544 THE CRETACEOUS PERIOD 



ceous of southern Europe, showing that clear seas still prevailed, as in 

 the Early Cretaceous period. From a characteristic genus of fossils, 

 much of the limestone is known as Hippurite limestone. In the 

 system farther north, there is more clastic material. 



The most notable petrographic feature of the Upper Cretaceous 

 of Europe is the chalk. Both in England and France it attains an 

 aggregate thickness of several hundred feet, though much of it is 

 far from pure. It grades into marls and clays on the one hand, and 

 into sandstone on the other. Chalk is, however, by no means 

 co-extensive with the system, for it has little development outside 

 of the Anglo-French area. Greensand occurs in the Upper Creta- 

 ceous as well as in the Lower. 



Asia. The submergence of Europe and North America at the 

 beginning of the Upper Cretaceous finds its parallel in other conti- 

 nents. There are extensive areas of Hippurite limestone in south- 

 western Asia, closely connected with that of Europe on the one hand, 

 and with that of North Africa on the other. The Himalayan region 

 seems to have been still beneath the sea, for Upper Cretaceous forma- 

 tions are found in the mountains at great elevations. South of 

 these mountains there appears to have been a large tract of land, in- 

 cluding much of the peninsula of India, which has been thought 

 to have stretched southwest to Africa; but the configuration of 

 the sea-bottom does not lend this view much support. 



Upper Cretaceous beds occur on the coast of China,, and in 

 Japan. In many places they rest on formations older than the 

 Lower Cretaceous, and therefore record an increased submergence 

 dating from the beginning or early part of the Upper Cretaceous. 

 On the other hand, northern Asia, which was largely submerged 

 during the earlier Cretaceous period, was largely land during the 

 later. Late in the Upper Cretaceous occurred the extensive lava- 

 flows of the Deccan. These flows, 4,000 to 6,000 feet in thickness, 

 cover an area of something like 200,000 square miles, and are the 

 most stupendous outflows of lava recorded. The fossils in 

 sediments interbedded with the lava show that the flows were 

 subaerial. 



Africa. In northern Africa, the Upper Cretaceous beds overlie 

 the Lower unconformably, and spread southward, covering most of 

 the desert, and so indicating great submergence in the north African 

 region. South of the Sahara, no Upper Cretaceous beds are known 

 except in a few small areas about the coast, where they rest on 



