Friday 16th May 2025. North Branch visit to Eastgate Quarry, Eastgate, Stanhope, County Durham. (NY 950 370). Field trip coordinator: Ian Dossett, President, The Russell Society:
Eastgate Quarry is private land, not open access, and is monitored by CCTV. The visit was only possible with explicit permission being granted by the landowner.
The North Branch of the Russell Society field trip members met at the entrance gate to the Eastgate Quarry at noon. The weather was perfect for the visit – blue sky with a light cooling breeze.
Eastgate Quarry worked an exposure of the Carboniferous age Great Limestone Formation from the mid-1960s to provide limestone for cement manufacture. Originally worked by Blue Circle Industries, the quarry was acquired by the French company Lafrage in 2001.
Quarry operations were concluded in 2003. The quarry workings are crossed by a major shear which acted as a conduit for hydrothermal brines and during its operation three cross-cutting veins were intersected: The Bull Vein, Fairy Hole Vein, and Wilson Vein.
Before travelling up to the quarry itself the group was met by the land manager who advised us how to avoid the nesting birds and who also pointed out a vein outcrop close to the entrance gate (possibly the Heights West Cross Vein). The exposed vein was substantial, consisting primarily of quartz with some fluorite, trace galena plus a few smudges of malachite.
The long track leading up to the quarry was in reasonable condition and the lower quarry bench was clear and provided a good parking area. It was noted that the bench itself contained a large number of fossil corals indicating an extensive reef structure. Later it was noted that loose material in the quarry area contained segments of crinoid stems (looking like discarded shirt buttons) and brachiopods.
A few areas were out of bounds to avoid disturbing nests but that did not detract from the visit. Although the mine workings have been back filled, some fluorite was still observed in that backfill, including some occurrences with large, though corroded, mostly damaged, modified octahedral galena crystals often associated with clear quartz and with a carbonate coating.
The fluorite was noted in several colour variations including purple, green, clear and yellow. The mine was noted for its green fluorite specimens but none of this was observed in upward facing surfaces. It was speculated that the dominance of purple fluorite in the remaining material may reflect extended exposure of the green fluorite to daylight. Many of the small fluorite crystals displayed twinning and some of the crystal groups were observed with a coating of quartz crystals.
Our sincere thanks go to the landowner Weardale Quarry Ltd for allowing us access and to the manager for his input. Many thanks are also due to Ian for setting up such an interesting visit.
With thanks to Allan Ryan for his report on this visit.
The Russell Society is Britain’s leading society specialising in topographical mineralogy (the study and description of the mineralogy of a geographic region). It is named after the eminent amateur mineralogist Sir Arthur Edward Ian Montague Russell (1878 – 1964), who is pictured digging for pyromorphite on Bulmers’s vein at Leadhills, Scotland. The writing on the photograph is in Russell’s characteristic hand which is seen on his specimen labels. The wide spectrum of Russell Society members ranges from beginners to professional mineralogists and geologists. Nearly 400 members are spread throughout the United Kingdom and overseas.
For more information on the Russell Society follow this link.
Photographs:
Featured Image: Quartz/fluorite vein outcrop near quarry entrance gate.
