Cleveland Ironstone Formation
The Cleveland Ironstone Formation is a sequence of marine ironstone seams interbedded with shale and siltstone units which collectively form a part of the Lower Jurassic System of rocks underlying Cleveland in North Yorkshire. Exploitation of the ironstone seams became a major driving force behind the industrialisation of the Teesside district during the mid- to late-1800s.
| Cleveland Ironstone Formation | |
|---|---|
| Stratigraphic range: | |
Exposure of the Cleveland Ironstone Formation near Skinningrove | |
| Type | Geological formation |
| Unit of | Lias Group |
| Underlies | Whitby Mudstone Formation |
| Overlies | Staithes Sandstone Formation |
| Thickness | up to 25 metres (80 ft) |
| Lithology | |
| Primary | Mudstone, Siltstone, Ironstone |
| Other | Sandstone |
| Location | |
| Region | Europe |
| Country | UK |
| Extent | Cleveland Basin |
| Type section | |
| Named for | Cleveland, England |
| Location | cliffs near Staithes |
Based on the stratigraphy of the formation, the Cleveland Ironstone was found to belong within the Upper Pliensbachian (Domerian) universal stage. Ironstone seams and accompanying shales may be highly fossiliferous with remains so abundant in parts as to form well-developed shell-beds. Analysis reveals a wealth of shallow-water marine species, some in life position, along with trace fossils including Rhizocorallium burrows well exposed at Old Nab, east of Staithes.