Nodule tools, Kent's Cavern, Torquay.

BGS Image ID: P232125

Photographs of nodule tools (breccia) from Kent's Cavern, Torquay. Photographs taken by A.R. Hunt. Photographs are from the British Association for the Advancement of Science photograph collection.

BGS Image ID: P232126

BGS Image ID: P232127

BGS Image ID: P232128

BGS Image ID: P641048

BGS Image ID: P641049

Posted by Bob McIntosh

Black Moss, Dinnet, Aberdeenshire. Kieselguhr or diatomite works 1917

BGS Image ID: P000025

Black Moss, 2.4 km. north of Dinnet Station. Aberdeenshire. 1917. The kieselguhr (diatomite) works. Extracting the kieselguhr. Kieselguhr overlain by peat marking site of silted-up lake. The vertical trenches show the method of draining the peat. Before silting-up, the shallow lakes had an abundant supply of nutrients and silica from the surrounding granites. Conditions were ideal for the prolific growth of lacustrine diatoms and the formation of fairly pure diatomite. Subsequent climate change and lowering lake levels lead to the formation of the overlying peat.

BGS Image ID: P000028

Processing the kieselguhr (diatomite). Drying in open-sided covered sheds. A close-up of the second process in the method of drying the kieselguhr. The cut blocks are clearly seen in rows of low open sheds. On the left blocks are placed on an uncovered low wooden structure with the blocks of the first drying process on the ground behind.

BGS IMage ID: P000031

Inside the large kieselguhr (diatomite) storage sheds. The photograph shows the method of building and piling the dried kieselguhr blocks within the sheds. The blocks are arranged in a herringbone fashion. Two bicycles are propped against the blocks.

BGS Image ID:  P527719

A specimen of diatomite from the deposit at Muir of Dinnet near Ballater, Aberdeenshire. Diatomite is a fine-grained earth substance resembling chalk or white clay in appearance and when dry easily breaking down into a white powder. Some specimens are as light as cork and can absorb four times their weight of water. It is composed of frustules of diatoms, extremely minute siliceous organisms. British Geological Survey Petrology Collection sample number MC 7496. In about 1880 a substance referred to as 'white moss' was reported underneath the peat at Muir of Dinnet. It was recognized as a diatomaceous deposit by the Rev. George Davidson and was regarded as a substance that could replace kieselguhr in the manufacture of dynamite. Practically the whole commercial output was sent to the Ardeer explosive works in Ayrshire where the organic matter was burnt away in kilns before use as an absorbent for nitro-glycerine in the manufacture of dynamite.

Posted by Bob McIntosh

Plates from James Sowerby's British Mineralogy 1802-1817

BGS Image ID: P704650

PLUMBUM Galaena. Sulphure of Lead; Galena. Plate no. 24. From: Sowerby, James. 1802-1817. British Mineralogy: Or Coloured figures intended to elucidate the mineralogy of Great Britain. Plate from vol: 1. page no.55. Modern name: Galena. Location: Collected found in Derbyshire.

BGS Image ID:  P705138

FERRUM carbonatum. Carbonate of Iron in rhomboidal spiculae. Plate no. 512. From: Sowerby, James. 1802-1817. British Mineralogy: Or Coloured figures intended to elucidate the mineralogy of Great Britain. Plate from vol: 5. page no.209. Location: Highgate Tunnel.

BGS Image ID: P704728

SILEX Quartzum, crystallisation. Crystallized Quartz; Cairn Gorum Crystals. Plate no. 102. From: Sowerby, James. 1802-1817. British Mineralogy: Or Coloured figures intended to elucidate the mineralogy of Great Britain. Plate from vol: 2. page no.1. Modern name: Smokey quartz (var. Cairngorm).

Posted by Bob McIntosh

Marbles from the Walter Brown Collection

BGS Image ID: P576068

P576068
Marble specimen. Calabria, Italy. Pallizzi Quarries, Calabria, Italy.
Calabria, Italy. Alternative name: Agrillei. Specimen description: Red/brown, orange and white fragments-veins. Anselm Odling. 

Text from: Watson, J. British and foreign marbles and other ornamental stones. Cambridge : University Press, 1916:

317 AGRILLEI. Pallizzi Quarries, Calabria. This specimen is an example of the dark variety of Calabresian Marble. It is composed of reddish brown and orange-coloured brecciated fragments, in a greyish brown matrix.

BGS Image ID: P576086

Marble specimen. Emperor Red, Portugal. Pedra Furada Quarries, Pero Pinheiro, Estremadura.

Emperor Red, Portugal. Alternative name: Encarnado. Specimen description: Red with pink/white markings and small fossil fragments. 

Text from: Watson, J. British and foreign marbles and other ornamental stones. Cambridge : University Press, 1916:

388 ENCARNADO (Emperor's Red). Pedra Furada Quarries, Pero Pinheiro, Estremadura. This is a red marble varied with streaks of dale pink and white, and faint outlines of small fossils may also be seen. In the British Isles this variety of Portuguese Marble is known commercially as Emperor's Red. It is not only in constant demand in Lisbon and other cities of Portugal for decorative purposes, but it is freely exported to England and other countries for similar work. Good examples of its use may be seen in St Roque's Church, Lisbon, and in the Municipal Hall, the internal decorations of both buildings being largely composed of it.

