53 



Figure IV -2.— The Murchison carbonaceous chondrite. Most of our understand- 

 ing of the organic matter in meteorites has been derived from studies of the 

 Murchison meteorite. 



environment. Thus, the oldest known clays in the solar system were 

 probably produced on parent bodies of carbonaceous meteorites. 



The organic matter in carbonaceous meteorites occurs in various 

 forms. A high-molecular-weight complex material characterized by 

 insolubility in solvents and acids makes up the major carbon- 

 containing component in all three types of meteorites. (Terrestrial 

 sediments contain a material called "kerogen," which has similar 

 characteristics but is obviously of different origin.) The source(s) and 

 production mechanism(s) for this insoluble material are unclear, but 

 may involve interstellar environments as well as environments in the 

 solar nebula and on the parent bodies themselves. 



