Johnson Formation
Geologic formation in the United States
From Wikipedia, the free encyclopedia
The Johnson Formation (or Johnson Limestone) is a thick geologic formation of soft shale with thin, resistant beds of chalkier mudstone and limestone in Nebraska, Kansas, and Oklahoma rarely exposed outside of road cuts. It preserves fossils dating back to the late-Carboniferous period.[1]
| Johnson Formation | |
|---|---|
| Stratigraphic range: Carboniferous[1] | |
Head cut of Johnson Shale in the Tuttle Creek Lake spillway freshly exposed by the 1993 flood, showing unweathered coloration. (capped by the bright Glenrock limestone member of the Red Eagle Formation) | |
| Type | Formation |
| Underlies | Red Eagle Formation |
| Overlies | Foraker Formation |
| Lithology | |
| Primary | Shale |
| Other | resistant beds of argillaceous mudstone to well-laminated limestones[2] |
| Location | |
| Region | Midcontinent (Nebraska, Kansas, Oklahoma)[2] |
| Country | United States |
| Type section | |
| Named for | Johnson, Oklahoma[2] |
