30 



THE ORIGIN AND EVOLUTION OF LIFE 



action with little erosion or sedimentation because of the lack 

 of water. 



The surface of the earth, then, was chiefly spread with 

 granitic masses known as batholiths and with the more super- 

 ficial volcanic outpourings. There were volcanic ashes; there 







W - ^ y^ ..^.-- ."t^i^ -V---, '■•..*• -■^■^ 







>_ 





l''i(;. I. Tiiii Moon's SL:RrAcK. 



"The lifeless primordial earth can best be imagined by looking at the lifeless surface of 

 the moon." A portion of the moon's surface, many miles in diameter, illuminated 

 by the rising or setting sun and showing the craters and areas of lava outflow. The 

 Meteor Crater of Arizona, formerly known as Coon Butte — a huge hole, 4,500 feet in 

 diameter and 600 feet in depth, made by a falling meteorite — is strikingly similar to 

 these lunar craters and suggests the possibility that, instead of being the result of 

 volcanic action, the craters of the moon may have been formed by terrific impacts of 

 meteoric masses. Photograph from the Mt. Wilson Observatory. 



were gravels, sands, and micas derived from the granites; there 

 were clays from the dissolution of granitic feldspars; there were 

 loam mixtures of clay and sand; there was gypsum from min- 

 eral springs. 



Bare rocks and soils were inhospitable ingredients for any 

 but the most rudimentary forms of life such as were adapted 

 to feed directly upon the chemical elements and their simplest 



