Grassington: Lead Mining Trail

© Craven & Pendle Geological Society

Village Centre in Winter

Grassington is one of many charming villages in the Yorkshire Dales and is the focal point of Upper Wharfedale.  There are many fascinating walks in and around the village but the Lead Mining Trail is perhaps the most facsinating one!  The trail lies about 3 kilometres to the north east on Grassington Moor at Grid Reference SE 015 659 (OS Outdoor Leisure 10: Yorkshire Dales Southern.  Here you can stroll around Yarnbury Orefield where lead was commonly mined by a variety of enterprises throughout the years.

To get to the mining area follow the left-hand road in the photograph above (or walk) to the top of the village and take Moor Road which terminates more or less at what was once the Mining Offices but is now a collection of privately owned cottages.  On arrival at the orefield you may notice that Grassington Moor is quite dissimilar to the other prominent lead mining areas in the Yorkshire Dales (Swaledale and Arkengarthdale to name two) as there are no steep-sided valleys.

Photo: Paul Kabrna (April 2008)

Lead Mining Trail

The mines were very poor during the first 20 years of the 19th century, but in 1818 John Taylor was made the Duke's Mineral Agent. He built dams and brought water to a 15 metre diameter waterwheel, which he used to drive pumps in the Coalgrovebeck Mine, allowing production to resume 10 years before the drainage adit driven from Hebden Gill reached it. Taylor also sank new, deep shafts which were accessed by ropes wound by horse powered winding machines or whims. These shafts were linked by roads to mechanised dressing mills where the ore was crushed and separated before going on to be smelted.

The mines entered their most prosperous phase between 1821 and 1861, when they produced 20 273 tons of lead, averaging 965 tons a year and employed about 170 people. During this prosperous period, deeper trials were made to find new reserves of ore, but, apart from a rich strike at Sarah's Shaft, they were disappointing. After 1861, output fell steadily as the mines became exhausted. By 1881, the population of Crassington had fallen by 400 accordrng to the census. These problems were made worse by the fmpact of rising imports, mainly of Spanish lead, which kept prices low by underselling English lead. Work around Bcever's Engine Shaft, at Yarnbury. and Old Moss Shaft, on the Out Moor, stopped in May 1880. The smelt mill kept going a little longer using up stocks of ore mined previously.

There has been no serious attempt to reopen the mines since 1880. but barytes, fluorspar and some lead ore has been recovered from the waste dumps The largest of these operations were the Crassington Lead Mines Ltd between 1916 and 1920 and the Dales Chemical Company between 1956 and 1963.

The installation of the Grassington Moor Leadmlning Trail has been carried out in partneiship with the Yorkshire Dales Millennium Trust using funds from the Millennium Commission.

Galena

Galena is the mineralogists' name given to lead ore.  It does not commonly occur on its own but with a host of other metallic minerals including sphalerite (zinc sulphide), and malachite and azurite (both ores of copper).  Also associated with the metallic ores are the gangue minerals such as fluorite, barite and calcite. 

Galena is usually formed in sedimentary rocks as vertical veins and less frequently as horizontal deposits called 'flats'. The ores were deposited out of mineral-rich saline waters that penetrated the joints and fractures in the Carboniferous limestone on the Askrigg Block. 

By the end of the Carboniferous and into early Permian times, the minerals were precipitated out of solution with the hottest fluids producing the distinctive cube-shaped crystals of galena around Grassington.

More recently in the Yorkshire Dales dumps of old workings have been reworked for their gangue minerals.  Gangue minerals were traditionally considered waste products.  Modern uses for fluorite (as furnace flux), and barite as an additive to drilling mud, have generated this recent interest.

Miners Buildings

The tour of Yarnbury Orefield begins where the cars can be parked at Yarnbury House (where the mine agent would have lived).  The building by the track is thought to be the Weigh House - the place where mine ore was weighed before being transported out of  Grassington.  The smaller building to the right is thought to have been where explosives were carefully and securely stored.

The 10 years between 1750 and 1760 were perhaps the busiest and most profitable time for the miners on Grassington Moor.  It is thought that up to 150 men were involved in mining activities of one kind or another. The Duke of Devonshire in 1790 strategically set about making profit from what was believed to be an exhausted orefield.  His plan of driving deeper shafts and controlling excess mine water paid off and so the orefield became profitable once more.

Photo: Paul Kabrna (April 2008)

Barrett's Incline

The Duke of Devonshires Cornish mining engineer, Capt. Barratt is believed to be responsible for driving Barratt's Incline to link up the main shafts at the 20 fathom level (120 feet - approx. 40 metres). 

On close inspection you will note the datestone on the arched entrance to the incline.  This locality is no more than 100 metres from Yarnbury House.

As you can see from the photograph to the right, there are now a number of site plaques around the orefield providing critical information on the history of Grassington Moor's lead mining activities.  Also look out for evidence of the railway dating back to the 1820's which carried ore from Barratt's Incline to the dressing floor.  There should be a few stone sleepers close to the wall. Barrett's Incline is marked number one on the Grassington Lead Mining Trail Millenium Project information board (Yorkshire Dales National Park Authority).

Orefield bell-pits?

Grassington Moor Orefield is typically 'pock - marked' with bell pits and spoil heaps. 

The photo to the right shows clearly a number of 'bell-pits' on the moor. The bell-pits, ranging from the 14th Century to the 18th Century, were usually 20 - 30 feet deep (7 - 10 metres) and commonly sunk at 30 yard (10 metre) intervals along the vein. The partnerships worked laterally along the vein and 'stoped' ore from above their heads.  Settling has produced the characteristic 'bell-shape' of these pits. Another interpretation is that they are not bell-pits but sites where shallow mining took place. These shallow shafts are marked number six on the Grassington Lead Mining Trail Millenium Project information board (Yorkshire Dales National Park Authority).

Photo: Paul Kabrna (April 2008)

Orefield Landscape

Grassington Moor has a long history of lead mining with records dating back to the 15th Century at a time when the monks of Fountains Abbey worked a smelt mill. When visiting the orefield there are many interesting viewing points all carefully mapped out to make a splendid day out. Besides the sites already mentioned you will be able to view such things as Beever Reservoir, Cupola Smelt Mill and High Winding Dam and chimney. The photograph above is the High Grinding Mill close to the Chimney as also shown. The High Grinding Mill is marked number sixteen on the Grassington Lead Mining Trail Millenium Project information board (Yorkshire Dales National Park Authority).

Grassington Grit

This small quarry exposing Grassington Grit is easily accessible on route to Yarnbury Orefield.  It can be found just off the trackway on the right-hand side as you are driving (or walking) up to the orefield. Interestingly enough the former lead miners of the area called it the Bearing Grit because it bore the main veins of the lead ore.

Photo: Paul Kabrna (April 2008)

In stratigraphical terms the Grassington Grit (Daykyns, 1892)  is of Namurian age and is part of the Pendle Formation, an integral part of the Millstone Grit Group.  The grit is made up of two or three main sand bodies including a coarse unit which proved ideal for making millstones.  It is of variable thickness and can contain thin coal seams at a number of levels. The seams were formed by the swamp vegetation that thrived on the ancient river delta.

Recommended Reading:
Lead Mining in the Yorkshire Dales by John Morrison ISBN 185568 138 2 published by the Dalesman Publishing Company (1998).