Pennylands
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Condition (NatureScot)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| F1 | Non-marine Devonian | Favourable | — | 2008-12-03 |
| F2 | Silurian - Devonian Chordata | Favourable | — | 2014-01-17 |
Climate exposure
This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.
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
Geological Period: Devonian · Rock Type: Sandstone
Landscape processes: Coastal
Description
Pennylands Pennylands SSSI is located on the foreshore between Thurso and Scrabster on the north coast of Caithness. The site has been notified due to the exposure of a sequence of layers of sedimentary rocks which contain both fossil fish and evidence of the geography and environment in which the fish lived. These rocks were deposited around 380 million years ago during the Middle Devonian geological era. Stratigraphy The cliff and foreshore rock outcrops at Pennylands provide important exposures through sedimentary rocks in the youngest part of the Caithness Flagstones and the transition to the overlying John O’Groats Sandstone. The section shows a sequence of shallow lake sediments with numerous thin beds containing fossil fish. Several sandstone layers occur in the sequence, laid down by rivers, lakes or as wind-blown sand. The flagstone sequence found at Pennylands has a higher sand content than the exposures at Wick and Stromness and is thought to come from near the edge of the Orcadian Basin. The rocks at Pennylands are important because they occur in a part of the Middle Old Red Sandstone succession that is often poorly exposed elsewhere. Palaeontology Important fossil fish beds occur within the sequence of rocks, providing the richest known locality for Millerosteus minor, which is well preserved here. Nine species of fossil fish have been found at Pennylands so far, including Thursius philodotus, Dipterus and Homosteus. The site has potential for future research on Orcadian Basin fish.