222 Notices of Memoirs — 



II. — The Olb Ehtne Valley. By Dr. Hibbert, F.E.S. 



THE physical structure of the Old Rhine Valley is treated of by 

 Dr. Mibbert in "The History of the Extinct Volcanos of the 

 Basin of Neuwied," published more than 40 years ago,^ in which he 

 gives his views for inferring that the Rhine has not always followed 

 its present course from south to north. The subject is noticed in the 

 chapter on the state of the Rheinland at the commencement of the 

 Tertiary epoch, illustrated by a sketch of the Tertiary geography of 

 the Lower Rheinland, showing the division of the Upper and Lower 

 Rhine basins. In consequence of a barrier of high land stretching 

 across the present site of the Straits of Bingen, and thus filling up 

 the small geographical space intervening between the chains of the 

 Hundsruck and the Taunus, the marine basin from Mayence to Basle'* 

 had no connexion with the present channel of the Rhine from 

 Bingen to Cologne, or farther north. Its waters flowed in a direction 

 quite opposite to that they now maintain, being from north to south, 

 while its southerly extremity was connected with the other marine 

 basins of Europe by means of narrow channels. The first com- 

 mencement of the drainage of the Lower Rhine was through a 

 prolonged rent (due to some elevation of the Rheinland), which 

 commenced near the present site of Bingen, and was continued in a 

 northerly direction as far as that of Coblentz, where the freshwater 

 basin of Neuwied commenced, which was of some extent, and con- 

 siderably elevated above the level of the sea. The discharge from 

 this basin was effected through a subsequent fissure of disruption, 

 gradually widened and deepened, by which the water from the 

 ancient lake of Neuwied was conveyed to the then extensive lower 

 freshwater basin of Cologne, which overflow, in part of its course 

 north of Andernach, must have been originally precipitated in the 

 form of a cataract. Into the inquiry, whether a still lower fresh- 

 water expanse occupied the site of the lower flats of Holland, ex- 

 tending even to the shores of England, or into what sea the ultimate 

 drainage of this chain of lakes was conducted. Dr. Hibbert does not 

 enter, as being beyond the limits of his memoir. 



It is thus seen that the Hundsruck and Taunus were the dividing 

 range from which, at an early period, the streams were directed 

 north and south, and the inversion of the current of the basin of the 

 Upper Rhine was subsequently effected by the last elevation of the 

 European Alps, which was the most considerable in the vicinity of 

 the lake of Constance, and effected a change in the level of all the 

 districts along the valley of the Rhine extending from Basle to 

 Bingen, and perhaps even beyond the ancient barrier of Bingen, as 

 far as the basins of Neuwied and Cologne, so that a continuous 

 declivity was thus formed along the united courses of the Upper and 

 Lower Rhine. 



In short, says Dr. Hibbert, the sum of the change effected by the 

 elevation of the Alps was as follows : — The waters of the upper 



» London, 1832. 



"^ M. Bone considers this a marine basin of an early Tertiary period. 



