Pen Benar

Site of Special Scientific Interest · 52.8263, -4.5011

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Coastal

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, Siltstone

Landscape processes: Coastal

Description

Description Pen Benar forms a rocky promontory in Abersoch, a village some 12 km south west of Pwllheli, at the south-western end of Llyn, North Wales. The site is confined to an east-west coastal section containing vertical cliffs and foreshore exposures. The interest of this tectonically-disturbed shore section lies in its illustration of datable lower Tremadoc Series rocks of facies very different to those seen elsewhere in North Wales. Sandstone and siltstone are the prominent rock types, but it is the mudstones present which yield zonally-important assemblages of Dictyonema flabelliforme and Clonograptus tenellus, together with sponge spicules and inarticulate brachiopods. This is a site significant in studies of Tremadoc palaeogeography.