Mermaid's Pool to Rowden Gut
Also within
Devon County North Devon Scenic Area King Charles Way - Combe Martin to Marsland Mouth National TrailSouth West Coast Path National Trail
Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| SS395257 | — | Favourable | 25.68 | 2011-11-07 |
| SS402269 | — | Favourable | 119.21 | 2011-11-07 |
| SS412281 | — | Favourable | 7.34 | 2011-11-07 |
Climate exposure
This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.
Peat habitats store centuries of carbon and depend on a stable, waterlogged water table. Warmer, drier summers dry out peat, making it far more vulnerable to wildfire and to carbon release — a pressure that can undo years of restoration work regardless of how well the site is otherwise managed.
Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.
Geology & landscape
Rock Type: Sandstone
Landscape processes: Coastal, Peatland / Mire
Description
Mermaid's Pool to Rowden Gut SSSI Description The 5.5 kilometre long coastal section from Mermaid’s Pool to Rowden Gut exposes the only complete sequence available through the Bideford Formation – a localised development of fluvio-lacustrine ‘Coal Measure’ type deposits. The partly coeval Crackington and Bude Formations, which represent more marine-influenced sediments of the southwest England ‘Culm Basin’, are also exposed within the site. The strata are extensively exposed within a series of broad and slightly asymmetrical folds, causing repetition of the sequence along the cliffs and foreshore. Further structural complications are provided by two sets of wrench faults. The sediments comprise 750-800 metres of alternating mudstones, siltstones and sandstones. At least nine sedimentary cycles have been recognised, each grading upwards from black mudstones into coarser beds, eventually culminating in distinctive, sharply defined sandstones which are bioturbated or include rootlet horizons. Sedimentary structures including cross-stratification and trace-fossil assemblages are locally well developed. Palaeocurrent directions indicate a provenance to the northwest. Biostratigraphical evidence demonstrates that the Bideford Formation is laterally equivalent to the upper part of the Crackington Formation and the basal part of the Bude Formation. One marine marker band, characterised by the goniatite Gastrioceras amaliae (of Langsettian age) occurs within both a Crackington Formation sequence at Babbacombe Mouth and within a Bideford Formation facies west of Cornborough. In addition to marine horizons, the Bideford Formation yields important non-marine bivalve assemblages including faunas of the Carbonicola lenisulcata Zone. The basal part of the overlying Bude Formation (1m above the Cornborough Sandstone) includes an impure coal seam with traces of a peat earth. Close to this level, elements of a Coal Measure flora have been recorded including Neuropteris obliqua, Sphenophyllum cuneiforme and Kariopteris acuta which suggest the Lyginopteris hoeninghausii Zone. The coastal exposures from Mermaid’s Pool to Rowden Gut exhibit the best available sections through the Bideford Formation and provide detailed sedimentological and biostratigraphical information. The combination of a major lateral change from Crackington to Bideford Formation facies and the associated biostratigraphical control makes this site of very considerable importance for regional and national palaeoenvironmental and palaeogeographical studies.