Harper Clough and Smalley Delph Quarries
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Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| SD717316 | — | Unfavourable Declining | 1.34 | 2023-03-20 |
| SD719319 | — | Unfavourable Declining | 1.56 | 2023-03-20 |
Habitats
Description
Area, 1.3 hectares 3.2 ac Description Harper Clough and Smalley Delph Quarries are situated about three kilometres north east of Blackburn. Their geological interest may be defined in technical terms as follows, These two adjacent quarries combine to present an excellent section in the Namurian, cut through the upper part of the Marsdenian and lower part of the Yeadonian Stages. One of the quarries, Harper Clough, contains a remarkable cast of a Stigmarian system, consisting of a series of radial roots. Key sections demonstrating the stratigraphy of the later Namurian. In layman's terms, the interest of this site may be expressed more simply and such a statement is provided below. This should not be taken as definitive and further information as to details of the interest can be obtained from the Nature Conservancy Council. These quarries provide excellent exposures of a series of rock layers originally formed in the Namurian period of geological time, about 315 million years ago. The rocks originated as sediment carried by a major river which built a vast delta southwards from uplands in Scotland. At times the delta became densely vegetated and the fossilised roots of a large tree that lived on the delta are preserved in an upright position on one of the rock layers in Harper Clough. In general, the quarries are of special geological interest as reference sections for study of rocks of Namurian age.
Plant communities
A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream
Potamogeton natans community
Show 20 indicator speciesSchoenoplectus 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
Show 15 indicator speciesIsolepis 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
Show 11 indicator speciesBerula 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
Show 12 indicator speciesFontinalis 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