1824.] Older Red Sandstone Formation, fyc. 13 



It might indeed be supposed from the structure of the map 

 that the group in question was intended by its author to repre- 

 sent the carboniferous series ; and such will clearly be found to 

 be the case, if we compare the corresponding coloured districts 

 with the memoirs which tend to elucidate them, whether relat- 

 ing to France, or to Germany. See the memoir of M. Omalius 

 d'Halloy in illustration of his map ; that of M. de Bonnard on 

 the Geology of the Western Part of the Palatinate ; of M. von 

 Hoffon the Thuringerwald ; of M. Beaunier on the Coal District 

 of St. Etienne ; of M. Le Chevalier du Bosc on the Coal Mines 

 of the Basin of the Aveyron.* 



It will be sufficient for our purpose if we confine our attention 

 to the memoir of M. de Bonnard on the Palatinate, selecting 

 such parts as bear immediately on the question, and adding a 

 few observations. 



P. 220, et seq. " The mountainous country on which I pro- 

 pose to offer some geological remarks, is limited on the west 

 and north-west by the course of the Brems and that of the Nahe 

 on the south by the frontier of France ; on the east by the pro- 

 longation of the Vosges chain to the foot of Mont Tonnerre ; 

 lastly, on the north-east by. a curved line passing within the 

 limits of the small towns of Gselheim, Alzey, Wsellstein, and 

 Creutznach." 



" On the left bank of the Nahe, and at a short distance from 

 its bed, the schistose and compact quartzite formations com- 

 mence, which form the mountains of the Hundsruck. On the 

 right bank, and also at a short distance from the river, are situ- 

 ated the coal measures and red sandstones of the Palatinate." 



" The Hundsruck, bounded by the Rhine, the Moselle, the 

 Sarre, and the Nahe, forms part of the great schistose zone 

 which is prolonged from the department of the Ardennes across 

 the north of Germany, and which appears in a great measure 

 composed of transition rocks. The red sandstones of the Pala- 



* In a former memoir on the North of France and the adjacent Parts of the Nether- 

 lands ( Journal des Mines, vol. xxiv), M. Omalius d'Halloy had erroneously applied 

 the term rothe todtc liegende to the gypseous and saliferous red sandstone which is 

 found in Luxemburg, extending toward the Sarre, &c. But in the present map, and in 

 the memoir by which it is accompanied, the saliferous or new red sandstone is placed in 

 its correct position, while the term rothe todte liegende is employed in the appropriate 

 ( ierman sense. 



There is, however, unfortunately, one great inconsistency in the map, upon which 

 Mr. Dela Beche has justly remarked ; the carboniferous series of the nortli of France and 

 of the Netherlands being, in conformity with the former view of M. O. d'Halloy 

 (Journal des Mines, vol. xxiv), included in the transition series. 



It is also to be regretted that in the construction of the map, so important a group as 

 the carboniferous scries should in several case* have been wholly omitted, c. g. in Ger- 

 many, in the tract extending from the Hartz to the banks of the Saale, that adjacent to 

 the river Ruhr; in France, on the Loire between Angers and Nantes; "it St. Litry, 

 south-west ofBayeux, &c. . Their distinct introduction, wherever omitted, would have 

 added to the value of the map, however small the scale might have been. The same 

 indeed may be said of other groups, the scale of which, as omitted, must also necessarily 

 have been small. 



