) | Croton Chalcedonic | | S |
| Washington | WS-A+ | 166 | 11 | Mississippian (Middle) | Croton Chalcedonic | + | S |
| Washington | WS-B2 | 187 | 14 | Mississippian (Lower) | Wassonville | | O |
| Washington | WS-B2+ | 187 | 14 | Mississippian (Lower) | Wassonville | + | O |
| Washington | WS-C | 44 | 14 | Mississippian (Lower) | Wassonville | | O |
| Washington | WS-C+ | 44 | 14 | Mississippian (Lower) | Wassonville | + | O |
| Washington | WS-C1 | 188 | 14 | Mississippian (Middle) | Burlington | | O |
| Washington | WS-C1+ | 188 | 14 | Mississippian (Lower) | Wassonville | + | O |
| Washington | WS-D | 190 | 14 | Mississippian (Lower) | Wassonville | | O |
| Washington | WS-D+ | 190 | 14 | Mississippian (Lower) | Wassonville | + | O |
| Washington | WS-E1 | 191 | 15 | Mississippian (Lower) | Wassonville | | O |
| Washington | WS-E1+ | 191 | 15 | Mississippian (Lower) | Wassonville | + | O |
| Washington | WS-E2 | 192 | 15 | Mississippian (Lower) | Wassonville | | O |
| Washington | WS-E2+ | 192 | 15 | Mississippian (Lower) | Wassonville | + | O |
| Washington | WS-E3 | 193 | 15 | Mississippian (Lower) | Wassonville | | O |
| Washington | WS-E3+ | 193 | 15 | Mississippian (Lower) | Wassonville | + | O |
| Washington | WS-F | 198 | 15 | Mississippian (Lower) | Wassonville | | O |
| Washington | WS-F+ | 198 | 15 | Mississippian (Lower) | Wassonville | + | O |
| Webster | WB-A | 157 | 6 | Quaternary | Argillaceous Mudstone | | O |
| Webster | WB-A+ | 157 | 6 | Quaternary | Argillaceous Mudstone | + | O |
| Webster | WB-C | | 6 | Quaternary | Argillaceous Mudstone | | |
| Webster | WB-C+ | | 6 | Quaternary | Argillaceous Mudstone | + | |
| Webster | WB-B | 477 | 6 | Quaternary | Kakabeca | | |
| Webster | WB-B+ | 477 | 6 | Quaternary | Kakabeca | + | |
| Winnshiek | WH-D | 451 | 20 | Silurian (Lower) | Buck Creek Quarry | | |
| Winneshiek | WH-D+ | 451 | 20 | Silurian (Lower) | Buck Creek Quarry | + | |
| Winneshiek | WH-A | 152 | 23 | Ordovician (Middle) | Galena | | O |
| Winneshiek | WH-A+ | 152 | 23 | Ordovician (Middle) | Galena | + | O |
| Winneshiek | WH-B | 171 | 24 | Ordovician (Middle) | Galena | | Q |
| Winneshiek | WH-B+ | 171 | 24 | Ordovician (Middle) | Galena | + | Q |
| Winneshiek | WH-C | 369 | 24 | Ordovician (Middle) | Galena | | |
| Winneshiek | WH-C+ | 369 | 24 | Ordovician (Middle) | Galena | + | |
| Winneshiek | WH-C2 | 369 | 24 | Ordovician (Lower) | Shakopee | | O |
| Winneshiek | WH-C2+ | 369 | 24 | Ordovician (Lower) | Shakopee | + | O |
| Woodbury | WD-B1 | 366 | 6 | Quaternary | Bijou Hills Orthoquartzite | | M |
| Woodbury | WD-A | 72 | 6 | Quaternary | Tongue River Silica | | S |
| Woodbury | WD-A+ | 72 | 6 | Quaternary | Tongue River Silica | + | |
| Woodbury | WD-B2 | 367 | 6 | Quaternary | Tongue River Silica | | M |
| Woodbury | WD-B2+ | 367 | 6 | Quaternary | Tongue River Silica | + | M |
