Chap. XVII.] 
CARBONIFEROUS ROCKS IN FRANCE. 
413 
Mountain-limestone was at once met with, to the entire exclusion of the Coal- 
measures. 
In Brittany and the West of France, the Lower Carboniferous deposit rests 
at once upon the Lower Devonian, as is seen "between Sable and Juigne and at 
the coal-pits of Ferce. The anthracitic group of the Department of the Sarthe 
(Nos. 14, 15, 16 of the preceding section, p. 408) is composed of conglomerates, 
sandstones, shale, coal, and limestone, all unquestionably belonging to the Car- 
boniferous series, of which they constitute a lower member. In the "West of 
France, as at St. Pierre-la-cour, between Laval and Rennes, they are unconform- 
able to the superjacent Coal-measures. 
A like physical arrangement has already been alluded to as occurring through- 
out Germany. True Carboniferous Limestone, with large Producti, was de- 
scribed by Professor Sedgwick and myself at Hof, in Bavaria *, as being there 
inclined conformably with the Devonian on which it rests, and unconformably 
to the horizontal Coal-measures of Bohemia. Similar physical relations led 
]j]lie de Beaumont to group the Lower Carboniferous division with the Lower 
Palaeozoic rocks to which it is conformable, though their respective organic re- 
mains are so very distinct. The geologist who combines stratigraphical with 
zoological evidences is therefore bound to state that the dislocations of the older 
rocks on the Continent have occurred at periods different from those of forma- 
tions of the same age in Britain and America. In both the latter countries 
the great superjacent Coal-measures have partaken of the movements which 
affected the limestones whereon they rest. Thus we are still further con- 
firmed in the belief that all fractures of the crust of the earth are local pheno- 
mena only. 
As the strata containing large Producti (Sable, Ferce, Juign6, La Bazouge, 
&c.) were shown to be truly of Carboniferous age, their fossils being absolutely 
those of the Mountain-limestone of England, it followed that many other con- 
siderably metamorphosed rocks in the South-east of France, but in which such 
fossils were detected, must also be referred to the same era of formation. Thus 
de Verneuil and Jourdan have proved that the schists, slates, and quartz -rocks 
of Central and Eastern France, particularly in the Department of the Haute 
Loire (Roanne to Lyon), which from their crystalline aspect had been grouped 
with those of a much older epoch, are clearly to be classed with the Carboni- 
ferous rocks. Though in parts highly altered, and having a very antique and 
crystalline aspect, they have been found to contain the well-known fossils of the 
Coal-period, Productus Cora, Chonetes papilionacea, Spirifer bisulcatus, Orthis 
crenistria, Goniatites diadema, &c. 
It was in the northern extension of this chain of hills from Thiers to Cusset 
near Vichy, where the schists have a still more ancient character and are pierced 
by numerous porphyries and syenitic rocks, that, by the help of a few fossils, I 
was enabled to satisfy myself that the slaty rocks on the banks of the Sichon 
also belonged to the Carboniferous era f. 
The Permian rocks of France may be disposed of in a few words j for they are 
very inadequate representatives of the diversified and complex assemblage of 
strata which constitute the Permian of Russia, Germany, and Britain. The 
lower portion of a series of red rocks in the Vosges Mountains, usually known as 
the ' Gres des Vosges,' is considered by Elie de Beaumont and myself to be of 
this age ; and it has also been shown how other red sandstones, near Lodeve in 
the South of France, may, on account of their Plants, be classed as Permian. 
* Trans. G-eol. Soc. Lond., 2nd series, vol. vi. p. 298, pi. 23. f. 15. 
t Quart. Journ. Greol. Soc Lond. vol. vii. p. 13. 