Emperor's Red is frequently used for ecclesiastical work in England. It appears in the Opus Alexandrinum pavement in the chancel of Bristol Cathedral (1895), and there are other examples in the chancel pavement of Truro Cathedral (1886), and in that of Peterborough (1895). It may be seen in many of the public buildings and hotels in London; for instance, in the Norfolk Hotel, and in the Drapers' Hall, built in 1898, where the handrails of the staircase and some of the door casings are composed of it.
It may interest the Cambridge student to hear that it was intended by Sir Gilbert Scott, the architect of St John's College Chapel, that the Communion-table slab in the chapel should be composed of Portuguese Emperor's Red Marble. It is stated that Sir Gilbert arranged with a marble merchant for the supply, but it was found afterwards that a block of Belgian Rouge Royal Marble (see No. 158 Watson J. British and foreign marbles. 1916.) had been furnished instead.

BGS Image ID: P576016

Marble specimen. Yellow Brocatelle, Spain. Tortosa Quarries, Prov. Tarragona, Spain.
Label name: Yellow Brocatelle, Spain. Alternative name: Tortosa Brocatello. Specimen description: Deep Red; containing yellow, white and transparent fossil fragments. Also known as / Brocatelle d'Espagne. 

Text from: Watson, J. British and foreign marbles and other ornamental stones. Cambridge : University Press, 1916:

421 TORTOSA BROCATELLO. Tortosa Quarries, Prov. Tarragona. This large slab is a typical example of a class of marbles known in Spain as Brocatello, a term applied with slightly different meanings in Spain, France, and Italy. Spanish Brocatello, known usually as Tortosa Brocatello, and sometimes distinguished as Brocatelle d'Espagne, resembles a mottled marble in general appearance, but on closer inspection, it is found to be made up of a red ground, in which there are a multitude of fossils. Many of the shells are crushed, and are so closely packed as to form the body of the marble, a characteristic which causes it to be included in the group of marbles known as Lumachella, a name given to an ancient marble sometimes found in excavations at Rome, chiefly made up of small shells. The groundmass is deep red, but as the numerous fossils vary in colour from yellow to snow white, and are sometimes replaced by colourless transparent calcite, the marble, generally, has a light appearance.

The quarries are situated near Tortosa, a town in the Province of Tarragona. They were worked vigorously in ancient times, and the marble was then known as Marmor Schiston. During the Roman occupation large quantities were sent to Rome. It may be seen in the Church of St Maria Maggiore in that city, there being an example at the side entrance of the chapel. The high altar of St Cecilia is also partly composed of it. The altar of the Transept Chapel of the Church of St Paolo fuori le Mura has colonnettes of Tortosa Brocatello. There are numerous examples of its use in Naples, where columns of it may be seen in the Chapel of St Januarius. It is now chiefly used in Spain for small panels, mantelpieces, and clock cases, for which purposes it is also employed in England. It is, however, sometimes used in this country for ecclesiastical decorative work, together with other marbles. Instances of its use to form a mosaic pavement may be seen in the chancel of Bristol Cathedral (1895), and in those of Truro (1886) and Peterborough (1892).

BGS Image ID: P576026

Marble specimen. Red Onyx. Ain Smara Quarries, Algeria.

Red Onyx. Alternative name: Rouge Agate. Specimen description: Crimson with white, pink, purple and orange veins and mottled markings. M Marius Cantini, Marseilles. 

Text from: Watson, J. British and foreign marbles and other ornamental stones. Cambridge : University Press, 1916:

 694 ROUGE AGATE. Ain Smara Quarries, Constantine. This example represents a much more brilliantly coloured variety of Constantine Onyx Marble than those already described. As the specimen shews, a rich crimson colour dominates, besides which, white, pink, amber, and purple are present in the form of mottled markings and ribboned veins, so that the rock resembles polished agate.

The Walter Brown Collection of marbles is held at the Scottish Mineral and Lapidary Club. They were photographed at the British Geological Survey.

Posted by Bob McIntosh

Landslip, Headon Hill, Totland Bay, 1921

BGI Image ID: P201811

Cliff N. side of Headon Hill, Totland Bay. Isle of Wight. Looking SW. Headon Beds, landslip in foreground. The white band in lower part of cliff is the Limnaean limestone (How Ledge Limestone) at top of Lower Headon Beds. The marine sandy clays of the Middle Headon Beds form the upper part of the cliff. White Limnaean limestone in the lower part of the Upper Headon Beds is indistinctly seen in the slope above the cliff. Ref: 'A short account of the geology of the Isle of Wight', p.115.

BGS Image ID: P201813

BGS Image ID: P201814

Mud-flow, Headon Hill. Fissured crust of mud-flow from slipped clays of the Headon Beds. The water in background is that of a pond in the hollow of a landslip. The fissures are due to a renewal of the slipping in the Lower Headon Beds.

BGS Image ID: P201815

On N. side of Headon Hill, Totland Bay. Looking NE. Mud-flow, Headon Hill. Concentric fissures in crust of mud-flow from the clays of the Headon Beds on the floor of a land-slip hollow. The fissures are due to a series of settlements originating to the right of the view.

Photographs taken March 1921.

Posted by Bob McIntosh