248 



TERTIARY STRATA OF (ENINGEN. 



of the large bones of terrestrial and marine animals. Let us farther 

 suppose, that subterranean fire, like that which exists under va- 

 rious parts of Italy, should upheave the chalk hills of the South 

 » Downs, and all the surrounding country, to the height of two thou- 

 sand feet above the present level : the bed of the Newhaven estuary 

 would then resemble, in all its essential characters, the deposition at 

 Castello Arquata, in Italy. 



The freshwater strata at (Eningen, near Constance, are, perhaps, 

 the most recent of all that have been described as tertiary or quater- 

 nary formations. Quarries have for many years been worked in 

 these strata, and they have been long celebrated for the great variety 

 of organic remains which they contain, consisting of quadrupeds, 

 birds, a vast number of fishes, reptiles, insects, and innumerable 

 plants. These quarries were, for a considerable time, supposed to 

 contain human skeletons : it has been ascertained by Cuvier, that the 

 bones belonged to the aquatic salamander, an animal nearly resem- 

 bling the lizard in form. The body is about four feet in length, and 

 it had beside a long tail. One of these skeletons is in the British 

 Museum. The strata are chiefly indurated calcareous marl, and 

 freshwater limestone or marlstone. Mr. Murchison, who has lately 

 visited the quarries at CEnlngen, and brought from thence the entire 

 skeleton of a fossil fox, has given a brief but very clear description 

 of this formation : — 



" The Rhine, in its course from Constance to SchafFhausen, flows 

 for many miles in a depression of the molasse (or sandstone), which 

 being cut through transversely, is exposed in hills on both banks, at 

 heights varying from seven to nine hundred feet. These hills, con- 

 sisting of micaceous sandstone and conglomerate, form the western 

 prolongation of that great range of tertiary deposits, which extends 

 along the flanks of the Austrian and Bavarian Alps, and has been 

 described by Professor Sedgwick and myself. The marls and lime- 

 stone of QEningen are recumbent on the molasse, they are seen in 

 various patches on the sides of the hills, and are worked in two quar^ 

 lies at different elevations above the Rhine. The lowest is about 

 two hundred feet above the level of the Rhine ; the highest is about 

 six hundred feet above its level. The marl beds in both, rest on 

 molasse, which, forming the bottom of the basin, is exposed beneath 

 the lower quarries in the denudation of the Rhine, and rises behind 

 them into the hills of Schienen. It would, therefore, appear, that 

 the valley in which the Rhine now flows was, at a remote period, 

 deeply excavated in the molasse ; and that, subsequently, a lake was 

 formed in one of the broader parts of the valley, in which marls and 

 limestones were deposited. The nature of the organic remains, and 

 their deposition in successive layers, not only prove the long period 

 of time which must have elapsed during their accumulation, but also 

 demonstrate the lacustrine origin of the deposit." 



Mr. Murchison has annexed some judicious observations on the 

 relative geological age of the tertiary limestone of CEningen : — 



