Carte géologique du terrain entre le lac d'Orta et celui de Lugano. Leopold von Buch. [1829]

Extract from the map

Geological cross-section

Section of the key

Carte géologique du terrain entre le lac d'Orta et celui de Lugano. Leopold Buch. [1829].

An image of the full map can be found here

Christian Leopold von Buch (1774 – 1853) was a German geologist and paleontologist. He was the first Foreign Member of the Geological Society of London.

A biography of  Christian Leopold von Buch

Posted by Bob McIntosh

Eruptive rocks of Brent Tor by Frank Rutley, 1878.

Plate VIII. 
Basalt with glassy magma mainly devitrified. Brent Tor, North-west side of the foot of the Tor, Magnification x55.

The 'Eruptive rocks of Brent Tor and its neigbourhood' was the first special petrographical work issued by the Geological Survey. It is dated 1878.  It denotes a time when microscopic examination of rocks collected during the mapping of new districts became routine. Colour chromolithographs.

Frank Rutley was also the author of Elements of Mineralogy first published in 1874 and still available in print today in its 27th edition!

Plate IX.
1. Decomposed Greenstone, Greston Bridge.
2. Slate beneath lower Greenstone, Greston Bridge.
3. Elvan, S. end of Shilla Mill Quarry (Polarized).
4.Mag'n. Mica and cavities in Quartz of Granite, Brazen Tor.
5. Fluid cavities containing cubes of NaCl, Brazen Tor.
6. Amygdaloidal Schalstein, Churlhanger, near Lamerton.

Plate X
No. 1 Hornblende, Pyrites and Quartz in Amphibolite, Brazen Tor, Devon
No 2 Schorl in the Granulitic margin of the Granite in contact with No. 1
No 3. Pyroxene (probably Diallage) in Gabbro? Cottage Inn, Main Road to Marytavy.
No. 4 Titaniferous Iron, partly altered (Gabbro) Cock's Tor, near Tavistock.
Bo. 1 x55. Nos. 2,3 and 4 x25. ordinary transmitted light. On the surface of No. 4 a little light was also reflected simultaneously.

Brent Tor. (South side near the base) x25
Brent Tor. (North side) x25

A selection of plates from the memoir:

Brent Tor from Hart's Hall, near Morwellham

 Great Staple Tor on the western Margin of Dartmoor (mural jointing in granite).

The Master Rock, Horndon. (woodcut)

Posted by Bob McIntosh

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

Brora coal pit, Sutherland, 1899

Brora coal-pit, 0.8 km. west of Brora. Sutherland. Coal-pit and rock exposures (lower part of the Jurassic Corallian and Oxford Clay). The photograph shows the small colliery workings with a row of cottages to the right. The main seam of the Brora Coal was c. 3 feet 6 inches thick within which was a band of pyrites. This greatly reduced its value. Most coal in Scotland is derived from Carboniferous strata, the Brora Coal is unusual in that it is of much younger Jurassic age. The coal had a strong sulphurous odour, was liable to spontaneous combustion both in the mine and on the spoil heaps or even in transit and it had a high ash content. The history of mining of this coal dates back to 1598 when Jane, Countess of Sutherland opened the first pit. Many other records of mining exist since then. In 1910 output was 6000 tons. The coal raised was used in the immediate neigbourhood, at the brickworks adjacent to the mine, in the Brora Wool Mill which also supplied Brora with electric light and the local inhabitants used it as a domestic fuel.

Photograph by Robert Lunn, 1899.

Posted by Bob McIntosh

Oblique aerial view of Craigielaw Point, Aberlady. East Lothian

BGS Image ID: P000795

Oblique aerial view of Craigielaw Point, Aberlady. East Lothian. Looking north-west. Bedded sediments. Lower Limestone Group. The Lower Limestone Group is the uppermost division of the Lower Carboniferous in the district. The strata has a regional dip to the west or north-west of up to 5 degrees, though between Craigielaw Point and Aberlady Point gentle minor folds are superimposed on the larger structure. Note the concrete anti-landing defences from World War 2.

Posted by Bob McIntosh

Coe's Chalk-pit, Bramford, Suffolk 1925

BGS Image ID: P202970

Coe's Chalk-pit, Bramford, Suffolk, 1 1/4 m. N. of railway-station. Looking E. General view of pit. The succession shown is quadratus-chalk, mucronata-chalk (uppermost 30 ft.), Thanet Beds, Reading Beds, Red Crag (?), glacial sands.

Posted by Bob McIntosh

Agglomerate, Mortonhall Quarry

Agglomerate. From neck; rhyolitic matrix. Mortonhall Quarry, near Buckstone. The first  of c 17,000 photographs of rock specimens from the BGS Systematic Series captured and processed by BGS volunteers in Edinburgh.

The Systematic Series is arranged by Geological Survey 1"/1:50,000 map sheet area. Representative rocks from each sheet were collected or drawn from other collections to make a teaching collection for new Survey field geologists.

Working Portland Stone

BGS Image ID: P023985

Easton, Bath and Portland Stone Firms, Ltd., Portland. General view of mason's workshop in Portland Stone works. Works of Bath and Portland Stone Firms, Ltd. 1930.

BGS Image ID: P204941

Easton Quarry, Isle of Portland, Dorset. There are several quarries in the Easton area working the white freestone limestones known as Portland Stone. In the early 19th century, when many of the quarries were still in the hands of the Crown, they were principally worked by convict labour. Large stone columns are a feature of most classical stone buildings and in later times many British architects copied such classical themes. Portland Stone proved to be ideal for this purpose because the beds of limestone are quite thick. Here a section of stone column is being turned on lathe at the works of the Bath & Portland Stone Company. The section is of 4 ft. diameter, and is one of five constituting a column 25 ft. high. As Portland Stone seems to be less affected by pollution than other United Kingdom limestones it has been widely used in London, particularly since the early 19th century e.g. Custom House, St. Paul's Cathedral, The Bank of England, Whitehall and Downing Street.

BGS Image ID: P204947

Easton, Bath and Portland Stone Firms, Ltd., Portland. Hand-carving in Portland Stone. Only straightforward work such as that on ashlar and on mouldings is carried out by machine. Finer work is all done by hand. Works of Bath and Portland Stone Firms, Ltd.

BGS Image ID: P204950

Easton, Bath and Portland Stone Firms, Ltd., Portland. Travelling crane lifting block of masonry in Portland Stone. Works of Bath and Portland Stone Firms, Ltd.

BGS Image ID: P204951

Easton, Bath and Portland Stone Firms, Ltd., Portland. Stack of finished masonry in Portland Stone. The diameter of sections of fluted columns in foreground is 4 ft. Works of Bath and Portland Stone Firms, Ltd.

Posted by Bob McIntosh