THE CRETACEOUS PERIOD 255 



if not fairly deep, sea water for its accumulation. Considerable 

 greensand also occurs in the European Upper Cretaceous. 



Toward the close of the period (Danian time) there were up- 

 ward movements sufficient to increase the land areas and establish 

 basins of non-marine sedimentation from Spain to and across the 

 Alpine region as shown by the Cretaceous fresh-water deposits 

 there. 



Other Continents. — Rather extensive areas of Cretaceous 

 occur in New Zealand and Australia, where the rocks are frequently 

 coal bearing and an unconformity often separates the Lower and 

 Upper portions of the system. 



Southwestern Asia, India (in the Himalayas), China, Japan, 

 and Siberia all show more or less extensive development of Cre- 

 taceous strata. Over northern Africa extensive areas of marine 

 Cretaceous rocks show much of that region to have been sub- 

 merged during the period. In South Africa Cretaceous rocks 

 (especially the Lower) are considerably developed. A feature of 

 special importance in India was the inauguration, late in the period, 

 of one of the greatest times of vulcanism since the pre-Cambrian 

 and quite comparable to that of western North America already 

 referred to. This is known as the Deccan lava region where some 

 200,000 square miles are covered by lava flows whose aggregate 

 thickness reaches several thousand feet. 



In South America Cretaceous rocks are widely distributed, 

 especially in Brazil, where a notable marine invasion occurred in 

 the Upper Cretaceous, though in places only continental deposits 

 were formed. East of the Andes the Lower Cretaceous rocks are 

 mostly non-marine. High in the eastern Andes and in southern 

 Patagonia marine Upper Cretaceous strata are known. Toward 

 the close of the period came the great orogenic disturbance, accom- 

 panied by much volcanic activity, in the Andes Mountains district. 



Climate 



As would be expected because of the unusually extensive 

 epicontinental seas, the climate of the period seems to have been 

 mild to warm and pretty uniform but with some distinction of 

 climatic zones. The fossil evidence (e.g. plants in the Cretaceous 

 of Greenland) indicates mildness of climate even within the Arctic 

 circle. 



