

TIIK JURASSIC SYSTEM 431 



2. Germany 



In the south of Germany the outcrop of this series follows that 

 of the Lias from the Black Forest through .Swnbi a ;ind Franconia. 

 In the south-west of this tract, near Tuttlingen and Nusplingeu, 

 the facies is calcareous and similar to that of the Northern Jura, 

 but eastward the limestones are largely replaced by clays, and the 

 Bathonian portion becomes much thinner as if approaching a shore- 

 line. In East Swabia the succession is as follows : 



Clays and marls with Rkynchonella varians and Parkinsonia 

 ferruginea, 16 feet. 



Limestone with Oppeliafusca passing into blue clay, with Parkin- 

 sonia Parkinsoni, 10 to 100 feet. 



Clays and limestones with Cosmoceras subfurcatum, 10 feet. 



'Zone of Witchellia Romani, limestones with Slepheoceras subco- 

 ronatum and clays with Belemnites giganteus. 



Zone of Spharoceras Sauzei, blue limestones. 



Zone of Lioceras concavum, clays and marls. 



Zone of Ludwigia Murchisonae, sands, clays and ironstones, 80 

 feet. 



Zone of Lioceras opalinum, dark clays, 200 feet. 



Apart from the lithological composition of the series the most 

 noteworthy fact is the great expansion of the opalinum and Murchi- 

 son<K zones, as compared with the lesser thickness of the overlying 

 limestones. In Northern Germany there is a similar succession 

 of shales with very little limestone, and the whole series is not 

 more than 100 feet thick. It probably underlies the greater part 

 of the Hanoverian and Prussian plains, and is known to occur in 

 Pomerania ; eastward in Silesia the lowest Jurassic Beds belong to the 

 Parkinsoni zone ; while in Poland near Cracow there are sands and 

 clays of Bajocian age overlain by 100 feet of dark-grey clays with 

 Parkinsonia wurtemburgica (Bathonian) and succeeded by a ferru- 

 ginous oolite with Rhynchonella varians and Belemnites bessinus ; 

 but farther east these beds thin out, leaving the Callovian to form 

 the base of the Jurassic System. 



3. Alpine and Mediterranean Facies 



In the western sub- Alpine region, Savoy and Lower Provence, 

 the Middle Jurassic has a thick and special development, and is 

 over 1000 feet thick. The Bajocian consists of regular alternating 

 beds of marly limestone and shaly marl, characterised by the 

 abundance of Ammonites of the genera Lytoceras and Phylloceras. 

 The succession of zones is similar to that of the Jura and Swabia, 

 and the same species can be taken as indices, but each zone is also 

 characterised by one or more species of Phylloceras, and this is a 



