CHAPTER I 



FOUNDATIONS OF THE 

 GREAT DEEP 



Introduction 



Whatever his remote ancestors may have been, man is now a 

 land animal. Because he lives off the land, he needs to learn 

 all he can about the rock formations under his feet. Knowl- 

 edge of this kind guides him to raw materials on which his 

 necessities and comforts largely depend. With living secured, 

 he has time and surplus energy to think — to think more and 

 more intensely about his planetary home. Thus from the de- 

 mands of practical life and from the philosophical urge has 

 come one of the youngest of the sciences, geology, which in 

 anything like a systematic development did not exist before 

 the nineteenth century. 



As a result of regional surveys in detail, supplemented by 

 more rapid studies all across continents, many principles of 

 earth science have been established, even though, as the work 

 goes on, new discoveries are keeping geological philosophy in 

 a state of flux. It is also true that many fundamental questions, 

 including those that must occur to every intelligent traveler, 

 are still elusive for the specialist in geology. For example, a 

 century of research has still left wide gaps in our knowledge 

 about the ultimate cause of mountain-building; about the 

 origin of continents; about the structure and history of the 

 Basement Complex, the oldest and most important visible part 



