Hayes Point to Bendrick Rock

Site of Special Scientific Interest · 51.3971, -3.2420

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

Geological Period: Triassic · Rock Type: Conglomerate, Limestone, Mudstone

Landscape processes: Coastal, Fluvial

Description

Description This 1.8 km stretch of coastline lies to the south east of Barry on the northern shore of the Bristol Channel. The whole length of the cliffline and foreshore provides excellent exposures through important rock sections of Triassic age while the vicinity of Bendrick Rock is one of the best localities in Britain for fossil footprints. The Hayes Point to Bendrick Rock coastal section provides excellent exposure of Triassic lake and river deposits. Fine-grained, lake-margin sediments occur here, interbedded with coarse-grained fluviatile (river) sediments, representing the marginal facies of the Triassic Mercian Mudstone Group of South Wales. The finer sediments include siltstones with nodular evaporites, wave-rippled siltstones and fine sandstones, and thin graded sandstones of sheet-flood origin. The coarse fluvial sediments include a limestone conglomerate up to two metres thick, together with occasional thin, matrix-supported conglomerates, interpreted as the products of debris flows. Sediment transport was towards the east and south west. This is a key locality for the interpretation of Triassic lake and river environments. Bendrick Rock is one of Britain's best localities for fossil footprints and the best for such trace-fossils in rocks of Triassic age. Dinosaur trackways have been known from South Glamorgan for over 100 years, and were first described by Sollas under the name of Brontozoum thomasi. Latterly the specimens from this new site have been attributed to the ichnogenus Anchisauripus, a form name normally associated with bipedal prosauroped dinosaurs.

Plant communities

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea