This article was accepted into the corpus but its outbound wikilinks were never NER-processed — typical at the deepest BFS hop or when the run's entity cap was reached. No expansion funnel to show.
| Ermeensburg Formation | |
|---|---|
| Name | Ermeensburg Formation |
| Type | Geological formation |
| Period | Devonian |
| Primary lithology | Mudstone, Siltstone |
| Other lithology | Limestone, Sandstone, Dolomite |
| Region | South West England |
| Country | United Kingdom |
| Named for | Erme River |
| Unit of | Devonian Supergroup |
| Underlies | Dartmouth Group |
| Overlies | Meadfoot Group |
Ermeensburg Formation is a Devonian lithostratigraphic unit in South West England that preserves marine and marginal marine sediments deposited during the Devonian period. The formation has been studied in the context of British regional geology by institutions such as the British Geological Survey and in classic field localities near Dartmoor, Plymouth, and the Devon coast. It is notable for its variation in lithology and its record of faunal assemblages correlated with broader European and global Devonian sequences, including ties to research by figures like Roderick Murchison and comparative stratigraphy with the Old Red Sandstone.
The unit comprises predominantly fine-grained siliciclastic rocks intercalated with carbonate horizons described in classical accounts originating from surveys by the Geological Survey of Great Britain and later mapped by the British Geological Survey. Field guides produced for the Geologists' Association and academic monographs from the University of Exeter and University of Plymouth emphasize the exposure of mudstone, siltstone, and subordinate limestone near river valleys such as the River Erme and coastal cliffs adjacent to Wembury Bay. Historical works referencing the sequence include early regional syntheses by Adam Sedgwick and later synthesis articles in journals like the Quarterly Journal of the Geological Society.
Stratigraphically, the formation sits within the Devonian Supergroup and is commonly described as overlylying the Meadfoot Group and being overlain by the Dartmouth Group in classical stratigraphic columns used by the British Geological Survey. Lithofacies include laminated mudstone, silty mudstone, thin-bedded calcareous siltstone, nodular limestone, and localized sandstone units mapped in detail during surveys by the Royal Society-funded projects and university field programmes. Correlations have been proposed with the Old Red Sandstone facies and with coeval units in Cornwall and the South Wales Coalfield, drawing on biostratigraphic markers recognized in work by paleontologists associated with the Natural History Museum, London and the Plymouth Marine Laboratory.
The formation is assigned to the Middle–Late Devonian on the international timescale established by the International Commission on Stratigraphy. Fossil content includes marine invertebrates, with occurrences of brachiopods, bivalves, trilobites, and reef-influencing organisms referenced in faunal lists in publications affiliated with the Linnean Society of London and the Palaeontological Association. Microfossil and conodont studies, undertaken in collaboration with laboratories at the University of Oxford and University College London, have aided correlation with the Givetian and Frasnian stages. Comparisons to faunas from the Rhenish Massif and the Armorican Massif have been used to infer paleoecological gradients and faunal interchange documented in international paleontological symposia hosted by the Geological Society of London.
Key exposures occur along coastal sections near Wembury, river-cut exposures by the River Erme, and inland quarries that have been the subject of mapping by the Nature Conservancy Council and successor agencies. Regional geological maps produced by the British Geological Survey show the unit extending across parts of Devon and into adjacent Cornwall in discontinuous belts, with classic sections accessible from reserves managed in part by the National Trust and scientific access coordinated through university field classes. Historic collectors and authors such as members of the Plymouth Scientific Society have documented notable localities where bedding, structural dip, and fossil horizons are well displayed.
Interpretations of depositional settings invoke marginal shelf to prodeltaic environments influenced by relative sea-level changes widely discussed in syntheses from the International Commission on Stratigraphy and regional tectonic reconstructions tied to the evolution of the Variscan orogeny. Sedimentological studies published in journals associated with the Geological Society of America and case studies by researchers from the University of Cambridge suggest alternating low-energy hemipelagic deposition and episodic storm-influenced events producing tempestite layers, with carbonate production in restricted shallow shelves. Paleogeographic reconstructions align the area with the southern margin of the Old Red continental assemblage and the peri-Laurentia to Avalonia transition represented in maps prepared by the British Geological Survey and discussed at meetings of the European Geosciences Union.
Although not a major hydrocarbon or metalliferous mineral target compared with other British units studied by the British Geological Survey and industrial partners such as BP and Shell plc, the formation has local economic significance for dimension stone, aggregate extraction, and as a substrate influencing soil development and agricultural patterns analyzed in reports by the Department for Environment, Food and Rural Affairs. Quarry exposures have provided material for educational collections used by the Open University and museum displays at institutions including the Royal Albert Memorial Museum, Exeter and the Natural History Museum, London, while its stratigraphic and paleontological data contribute to regional heritage tourism supported by bodies like Visit Devon.
Category:Geologic formations of England Category:Devonian System of Europe