West Rigg Open Cutting

West Rigg Open Cutting
Site of Special Scientific Interest
The disused West Rigg open-cast iron-stone mine.
Country	England
Region	North East
District	Wear Valley

Location	NY911391
- coordinates	GB-ENG 54°44′50″N 2°8′20″W / 54.74722°N 2.13889°W / 54.74722; -2.13889Coordinates: GB-ENG 54°44′50″N 2°8′20″W / 54.74722°N 2.13889°W / 54.74722; -2.13889

Area	4.8 ha (11.9 acres)

Notification	1968
Management	Natural England

Area of Search	County Durham
Interest	Geological

Location of West Rigg Open Cutting SSSI, Co Durham
Website: Map of site

West Rigg Open Cutting is a Site of Special Scientific Interest in the Wear Valley district of west County Durham, England. It is a disused ironstone quarry, located just over 1 km north of the village of Westgate, in Weardale.

At West Rigg, the Slitt Vein, a 20 km-long quartz intrusion in the Namurian Great Limestone, is exposed at the surface; the exposure is up to 5 m wide over a distance of some 200 m. During Late Permian times, extensive mineralisation occurred in the vicinity of the Slitt Vein: high salinity fluids, rich in iron, permeated the Great Limestone which, throughout its full thickness, was mineralised, producing siderite and ankerite minerals which were subsequently oxidised, yielding a limonitic ore with an iron content of over 40 percent. At West Rigg, the iron mineralisation extends up to 60 m on each side of the vein.^[1]

The Slitt Vein is predominantly composed of quartz, with smaller amounts of fluorite and uneconomic amounts of galena lead ore. The earliest mining activity at the site was the extraction of fluorite and galena from the Slitt Vein itself: the miners worked from levels driven into the vein from the west. In the late 19th century, quarrying of the ironstone began, the Slitt Vein being left untouched so that today it protrudes as a vertical 'rib' along the centre of the quarry.^[2]

The Geological Conservation Review has identified the site as being of national importance because it provides an accessible illustration of the formation of iron ore by replacement and oxidation. The site also offers a rare surface view of the Slitt Vein.^[3]

References

↑ Bouch, Jon E; Jonathan Naden; Thomas J Shepherd; Brian Young; Antony J Benham; John A McKervey; Hilary J Sloane (2008). Stratabound Pb-Ba-Zn-F mineralisation in the Alston Block of the North Pennine Orefield (PDF). British Geological Survey. ISBN 978-0-85272-625-9.
↑ Forbes, Ian; Elizabeth Pickett; Chris Woodley-Stewart; Brian Young. "Slitt Wood and West Rigg Geotrail". North Pennines AOB Partnership. Retrieved 26 July 2010.
↑ "West Rigg Open Cutting" (PDF). English Nature. 1989. Retrieved 19 July 2010.

Sites of Special Scientific Interest in County Durham

Backstone Bank and Baal Hill Woods Baldersdale Woodlands Bishop Middleham Quarry Bollihope, Pikestone, Eggleston and Woodland Fells Botany Hill Bowes Moor Bowlees and Friar House Meadows Brasside Pond Brignall Banks Burnhope Burn Butterby Oxbow Cassop Vale Castle Eden Dene Causey Bank Mires Charity Land Close House Mine Cornriggs Meadows Cotherstone Moor Crag Gill Crime Rigg and Sherburn Hill Quarries Dabble Bank Derwent Gorge and Horsleyhope Ravine Durham Coast Fairy Holes Cave Far High House Meadows Fishburn Grassland Foster's Hush Frog Wood Bog God's Bridge Grains o' th' Beck Meadows Green Croft and Langley Moor Greenfoot Quarry Hannah's Meadows Hawthorn Dene Hawthorn Quarry Hell Kettles Hesledon Moor East Hesledon Moor West Hexhamshire Moors Hisehope Burn Valley Hulam Fen Hunder Beck Juniper Kilmond Scar Low Redford Meadows Lune Forest Mere Beck Meadows Middle Crossthwaite Middle Side and Stonygill Meadows Middleton Quarry Middridge Quarry Moorhouse and Cross Fell Muggleswick, Stanhope and Edmundbyers Commons and Blanchland Moor Neasham Fen Newton Ketton Meadow Old Moss Lead Vein Park End Wood Pig Hill Pike Whin Bog Pittington Hill Pow Hill Bog Quarrington Hill Grasslands Railway Stell West Raisby Hill Grassland Raisby Hill Quarry Redcar Field Rigg Farm and Stake Hill Meadows Rogerley Quarry Sherburn Hill Shipley and Great Woods Sleightholme Beck Gorge - The Troughs Slit Woods Stony Cut, Cold Hesledon Teesdale Allotments The Bottoms The Carrs Thrislington Plantation Town Kelloe Bank Trimdon Limestone Quarry Tuthill Quarry Upper Teesdale Waldridge Fell West Newlandside Meadows West Park Meadows West Rigg Open Cutting Westernhope Burn Wood Wingate Quarry Witton-le-Wear Yoden Village Quarry

Neighbouring areas Cleveland Northumberland Tyne and Wear

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