﻿76 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Dec. 18, 



genus which are peculiar to it (Antinomia angulata, A. angusta, A. 

 dilatata). 



3rd. The parallelism of the epiolitic limestones and of the creta- 

 ceous limestones which cover them is everywhere evident, even when 

 the strata occur in all sorts of directions. 



3. On the Origin of fAe. Mineral Springs of Vichy. By Sir 

 Roderick Impey Murchison, G.C.St.S., F.R.S. G.S. L.S., 

 Hon. Mem. R.S. Ed., R.I. Ac, Mem. Imp. Ac. Sc. St. Pet., Corr. 

 Mem. Ac. France, Berlin, Turin, Copenhagen, &c. &c. 



In this memoir I wish to put on record a few observations I made 

 last summer at the baths of Vichy, which may serve to connect the 

 issue of the mineral waters of that place with certain geological phse- 

 nomena that then fell under my notice. 



The little town of Vichy is situated on the right bank of the Allier 

 in the southern portion of the Bourbonnais, and about twenty-five 

 miles south of Moulins. Geologically considered, Vichy is near the 

 northern termination of the great lacustrine formation of the Limagne 

 d'Auvergne, the lower parts of which have been considered to be 

 of older tertiary age. Occupying low hills and plateaux on both 

 banks of the Allier, around Vichy, the lacustrine limestones and 

 marls of that age extend to the north of the Sichon by Cusset as far 

 as Billy (in the direction of Moulins), where they stand out in great 

 horizontal masses to the plains of the Bourbonnais and the Orlea- 

 nais, without any existing traces of the barrier that formerly retained 

 the waters in which they were accumulated. This fact proves that 

 these deposits are of very remote age as respects the present outline 

 of the country, and leads us to suppose that they have since been 

 raised up en masse. The lowest members of this tertiary group are 

 well seen in various sections in different parts of Central France, and 

 consist of granitic arkose, red sandstone, and argillaceous marl, 

 Such strata are not visible in the neighbourhood of Vichy, where the 

 cream-coloured marls and limestone of the Cotes de St. Amand and 

 Cusset are at once in contact with the old slaty schists and porphy- 

 ries of the Sichon which I have already described*. Organic remains, 

 including the bones of many small quadrupeds, have been found to a 

 great extent, at some localities, in the limestones and marls around 

 Vichy since Sir C. Lyell and myself visited the spot in 1829. 



The freshwater limestones are surmounted by beds of pebbles and 

 sand ; the former being derived from all the harder rocks which con- 

 stitute the sides of the great tertiary trough. These pebble and 

 sand beds are of considerable thickness and great breadth, as is well 

 seen in traversing from the eastern side of the great depression near 

 Vichy to its western side beyond Gannat, and particularly in the 

 plateaux of Randans to the south of Vichy. The lowest of the pebble 

 beds rests conformably on the limestone. On the summits and slopes 

 of these central hills is a coarse water-worn drift or shingle, composed 



* See p. 13 of this volume. 



