Dan y Graig Quarry, Risca

Site of Special Scientific Interest · 51.6097, -3.1099

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Also within

Gwent County

Habitats

Fast flowing river and stream

Geology & landscape

Geological Feature: Gorge / Ravine · Mining / Industrial: Quarry · Geological Period: Carboniferous · Rock Type: Carboniferous Limestone, Limestone, Sandstone

Landscape processes: Fluvial

Description

Description Dan y Graig Quarry lies on a steep, wooded slope that rises to the south of the town of Risca and is situated above the main A467 Newport to Crosskeys road and the River Ebbw. The quarry is in the area of the South Wales Coalfield where the River Ebbw flows out of the coalfield through a gorge in the Carboniferous and Old Red Sandstone rocks. This locality shows the Oolite Group and Llanelly Formation of the Carboniferous Limestone. It provides the most southerly section of the Llanelly Formation showing fine exposures of peritidal carbonates with algal laminates, evaporites, palaeosols and clay dykes. This is a locality with great research potential for studies of palaeoenvironments in Tournaisian and early Visean times.

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