Sunken lanes in southern England

BGS Image ID: P209857

Sunken lane, road from Thorncombe Street leading to Godalming via Munstead Heath, Surrey. Looking north-west at the road from Thorncombe Street (2 m. south-east of Godalming) leading to Godalming via Munstead Heath. A sunken lane in Hythe Beds. A section in 15 to 20 ft. of evenly-bedded loamy sand, containing seams of siliceous sandstone up to 3 inches thick. This road-cutting results from the wear caused by wheeled and hoofed transport over the years (before the road was metalled) and the removal of the sandy debris by rainwash and wind etc. on this sloping ground, which lies below the plateau formed by the Bargate Beds at the top of the hill beyond the car. The sunken roads of the Weald are a good example of man as a geological agent. Roads and farm tracks of this type are common over the whole of the Lower Greensand outcrop and in some localities on the outcrops of the Lower Tunbridge Wells Sand the Upper Greensand and the Chalk. All stages of their formation can be seen from simple tracks to cuttings 20 feet deep.

BGS Image ID: P212403

Sunken lane, South Ambersham. Deep sunken lane in Selham Ironshot Sands. These coarse-grained limonite-rich sands are a local development within the Lower Greensand.

BGS ImageID: P212907

Lane to the S. of Wotton hamlet. Sunken lane in Hythe Beds near Wotton.

BGS ImageID: P212404

Sunken lane approximately 850 m. SSE of Tillington Church. Sunken lane in Lower Greensand sandstones. Pale fawn silty sandstones in Lower Greensand exposed in west side of lane. Fine-grained sands with nodular chert horizons are present.

Posted by: Bob McIntosh

Landslip at Holbeck Hall Hotel, Scarborough 1993

BGS Image ID:P509016

The recent landslip at Mappleton demonstrates what an active coast Yorkshire has. The pictures from the archive today shows a landslide that happened in June 1993 further up the coast from Mappleton and just south of Scarborough.

The Holbeck landslide, south of Scarborough in North Yorkshire, attracted considerable interest when it destroyed the four-star Holbeck Hall Hotel between the night of 3 June and 5 June 1993. A rotational landslide involving about 1 million tonnes of glacial till cut back the 60 m high cliff by 70 m. It flowed across the beach to form a semicircular promontory 200 m wide projecting 135 m outward from the foot of the cliff. 

The likely cause of the landslide was a combination of: rainfall of 140 mm in the two months before the slide took place; issues related to the drainage of the slope; pore water pressure build up in the slope and the geology. 

The first signs of movement on the cliff were seen six weeks before the main failure, when cracks developed in the tarmac surface of footpaths running across the cliffs. These were filled to stop ingress of water to the cliff, but when the cracks reopened, shortly before the main failure, the council closed the cliff paths below the hotel. At this time a small part of the hotel garden was also observed to have suffered a minor movement.

There was originally 70 m of garden between the hotel and the cliff edge. At 6 am on the 4 June a guest saw that 55 m of the garden had disappeared. The hotel was evacuated and the landslide continued to develop, culminating in the collapse of the east wing of the hotel by the evening of 5 June.

The landslide is a rotational landslide degrading to a mud/debris flow which covered the rocks on the beach (platform).

The cliff consists of Glacial Till (sandy, silty clay) resting on a low cliff of the Middle Jurassic Scalby Formation. The Scalby Formation comprises Scalby Mudstone and Moor Grit (sandstone).

BGS Image ID:  P707131

Post by Bob McIntosh

Camborne mining district, Cornwall. 1904

BGS image ID: P200035

View of the Camborne mining district taken from the engine house of Dolcoath Mine. Looking E. In the distance, to the right, can be seen Carn Brea. 1904.

Photo by T.C. Hall

Posted by Bob McIntosh