Farrant, A R. 2008.A walkers’ guide to the geology and landscape of eastern Mendip. Book and map at 1:25 000 scale. (Keyworth, Nottingham: British Geological Survey.) This guide is available to purchase from the British Geological Survey https://shop.bgs.ac.uk/Shop/Product/BSP_BEMEND
The Vobster area
Parking is limited to roadsides and lay-bys.
The pretty village of Vobster is situated just north of the Nettlebridge Valley, seven kilometres north-west of Frome. Its rural tranquility belies an industrial past at the heart of the Somerset Coalfield. This area of Mendip contained numerous collieries working, on and off, from medieval times until the 1970s.
The Vobster area lies north of the Beacon Hill Pericline and is underlain by some complicated geology. The majority of the rocks here are late Carboniferous in age. They are highly contorted and have been folded and faulted by earth movements at the end of the Carboniferous.
Three kilometres to the north of the village, the Carboniferous rocks are unconformably overlain by the gently dipping Jurassic Charmouth Mudstone and the Inferior Oolite. The higher ground of Mells Down and Kingsdown, three kilometers to the north, is part of the Great Oolite escarpment.
The quarries at Upper Vobster [21]
The Vobster quarries were worked for aggregate but closed in the 1950s. One of the quarries, Vobster Quay, is now flooded and is used as an inland diving centre. The old quarry workings can still be seen if you are a diver!
Most of the area south of the quarries is underlain by highly contorted sandstones and mudstones of the Coal Measures. These are occasionally exposed in stream gullies and along the banks of the Mells River. Some coal seams have proved workable, for example the Standing Coal and Dungy Drift seams. Many small collieries and pits were worked around the area; the main collieries were Vobster, Vobster Old, Vobster Breach, Newbury and Mells.
Newbury Colliery [23]
The Newbury collieries were connected by rail to the broad-gauge Great Western Railway, Frome to Radstock line. Opened about 1857, the remains of this line can still be seen between Newbury and Upper Vobster. It ran close to the route of the Dorset and Somerset Canal, and in places used the old canal bed. The line of the canalcan still be seen just south of Vobster Cross, where there is a well- preserved bridge beneath the road [24]
The opening of the Newbury Railway stimulated the development of the Mells Colliery [25]
2A narrow-gauge tramway was laid to connect the railway with the pits in the Nettlebridge Valley to the south. Part of the tramway, which is now followed by a footpath, was up an inclined plane just east of the pub in Vobster. At Vobster Colliery [26]
The opening of the Newbury Railway and the tramway also stimulated the development of Vobster Breach Colliery [28]
Vobster Breach Colliery is now overgrown. Most of the mine buildings were grouped around an infilled shaft in the centre of the site. The remains of two banks of coking ovens can be seen from the path. Most have now collapsed, but approximately 12 remain intact. To the north lies the spoil tip which is bounded by a leat that once fed water-powered pumps at Vobster Colliery. From here, footpaths lead up the Nettlebridge Valley to Coleford (see Nettlebridge) and the Stoke St Michael area (see Stoke St Michael).