FORMATIONS AND PHYSICAL HISTORY 



375 



Foreign Ordovician 



The Ordovician formations appear at the surface in various 

 parts of Europe, and they exist beneath younger formations over 

 considerable areas where not seen. Fig. 334 represents the general 



Fig- 334- Diagram showing the relations of land and water in western Europe 

 in the Ordovician period. The shaded parts represent areas of marine sedimenta- 

 tion. (After DeLapparent.) 



geographic relations of land and water in Europe during this period. 

 The submerged area represents in a general way the area where the 

 Ordovician formations are present. In contrast with North Amer- 

 ica, the Ordovician formations of Europe are largely fragmental. 

 In the British Isles Ordovician strata are very thick (something like 



