THE MIOCENE PERIOD. 



277 



surface. 1 Such thick beds of coarse sediment tell something of the 

 relief of the Alpine region at this time. 



A shallow epicontinental sea covered a part of Belgium and France, 

 overspreading the plains of the Loire and Garonne. From the basin 

 of the latter, there may have been a sea connection with the Mediterra- 

 nean along the northern base of the Pyrenees. Parts of the Iberian 

 peninsula also, were submerged. 



fe Mf^f 1 - 



Fig. 452. — Sketch-map of Europe in the Miocene period (Helvetian). The continu- 

 ous lines are the areas of marine deposition; the broken lines areas of non-marine 

 deposits. (After De Lapparent.) 



The sea covered much of southern Europe, sending an arm up 

 the valley of the Rhone as far as Mayence, but the water at the head 

 of this basin was changed from marine to brackish in the course of 

 the period. From this bay a strait ran eastward between the Alps 

 and the present Danube, and expanded in the basin of Vienna, one 

 of the most important areas of the Miocene system. An arm of the 



Geikie, Text-book, 4th ed., p. 1270. 



