River Rawthey, Wandale Beck and Sally Beck

Site of Special Scientific Interest · 54.3827, -2.4374

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Also within

Cumbria County YORKSHIRE DALES National Park

Condition (Natural England)

Favourable (10)
UnitFeatureConditionArea (ha)Assessed
SD703972 — Favourable 4.29 2011-12-08
SD706974 — Favourable 14.24 2011-12-07
SD707981 — Favourable 7.58 2011-12-08
SD708978 — Favourable 3.27 2011-12-08
SD714976 — Favourable 1.73 2011-12-07
SD716986 — Favourable 10.83 2011-12-08
SD717982 — Favourable 10.83 2011-12-08
SD717987 — Favourable 10.83 2011-12-08
SD719988 — Favourable 10.83 2011-12-08
SD721989 — Favourable 10.83 2011-12-08

Habitats

Fast flowing river and stream

Geology & landscape

Geological Period: Ordovician, Silurian · Rock Type: Limestone, Mudstone

Description

Description The site consists of exposures along the bed and banks of the River Rawthey, Wandale Beck and Sally Beck and their tributaries. It lies about seven kilometres north east of Sedbergh on the eastern side of the Howgill Fells. River Rawthey, Wandale Beck and Sally Beck is a dual interest geological site covering most of the Ordovician and Silurian exposures in the Murthwaite Inlier, Cautley in Westmorland. The first area of interest is located in Wandale Beck and Sally Beck streams which flow to the west and east respectively of Murthwaite. The rocks exposed in these streams are of late Ordovician age and all eight zones of the Ashgill Series are recorded within the site. In addition, the Cautley area has been designated as the type area for the Ashgill Series, the site also exposes the type successions for the Cautleyan and Rawtheyan stages and represents the most complete development of the Pusgillian Stage in the Murthwaite Inlier. The succession is represented mainly by the Cautley Mudstone Formation which is approximately 580 metres thick and comprises grey calcareous mudstones with variably developed limestone nodules. The strata contains a rich fauna of trilobites, brachiopods, bryozoans and corals. The oldest beds are of latest Caradoc Onnian age and contain the diagnostic trilobites Onnia and Flexicalymene. The succeeding, more varied Pusgillian trilobite fauna includes Attractopyge, Gravicalymene, Paracybeloides and Tretaspis. However, it is in Cautleyan aged strata that the most diverse faunas occur with trilobites Calymene, Toxochasmop, Tretaspisand orthid and strophomenid brachipods including Catazyga, Dicoelosia, Nicolella, Oxoplecia, Platystrophia, Rhactomena and Triplesia. Faunas in the Cautley Mudstones of Rawtheyan age are more restricted with the virtual disappearance of the orthacean brachiopods to leave a dominantly dalmanellid plectambonitacean assemblage. Among the trilobites Dindymene, Kloucekia, Tretaspis and Trinodus are important forms.

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