TABLE 3A. Weathering of AMOCO CADIZ oil. 



RAPID 



1. Loss of volatile (<n-C^5) hydrocarbons due to evapora- 

 tion of: 



a. alkanes 



b. aromatics - benzenes, naphthalenes, biphenyl (one- to 

 two-ring aromatics) 



2. Relative and/or absolute increase in unresolved complex 

 mixture. 



MODERATE 



1. Microbial degradation of n-alkanes; preferential attack of 

 n-alkanes versus branched alkanes (i.e., decrease in ratio 

 of alkanes to isoprenoids) . 



2. Loss (to solution or other processes) of most resolved 

 saturated hydrocarbon GC traces. 



3. Emergence of triterpanes as major molecular markers in 

 saturated fraction. 



4. Increase in UCM, with formation of secondary (bimodal) UCM 

 distribution. 



5. Loss of fluorenes (two aromatic rings, one saturated ring) 

 and alkyl naphthalenes. 



6. Increase in abundance of polar fraction. 

 LONG 



1. Persistence of alkylated phenanthrenes and alkylated 

 dibenzothiophenes. 



2. Increase in polar fraction. 



3. Loss of long chain n-alkanes and isoprenoids. 



46 



