'General Map of Strata found in England & Wales', 1801
William Smith's original 'General map of strata', 1801. Archive ref: LDGSL/740.
Photographic facsimile of William Smith's general map of strata, commissioned by John Wesley Judd, and coloured by Miss Margaret Reekes, 1897. Archive ref: LDGSL/743.
Smith's and Judd's images merged together
The small ‘General Map of Strata found in England & Wales', coloured in 1801, is Smith’s first attempt at collating the knowledge acquired through his many surveying and engineering projects, and that long 900 mile journey from Bath to Newcastle-on Tyne and back again in a post-chaise which he made when researching coal canals in 1794.
Like Smith’s Geological Map of Bath, the colouring has been added to a pre-existing base map, in this case Robert Wilkinson’s map of England and Wales from 1794. The original, on the left, has faded over the years after being varnished and hung on the walls of the Society. The image in the centre gives a better indication of Smith's intentions, being a photographic enhancement with hand colouring created in 1897 by the geologist John Wesley Judd (1840-1916) for a paper he was writing on Smith. The image on the right merges the two to give a better idea of what the map may have looked like originally.
Again no colour key is provided but Judd coloured his reproduction (based on Smith's known palette) as follows:
GREEN - Chalk
PURPLE - ?Portland Sand [Tithonian] which Smith has confounded with the Carstone Formation [Albian]
GREY - Oxford Clay (or 'Church Clay' as Smith referred to it)
YELLOW - Oolite, showing the outcrop of the Great Oolite of the Bath area and the Inferior Oolite both south and north of that area
DULL BLUE - Lias
LIGHT RED - Trias and Permian (or 'Red Marl' of Smith)
BRIGHT BLUE - Carboniferous Limestone which Smith has confounded with the Magnesian Limestone [Ford Formation, Late Permian]
REDDISH-BROWN - Old Red Sandstone [Devonian]
Black cross + colliery
Three dots ∴ mine
Diamond ◆ slate