376 



STKATIGRAPHICAL GEOLOGY 



of A. exilis was contemporaneous with the highest part of the 

 Keuper. 



The probable correlation of the several series of beds in England, 

 Germany, and the Tyrol is shown in the following table : 



BRITAIN 



GERMANY 



THE TYROL 



Vertical Scale 6000 feet to an inch . 



3. France 



The surface areas occupied by Trias in France are small, 

 though the Keuper probably has a considerable subterranean 

 extension both in the northern and southern parts of the country. 



From the Vosges district and the Sarrebruck area in Alsace a 

 broad tract of Trias reaches westward into France, passing under 

 the Jurassic strata which occupy the great basin between the 

 plateau of the Ardennes and that of the Morvan. All the 

 members of the German Trias are here present, but 'both the 

 Bunter and the Muschelkalk thin rapidly to the westward ; their 

 attenuation can be followed along the northern outcrop in 

 Luxemburg, and both are very thin before they are overlapped by 

 the Lias north-west of Arlon. 



There can be no doubt that a similar thinning out takes place 

 to the south-west of the Vosges, for when the beds emerge on the 

 borders of the Morvan only Keuper remains, but this is exposed at 

 intervals round the Morvan and along the north side of the 

 Central Plateau from the valley of the Allier to a point about 15 

 miles west of La Chatre. Though the beds are of no great thick- 

 ness, they seem to represent the Lower or Kohlenkeuper as well as 

 the higher marls. They can be traced southward along the 

 eastern border of the Plateau to Macon, Villefranche, and Lyons, 

 the beds consisting of coarse quartzose and felspathic sandstones 

 from 50 to 100 feet thick, surmounted by a pink dolomitic lime- 

 stone with Myophoria Goldfussi, which is succeeded by Keuper marls. 



At Lyons the sandstone rests directly on the ridge of Archaean 



