Geology Site Account

Site name: Mistley High Street Cobble Wall

Grid reference: TM 11741 31822

Brief description of site:

Wall of considerable historic and geological interest.

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Summary of geological interest

On the south side of Mistley High Street, east of the Post Office, is a brick wall, probably over 150 years old, with a section composed entirely of rounded cobbles. What makes this wall particularly unusual is the very high proportion of exotic rock types such as granite, lava, dolerite and gneiss. There are even several cobbles of rhomb-porphyry, a distinctive lava from Larvik, in the Oslo region of Norway.

It was originally thought that the stones in the Mistley Wall might have been gathered locally. This is because 'exotic' rocks do occur in Essex, having been brought here during the Ice age by the Anglian Ice Sheet, some even from Norway. However, the great variety of rock types in this wall made this unlikely.

The answer was found following extensive research by geologist Ian Mercer who established from various written records and oral testimonies beyond any doubt that these rocks were brought to Mistley from Norway in ballast in trading ships in the early 19th century.

In the wall there are 280 million year old lavas from Larvik, near Oslo, with their distinctively-shaped crystals. These have provided a rock-sold link between Mistleys maritime past and this surviving, historic wall. A valuable display of geology as well as history lesson, the Mistley wall is a treasure of the Essex coast. It has considerable local historical conservation value.

The full story of the wall, and how the link with Mistleys maritime history was established, can be found in the December 2014 issue of the Magazine of the Geologists association (Mercer 2014).

The remarkable cobble wall in Mistley High Street. Photo © G. Lucy