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Geology Site Account

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Little Oakley Red Crag pit (site of Harmer’s pit), LITTLE OAKLEY , Tendring District, TM223293, Historical site only

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Site of Harmer’s Red Crag pit - approx TM 223 293 (precise location not known)


Site description

The existence of shelly Red Crag capping the high ground at Little Oakley has been known since at least the 1860s but it was not until the remarkable work of amateur geologist Frederick Harmer (1835-1923) in the early years of the twentieth century, that the site received any attention.

Harmer was a Norwich wool merchant and textile manufacturer who was also Mayor of Norwich between 1887 and 1888. In his spare time, however, he was a specialist in fossil molluscs and his thorough study of British Tertiary and Quaternary deposits provided the basis for today’s accepted views. The invention of the motor car gave Harmer the opportunity to do more geological field work especially at Little Oakley, where, with the permission of the landowner, he reopened a shallow pit to the east of the village near Foulton Hall and sieved the sand for fossil shells over a period of several years.

The result of these efforts was his two volume work ‘The Pliocene Mollusca of Great Britain’ published in 1919 in which he states that over 600 different species of mollusc were found in this pit (nearly 400 of the species illustrated in the book are from Little Oakley). Harmer’s work has shown the extraordinarily rich molluscan fauna of the Red Crag sea which existed over Essex and East Anglia about two million years ago. Harmer records that all of the fossils came from ‘an area of twenty yards square’ and says that they were obtained ‘during many years labour, and by the sifting and examination of something like 200 tons of material’.

Harmer’s pit has long ago been filled in but between 1973 and 1975 the Ipswich Geological Group carried out an excavation near Foulton Hall at grid reference TM 224 292 to re-expose the fossiliferous Red Crag. Their excavation was reported in the Bulletin of the Ipswich Geological Group (Stidwill 1976). It was about 8 feet long by 3 feet wide and up to 8 feet deep and produced a large number of fossil molluscs. The 1976 report contains a detailed faunal list and an illustration of the section.

More recently, between 2002 and 2004, two separate excavations were carried out near Foulton Hall by the late amateur collector John Hesketh. His collection of molluscs from these sites has been donated to the Essex Field Club.

Harmer’s Red Crag excavation at Little Oakley at the beginning of the 20th century in which he found over 600 different species of fossil shells. On the left of the picture can be seen Harmer’s motor car. Photo reproduced from ‘The Pliocene Mollusca of Great Britain’ by F.W.Harmer (1919). The photo is now part of the British Geological Survey collection (P680273).


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Reference: Harmer 1900 (p.717-718), Harmer 1919, Cleevely 1983 (p.144), Stidwill 1976, Markham 2007.

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