1889.] THE DISPLACEMENT OF BEACH-LINES. 27 



it forms entire mountains, but the Aquitanian at Bormida in 

 Liguria has, according to Charles Mayer-Eymar, a still greater 

 and perfectly unique thickness. Here, there is found (probably 

 originally dipping) freshwater, with superimposed marine beach- 

 formations having many alternations of sandstone and slate, whose 

 thickness has not been accurately measured, but is supposed to 

 be 3000 m. and the whole is supposed to have been formed in the 

 Aquitanian age. And the same stage has a similar thickness in 

 Bavaria, according to Gumbel Mount Etna (12000 feet) is 

 built up from volcanic eruptions in the latest geological ages, 

 and after the Mediterranean had got a fauna resembling, in most 

 respects, that of modern times. 



The Mediterranean regions, with their great volcanicity. have 

 (according to Suess and Neumayr) distinguished themselves by 

 very considerable displacements of the crust of the Earth. The 

 Aegean Sea and the Adriatic Sea have been formed by subsidences 

 occurring in the latest geological ages. Under such conditions 

 thick layers must have been formed near land in a short time. 

 Eocene marine layers have been upheaved in folded chains 

 31000 feet above the sea, e. g. in Upper Asia. But all these are 

 merely local revolutions. If we, on the other hand, look at those 

 regions where the relations have been more slowly developed, 

 we find, as seen from what has been said above, that the stages 

 have only a small thickness. The layers of which they consist 

 Are partly fresh-water formations, partly formations from the 

 shallow sea; there are no distinguished deep-water formations 

 among them. They are in a great measure, probably for the 

 greater part, formed in inland seas and bays, in basins that 

 have been cut off from the Ocean by embankments. This we 

 may conclude from the circumstance that salt-water and fresh- 

 water formations so frequently alternate in the tertiary layers; be- 

 cause only when the sedimentation takes place in basin-shaped hol- 

 lows can fresh-water basins be formed every time the sea retreats. 



And if we have deep basins which are separated by embank- 

 ments from the great ocean, a rise or fall of only a few metres 

 m the beach-line will be sufficient to cover or drain the bank. 



