Grimmen Formation
| Grimmen Formation | |
|---|---|
| Stratigraphic range: Lower Toarcian ~Tenuicostatum-Exaratum | |
Clay pit outcrop near Grimmen | |
| Type | Geological formation |
| Unit of | Kamienna Group |
| Underlies | Glashütte Formation, Dörnten Member (Posidonia Shale Formation) |
| Overlies | Posidonia Shale Formation, Wolgast Formation |
| Thickness | Up to 100 m (330 ft) |
| Lithology | |
| Primary | Claystone, Siltstone |
| Other | Mudstone, fine-grained Sandstone, Siderite and carbonate concretions |
| Location | |
| Region | Mecklenburg-Vorpommern |
| Country | Germany |
| Extent | North German Basin |
| Type section | |
| Named for | Grimmen, Germany |
The Grimmen Formation is a Lower Jurassic (Toarcian) geological formation in northeastern Germany, primarily exposed in the Grimmen and Klein Lehmhagen clay pits and documented in wells such as Reinberg 1E. Formally established in 2025, it was previously part of the informal “Green Series” of the Ciechocinek Formation. It represents a prodelta to brackish-marine depositional system in the eastern North German Basin (NGB), shaped by sea-level changes and the Toarcian anoxic event.