STRUCTURAL RELATIONSHIP BETWEEN HUMIC FRACTIONS FROM PEAT AND LIGNITES FROM THE MIOCENE GRANADA BASIN

Fulvic acids, humic acids and humins, isolated from two closely situat ed peat and lignite deposits, have been examined by solid-state C-13 n .m.r. and analytical pyrolysis. No marked structural differences were found between the humic fractions from the various deposits, suggestin g a common origin. Within each deposit some distinguishing structural characteristics were observed between the humic fractions. The differe nces observed showed that the loss of carbohydrate and lignin during t he early coalification process led to the accumulation of a predominan tly polyalkyl, kerogen-like residue. The humin fractions from both mat erials contain the greatest amounts of aromatic structures, although t hey also present high proportions of aliphatic components. Thus, their n.m.r. spectra consist almost exclusively of alkyl and aromatic hydro carbon entities. This agreed with the results of pyrolysis, which refl ected the presence in humins of condensed alkyl material.