Chapter VI 



WHERE TO LOOK FOR REMAINS OF EARLY LIFE 



THE OLD SHIELDS 



PAUCITY OF EARLY RECORDS 



If we now turn again to geology in our search for facts about the 

 origin of life, we find them deplorably scarce. There are very few 

 fossil finds from the early history' of the earth. 



This is so for a variety of reasons, which can be summarized as 

 follows: small size and softness of early forms of life, whilst most of 

 the old rocks are masked by younger ones. Also, great age has 

 destroyed many primary structures of the rocks formed at those times. 



All early life forms were small, consisting of protoplasm or similar 

 soft tissue, and without hard parts. In the next chapter we will go 

 further into this. Let us only bear in mind here, that the early forms 

 of life are comparable to our microbes, and microbes in general 

 stand an extremely slim chance of becoming fossilized. 



Moreover, most of the rocks formed in those early days are not 

 visible for inspection now. They have been buried by thick piles of 

 younger rocks, mostly sediments, and are now situated at depths of 

 several kilometers or even several tens of kilometers. Even where they 

 are again exposed at the surface of the earth, they have often suffer- 

 ed considerable damage during their billion-year history. 



They also, although now exposed at the surface, have in most 

 cases been temporarily buried by younger sediments, which have 

 since been removed again. They have often been folded, or intruded 

 by large batholites of granite. All such mishaps expose the rocks to 

 a temporarily elevated temperature or pressure, or both. Through 

 this the minerals which consitute the rock tend to become mobile. 

 They will recombine and recrystallize either into larger crystals of 

 similar composition, or even into crystals of quite different composi- 



