| Description | Geological colouring with key and some notes, mainly on topographical heights around the Mississippi Valley, by George Bellas Greenough, [c.1843-1851] on base 'Map of the United States compiled from the latest and most accurate surveys'' by Amos Lay, London, 1834. Greenough no.1101. Scale 1:1 600 000. Dissected on cloth. 132 x 159cm. The geological colouring, although with a slightly different colour scheme, is after James Hall's 'Geological map of the Middle and Western States', published in 'Geology of New York. Part IV. Comprising the Survey of the Fourth Geological District' (1843). |
| Administrative History | The front labels of the map have the key to the stratigraphic units based on James Hall's New York System. On the map itself, however, are small keys which use the British terminology.
Apart from the work of James Hall, the map contains one other bibliographic reference - C Martins,"Notes sur l'existance de coquilles marines des mers actuelles dans le bassin du lac Ontario (Canada), jusqu'à l'altitude de 310 pieds" 'Bulletin de la Société géologique de France', S2, vol 8 (1851), pp420-423. |