Greenfoot Quarry
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Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| NY982391 | — | Favourable | 0.92 | 2024-08-15 |
Habitats
Geology & landscape
Geological Feature: Igneous Intrusion · Mining / Industrial: Quarry · Rock Type: Limestone
Landscape processes: Volcanic / Igneous
Description
Area, 0.9 hectares 2.2 ac Description Greenfoot Quarry provides the most important exposure of the distinctive Little whin Sill. The abandoned quarry exposes up to 12 metres of dolerite intruded as hot molten rock between successive strata of the Three Yard Limestone, which solidified as a flat sheet after bringing about slight metamorphism of the adjacent rock. A unique section of the sill displaying columnar joints with limestone above and below, is exposed in the western end of the quarry face and the upper part of the south facing quarry wall displays a long section of the upper contact of the sill and limestone. The Little whin Sill differs in its chemical composition from the great whin Sill; it is less magmatically evolved and is considered to represent the nearest approach to the unchanged parental magma of the whin Sills and their associated dykes. It is mineralogically unusual amongst the whin group of rocks in that it contains olivine Mg Fe Si O and under saturated silicate of magnesium and iron. Exposures of the sill occur in the River Wear close to and downstream of Greenfoot Quarry, but the site has been selected as the most complete exposure of this unusual member of the whin suite of intrusions.
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