| Joachim Dolomite | |
|---|---|
| Stratigraphic range: Ordovician | |
 Joachim Dolomite over St. Peter Sandstone (Pacific, Missouri) | |
| Type | Formation |
| Unit of | Ancell Group |
| Underlies | Pecatonica Formation and Plattin Limestone |
| Overlies | St. Peter Sandstone |
| Thickness | 0 to 100+ feet in Arkansas[1] |
| Lithology | |
| Primary | dolomite |
| Location | |
| Region | Arkansas, Illinois, Missouri |
| Country | United States |
| Type section | |
| Named for | Joachim Creek, Jefferson County, Missouri |
| Named by | Arthur Winslow[2] |
The Joachim Dolomite is a Middle Ordovician geologic formation in Arkansas, Illinois, and Missouri.[1] The name was first introduced in 1894 by Arthur Winslow in his study of the geology of Missouri.[2] Winslow designated a stratotype along Plattin Creek, which was misidentified as Joachim Creek, in Jefferson County.[3] The name was introduced into Arkansas in 1911, replacing part of the, now abandoned, Izard Limestone.[4]
- ^ a b McFarland, John David (2004) [1998]. "Stratigraphic summary of Arkansas" (PDF). Arkansas Geological Commission Information Circular. 36: 5. Archived from the original (PDF) on 2016-12-21. Retrieved 2018-01-10.
- ^ a b Winslow, A. (1894). "Lead and zinc deposits, section 1". Geological Survey of Missouri. 6: 331, 352–353.
- ^ Grohskopf, John G. (1948). "Zones of Plattin-Joachim of eastern Missouri". Bulletin of the American Association of Petroleum Geologists. 332 (3): 351–365.
- ^ Ulrich, E.O. (1911). "Revision of the Paleozoic systems". Bulletin of the Geological Society of America. 22: 281–680.