432 STKATIGEAPHICAL GEOLOGY 



special feature of the Mediterranean and Alpine facies. Near 

 Digne the Bajociau is 660 feet thick. In the same region the 

 Bathonian consists mainly of black shales which are divisible into 

 two zones, viz. : 



2. Black marly shales with Posidonia alpina, 300 to 400 feet. 

 1. Black shales and marly limestone with Oppeliafusca, 170 feet. 



Eastward, however, both stages pass into the condition of marly 

 limestones, and in a more or less metamorphosed form they show 

 themselves at intervals through the Swiss and Italian Alps, and 

 recur in the Apennines. In the Eastern Alps (Klaus Alp) 

 Bathonian shales with Posidonia alpina occur, and again near 

 Vienna there is Bajocian with Phylloceras and Bathonian with 

 Posidonia. These beds extend to the Carpathians, and occur also 

 in Servia, where (near Milanovitz) the Bajocian is absent, and beds 

 with Oppelia fusca and Zigzagiceras arbustigerum rest directly on 

 crystalline schists. 



III. UPPER JURASSIC SERIES 

 A. SUBDIVISION AND NOMENCLATURE 



In England, where fully developed, this series is divisible into 

 five groups or stages two great argillaceous formations (the 

 Oxford and Kimeridge clays), each overlain by a group of sand- 

 stones and limestones (the Corallian and the Portland Beds) ; 

 while at the summit are the Purbeck Beds, a set of estuarine and 

 lacustrine strata which may be regarded as formed during a 

 continuance of Portlandian conditions in the purely marine areas. 



On the continent the thick clays are in many places repre- 

 sented by limestones and marls, so that the British names are not 

 literally applicable ; but in Germany and Northern France the 

 general succession is similar, and many of the English names have 

 been employed in a latinised form. In Southern France and the 

 south of Europe generally there is a very different facies, wholly 

 calcareous and marine with a different assemblage of fossils. 



The following table shows the nomenclature used in Northern 

 Europe, but the French stages do not exactly correspond with 

 those of England and Germany, as will be shown in the sequel. 



England. North France. North Germany. 



5. Purbeck Beds \ p nT .fi ,, Munder Mergel 

 4. Portland Beds/ and Plattenkalk. 



3. Kimeridge clay Kimeridgian Kimeridgian. 



2. Corallian Beds Corallian Corallian. 



1. Oxford clay and /Oxfordian\ Oxfordian 



Kellaways Beds \Callovian / 



