1 6 Bulletin 15 326 



A Review of the Oligocene of Western Europe. 



The Oligocene in Germany. The Oligocene of northern 

 Germany is chiefly marine, while that of the valleys of the Oder, 

 the Elbe and the Rhine is of freshwater or brackish origin. 



The lignitic formation . The freshwater beds, which are gulf 

 deposits, are composed of conglomerates, siliceous sands, sand- 

 stones, clays and shales; but lignitic remains of cypress and other 

 coniferous woods predominate. At Cassel these lignitic beds are 

 referable to the middle Oligocene (Rupelian). Similar deposits 

 in the Rhenish provinces, however, probably represent the upper 

 Oligocene (Aquitanian of Mayer). In 1864 Giebel'=^ described 

 the fauna of the lignitic formation. 



Marine beds. Marine deposits representing the lower Oligo- 

 cene (Tongrian) lie to the north of Berlin, and to the southwest 

 of Magdeburg. The middle and upper Oligocene (Rupelian and 

 Anquitanian) marine beds are, however, of greater importance 

 and cover a large part of the northern plains of the country. 



Geological map. A geological map of Germany, which has 

 long been needed, is in preparation. Of this a portion was pub- 

 lished in 1894 by Richard Lepsius,t but the complete map is 

 presumably still unfinished. 



B ey rich' s classification of the marine beds. Beyrich, in 1853, 

 made the following classification J of the Tertiary formation of 

 northern Germany: 



3. Beds equivalent to the Bordeaux formations Miocene? 



2 . Septaria clays ) Fauna intermediate between 



I . Magdeburg sands i Eocene and Miocene. 



In his description of these beds Prof. Beyrich notes the 



* Die Fauna der Braunkohl. form. Latdorf, 1864. 

 t Geologischer Karte des Deutschen Reichs. 



X Die Conchylien der Norddeutschen Tertiargebirges. Zeitschrift der 

 Deutschen geol. Gesellschaft, 1853, 1855, 1856. Also published sep. vol. 8°. 



