726 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



The Tertiary rocks of Germany occur in the North German Plain, the Rhine- 

 land Basin, and the Schwabian-Bavarian Plateau. The areas of outcrop in north- 

 ern Germany are relatively small and disconnected, and sections with a complete 

 succession of formations are almost nonexistent, rending it difficult to make 

 direct correlations with the well-established stages elsewhere in western Europe. 

 The Tertiary beds in the Maintz Basin were studied by Sandberger (1858-1863) 

 and divided into nine paleontological zones, which were correlated with the 

 stages of Dumont in Belgium. 



The investigations of Heinrich Beyrich during the middle and second half of 

 the past century shed much light on the North German Tertiary deposits and 

 his detailed studies of the invertebrate faunas led to important refinements in 

 the classification and correlation of the strata. In 1847 he correlated the Sep- 

 tarian clays of north Germany with the Rupelian stage of Belgium because of 

 the identity of fossils. In 1853 in his mongraph on the North German Tertiary 

 Deposits he showed that the fossil species in beds between Magdeburg and Egeln, 

 which he considered Miocene, contained many forms characteristic of older hori- 

 zons and correlated these strata with the Lower Tongrian of Belgium and the 

 Septarian clay with the Rupelian. In 1854 he proposed that these stages, both 

 in Germany and Belgium, should be regarded as an independent series, which he 

 named Oligocene, subdividing this into lower, middle, and upper members. This 

 new unit in the geologic time scale was generally accepted by European geolo- 

 gists and later in the nineteenth and early in the present century was widely 

 used in North America. 



The Tertiary deposits in the Schwabian-Bavarian Plateau occupy an inter- 

 mediate position between the Swiss and Austrian areas. They were investigated 

 in great detail by Bernhardt Studer, who in 1855 published his Geologie der 

 Schiveiz. He recognized a Jura and sub-Alpine group of deposits, the former 

 consisting of a lower marine division with fossils similar to those in the Mainz 

 Basin and an upper series of freshwater limestones and marls which he con- 

 sidered Upper ]\Iiocene. The sub-Alpine deposits, consisting of freshwater red 

 marls, molasse, sandstone, and beds containing brown coal, extend southwest 

 into the Rhone Valley. The marine fossils obtained from these beds were studied 

 by K. Mayer (1858) who divided the Tertiary deposits into eleven paleonto- 

 logical zones. These stages in ascending order were named Garumnien, Sues- 

 sonien, Londonien, Parisien, Bartonien, Ligurien, Tongrien, Aquitanien, Ilelve- 

 tien, Tortonien, and Astien. The first five were assigned to the Eocene, tlie 

 Helvetien and Tortonien to the Miocene, and the Astien to the Pliocene. In 

 Bavaria the sub-Alpine deposits which lie immediately north of the limestone 

 mountains consist of flysch deposits of Eocene and Lower Oligocene age. These 

 were described in 1861 by Giirabel with a full analysis of the fossils. The peculiar 

 lithologic and paleontologic development of the Tertiary deposits in different 

 geological provinces present great difficulties in making exact correlations from 

 one area to another, and many papers have appeared in the past fifty years which 

 attempt to solve such problems. The fundamental classifications established in 

 Europe have been used as a standard for investigation of the Tertiary in other 

 parts of the globe, but not always with success. 



The marine Tertiary deposits of North America are confined to the Atlantic 

 and Gulf Coastal Plains and the Coast Ranges of the Pacific slope. The deposits 



