| Kw - Windrow |
| Dc - Cedar Valley Group |
|
| Dcuu - Lithograph City |
|
| Dcum - Coralville + Hinckley Member |
|
| Dclp - Little Cedar Valley and Pinicon Ridge |
|
| Dclc - Chicksaw Shale |
| Dw - Wapsipinicon / Spillville |
| Omaq - Maquoketa |
|
| Omd - Maquoketa and Dubuque |
|
| Odub - Dubuque |
| Ogs - Stewartville |
| Ogsc - Stewartville and Cummingsville |
| Ogp - Prosser |
| Oc - Cummingsville |
| Od - Decorah Shale |
|
| Odpg - Decorah and Platteville |
|
| Odpg - Decorah, Platteville and Glenwood |
|
| Opl - Platteville |
|
| Opg - Platteville and Glenwood |
| Os - St. Peter Sandstone |
| Op - Prairie Du Chien Group |
|
| Ops - Shakopee |
| Opo - Oneota Dolomite |
| Cj - Jordan Sandstone |
| Cs - St. Lawrence |
| Cst - St. Lawrence and Tunnel City |
| Ct - Tunnel City Group |
|
| Clr - Lone Rock |
| Cw - Wonewoc Sandstone |
|
| Cwe - Wonewoc and Eau Claire |
| Ce - Eau Claire |
| Cm - Mt. Simon Sandstone |
|
| Kw - Windrow |
|
| Dc - Cedar Valley Group |
|
| Dcuu - Lithograph City |
|
| Dcum - Coralville + Hinckley Member |
|
| Dclp - Little Cedar Valley and Pinicon Ridge |
|
| Dclc - Chicksaw Shale |
|
| Dw - Wapsipinicon / Spillville |
|
| Omaq - Maquoketa |
|
| Omd - Maquoketa and Dubuque |
|
| Odub - Dubuque |
|
| Ogs - Stewartville |
|
| Ogsc - Stewartville and Cummingsville |
|
| Ogp - Prosser |
|
| Oc - Cummingsville |
|
| Od - Decorah Shale |
|
| Odpg - Decorah and Platteville |
|
| Odpg - Decorah, Platteville and Glenwood |
|
| Opl - Platteville |
|
| Opg - Platteville and Glenwood |
|
| Os - St. Peter Sandstone |
|
| Op - Prairie Du Chien Group |
|
| Ops - Shakopee |
|
| Opo - Oneota Dolomite |
|
| Cj - Jordan Sandstone |
|
| Cs - St. Lawrence |
|
| Cst - St. Lawrence and Tunnel City |
|
| Ct - Tunnel City Group |
|
| Clr - Lone Rock |
|
| Cw - Wonewoc Sandstone |
|
| Cwe - Wonewoc and Eau Claire |
|
| Ce - Eau Claire |
|
| Cm - Mt. Simon Sandstone |
|
| Kw - Windrow |
|
| Dc - Cedar Valley Group |
|
| Dcuu - Lithograph City |
|
| Dcum - Coralville + Hinckley Member |
|
| Dclp - Little Cedar Valley and Pinicon Ridge |
|
| Dclc - Chicksaw Shale |
|
| Dw - Wapsipinicon / Spillville |
|
| Omaq - Maquoketa |
|
| Omd - Maquoketa and Dubuque |
|
| Odub - Dubuque |
|
| Ogs - Stewartville |
|
| Ogsc - Stewartville and Cummingsville |
|
| Ogp - Prosser |
|
| Oc - Cummingsville |
|
| Od - Decorah Shale |
|
| Odpg - Decorah and Platteville |
|
| Odpg - Decorah, Platteville and Glenwood |
|
| Opl - Platteville |
|
| Opg - Platteville and Glenwood |
|
| Os - St. Peter Sandstone |
|
| Op - Prairie Du Chien Group |
|
| Ops - Shakopee |
|
| Opo - Oneota Dolomite |
|
| Cj - Jordan Sandstone |
|
| Cs - St. Lawrence |
|
| Cst - St. Lawrence and Tunnel City |
|
| Ct - Tunnel City Group |
|
| Clr - Lone Rock |
|
| Cw - Wonewoc Sandstone |
|
| Cwe - Wonewoc and Eau Claire |
|
| Ce - Eau Claire |
|
| Cm - Mt. Simon Sandstone |