506 THE JURASSIC PERIOD 



the Lower Cretaceous unconformably in the axis of the range; but 

 the movements which gave the Coast Range its present form 

 (modified by erosion), took place much later. Various other ranges 

 of the west are thought to have begun their history as mountains 

 at about the same time. After this closing- Jurassic period of 

 erogenic movement, the coast was somewhat farther west than now 

 in northern California and southern Oregon. 



Toward the close of the period, much, if not all, of the great 

 Upper Jurassic gulf of the northwestern part of the continent dis- 

 appeared. All in all, the deformations at this time were greater 

 than those which mark the close of most periods. 



Foreign Jurassic 



Europe. Jurassic strata are exposed in many and widely sepa- 

 rated parts of Europe, though for the most part in small areas only. 

 It has been thought that the Jurassic of England is probably con- 

 tinuous with that of France beneath the English Channel, and 

 thence, by way of southeastern France, with those parts of the 

 system which appear about the Mediterranean, and by way of 

 Belgium, the Netherlands, and the German lowlands, with those 

 parts which appear in Poland and Russia. The lower part of the 

 system (Lias] is less extensive than the Middle, and the Middle 

 less widespread than the Upper. Progressive submergence was, 

 indeed, one of the features of the period. 



Among the more distinctive features of the system in Europe are 

 the following: (i) A considerable content of coal in some places, 

 notably Hungary. (2) The abundance of oolitic limestone, both in 

 England and on the continent. (3) The presence of lithographic 

 stone (Solenhofen limestone of southern Germany). This stone is 

 so fine and so even-grained, and at the same time so workable and 

 so strong, that it has come into use the world over for lithographic 

 purposes. The stone is also remarkable for the perfection of its 

 fossils, including such delicate parts as the gauzy wings of insects. 

 (4) The considerable development of non-marine beds in the lower 

 part of the system, and again at its very top. 



The close of the period in Europe was marked by a somewhat 

 widespread emergence of land. In central Europe, the emergence 

 began before the close of the Jurassic, for the latest beds (Purbeck) 

 of the system in England are unconformable on beds lower in the 

 system. Similar changes are known to have occurred in late 



