Main Dyke Stone

This weekend, we skipped the hills and stayed local, driving to Gosforth to complete one of Pevsner's'Perambulations'.

Lots of fascinating things to dig up and digest about what used to be known as Bulman Village, but a little further down the road in South Gosforth lies this memorial, the Main Dyke Stone.

Well done if you've done your geology homework and know this spot! We didn't and were excited to read about the history behind it!

The Main Dyke Stone (also known as the Dike Stone) marks the line of a geological fault in the land. When the Gosforth Colliery was established in 1825, a shaft was sunk to try and establish the source of the coal, but lo and behold, the colliery company ran into bother because they hit the 90 Fathom Dyke. There would have been a lot of damning and blasting as the 90 Fathom Fault is a complicated geological phenomenon, which was discovered in Northumberland, where, over mega annums, the earth has been crunched up and displaced over 290 million years ago by a long period of mountain building, and which has left a weak point in the land.

The image is an antique line engraving published in 'A History of Coal, Coke and Coal Fields' by W. Fordyce in 1860.

If you go to the shore at Cullercoats, you see evidence of this where there are two sections of rock that are millions of years different in age lying side by side. The Carboniferous shale lies to the south, and to the north is Permian, yellow sandstone, much younger in age. This is a fault line where many millions of years ago a series of breaks in the earth's crust created a weak point after continents collided and the Iapetus Ocean closed. This is known as the 90 Fathom Fault Line.

Anyhooooo...back to South Gosforth and the damning and blasting...literally! Miners couldn't reach the coal they needed as a result of the fault line, and work continued over the next few years to try and ascertain the location of the coal seam. At first just hit a plateau of solid rock. This was at great cost to the executors Messrs Brandling, as the shaft had to be sunk to 181 fathoms (1 fathom equates to 6ft) before any sort of quality coal was found.

It was no picnic! There were two shafts with a pumping engine and a wagonway three and a half miles long to the Tyne. Although the first shaft was sunk in 1825, it was four years before the first coal was 'won' on 31st January 1829, when a good seam was identified, and work commenced.

There was much jubilation and celebration and to mark the occasion, a grand subterranean ball was held for those who had put in the back-breaking work to reveal the seam. Who'd say no to a subterranean ball after all?

A huge L shaped room was hewn 1100ft (335m) below the earth which was 15ft (4.5m) wide and the floor was flagged. Organisers placed seats around the 'ballroom' and illuminated the area with candles and oil lamps. Can you imagine? Sadly no polaroids of the overmen and under managers in their glad-rags.

Image is from the IBEW (the History of Brass Bands) website.

In a turn up for the books, the grand of Gosforth mixed with the hoi-polloi, fraternising beneath the earth's surface with the miners. Between 9:30 in the morning and 3:00 in the afternoon, people of all social standings were ferried up and down in a basket between the surface and the ballroom to partake in the dancing and merriment where the Coxlodge Brass Band (this image is taken 94 years later!) played a plethora of tunes, and people drank punch and malt liquor and lined their giddy tummies with plain biscuits. Guests were ceremoniously shown the coal face and were encouraged to hew their own piece of coal as a keepsake of the prestigious occasion.

So, in between the pebbledash of these wartime prefabs, so untypical of Gosforth, which were only ever built as temporary accommodation, but are still standing eighty years on, lies the Main Dyke Stone; a reminder of what lies beneath, and the efforts and energies that went into securing the black stuff for Tyneside.