Ciechocinek Formation
| Ciechocinek Formation | |
|---|---|
| Stratigraphic range: Lower Toarcian ~Tenuicostatum-Bifrons | |
Northern Germany units, including the Ciechocinek and it´s sister Grimmen Formation | |
| Type | Geological formation |
| Unit of |
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| Sub-units | |
| Underlies |
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| Overlies |
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| Area | Polish Basin |
| Thickness | 140 m (460 ft) |
| Lithology | |
| Primary | Claystone & abundant Clay Pits |
| Other | Sandy-clayey sediments deposited with traces of breaks and weathering. Grey heteroliths, Mudstones, Claystones, Siltstones and fine-grained Sandstones |
| Location | |
| Country |
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| Extent | Approx. 205,000 km2 (79,000 sq mi) |
| Type section | |
| Named for | Ciechocinek, Poland |
| Named by | Stefan Zbigniew Różycki (as an informal unit) |
| Year defined | 1958 |
The Ciechocinek Formation (also known as the Gryfice Formation at Suliszewo) is a Jurassic (lower Toarcian) geological formation extending across the Baltic coast, primarily in Poland, with minor occurrences in Lithuania and Kaliningrad. It represents one of the largest deltaic systems in the fossil record, covering approximately 7.1 × 100,000 km² in the Polish realm. Deposited in a brackish-marine embayment within the eastern arm of the Mid-European Toarcian Basin, it is a sister unit to the Grimmen Formation, the Sorthat Formation (Bornholm) and Lava Formation (Lithuania), with interfingering relationships with the Posidonia Shale in western regions. Its main equivalents include the Posidonia Shale, upper Rydeback Member (Rya Formation, southern Sweden), Fjerritslev Formation (Danish Basin), Sorthat Formation, and Lava Formation. Informal units in Poland, such as the Gryfice Beds (now fused with the Ciechocinek, Pomerania region), Lower Łysiec beds (Częstochowa region), and "Estheria series", are also correlated.