China Clay works, Lantern Pit and Cleaves Pit, North Cornwall, April 16th 1914

BGS Image ID: P804212

Lantern Pit, North Cornwall, April 16th 1914

BGS Image ID: P804218

Cleaves Pit, North Cornwall, April 16th 1914.

China clay is a material called kaolin and was used to make fine white porcelain. The extraction of China clay in the St. Austell area was one of the great extractive industries in Cornwall.

Bob McIntosh

Leading ladies - 1912 GA Field Excursion to Leith Hill

Leading ladies - 1912 GA Field Excursion to Leith Hill. From the Geologists' Association 'Carreck Archive'

Bob McIntosh

Signatures - women geologists, Geologists' Association 'Carreck Archive'

Signatures from an album in the Geologists' Association 'Carreck Archive'. The signatures are all women members. Above, left page; Below, right page.

Awesome trowel-wielding women in archaeology, palaeontology, geology

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Bob McIntosh

100 years ago - Geologists' Association Field trip to the Lizard, Cornwall, Easter 1913. Director Sir John Flett.

Geologists Association Field trip to the Lizard, Cornwall, Easter 1913. Director Sir John Flett. Group photograph and key.

Bob McIntosh

Page of signatures of Geological Survey of Great Britain staff. From the Geologists' Association 'Carreck Archive'

Page of signatures of Geological Survey of Great Britain staff. From the Geologists' Association 'Carreck Archive'.

The GA albums contain many pages of signatures of members, an archivist's delight!

Bob McIntosh

Descending a denehole at Hangman's Wood, West Thurrock, Essex.

BGS Image ID: P805290

Descending a Denehole at Hangman's Wood at West Thurrock, Essex. 1908. From the GA 'Carreck Archive'

'In the course of ploughing this field the horse's feet broke through the surface. We procured a rope and the pole of a waggon and investigated the interior. The shaft descended through about 12 feet of Thanet Sand and entered into a beehive-shaped chamber about 20 ft. high. These deneholes were formed in getting the chalk in past ages for marling the land.'

Deneholes are typically about 60 feet deep with steps cut into the side of the shaft to allow climbing in and out. At the bottom they open out to a domed chamber, often with sub-chambers.

It is though that chalk was mined this way from pre-Roman times.

Photographer: T.W. Reader

Bob McIntosh

Tufa eggs for Easter, Matlock Bath, Derbyshire

Birds nest and eggs encrusted in tufa, Matlock Bath, Derbyshire. Photograph from the Geologists' Association 'Carreck Archive'

Original description: 'Tufa which also goes by the name of Travertin [Travertine] or Calcareous Sinter is a deposit of Carbonate of Lime thrown down by springs which flow through beds of limestone. In this case at Matlock these specimens are from lime obtained from the Carboniferous Limestone. The rain in passing through the atmosphere takes up Carbonic acid and assisted by humic acid from the soil when it sinks into the limestone dissolves portions of it away. When it comes to the surface again in the form of springs it loses some of the Carbonic acid and the lime is thrown down in the form of tufa and incrusting any object that happens to be present.'

T.W. Reader photograph album. Derbyshire, August 3rd 1914.

Bob McIntosh