280 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1937 



served in the form of an immense body of nearly flat-lying beds or 

 layers of fine-grained rock similar to lithographic stone. This great 

 body of rock is as long as Vermont but considerably wider, and in 

 places it is almost a mile thick. Deep canyons and wide valleys are 

 now cut through it in all directions, so that the whole record is accessible. 



Figure 1.— Index map showing the location and approximate extent of the ancient Lake Uinta. 



The tliin layers thus exposed bear a remarkably close resemblance to 

 the leaves of a book. Indeed, it is more than a superficial resemblance 

 for the layers are in fact pages upon which are impressed symbols that 

 portray events of that age so long past. 



Modem books are so familiar that we take Uttle thought of their 

 construction and have no diflficulty in reading their meaning. But 

 w^hen the earliest written records of man were found they could be 



